A complex region generation and display method for browser-side global situation map

Abstract

The application discloses a complex region generation and display method for a browser-side global situation map, and the method comprises the following steps: acquiring a sequence of contour positioning points of a region to be displayed; performing longitude sequence continuous unfolding correction processing on the sequence of contour positioning points of the region to be displayed, so as to obtain a sequence of corrected contour positioning points of the region to be displayed; performing plane self-intersection detection based on the sequence of corrected contour positioning points of the region to be displayed, so as to obtain a self-intersection detection judgment result; performing differential processing on the sequence of corrected contour positioning points of the region to be displayed according to the self-intersection detection judgment result, so as to obtain a first or second standardized polygon hierarchical structure set; performing output scene adaptation processing on the first or second standardized polygon hierarchical structure set, so as to obtain a renderable graph; and performing filling rendering processing on the renderable graph, so as to obtain a region-to-be-displayed image. The method can improve the rendering stability and visual display effect of a complex region in a CesiumJS global situation map on the browser side.

Description

Technical Field

[0001] This invention relates to the fields of browser-based WebGIS geometric processing, situational mapping, and map rendering, and particularly to a method for generating and displaying complex regions of global situational maps for browsers, based on secondary development of CesiumJS. Background Technology

[0002] Geographic information visualization technology is widely used in business scenarios such as global situational simulation and airspace and maritime monitoring, and is generally implemented through desktop GIS, professional mapping software, or browser-based WebGIS. In desktop GIS or professional mapping software, the capabilities for complex surface clipping, topology repair, projection transformation, and handling across meridians are relatively mature, and can usually rely on local computing resources, dedicated geometry engines, or offline preprocessing workflows. However, in browser-based WebGIS, relying on the browser's 3D map engine to load and render regional outlines, a series of visualization anomalies easily occur when handling complex regions such as those crossing antimeridians, concave polygons, figure-eight shapes, pentagrams, self-intersecting contours, and other complex regions that are difficult to represent stably with ordinary convex polygons. These anomalies include missing region fills, large areas of abnormal faces, disordered boundary lines, and geometric structure errors. To solve these visualization anomalies, existing solutions generally perform topological splitting on the aforementioned complex regions before rendering, cutting a single self-intersecting closed contour into multiple simple closed sub-loops without self-intersecting edges. However, current conventional splitting solutions have the following engineering defects: First, longitude jumps are prone to occur in regions crossing antimeridians. Geographic longitude values ​​range from -180° to 180°. When a region's boundary crosses an antimeridian of ±180°, the original point sequence will experience a sudden change in value, jumping directly from 179° to -179°. If self-intersection detection is performed directly based on the original longitude, the algorithm will misjudge the normal long side crossing the antimeridian as a line segment intersection, generating a large number of false intersection points and causing incorrect splitting. Existing methods lack a longitude correction mechanism adapted to global scenarios to distinguish between true self-intersections and cross-meridian numerical jumps.

[0003] Second, the coupling between topology splitting and the final rendering preprocessing workflow is chaotic. Some solutions insert the antimeridian transition points into the contour sequence in advance to participate in self-intersection detection and topology splitting. These antimeridian transition points are auxiliary points temporarily generated during the rendering stage. Involving them in the topology calculation in advance will introduce additional intersection points, change the original contour topology structure, and cause distortion of the splitting results and deformation of the region boundary shape. On the other hand, the solution that generates the transition points at the end of the rendering process lacks complete data link support and cannot work smoothly with the self-intersection splitting and smoothing processing workflow.

[0004] Third, after splitting, a large number of tiny fragmented sub-loops are easily generated. After the self-intersecting contour untangling and segmentation operations are completed, invalid fragmented loops with too few points and extremely small enclosing areas are often generated. Invalid fragmented loops have no visualization value, but they will still participate in subsequent coordinate transformations and triangle construction, continuously consuming browser computing resources, reducing the rendering frame rate of large-scale situational elements, and in severe cases, causing excessive front-end memory consumption and rendering lag.

[0005] Fourth, there is a lack of a unified data processing link between 2D scenes and 3D spherical scenes. 2D planar views and 3D spherical views have different requirements for coordinate formats and boundary processing logic. Most existing technologies use two independent sets of data processing logic, repeatedly performing coordinate transformation and boundary interpolation calculations, resulting in low code reusability. At the same time, there is a lack of a standardized polygon hierarchy structure as an intermediate carrier, making it difficult to achieve a single contour data source that can adapt to dual-scene rendering output.

[0006] In addition, traditional solutions suffer from unreasonable timing design in point coordinate management and unclear timing for elevation information insertion. Some solutions force elevation configuration during the topology calculation stage, increasing the computational load of self-intersection detection; others delay adding elevation dynamically until the rendering stage, causing duplication of 2D and 3D branch logic. How to reasonably introduce elevation information without interfering with planar topology calculations to form a unified latitude, longitude, and elevation coordinate sequence is also a technical pain point that urgently needs optimization in existing technologies.

[0007] Therefore, there is an urgent need to propose a method for generating and displaying complex regions of global situation maps for browsers, which can achieve longitude correction across antimeridians, self-intersecting contour topology splitting, invalid broken ring filtering, and differentiated adaptation between 2D and 3D scenes. At the same time, it can standardize the timing of elevation information injection and the timing of antimeridian transition point generation, and overcome the defects of existing technologies such as contour rendering disorder, topology splitting distortion, large front-end rendering overhead, and poor multi-scene adaptability. Summary of the Invention

[0008] The technical problem to be solved by this invention is to provide a method for generating and displaying complex regions in a global situation map for browsers, which solves the problems of existing technologies such as confusion between longitude jumps across antimeridians and self-intersection of the true contour, distortion of topological splitting results, presence of a large number of invalid fragment sub-loops, and improper timing configuration of antimeridian transition points, which lead to abnormal rendering of complex region contours and high browser rendering overhead.

[0009] To address the aforementioned technical problems, a first aspect of this invention discloses a method for generating and displaying complex regions in a global situation map for browser-based applications, characterized in that the method includes: S1, Obtain the sequence of positioning points for the outline of the area to be displayed; the sequence of positioning points for the outline of the area to be displayed includes N positioning point coordinates; the positioning point coordinates include longitude and latitude values; N is an integer greater than or equal to 3; S2, perform longitude sequence continuous expansion and correction processing on the longitude sequence of the outline positioning point sequence of the area to be displayed to obtain the outline positioning point correction sequence of the area to be displayed. S3, based on the correction sequence of the contour positioning points of the area to be displayed, perform planar self-intersection detection to obtain the self-intersection detection judgment result; When the self-intersection detection result is negative, the correction sequence of the outline positioning points of the area to be displayed is converted to obtain the first standardized polygon hierarchical structure set, and S6 is executed. When the self-intersection detection result is yes, execute S4; S4, perform self-intersecting decomposition processing on the contour positioning point correction sequence of the area to be displayed to obtain a renderable closed sub-ring set; S5, the renderable closed sub-ring set is transformed to obtain the second standardized polygonal hierarchical structure set; S6, perform output scene adaptation processing on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain renderable graphics; S7, perform fill rendering processing on the renderable graphic to obtain the image of the area to be displayed.

[0010] As an optional implementation, in the first aspect of the present invention, the step of performing longitude sequence continuous expansion correction processing on the sequence of contour positioning points of the area to be displayed to obtain a corrected sequence of contour positioning points of the area to be displayed includes: S21, traverse all the coordinates of the positioning points in the sequence of positioning points of the area to be displayed, calculate the difference between the longitude value of the current positioning point coordinate and the longitude value of the previous adjacent positioning point coordinate, and obtain the longitude difference sequence. S22, using the longitude sequence continuous expansion correction model, process the longitude difference sequence and the outline positioning point sequence of the area to be displayed to obtain the outline positioning point correction sequence of the area to be displayed; The expression for the longitude sequence continuous expansion correction model is: In the formula, The longitude value of the i-th positioning point in the sequence of positioning points for the outline of the area to be displayed; The longitude value of the i-th positioning point in the correction sequence of the outline positioning points of the area to be displayed; It is the i-th longitude difference in the longitude difference sequence.

[0011] As an optional implementation, in the first aspect of the present invention, the step of performing planar self-intersection detection based on the correction sequence of the contour positioning points of the area to be displayed, and obtaining the self-intersection detection judgment result, includes: S31, Based on the correction sequence of the outline positioning points of the area to be displayed, a set of outline line segments of the area to be displayed is constructed; S32, Select and pair the set of outline line segments of the area to be displayed to obtain a set of line segment pairs to be detected; the set of line segment pairs to be detected includes several sets of line segment pairs to be detected. S33, traverse all the line segment pairs to be detected in the set of line segment pairs to be detected, determine whether each pair of line segment pairs intersects in the middle of the line segment, and obtain several line segment pair intersection judgment results; If all line segment pairs are negative when they intersect, then the self-intersection detection result is negative. If at least one line segment pair intersects and the result is yes, then the result of the self-intersection detection is yes.

[0012] As an optional implementation, in the first aspect of the present invention, the step of performing self-intersecting decomposition processing on the contour positioning point correction sequence of the area to be displayed to obtain a renderable closed sub-loop set includes: S41, Based on the correction sequence of the outline positioning points of the area to be displayed, the outline of the area to be displayed is constructed; S42, Based on the outline of the area to be displayed, a set of shared intersection points is collected; the set of shared intersection points includes several shared intersection points; S43, determine whether the number of shared intersections in the shared intersection set is equal to 1, and obtain the result of the number of shared intersections; If the result of the determination of the number of shared intersections is yes, execute S44; If the result of the determination of the number of shared intersections is negative, execute S45; S44, perform double-leaf splitting on the outline of the area to be displayed to obtain a renderable closed sub-ring set; S45, the outline of the area to be displayed is unwound and split to obtain the renderable closed sub-ring set.

[0013] As an optional implementation, in a first aspect of the present invention, the step of performing a two-leaf splitting process on the outline of the region to be displayed to obtain a renderable closed sub-ring set includes: S441, Based on the shared intersection set, perform topological cutting processing on the outline of the region to be displayed to obtain two sub-outlines of the region to be displayed; S442, taking the shared intersection point of the shared intersection point set as the sequence starting point, extract the positioning points of the two sub-contours of the area to be displayed respectively, and obtain the positioning point correction sequence of the two sub-contours of the area to be displayed; S443, perform anchor point smoothing processing on the correction sequence of the sub-contour positioning points of the two regions to be displayed to obtain a renderable closed sub-ring set.

[0014] As an optional implementation, in a first aspect of the present invention, the unwinding and splitting of the outline of the region to be displayed to obtain the renderable closed sub-ring set includes: S451, based on the shared intersection point set, perform topological cutting processing on the outline of the region to be displayed to obtain a sub-outline set of the region to be displayed; the sub-outline set of the region to be displayed includes several sub-outlines of the region to be displayed. S452, taking the shared intersection point of the shared intersection point set as the sequence starting point, extract the sub-contour positioning points of the sub-contour set of the region to be displayed respectively to obtain the first sub-contour positioning point correction sequence set of the region to be displayed; S453, the first set of sub-contour positioning point correction sequence for the display area is filtered to obtain the second set of sub-contour positioning point correction sequence for the display area. S454, perform anchor point smoothing processing on the second display area sub-contour positioning point correction sequence set to obtain the renderable closed sub-loop set.

[0015] As an optional implementation, in a first aspect of the present invention, the transformation process of the renderable closed sub-loop set to obtain a second normalized polygonal hierarchy structure set includes: S51, the renderable closed sub-loop set and the preset positioning point elevation value information are fused to obtain a renderable closed sub-loop set with additional elevation values. S52, the renderable closed sub-loop set with the additional elevation values ​​is encapsulated with positioning point coordinate information to obtain the second standardized polygonal hierarchical structure set.

[0016] As an optional implementation, in the first aspect of the present invention, the step of performing output scene adaptation processing on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain renderable graphics includes: S61, perform recognition processing on the output scene to obtain the output scene recognition result; the output scene recognition result is a two-dimensional scene or a three-dimensional scene. When the output scene recognition result is a two-dimensional scene, execute S62; When the output scene recognition result is a three-dimensional scene, execute S63; S62, perform two-dimensional view coordinate transformation on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain a renderable graphic; S63, perform three-dimensional view coordinate transformation on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain the renderable graphics.

[0017] As an optional implementation, in a first aspect of the present invention, the step of performing two-dimensional view coordinate transformation on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain a renderable graphic includes: S621, Perform longitude value restoration processing on the first standardized polygon hierarchical structure set or the second standardized polygon hierarchical structure set to obtain a set of latitude, longitude and altitude positioning point coordinate sequences; S622, Based on the set of latitude and longitude high positioning point coordinate sequences, perform cross-anti-meridian judgment to obtain the cross-anti-meridian judgment result; When the cross-anti meridian judgment result is negative, the coordinate transformation process is performed on the latitude and longitude high positioning point coordinate sequence set to obtain the first world coordinate sequence set, and S626 is executed. If the cross-meridian determination result is yes, execute S623; S623, Based on the set of latitude and longitude positioning point coordinates, calculate the coordinates of the anti-meridian transition points to obtain the set of anti-meridian transition points; S624, The latitude and longitude high-positioning point coordinate sequence set and the anti-meridian transition point set are fused to obtain a composite latitude and longitude high-positioning point coordinate sequence set; S625, Perform coordinate transformation on the composite latitude and longitude high positioning point coordinate sequence set to obtain the second world coordinate sequence set; S626, Based on the first world coordinate sequence set or the second world coordinate sequence set, a renderable graphic is constructed.

[0018] As an optional implementation, in the first aspect of the present invention, the step of calculating the coordinates of the antimeridian transition points based on the latitude and longitude coordinate sequence to obtain the antimeridian transition point set includes: S6231, Perform cross-meridian positioning point extraction processing on the latitude and longitude elevation positioning point coordinate sequence set to obtain a cross-meridian positioning point pair set; the cross-meridian positioning point pair set includes M cross-meridian positioning point pairs, where M is an integer greater than or equal to 1; The expression for the set of cross-meridian positioning points is: In the formula, P is the set of points located across the antimeridian; For the i-th pair of positioning points in the set of positioning points across the anti-meridian; for latitude and longitude coordinates Longitude value These are latitude values. Elevation values; for latitude and longitude coordinates Longitude value These are latitude values. Elevation values; S6232, Perform latitude and longitude difference ratio calculation on the set of cross-meridian positioning points to obtain the set of cross-meridian transition points; the set of cross-meridian transition points includes M cross-meridian transition points, where M is an integer greater than or equal to 1; The expression for the set of transition points along the antimeridian is: In the formula, Q is the set of transition points of the antimeridian; This refers to the i-th anti-meridian transition point in the set of anti-meridian transition points; for The latitude and longitude coordinates, where 180° represents the longitude value. These are latitude values. is the elevation value, and t is the linear longitude interpolation ratio coefficient, with a value range of [0,1].

[0019] Compared with existing technologies, the embodiments of the present invention have the following beneficial effects: The present invention discloses a method for generating and displaying complex regions of global situation maps for browsers. It uses a longitude sequence continuous expansion correction model to correct the longitude of contour positioning points, which can effectively distinguish between longitude jumps caused by crossing antimeridians and the phenomenon of true line segment intersections, avoiding false self-intersection judgment results. Based on the corrected coordinates, planar self-intersection detection is carried out. According to the number of self-intersection points, a double-leaf splitting or unwinding splitting scheme is used to perform topological cutting on the self-intersection contour, and combined with anchor point smoothing processing, a regular set of renderable closed sub-loops is obtained. In the conversion processing stage, elevation information is uniformly integrated, and small invalid fragment sub-loops are screened out and eliminated to construct a standardized polygonal hierarchical structure set. The scene adaptation process distinguishes between two-dimensional and three-dimensional scenes and performs differentiated processing. Antimeridian transition points are only interpolated at the end of the two-dimensional view rendering. These transition points do not participate in the early topological calculations, ensuring that the original contour topology structure is not distorted. This invention uses a standardized polygonal hierarchical structure as a unified intermediate carrier to enable a single data source to adapt to two types of scene rendering, reduce repetitive coordinate calculations, effectively improve the rendering anomalies of complex self-intersecting regions, reduce the geometric calculation overhead of the browser front end, and improve the visualization stability and rendering efficiency of complex regional outlines in global situation maps. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating a method for generating and displaying complex regions of a global situation map for browser-based applications, as disclosed in an embodiment of the present invention. Figure 2 This is a contour diagram of the sub-contour positioning point correction sequence of two regions to be displayed before the transition processing of the topology-locked potential field curve, as disclosed in an embodiment of the present invention. Figure 3 This is a renderingable closed sub-ring set effect diagram after transition processing of the topology-locked potential field curve disclosed in an embodiment of the present invention; Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The terms "first," "second," etc., used in the specification and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0026] It should be noted that in all computational expressions or mathematical functions in the embodiments of the present invention, the variables involved have been dimensionlessized before calculation. The values ​​of the independent variables in all computational expressions or mathematical functions in the embodiments of the present invention conform to the reasonable requirements of the input range of the computational expression or mathematical function, and ensure that the computational expression or mathematical function can be calculated smoothly without violating physical laws or mathematical rules.

[0027] Example 1 Please see Figure 1 , Figure 1 This is a flowchart illustrating a method for generating and displaying complex regions of a global situation map for browser-based applications, as disclosed in an embodiment of the present invention. Figure 1 The method described for generating and displaying complex regions in browser-based global situation maps can be applied to browser-based WebGIS, such as... Figure 1 As shown, the method for generating and displaying complex regions in a browser-based global situation map may include the following operations: S1, Obtain the sequence of positioning points for the outline of the area to be displayed; the sequence of positioning points for the outline of the area to be displayed includes N positioning point coordinates; the positioning point coordinates include longitude and latitude values; N is an integer greater than or equal to 3; It should be noted that the complex regions referred to in this invention are geographic vector regions in the global situation map whose boundary outlines have self-intersecting topological structures and whose boundary line segments cross antimeridians. If such regions are directly filled and rendered by WebGIS on the browser side, visualization anomalies such as screen tearing, polygon filling disorder, and failure to build patches are very likely to occur. These generally include shapes such as concave polygons, figure-eight shapes, and pentagrams.

[0028] It should be noted that the positioning points of the above-mentioned outline positioning point sequence of the area to be displayed have a strict fixed order. This order corresponds one-to-one with the order in which the outline lines are drawn during the browser's front-end graphics rendering. The points can be connected in sequence to outline the outer boundary of the complete area. If the point order is disordered, it will directly cause the outline to be distorted and the closure to fail. This outline positioning point sequence of the area to be displayed is the basic raw data for all subsequent correction, splitting and rendering processes.

[0029] S2, perform longitude sequence continuous expansion and correction processing on the longitude sequence of the outline positioning point sequence of the area to be displayed to obtain the outline positioning point correction sequence of the area to be displayed. S3, based on the correction sequence of the contour positioning points of the area to be displayed, perform planar self-intersection detection to obtain the self-intersection detection judgment result; When the self-intersection detection result is negative, the correction sequence of the outline positioning points of the area to be displayed is converted to obtain the first standardized polygon hierarchical structure set, and S6 is executed. When the self-intersection detection result is yes, execute S4; It should be noted that the above conversion process involves adding elevation numerical information to all positioning points in the contour positioning point correction sequence of the area to be displayed and encapsulating the coordinate information. The specific addition and encapsulation methods are consistent with the processing method of S5.

[0030] S4, perform self-intersecting decomposition processing on the contour positioning point correction sequence of the area to be displayed to obtain a renderable closed sub-ring set; S5, the renderable closed sub-ring set is transformed to obtain the second standardized polygonal hierarchical structure set; S6, perform output scene adaptation processing on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain renderable graphics; S7, perform fill rendering processing on the renderable graphic to obtain the image of the area to be displayed.

[0031] It should be noted that the above-mentioned fill rendering is a conventional and mature graphics processing method in the fields of WebGIS and CesiumJS browser visualization. Specifically, it refers to filling the internal area of ​​a renderable graphic that has undergone scene adaptation and coordinate transformation and has no topological errors and can be directly identified with a specified color, transparency, and texture style to complete the visual color output of the geographic region. This invention does not improve the fill rendering algorithm itself, but only uses it as a general post-processing step for the final visualization output. It only relies on the self-intersection splitting, coordinate correction, and scene adaptation processing mentioned above to obtain a regular renderable graphic without any abnormalities, ensuring that there are no blank gaps or large-area incorrect filling across meridians during the filling process.

[0032] As can be seen, the method for generating and displaying complex regions of a global situation map for browsers described in this embodiment of the invention solves rendering problems such as polygon construction failure, screen tearing, and fill disorder caused by self-intersection of complex global geographical contours and crossing of antimeridians from the source. It automatically completes the topology repair of complex contours and scene coordinate adaptation without the need for manual preprocessing of boundary data. At the same time, it is compatible with real-time visualization of two-dimensional plane and three-dimensional spherical dual-scene browsers, significantly improving the rendering stability and screen display integrity of complex geographical regions of the global situation map.

[0033] Optionally, the step of performing longitude sequence continuous expansion correction processing on the sequence of contour positioning points of the area to be displayed to obtain a corrected sequence of contour positioning points of the area to be displayed includes: S21, traverse all the coordinates of the positioning points in the sequence of positioning points of the area to be displayed, calculate the difference between the longitude value of the current positioning point coordinate and the longitude value of the previous adjacent positioning point coordinate, and obtain the longitude difference sequence. It should be noted that, since the outline of the area to be displayed is a closed polygon, and the first and last points of the sequence are also connected by a line, the first value of the above longitude difference sequence is the longitude difference between the first and last positioning points.

[0034] S22, using the longitude sequence continuous expansion correction model, process the longitude difference sequence and the outline positioning point sequence of the area to be displayed to obtain the outline positioning point correction sequence of the area to be displayed; The expression for the longitude sequence continuous expansion correction model is: In the formula, The longitude value of the i-th positioning point in the sequence of positioning points for the outline of the area to be displayed; The longitude value of the i-th positioning point in the correction sequence of the outline positioning points of the area to be displayed; It is the i-th longitude difference in the longitude difference sequence.

[0035] It should be noted that the original normalized representation of geographic longitude ranges from -180° to 180°. When a geographic line segment crosses a meridian of ±180°, the actual geographic distance between the two points is extremely close, but the longitude value will show a huge difference of nearly 360°. During browser rendering, the browser may mistakenly draw the short boundary as a long line encircling the globe, resulting in screen tearing. The aforementioned longitude sequence continuous expansion correction model is used to eliminate this numerical jump defect. The correction operation only calculates the longitude value separately, keeping the latitude value of the positioning point unchanged. Only the corrected positioning point sequence with continuous longitude without jumps is output. After correction, the longitude changes of adjacent points on the outline are gradual, without abrupt differences of nearly 360°, eliminating the underlying cause of rendering anomalies when crossing meridian segments from the source of coordinates.

[0036] As can be seen, the method for generating and displaying complex regions of a global situation map for browsers described in this embodiment of the invention utilizes a continuous longitude sequence expansion correction model to perform point-by-point cumulative offset correction based on the longitude difference of the complete closed-loop contour. This converts the longitude that causes discontinuous jumps when crossing antimeridians into continuous expanded longitude. Only longitude compensation calculations are performed, while retaining the original latitude information. The calculations only include basic addition and subtraction calculations, resulting in low computational overhead for the front-end browser. The positioning point sequence preprocessed by this model has longitude differences between adjacent points that are within a reasonable range, effectively reducing long-line tearing and boundary misalignment problems when the global geographic contour crosses antimeridians. This provides continuous and unambiguous standardized coordinate data for subsequent self-intersection detection, contour topology splitting, and multi-scene coordinate adaptation, ensuring the accuracy and stability of subsequent calculations and rendering processes.

[0037] Optionally, the step of performing planar self-intersection detection based on the correction sequence of the contour positioning points of the area to be displayed, and obtaining the self-intersection detection judgment result, includes: S31, Based on the correction sequence of the outline positioning points of the area to be displayed, a set of outline line segments of the area to be displayed is constructed; It should be noted that the above set of outline segments of the area to be displayed includes N segments, and the two endpoints of each segment are two adjacent positioning points of the positioning point correction sequence of the outline of the area to be displayed.

[0038] S32, Select and pair the set of outline line segments of the area to be displayed to obtain a set of line segment pairs to be detected; the set of line segment pairs to be detected includes several sets of line segment pairs to be detected. It should be noted that the above pairing process involves selecting two independent line segments within the set that do not have a common endpoint to form a pair of line segments to be detected.

[0039] S33, traverse all the line segment pairs to be detected in the set of line segment pairs to be detected, determine whether each pair of line segment pairs intersects in the middle of the line segment, and obtain several line segment pair intersection judgment results; If all line segment pairs are negative when they intersect, then the self-intersection detection result is negative. If at least one line segment pair intersects and the result is yes, then the result of the self-intersection detection is yes.

[0040] It should be noted that the vector cross product cross-intersection method can be used to determine whether there are intersecting line segments other than those sharing endpoints. Other lightweight intersection discrimination algorithms in the prior art can also be used for the determination. In particular, the embodiments of the present invention do not limit the specific methods.

[0041] As can be seen, the method for generating and displaying complex regions of a global situation map for browsers described in this embodiment of the invention accurately identifies true self-intersections of line segments through a lightweight line segment intersection judgment algorithm. It can efficiently and accurately distinguish between simple polygons and complex self-intersecting polygons, realize automatic judgment of contour topology status and process diversion, effectively avoid various visualization anomalies caused by direct rendering of self-intersecting contours, and provide a reliable topology judgment basis for subsequent polygon standardization processing and stable rendering.

[0042] Optionally, the step of performing self-intersecting decomposition processing on the contour positioning point correction sequence of the area to be displayed to obtain a renderable closed sub-loop set includes: S41, Based on the correction sequence of the outline positioning points of the area to be displayed, the outline of the area to be displayed is constructed; It should be noted that the above construction method is to connect adjacent positioning points in sequence according to the inherent drawing order of positioning points in the positioning point correction sequence of the area to be displayed, and at the same time connect the positioning point at the end of the sequence with the first positioning point to form a closed boundary, thus restoring a complete and continuous geographic contour carrier. This contour carries all the corrected latitude and longitude coordinate information and is the complete geometric object for subsequent intersection point collection and topology decomposition.

[0043] S42, Based on the outline of the area to be displayed, a set of shared intersection points is collected; the set of shared intersection points includes several shared intersection points; It should be noted that the above collection method involves traversing all intersecting line segments of the contour, extracting the intersection points formed by the intersection of the middle of all line segments, and uniformly collecting all intersection points into a shared intersection point set. Each shared intersection point in the set is a topological node generated by the intersection of the middle of two contour line segments, which is different from a vertex that only has endpoint contact. It is the core basis for determining the splitting method of self-intersecting complex contours.

[0044] S43, determine whether the number of shared intersections in the shared intersection set is equal to 1, and obtain the result of the number of shared intersections; If the result of the determination of the number of shared intersections is yes, execute S44; If the result of the determination of the number of shared intersections is negative, execute S45; S44, perform double-leaf splitting on the outline of the area to be displayed to obtain a renderable closed sub-ring set; S45, the outline of the area to be displayed is unwound and split to obtain the renderable closed sub-ring set.

[0045] As can be seen, the method for generating and displaying complex regions of a global situation map for browsers described in this embodiment of the invention first constructs a complete closed contour based on the contour positioning point correction sequence of the region to be displayed, then accurately collects all real self-intersecting intersection points to form an intersection point set, automatically distinguishes between single-intersection and multi-intersection self-intersecting topological structures by the number of intersection points, matches the corresponding double-leaf splitting and unwinding splitting schemes, specifically disassembles contours with self-intersecting defects, and uniformly outputs a set of renderable closed sub-loops without topological errors, thus eliminating the problem of rendering disorder of self-intersecting polygons from the root.

[0046] Optionally, the step of performing a two-leaf split on the outline of the region to be displayed to obtain a renderable closed sub-ring set includes: S441, Based on the shared intersection set, perform topological cutting processing on the outline of the region to be displayed to obtain two sub-outlines of the region to be displayed; It should be noted that the unique self-intersecting intersection point within the shared intersection point set is used as the topological splitting node, and the contour topological cutting is completed along the line direction of the original closed contour; the original single self-intersecting single closed contour will be split by this intersection point and decomposed into two complete closed contours.

[0047] S442, taking the shared intersection point of the shared intersection point set as the sequence starting point, extract the positioning points of the two sub-contours of the area to be displayed respectively, and obtain the positioning point correction sequence of the two sub-contours of the area to be displayed; It should be noted that the shared intersection point mentioned above is used as the starting reference point of the two sub-contour point sequences. All latitude and longitude positioning points are collected sequentially along the boundary of the two sub-contours to generate two sets of closed-ended sub-contour positioning point correction sequences for the display area. The unified sequence starting point can ensure that the contour drawing direction is consistent in the subsequent smoothing and coordinate transformation process, and avoid contour drawing reversal and closure failure.

[0048] S443, perform anchor point smoothing processing on the correction sequence of the sub-contour positioning points of the two regions to be displayed to obtain a renderable closed sub-ring set.

[0049] As can be seen, the method for generating and displaying complex regions of a global situation map for browsers described in this embodiment of the invention can perform topological decomposition of self-intersecting contours based on single-point shared intersections, unify the starting nodes of the point sequences of each sub-contour, and perform restricted smoothing processing on local abnormal inflection points that meet the preset deflection angle conditions, thereby obtaining a set of renderable closed sub-loops with no self-intersections, normal point order, and continuous boundaries. This reduces the probability of filling errors, local jagged edges, and polygon construction failures when rendering single-point self-intersecting geographical regions on the browser side, while taking into account both the fidelity of real geographical boundaries and the stability of front-end rendering.

[0050] Optionally, the step of performing anchor point smoothing processing on the correction sequence of the sub-contour positioning points of the two displayable regions to obtain a renderable closed sub-loop set includes: S4431, using a preset angular radius threshold, the correction sequence of the sub-contour positioning points of the two areas to be displayed is filtered to obtain a set of anchor points to be smoothed; the set of anchor points to be smoothed includes several anchor points to be smoothed. It should be noted that the above filtering process involves iterating through all the positioning points in the correction sequence of the sub-contour positioning points of the two display areas one by one. For each positioning point, the internal deflection angle in radians corresponding to the current point is calculated by extracting its adjacent points. Positioning points with deflection angles greater than the preset deflection angle threshold are filtered out and summarized to form a set of anchor points to be smoothed. Positioning points that do not reach the threshold retain their original coordinates and do not participate in subsequent smoothing calculations, thereby reducing meaningless floating-point calculations and reducing the computational load on the browser.

[0051] S4432, using the anchor point smoothing calculation model, the set of anchor points to be smoothed is corrected to obtain the smoothed anchor point set; The expression for the anchor point smoothing calculation model is: In the formula, , These are the longitude and latitude values ​​of the anchor point to be smoothed, respectively. , These are the longitude and latitude values ​​of the preceding adjacent positioning point of the anchor point to be smoothed, respectively. , These are the longitude and latitude values ​​of the next adjacent positioning point of the anchor point to be smoothed, respectively. The value of the radian of the angle formed by connecting the anchor point to be smoothed and the preceding and following positioning points, with the anchor point to be smoothed as the vertex. The preset original point weight attenuation coefficient has a value range of [0.8, 2], with a preferred value of 1.2; The preset smooth interpolation gain coefficient has a value range of [0.8, 2], with a preferred value of 1.2; The original points retain weights, with values ​​ranging from (0,1]. The weights of the neighborhood smoothing interpolation points are taken in the range of (0,1). It should be noted that the above anchor point smoothing calculation model maps the contour angle to normalized original points by using the natural exponent, retaining the weights of the weights and the weights of the neighborhood smoothing interpolation points, so that the smoothing intensity can be adaptively adjusted according to the sharpness of the inflection point. The geometric mean is used to complete the fusion of the two weights, which can constrain the contribution of the two sets of weights at the same time compared with the arithmetic mean. It can avoid the comprehensive weight from rapidly approaching zero due to a small decrease in a single weight. While penalizing the imbalance of weights, it retains the basic output capability. Then, the weights are converted into coordinate offsets through linear weighting. The whole process only involves exponentiation, square root, and four arithmetic operations, with low computational overhead, making it suitable for real-time calculation scenarios on the browser side.

[0052] It should be noted that the above anchor point smoothing calculation model only uses latitude and longitude positioning points for calculation, adapts to the data time sequence of the overall scheme, and only performs smoothing correction on jagged inflection points that exceed the angle threshold, fully preserving the original smooth real boundary inflection points, thus eliminating contour jagged noise and avoiding excessive smoothing of boundaries; the geometric quality of the rendered closed sub-ring set obtained after processing is improved, reducing the risk of failure in the construction of subsequent polygonal hierarchical structures, reducing redundant rendering patches on the front end, and improving the rendering stability and visualization effect of complex areas of the global situation map on the browser side.

[0053] S4433, the smoothed anchor point set and the two displayable area sub-contour positioning point correction sequences are integrated and replaced to obtain a renderable closed sub-loop set.

[0054] It should be noted that the above integration and replacement process uses the positioning points of the anchor point set after smoothing to replace the positioning points of the anchor point set to be smoothed according to the arrangement order of the positioning point correction sequence of the two sub-contours of the area to be displayed. This does not change the original drawing direction and closed topology of the contour, and completely preserves the true geographical boundary shape of the area. The processed sub-loops do not have geometric jagged defects and can be directly used for subsequent standardized polygon level conversion.

[0055] As can be seen, the method for generating and displaying complex regions of a global situation map for browsers described in this embodiment of the invention first filters out sharp inflection points that need to be smoothed by relying on the angle threshold, reducing invalid floating-point operations; then, a lightweight exponential geometric mean smoothing model is used to adaptively adjust the smoothing intensity according to the sharpness of the inflection points, balancing the preservation of the original geographical boundaries and the elimination of jagged edges; finally, the coordinates of the inflection points are replaced in an orderly manner without destroying the original topological structure of the outline, and the final output is a set of renderable closed sub-loops with regular geometric shape and no jagged defects, which reduces the probability of subsequent polygon construction failure, reduces the browser rendering load, and improves the visualization stability of the global situation map.

[0056] It should be noted that topology-locked potential field curve transition processing can also be used to replace the anchor point smoothing processing in step S443 to obtain a renderable closed sub-loop set; the step of performing topology-locked potential field curve transition processing on the correction sequence of the two sub-contour positioning points of the two displayable regions to obtain a renderable closed sub-loop set includes: A4431, using a preset deflection angle radian threshold, the correction sequence of the sub-contour positioning points of the two areas to be displayed is filtered to obtain a set of key anchor points for curve transition processing; the set of key anchor points for curve transition processing includes several key anchor points for curve transition processing. It should be noted that the above filtering process involves iterating through all positioning points in the sub-contour positioning point correction sequence of the two display areas one by one. For each positioning point, its immediate and adjacent points are extracted, the contour deflection angle in radians corresponding to the current point is calculated, and positioning points with deflection angles greater than a preset threshold in radians are selected as key anchor points for curve transition processing. For each key anchor point for curve transition processing, the distances to the nearest shared intersection points on its immediate and adjacent edges are simultaneously obtained; these shared intersection points serve as topology locking points and do not participate in coordinate movement. Positioning points that do not reach the threshold retain their original coordinates and do not participate in subsequent curve transition construction to reduce meaningless floating-point calculations and lower the browser's computational load.

[0057] A4432, using the topology-locked potential field curve transition calculation model, constructs the entry auxiliary point, exit auxiliary point, bicubic curve transition curve and local potential field offset of the key anchor point to be processed by the curve transition, respectively, to obtain the positioning point sequence after the first curve transition. The expression for the topology-locked potential field curve transition calculation model is as follows: In the formula, Let i be the latitude and longitude coordinates of the i-th key anchor point to be processed by curve transition. and These are its front and rear adjacent positioning points, respectively; and These are the lengths of the front and rear adjacent sides, respectively; and These are the unit direction vectors along the front and rear adjacent sides, respectively; ρ is the deflection angle in radians at the key anchor point, and ρ is the preset maximum transition ratio, preferably 0.35. and These are the distances from the key anchor point to the nearest shared intersection point along the front and rear adjacent edges, respectively. When there is no shared intersection point between adjacent edges, these distances are taken as infinity. The local transition radius is jointly constrained by the side length and the shared intersection clearance; and These are the auxiliary points for the incoming edge and the auxiliary points for the outgoing edge, respectively. This represents the shared tangent vector at the key anchor points of the bicubic transition; and These are the edge tangential control length and the critical anchor point tangential control length, respectively. and These are three sets of Bezier control points before and after the critical anchor point; ψ(t) is a cubic Bezier function; ψ(t) is the local potential kernel function. η is the local potential field normal vector determined by the turning sign; η is the preset potential field intensity coefficient, preferably 0.08. and These represent the potential field offset amplitudes of the transition curves between the first and second segments of the curve, respectively. and These are the transition curves for the first and second segments of the final curve, respectively. This represents the transition ratio of the annealing curve when the m-th topology check fails. It should be noted that the above-mentioned topology-locked potential field curve transition calculation model does not move the key anchor point towards the neighborhood mean position, but rather uses the key anchor point as the reference point. As the common endpoint of the first and second cubic Bezier curves. It can be seen that the key anchor points must be written into the smoothed positioning point sequence; and since the potential field kernel function satisfies ψ(0)=ψ(1)=0 and ψ 0)=ψ 1)=0, the local potential field will not change the auxiliary points of the incoming edge, the auxiliary points of the outgoing edge, the key anchor points, and their shared tangents. (From...) It can be seen that the two curves are first-order continuous at the key anchor points.

[0058] It should be noted that the local transition radius... Shared intersection clearance , The constraint ensures that the shared intersection point always lies on the original straight line segment that has not been replaced by the curve transition; auxiliary points for the outgoing edges of adjacent key anchor points. Auxiliary point of the incoming edge to the next critical anchor point The original direction is directly connected by a straight line, so the long straight side does not generate additional curve sampling or shape shift. The potential field offset amplitude is simultaneously modulated by the deflection angle, the intersection clearance, and the ratio of the side lengths on both sides, and only the normal fine adjustment occurs within the curve transition; when the potential field strength η is 0, the model degenerates into a bicubic local curve transition at the key point without a potential field.

[0059] A4433, Perform topological verification on the sequence of positioning points after the transition processing of the first curve to obtain the topological verification result; It should be noted that the above topology verification verifies whether the number and position of shared intersections in the positioning point sequence after curve transition processing are consistent with the results before processing. If both the number and position of shared intersections are consistent with the results before processing, the topology verification result is consistent. If either the number or position of shared intersections is inconsistent with the results before processing, the topology verification result is inconsistent.

[0060] A4434, Based on the topology verification result, the positioning point sequence after the first curve transition processing is differentiated to obtain the positioning point sequence after the second curve transition processing; It should be noted that when the above topology verification results are consistent, the sequence of positioning points after the first curve transition processing is determined to be the sequence of positioning points after the second curve transition processing; when the above topology verification results are inconsistent, it is determined according to... The curve transition ratio is gradually reduced and the curve transition curve is regenerated. After each reduction, an updated sequence of positioning points after curve transition processing is obtained and topologically verified. If the topological verification result is consistent, the updated sequence of positioning points after curve transition processing is determined to be the second sequence of positioning points after curve transition processing. If the topological verification result is inconsistent, the curve transition ratio is further reduced until the topological verification result is consistent. When m reaches a preset maximum value and still does not meet the topological verification, the corresponding key anchor point and its original adjacent straight line segment are retained to obtain the second sequence of positioning points after curve transition processing.

[0061] A4435, the sequence of positioning points after the transition processing of the second curve and the correction sequence of the positioning points of the two sub-contours of the area to be displayed are integrated to obtain a renderable closed sub-ring set.

[0062] It should be noted that the above integration process follows the original arrangement of the sub-contour positioning point correction sequence, replacing the neighborhood of each key anchor point with local curve transition sampling points that pass through the ingress auxiliary point, key anchor point and outgress auxiliary point in sequence; key anchor points are written only once to avoid the same shared intersection point from entering the same polygon loop as a duplicate vertex; the original direction straight line segment is retained between two adjacent curve transitions, without changing the original drawing direction and closed topology of the contour, and can be directly used for subsequent standardized polygon level conversion.

[0063] It should be noted that the above-described topology-locked potential field curve transition process first uses a deflection angle threshold to screen out the key anchor points that need to be processed; then, based on the key anchor points, entry auxiliary points, and exit auxiliary points, a bicubic local curve transition is constructed to pass through the key points, and the internal curvature of the angle is adjusted using a potential field kernel function with zero endpoints and first derivatives; subsequently, the transition radius and potential field amplitude are constrained using shared intersection net space, and annealing back is performed if the topology verification fails. Please refer to [link to relevant documentation]. Figure 2 and Figure 3 , Figure 2 This is a contour map of the sub-contour positioning point correction sequence of two regions to be displayed before the transition processing of the topology-locked potential field curve, as disclosed in an embodiment of the present invention. Figure 3 This is a rendering effect diagram of a closed sub-loop set after the transition processing of the potential field curve of the topology locking point disclosed in an embodiment of the present invention. It can be seen that the method improves the display effect of local jagged edges and sharp corners, and reduces the probability of subsequent polygon construction failure and browser rendering load, while ensuring that key anchor points are necessary, long side straight lines are faithful, and the position of shared intersection points is stable.

[0064] Optionally, the unwinding and splitting process of the outline of the area to be displayed to obtain the renderable closed sub-loop set includes: S451, based on the shared intersection point set, perform topological cutting processing on the outline of the region to be displayed to obtain a sub-outline set of the region to be displayed; the sub-outline set of the region to be displayed includes several sub-outlines of the region to be displayed. S452, taking the shared intersection point of the shared intersection point set as the sequence starting point, extract the sub-contour positioning points of the sub-contour set of the region to be displayed respectively to obtain the first sub-contour positioning point correction sequence set of the region to be displayed; S453, the first set of sub-contour positioning point correction sequence for the display area is filtered to obtain the second set of sub-contour positioning point correction sequence for the display area. It should be noted that the above filtering process includes two conditions: a threshold for the number of points and a threshold for the area of ​​the region. First, the number of valid distinct locations in each sub-contour sequence is counted, and sub-contour sequences with fewer than three valid distinct locations are removed, as these points cannot form closed polygons. Second, the geographic area corresponding to the remaining sub-contours is calculated, and fragmented sub-contours with areas smaller than a preset minimum area threshold are removed. This preset minimum area threshold is pre-configured based on the browser's display scale, data precision, or business display requirements, and is used to filter out fragmented surfaces generated during topology cutting, reducing redundant calculations in subsequent smoothing and rendering processes. The remaining sub-contour sequences after filtering are summarized to obtain the second set of sub-contour location point correction sequences for the area to be displayed.

[0065] S454, perform anchor point smoothing processing on the second display area sub-contour positioning point correction sequence set to obtain the renderable closed sub-loop set.

[0066] As can be seen, the method for generating and displaying complex regions of global situation maps for browsers described in this embodiment of the invention, for complex self-intersecting contours with multiple intersections, completes contour decomposition through multi-point topological cutting, standardizes and unifies the starting point of the sub-contour point sequence, and then relies on the dual screening of point quantity and area to eliminate invalid small fragment contours generated by topological cutting, reducing the front-end computing load; finally, the contour geometry is optimized by anchor point smoothing, and the final output is a compliant renderable closed sub-loop set without self-intersections, invalid fragments, and smooth lines. It can effectively solve the problems of polygon construction failure, filling disorder, and small fragmented edges in the browser rendering of complex geographical contours with multiple intersections, while taking into account the real geographical boundary restoration accuracy and the stability of real-time rendering of the front-end situation map.

[0067] Optionally, the transformation process of the renderable closed sub-ring set to obtain the second normalized polygon hierarchy structure set includes: S51, the renderable closed sub-loop set and the preset positioning point elevation value information are fused to obtain a renderable closed sub-loop set with additional elevation values. It should be noted that the above fusion process supplements elevation values ​​based on preset elevation, real-time elevation, or default elevation, traverses all positioning points within the above renderable closed sub-loop set, adds elevation values ​​to each positioning point, expands the coordinate information of all positioning points into complete three-dimensional coordinates of latitude, longitude, and altitude, and obtains a renderable closed sub-loop set with added elevation values.

[0068] It should be noted that the above elevation values ​​are the vertical height of the positioning point relative to the WGS84 reference ellipsoid.

[0069] S52, the renderable closed sub-loop set with the additional elevation values ​​is encapsulated with positioning point coordinate information to obtain the second standardized polygonal hierarchical structure set.

[0070] It should be noted that the above encapsulation process involves structurally packaging all positioning points according to the CesiumJS specification data structure, constructing a PolygonHierarchy polygon hierarchy object that is compatible with the rendering engine, and summing all the encapsulated polygon objects to form a second standardized polygon hierarchy structure set. The encapsulation process fully preserves the original point order, closed topological relationship and latitude, longitude and altitude 3D coordinate information of the sub-loops, unifies the data output format, and eliminates the problem of differences in data structure between different sub-loops.

[0071] As can be seen, the method for generating and displaying complex regions of a global situation map for browsers described in this embodiment of the invention obtains latitude and longitude coordinates by uniformly supplementing the positioning points with preset elevation data, eliminating the need for additional elevation acquisition processes. Furthermore, it completes the structured encapsulation of coordinates according to rendering engine standards, outputting a standardized polygonal hierarchical structure set with a unified and directly recognizable format. This provides well-organized and complete 3D vector data for subsequent 2D and 3D scene coordinate adaptation processing, avoiding rendering errors caused by missing elevation information or data format mismatches, and improving the efficiency of complex region scene adaptation and visualization rendering of the global situation map on the browser side.

[0072] Optionally, the step of performing output scene adaptation processing on the first or second standardized polygon hierarchy set to obtain renderable graphics includes: S61, perform recognition processing on the output scene to obtain the output scene recognition result; the output scene recognition result is a two-dimensional scene or a three-dimensional scene. When the output scene recognition result is a two-dimensional scene, execute S62; When the output scene recognition result is a three-dimensional scene, execute S63; It should be noted that the above recognition process determines the scene type based on the view switch parameters of the front-end rendering container, distinguishes between two-dimensional planar display scenes and three-dimensional spherical display scenes, and diverts the subsequent coordinate transformation process according to the recognition results, so as to realize an adaptive branching process that is compatible with two types of rendering modes by a set of polygon hierarchical structures.

[0073] S62, perform two-dimensional view coordinate transformation on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain a renderable graphic; S63, perform three-dimensional view coordinate transformation on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain the renderable graphics.

[0074] It should be noted that the above-mentioned 3D view coordinate transformation process performs ECEF geocentric rectangular coordinate transformation on all latitude, longitude, and elevation coordinate points within the standardized polygon hierarchical structure set. Using the WGS84 ellipsoid model as a reference, the latitude, longitude, and elevation 3D geographic coordinates relative to the ellipsoid are uniformly converted into Cartesian geocentric coordinates that can be directly called by the CesiumJS 3D engine. After the transformation, all points conform to the Earth's spherical space, fully preserving the 3D layering effect brought by the elevation. The resulting 3D spherical renderable graphics are then obtained.

[0075] As can be seen, the method for generating and displaying complex regions of a global situation map for browsers described in this embodiment of the invention relies on a standardized polygon hierarchy structure set to adapt to different display scenarios and performs differentiated coordinate transformation processing. It eliminates the need to store multiple sets of data separately, saving front-end storage space, while ensuring the complete and normal display of graphics in different scenarios.

[0076] Optionally, the step of performing a two-dimensional view coordinate transformation on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain a renderable graphic includes: S621, Perform longitude value restoration processing on the first standardized polygon hierarchical structure set or the second standardized polygon hierarchical structure set to obtain a set of latitude, longitude and altitude positioning point coordinate sequences; It should be noted that the above-mentioned longitude value restoration process for positioning points is performed on all positioning points within the polygonal hierarchical structure set. This process restores the longitude values ​​after continuous longitude expansion and correction to the standard original longitude within a range of ±180 degrees, providing an accurate original geographic coordinate reference for cross-meridian identification.

[0077] S622, Based on the set of latitude and longitude high positioning point coordinate sequences, perform cross-anti-meridian judgment to obtain the cross-anti-meridian judgment result; When the cross-anti meridian judgment result is negative, the coordinate transformation process is performed on the latitude and longitude high positioning point coordinate sequence set to obtain the first world coordinate sequence set, and S626 is executed. If the cross-meridian determination result is yes, execute S623; It should be noted that by traversing the coordinate sequence of latitude, longitude and altitude positioning points and focusing on adjacent points, the original longitude difference between two adjacent points is compared to determine whether the line segment connecting adjacent positioning points crosses the anti-meridian of ±180 degrees. If none of the line segments connecting the positioning points cross the anti-meridian, the result of the judgment is "yes"; if at least one line segment connecting adjacent positioning points crosses the anti-meridian, the result of the judgment is "no".

[0078] It should be noted that the above coordinate transformation is a Mercator coordinate transformation process, which is consistent with the coordinate transformation process of S625. It maps the latitude, longitude and height coordinates of the positioning points in the latitude, longitude and height positioning point coordinate sequence set to the planar world coordinates used by the two-dimensional planar map, and adapts to the two-dimensional map planar rendering standard.

[0079] S623, Based on the set of latitude and longitude positioning point coordinates, calculate the coordinates of the anti-meridian transition points to obtain the set of anti-meridian transition points; S624, The latitude and longitude high-positioning point coordinate sequence set and the anti-meridian transition point set are fused to obtain a composite latitude and longitude high-positioning point coordinate sequence set; It should be noted that the above fusion process inserts all the anti-meridian transition points of the anti-meridian transition point set into the corresponding line segment positions of the latitude and longitude positioning point coordinate sequence without changing the original positioning point order, thus fusion to generate a complete and continuous composite latitude and longitude positioning point coordinate sequence set and eliminating coordinate discontinuities across meridian line segments.

[0080] S625, Perform coordinate transformation on the composite latitude and longitude high positioning point coordinate sequence set to obtain the second world coordinate sequence set; It should be noted that the above coordinate transformation process is a Mercator coordinate transformation process, which maps the latitude, longitude and height coordinates of the positioning points in the composite latitude, longitude and height positioning point coordinate sequence set to the planar world coordinates used by the two-dimensional planar map, and adapts to the two-dimensional map planar rendering standard.

[0081] S626, Based on the first world coordinate sequence set or the second world coordinate sequence set, a renderable graphic is constructed.

[0082] It should be noted that the above process for constructing renderable graphics is as follows: according to the positioning point order of the first world coordinate sequence set or the second world coordinate sequence set, the Mercator transformed planar coordinates are connected sequentially, and the first and last points are closed to form independent polygons. Then, all polygons are integrated into a complete two-dimensional region graphic.

[0083] As can be seen, the method for generating and displaying complex regions of a global situation map for browsers described in this embodiment of the invention identifies cross-meridian segments by restoring the original standard longitude, eliminates coordinate discontinuities by adding transition points for cross-meridian segments, completes planar coordinate transformation by uniformly using Mercator projection, and finally reconstructs a two-dimensional renderable graphic based on the original topological structure. This effectively solves the visualization defects of outline stretching and line breakage in two-dimensional views, outputs two-dimensional graphics with continuous boundaries and reduces abnormal stretching or breakage caused by cross-meridians, and is highly adaptable to the rendering requirements of two-dimensional planar scenes in browsers.

[0084] Optionally, the step of calculating the coordinates of the antimeridian transition points based on the latitude and longitude positioning point coordinate sequence set to obtain the antimeridian transition point set includes: S6231, Perform cross-meridian positioning point extraction processing on the latitude and longitude elevation positioning point coordinate sequence set to obtain a cross-meridian positioning point pair set; the cross-meridian positioning point pair set includes M cross-meridian positioning point pairs, where M is an integer greater than or equal to 1; The expression for the set of cross-meridian positioning points is: In the formula, P is the set of points located across the antimeridian; For the i-th pair of positioning points in the set of positioning points across the anti-meridian; for latitude and longitude coordinates Longitude value These are latitude values. Elevation values; for latitude and longitude coordinates Longitude value These are latitude values. Elevation values; It should be noted that the above process for extracting and processing cross-antimeridian positioning points is as follows: traverse the set of latitude, longitude and altitude positioning point coordinate sequences, read two adjacent positioning points in the sequence, compare the original longitude values ​​of the two points to determine whether the line segment crosses the antimeridian, pair up all adjacent points that meet the conditions for crossing the antimeridian, and summarize to obtain a set of cross-antimeridian positioning point pairs.

[0085] S6232, Perform latitude and longitude difference ratio calculation on the set of cross-meridian positioning points to obtain the set of cross-meridian transition points; the set of cross-meridian transition points includes M cross-meridian transition points, where M is an integer greater than or equal to 1; The expression for the set of transition points along the antimeridian is: In the formula, Q is the set of transition points of the antimeridian; This refers to the i-th anti-meridian transition point in the set of anti-meridian transition points; for The latitude and longitude coordinates, where 180° represents the longitude value. These are latitude values. is the elevation value, and t is the linear longitude interpolation ratio coefficient, with a value range of [0,1].

[0086] It should be noted that the aforementioned set of transition points along the anti-meridian is calculated using linear longitude interpolation coefficients. Furthermore, an adaptive sharpening correction method can be used to process these linear longitude interpolation coefficients, yielding adaptively sharpened longitude interpolation coefficients. Based on these coefficients, the coordinates of the transition points along the anti-meridian can be calculated. The expression for the set of transition points along the anti-meridian obtained using this method is as follows: In the formula, s is the normalization coefficient of the longitude span of the cross meridian segment, and its value range is [0,1]. The sharpening intensity is an adjustable parameter with a value range of [1.5, 3], and the preferred value is 2; The longitude interpolation scaling factor is adjusted for adaptive sharpening.

[0087] It should be noted that the aforementioned adaptive sharpening correction longitude interpolation ratio coefficient is constructed based on the power function nonlinear correction mechanism. On the basis of the linear interpolation ratio coefficient, a longitude span normalization coefficient for cross-meridian segments and an adjustable sharpening intensity parameter are introduced to jointly regulate the shape of the interpolation curve. For large-span cross-meridian segments, the intermediate interpolation ratio is significantly reduced through exponential power operations, making the distribution of interpolation points in the longitude variation range sparser and the transition gradient more obvious, strengthening the coordinate differentiation on both sides of the cross-meridian and avoiding the problems of uniform transition and weakened features in linear interpolation. For small-span micro-cross-meridian segments, the model exponent term approaches 1, and the interpolation curve automatically degenerates into standard linear interpolation, ensuring a smooth and natural transition for small-amplitude offset segments without distortion. The overall calculation only uses basic power functions and four arithmetic operations, with controllable parameters, simple logic, and low computational cost, making it suitable for real-time interpolation calculation scenarios with large batches of contour points on the browser side.

[0088] It should be noted that the aforementioned adaptive sharpening correction longitude interpolation ratio is highly adapted to the scenario of solving transition points of cross-meridian contours in 2D maps, making up for the inherent defects of traditional fixed linear interpolation that indiscriminately and uniformly interpolates cross-meridian segments of different spans. Through differentiated and adaptive nonlinear interpolation optimization, typical rendering problems such as visual stretching, line blurring, and boundary breakage of large-span cross-meridian segments are significantly improved, making the contour boundary transition of cross-meridian more consistent with the real geographical features. It eliminates 2D view rendering anomalies from the underlying coordinate interpolation stage, and significantly improves the contour integrity, continuity, and visualization regularity of complex cross-border areas in global situation maps on the browser side.

[0089] As can be seen, the method for generating and displaying complex regions of a global situation map for browser-side applications described in this embodiment of the invention first accurately extracts all adjacent points crossing the antimeridian to obtain a set of cross-antimeridian positioning points, then calculates the latitude-longitude difference ratio to complete the unified solution of transition points, obtaining transition points located on the antimeridian, accurately completing the coordinates of the breakpoints of the cross-antimeridian line segments, ensuring the continuity of the point sequence before the two-dimensional Mercator projection conversion without any breaks, avoiding the display anomalies of stretching and breaking of the two-dimensional map outline across the meridian from the source, and improving the integrity of the geographical boundary display of the two-dimensional situation map.

[0090] Example 2 This embodiment engineered the capability to handle complex regions onto the browser-side CesiumJS situational mapping. From a mathematical processing perspective, when dealing with complex regions, this invention does not directly split the region into surfaces, but instead first corrects the longitude sequence to the same continuous coordinate zone. Let the original longitude of the i-th point be λ_i, and the expanded continuous longitude be λ_... Then it can be written as: λ_ =λ_0; when λ_i-λ_(i-1) When the angle is >180°, take λ_ =λ_i-360°; when λ_i-λ_(i-1) When <-180°, take λ_ =λ_i+360°; otherwise, take λ_i. =λ_i. The purpose of this formula is to eliminate the pseudo-jumps caused by the coordinate representation at the ±180° boundary, so that the subsequent self-intersection detection faces a continuous planar polyline, rather than a discrete longitude sequence truncated by the world boundary.

[0091] The main differences between the existing solutions and the solution of this invention are as follows: Example 3 This embodiment coordinates multiple processes on the browser side, including polygon parsing, facet splitting, scene determination, and geometry output. The key modules are as follows: The specific implementation steps are as follows: 1. Read the original latitude and longitude key points in the browser and retain this original input as the common data source for both 2D and 3D outputs.

[0092] 2. Before proceeding to self-intersection detection or complex contour splitting, the longitude sequence is continuously expanded using unwrapFlatLonLatForSplit(...) to express adjacent side segments spanning ±180° within a continuous coordinate zone.

[0093] 3. Determine whether the unfolded continuous plane sequence constitutes a true plane self-intersection; if it does not constitute a self-intersection after unfolding, then self-intersection splitting is not triggered.

[0094] 4. For complex contours that require splitting, call splitSelfIntersectingRegions(...) or splitSelfIntersectingPolygonRings(...) to generate one or more renderable child rings.

[0095] 5. Convert the splitting result into a PolygonHierarchy and use this splitting result as the common basis for filling surfaces, outlines, and point selection / inside / outside judgment.

[0096] 6. In getRenderablePolygonHierarchy(...), the final rendering output is generated based on the current scene mode: for 2D scenes, antimeridian seam points are only inserted in the final output stage, while for 3D scenes, no seam points are inserted and the original spatial shape is maintained.

[0097] 7. Use the same hierarchy to output fill geometry and outline geometry.

[0098] 8. Verify 2D / 3D, ordinary figure-eight, and Bering Strait pseudo figure-eight scenarios.

[0099] Key attribute descriptions Key Methodology Description Typical Input / Output Examples Example 4 Key code excerpt explanation: The following code is an excerpt of the core logic, and its technical contribution is explained in the manner of "function, problem solved, implementation method, and algorithm used".

[0100] Code: `unwrapFlatLonLatForSplit` Function: Convert latitude and longitude sequences that cross anti-meridians into continuous longitude sequences.

[0101] Solution: Avoid misinterpreting longitude jumps such as 179° to -179° as long sides spanning the globe or true self-intersections.

[0102] Implementation method: Read the longitude value point by point and compare it with the previous point; when the difference between adjacent longitudes exceeds 180°, adjust the longitude to the same continuous coordinate zone by adding or subtracting 360°.

[0103] Algorithms used: longitude normalization algorithm and continuous coordinate expansion algorithm.

[0104] The essence of the above expansion formula is to apply a continuous zone correction of ±360° only to the longitude component while keeping the point sequence and latitude values ​​unchanged, so that adjacent segments are connected along the shortest continuous direction as much as possible. After this processing, a segment that originally seems to jump suddenly from 179° to -179° will become an ordinary segment with a difference of about 2° in the continuous plane, thus avoiding the misjudgment of cross-world boundaries as long sides spanning the globe.

[0105] code Code: `getSplitHierarchiesFromCartographics` Function: Converts raw geographic coordinates into one or more polygonhierarchies that can be rendered by CesiumJS.

[0106] Problem solved: Complex regions cannot be simply output as a single face; otherwise, filling errors, contour misalignment, or geometry calculation failures are likely to occur.

[0107] Implementation method: First, perform longitude expansion on the input point set, then perform complex region splitting, and finally convert each splitting result into an independent hierarchical surface structure.

[0108] The algorithms employed are: longitude unfolding algorithm, self-intersecting region splitting algorithm, and polygon hierarchy construction algorithm. This invention does not consider the self-intersecting region splitting algorithm itself as an independent inventive point, but rather emphasizes continuous longitude unfolding before splitting, hierarchy reuse after splitting, and differentiation between 2D and 3D outputs.

[0109] code Code: `splitSelfIntersectingRegions` and `splitSelfIntersectingPolygonRings` Function: To identify and break down complex contours with self-intersecting features, such as figure-eight shapes and pentagrams.

[0110] Problem: When directly filling self-intersecting polygons in the browser, abnormally large faces, missing fill, disordered boundaries, or internal geometry errors may occur.

[0111] Implementation method: First, close the point set and check if it is self-intersecting; if it is a single-intersection figure-eight shape, prioritize splitting it into two sub-faces according to the shared intersection point; if it is a more complex multi-intersection shape, then untangle and split the self-intersecting polygon.

[0112] The algorithms employed include: line segment self-intersection detection, closed ring processing, figure-eight double-leaf splitting algorithm, uninkpolygon splitting algorithm, area sorting algorithm, and anchor point smoothing algorithm. These algorithms are implementation methods for complex contour processing. This invention does not rely on ordinary polygon clipping or simple self-intersection splitting as its core protection principle, but rather focuses on pre-expansion, necessary splitting, delayed seam, and unified output under the semantics of anti-meridians.

[0113] When the splitting results need to be sorted, the signed absolute area value A(R) = 1 / 2·Σ(xj·yj+1−xj+1·yj) can be used, where (xK,yK)=(x0,y0), and the sub-contours are sorted from largest to smallest according to |A(R)|. This formula can prioritize preserving the order of the main regions when there are shared intersections or multiple sub-faces, reducing the visual inconsistency between the filling results and the contour results.

[0114] code Code: `insertMeasurementAntiMeridianPoints` and `getMeasurementCartesianPositions` Function: In 2D map mode, it adds seam points to polylines or boundaries that cross antimeridians and outputs renderable 3D coordinates.

[0115] Problem: When a 2D world is displayed in a browser, if a line segment crossing a meridian is not supplemented with a transition point, it may be stretched into a long line or appear broken on the screen.

[0116] Implementation method: First, unify the input coordinates into latitude, longitude and height format; in the 2D scene, determine whether each segment crosses the anti-meridian line, and insert seam points if necessary; finally, convert them into Cartesian coordinates that can be rendered by CesiumJS.

[0117] The algorithms employed are: anti-meridian intersection point interpolation algorithm, 2D scene perception output strategy, and latitude-longitude to 3D Cartesian coordinate transformation algorithm. This invention does not consider seam point interpolation itself as an independent invention point, but emphasizes that seam points are only generated in the final 2D rendering output stage and do not participate in face splitting, self-intersection judgment, or topology processing in advance.

[0118] For the seam point in the final two-dimensional output stage, it can be considered as the intersection of the antimeridian segment and λ_s∈{180°,-180°}. If the longitudes of the starting point and the continuous ending point are λ_1 and λ_... Then the intersection ratio can be written as t=(λ_s-λ_1) / (λ_ -λ_1), further we can obtain φ_s=φ_1+t(φ_2-φ_1) and h_s=h_1+t(h_2-h_1). Here, φ_s and h_s represent the latitude and height of the seam point, respectively. This set of formulas indicates that the seam point is only generated through linear interpolation in the final rendering output stage, and should not be entered into the face splitting and topology judgment process beforehand.

[0119] code Code: etRenderablePolygonHierarch Function: Outputs the final renderable polygon hierarchy based on the current scene mode.

[0120] Problem: Two-dimensional maps require seam points to ensure the continuous display of world boundaries, but three-dimensional globes should not introduce two-dimensional filler points, otherwise it will destroy the true spatial form.

[0121] Implementation method: First, determine whether the current scene is a 2D scene; for 3D scenes, directly return the original hierarchy; for 2D scenes, insert antimeridian seam points in the final output stage and reconstruct the hierarchy.

[0122] Algorithms employed: Scene mode branching algorithm, delayed seam insertion strategy, and polygon hierarchy reconstruction algorithm. This step is used to limit the difference between 2D and 3D outputs: 2D displays the world with seam padding, while 3D maintains the original spatial shape, preventing 2D padding from contaminating the shared splitting result.

[0123] code Code: reateAntiMeridianPoin Function: To calculate the intersection of the segment crossing the anti-meridian with the ±180° meridian.

[0124] Problem: When outputting a 2D map, transition points need to be added at the world boundary; otherwise, the polygon boundaries and filled surfaces may break or detour on the screen.

[0125] Implementation method: First, determine whether the longitude difference between two adjacent points exceeds 180°; if they cross the opposite meridian, calculate the intersection ratio based on the difference in latitude and longitude between the two points and generate a seam point.

[0126] Algorithms used: reverse meridian crossing detection algorithm, linear interpolation algorithm, latitude and longitude coordinate reconstruction algorithm.

[0127] code Example description: In a typical cross-meridian polygon scenario, performing longitude expansion before face splitting can generally avoid mistaking the world boundary reversal for a self-intersection point.

[0128] In pseudo-figure-eight scenarios such as the Bering Strait, the original latitude and longitude may appear to intersect, but if the longitude is unfolded and does not constitute a planar self-intersection, then the face splitting is not triggered, thus avoiding abnormal ringing.

[0129] In 2D mode, after inserting seam points using createAntiMeridianPoint(...), the polygon can maintain continuous rendering at the world boundary; in 3D mode, no seam is inserted, preserving the original spatial shape.

[0130] In practical browser-based global situation map applications, the method described in this invention ensures that the contours of complex regions such as task areas, alert areas, and control areas maintain stable boundary shapes during generation and display. This reduces display anomalies such as region deformation, abnormal detours, incorrect filling, and broken contours caused by crossing meridians, self-intersecting contours, or switching between 2D and 3D scenes. For special graphic symbols such as pentagrams and figure-eights, the method maintains consistency between the filled surface and the contour line through continuous longitude expansion, self-intersecting splitting, and scene adaptation processing, thereby improving the display stability and interactive reliability of complex regions in the browser-based global situation map.

[0131] Test and verification of quantitative results: This invention organizes the verification criteria according to the typical usage of the browser-side CesiumJS situation map, and the verification covers 5 types of complex areas, 2 scene modes and 3 types of operation actions, forming a total of 30 sets of verification test cases; each set is executed 10 times, for a total of 300 rendering and interaction verifications.

[0132] The verification results show that, in 300 browser-side rendering and interaction verifications, no abnormal errors, abnormal large areas, fill loss, or contour misalignment caused by reverse meridians, complex self-intersecting contours, or 2D / 3D switching were observed. The verification conclusions indicate that this method can support the stable generation and display of complex task areas, alert areas, control areas, and special graphic symbols in browser-side situation maps.

[0133] Finally, it should be noted that the method for generating and displaying complex regions of a global situation map for browser-side applications disclosed in this invention is merely a preferred embodiment of the invention and is only used to illustrate the technical solutions of the invention, not to limit it. Although the invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the invention.

Claims

1. A method for generating and displaying complex regions in a browser-based global situation map, characterized in that, The method includes: S1, Obtain the sequence of positioning points for the outline of the area to be displayed; the sequence of positioning points for the outline of the area to be displayed includes N positioning point coordinates; the positioning point coordinates include longitude and latitude values; N is an integer greater than or equal to 3; S2, perform longitude sequence continuous expansion and correction processing on the longitude sequence of the outline positioning point sequence of the area to be displayed to obtain the outline positioning point correction sequence of the area to be displayed. S3, based on the correction sequence of the contour positioning points of the area to be displayed, perform planar self-intersection detection to obtain the self-intersection detection judgment result; When the self-intersection detection result is negative, the correction sequence of the outline positioning points of the area to be displayed is converted to obtain the first standardized polygon hierarchical structure set, and S6 is executed. When the self-intersection detection result is yes, execute S4; S4, perform self-intersecting decomposition processing on the contour positioning point correction sequence of the area to be displayed to obtain a renderable closed sub-ring set; S5, the renderable closed sub-ring set is transformed to obtain the second standardized polygonal hierarchical structure set; S6, perform output scene adaptation processing on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain renderable graphics; S7, perform fill rendering processing on the renderable graphic to obtain the image of the area to be displayed.

2. The method for generating and displaying complex regions of a global situation map for browser-based applications according to claim 1, characterized in that, The step of performing longitude sequence continuous expansion and correction processing on the sequence of contour positioning points of the area to be displayed to obtain the corrected sequence of contour positioning points of the area to be displayed includes: S21, traverse all the coordinates of the positioning points in the sequence of positioning points of the area to be displayed, calculate the difference between the longitude value of the current positioning point coordinate and the longitude value of the previous adjacent positioning point coordinate, and obtain the longitude difference sequence. S22, using the longitude sequence continuous expansion correction model, process the longitude difference sequence and the outline positioning point sequence of the area to be displayed to obtain the outline positioning point correction sequence of the area to be displayed; The expression for the longitude sequence continuous expansion correction model is: In the formula, The longitude value of the i-th positioning point in the sequence of positioning points for the outline of the area to be displayed; The longitude value of the i-th positioning point in the correction sequence of the outline positioning points of the area to be displayed; It is the i-th longitude difference in the longitude difference sequence.

3. The method for generating and displaying complex regions of a global situation map for browser-based applications according to claim 1, characterized in that, The step of performing planar self-intersection detection based on the contour positioning point correction sequence of the area to be displayed, and obtaining the self-intersection detection judgment result, includes: S31, Based on the correction sequence of the outline positioning points of the area to be displayed, a set of outline line segments of the area to be displayed is constructed; S32, Select and pair the set of outline line segments of the area to be displayed to obtain a set of line segment pairs to be detected; the set of line segment pairs to be detected includes several sets of line segment pairs to be detected. S33, traverse all the line segment pairs to be detected in the set of line segment pairs to be detected, determine whether each pair of line segment pairs intersects in the middle of the line segment, and obtain several line segment pair intersection judgment results; If all line segment pairs are negative when they intersect, then the self-intersection detection result is negative. If at least one line segment pair intersects and the result is yes, then the result of the self-intersection detection is yes.

4. The method for generating and displaying complex regions of a global situation map for browser-based applications according to claim 1, characterized in that, The step of performing self-intersecting decomposition processing on the contour positioning point correction sequence of the area to be displayed to obtain a set of renderable closed sub-rings includes: S41, Based on the correction sequence of the outline positioning points of the area to be displayed, the outline of the area to be displayed is constructed; S42, Based on the outline of the area to be displayed, a set of shared intersection points is collected; the set of shared intersection points includes several shared intersection points; S43, determine whether the number of shared intersections in the shared intersection set is equal to 1, and obtain the result of the number of shared intersections; If the result of the determination of the number of shared intersections is yes, execute S44; If the result of the determination of the number of shared intersections is negative, execute S45; S44, perform double-leaf splitting on the outline of the area to be displayed to obtain a renderable closed sub-ring set; S45, the outline of the area to be displayed is unwound and split to obtain the renderable closed sub-ring set.

5. The method for generating and displaying complex regions of a global situation map for browser-based applications according to claim 4, characterized in that, The step of performing a two-leaf split on the outline of the region to be displayed to obtain a renderable closed sub-ring set includes: S441, Based on the shared intersection set, perform topological cutting processing on the outline of the region to be displayed to obtain two sub-outlines of the region to be displayed; S442, taking the shared intersection point of the shared intersection point set as the sequence starting point, extract the positioning points of the two sub-contours of the area to be displayed respectively, and obtain the positioning point correction sequence of the two sub-contours of the area to be displayed; S443, perform anchor point smoothing processing on the correction sequence of the sub-contour positioning points of the two regions to be displayed to obtain a renderable closed sub-ring set.

6. The method for generating and displaying complex regions of a global situation map for browser-based applications according to claim 4, characterized in that, The unwinding and splitting process of the outline of the area to be displayed to obtain the renderable closed sub-ring set includes: S451, based on the shared intersection point set, perform topological cutting processing on the outline of the region to be displayed to obtain a sub-outline set of the region to be displayed; the sub-outline set of the region to be displayed includes several sub-outlines of the region to be displayed. S452, taking the shared intersection point of the shared intersection point set as the sequence starting point, extract the sub-contour positioning points of the sub-contour set of the region to be displayed respectively to obtain the first sub-contour positioning point correction sequence set of the region to be displayed; S453, the first set of sub-contour positioning point correction sequence for the display area is filtered to obtain the second set of sub-contour positioning point correction sequence for the display area. S454, perform anchor point smoothing processing on the second display area sub-contour positioning point correction sequence set to obtain the renderable closed sub-loop set.

7. The method for generating and displaying complex regions of a global situation map for browser-based applications according to claim 1, characterized in that, The transformation process of the renderable closed sub-ring set to obtain the second normalized polygon hierarchy structure set includes: S51, the renderable closed sub-loop set and the preset positioning point elevation value information are fused to obtain a renderable closed sub-loop set with additional elevation values. S52, the renderable closed sub-loop set with the additional elevation values ​​is encapsulated with positioning point coordinate information to obtain the second standardized polygonal hierarchical structure set.

8. The method for generating and displaying complex regions of a global situation map for browser-based applications according to claim 1, characterized in that, The step of performing output scene adaptation processing on the first or second standardized polygon hierarchy set to obtain renderable graphics includes: S61, perform recognition processing on the output scene to obtain the output scene recognition result; the output scene recognition result is a two-dimensional scene or a three-dimensional scene. When the output scene recognition result is a two-dimensional scene, execute S62; When the output scene recognition result is a three-dimensional scene, execute S63; S62, perform two-dimensional view coordinate transformation on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain a renderable graphic; S63, perform three-dimensional view coordinate transformation on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain the renderable graphics.

9. The method for generating and displaying complex regions of a global situation map for browser-based applications according to claim 8, characterized in that, The step of performing a two-dimensional view coordinate transformation on the first standardized polygon hierarchy set or the second standardized polygon hierarchy set to obtain a renderable graphic includes: S621, Perform longitude value restoration processing on the first standardized polygon hierarchical structure set or the second standardized polygon hierarchical structure set to obtain a set of latitude, longitude and altitude positioning point coordinate sequences; S622, Based on the set of latitude and longitude high positioning point coordinate sequences, perform cross-anti-meridian judgment to obtain the cross-anti-meridian judgment result; When the cross-anti meridian judgment result is negative, the coordinate transformation process is performed on the latitude and longitude high positioning point coordinate sequence set to obtain the first world coordinate sequence set, and S626 is executed. If the cross-meridian determination result is yes, execute S623; S623, Based on the set of latitude and longitude positioning point coordinates, calculate the coordinates of the anti-meridian transition points to obtain the set of anti-meridian transition points; S624, The latitude and longitude high-positioning point coordinate sequence set and the anti-meridian transition point set are fused to obtain a composite latitude and longitude high-positioning point coordinate sequence set; S625, Perform coordinate transformation on the composite latitude and longitude high positioning point coordinate sequence set to obtain the second world coordinate sequence set; S626, Based on the first world coordinate sequence set or the second world coordinate sequence set, a renderable graphic is constructed.

10. The method for generating and displaying complex regions of a global situation map for browser-based applications according to claim 9, characterized in that, The calculation of the antimeridian transition point coordinates based on the latitude and longitude elevation positioning point coordinate sequence set, to obtain the antimeridian transition point set, includes: S6231, Perform cross-meridian positioning point extraction processing on the latitude and longitude elevation positioning point coordinate sequence set to obtain a cross-meridian positioning point pair set; the cross-meridian positioning point pair set includes M cross-meridian positioning point pairs, where M is an integer greater than or equal to 1; The expression for the set of cross-meridian positioning points is: In the formula, P is the set of points located across the antimeridian; For the i-th pair of positioning points in the set of positioning points across the anti-meridian; for latitude and longitude coordinates Longitude value These are latitude values. Elevation values; for latitude and longitude coordinates Longitude value These are latitude values. Elevation values; S6232, Perform latitude and longitude difference ratio calculation on the set of cross-meridian positioning points to obtain the set of cross-meridian transition points; the set of cross-meridian transition points includes M cross-meridian transition points, where M is an integer greater than or equal to 1; The expression for the set of transition points along the antimeridian is: In the formula, Q is the set of transition points of the antimeridian; This refers to the i-th anti-meridian transition point in the set of anti-meridian transition points; for The latitude and longitude coordinates, where 180° represents the longitude value. These are latitude values. is the elevation value, and t is the linear longitude interpolation ratio coefficient, with a value range of [0,1].

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