Print text content display method and device based on cross-platform consistency
By defining a unified text description protocol and measurement method, and utilizing the Skia rendering engine, cross-platform consistent text display between the inkjet printer and the PC host computer is achieved. This solves the text display error under different operating systems and ensures that the measurement and drawing results of the inkjet printer and the host computer are consistent.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-03-24
AI Technical Summary
Differences in measurement results between inkjet printers and PCs operating systems when displaying text content can lead to errors in the drawing and display process.
Define a unified text description protocol and measurement method, achieve cross-platform consistency between the inkjet printer and the PC host computer through the Skia rendering engine, and use HarfBuzz and FreeType for text shaping and rasterization to ensure that the text measurement and drawing results of the inkjet printer and the host computer are consistent on different platforms.
This achieves consistent text display between the inkjet printer and the PC host computer on different platforms, solving the problem of cross-platform text display errors.
Smart Images
Figure CN121722337A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of printing technology, in particular to a printing text content display method based on cross-platform consistency, a computer readable storage medium, a computer device and a printing text content display device based on cross-platform consistency. BACKGROUND
[0002] In the related art, a screen is usually provided on a code jet device to display the content to be printed by the device. In order to more conveniently remotely control the device, a host computer software is developed on a Windows PC, and the host computer software can also display the content to be printed on the device. When the content is displayed, coordinate information is provided to facilitate the user to accurately perceive the length, width, position and the like of the printed content.
[0003] Among them, the code jet device is generally developed based on an embedded Linux system or a FreeRTOS system, and the PC host computer is developed based on a Windows system. In the Windows system, font measurement usually relies on GDI or DirectWrite. In the embedded Linux system, the common implementation is FreeType+HarfBuzz. In the FreeRTOS or the like without an operating system environment, there is usually no ready-made font measurement API, and the developer needs to transplant or use a font matrix. Since the font measurement methods, rendering engines, font file versions and anti-aliasing algorithms of different operating systems are all different, even if the same font file (such as the same TTF) is used, the measurement results (width, height, line spacing, etc.) may still be different. When drawing and displaying, errors will occur. SUMMARY
[0004] The present application aims to at least solve one of the above technical problems in the art. To this end, one object of the present application is to provide a printing text content display method based on cross-platform consistency, which defines a unified text description protocol (font, coordinate, font size, inter-character spacing, etc.), a unified measurement method and a drawing engine to achieve consistency in cross-platform measurement and drawing of code jet text content.
[0005] A second object of the present application is to provide a computer readable storage medium.
[0006] A third object of the present application is to provide a computer device.
[0007] A fourth object of the present application is to provide a printing text content display device based on cross-platform consistency.
[0008] To achieve the above objectives, the first aspect of this application proposes a method for displaying printed text content based on cross-platform consistency, applicable to both a PC host computer and an inkjet printer. The method includes the following steps: obtaining the string to be printed and a defined text object description protocol, and obtaining a text attribute structure based on the defined text object description protocol; obtaining the resolution of the inkjet printer printhead, and ensuring that the resolution of the PC host computer matches the resolution of the inkjet printer printhead; using a text shaping engine to obtain corresponding glyph list information based on the text attribute structure; using a font rasterization engine to obtain corresponding font outline information based on the glyph list information and the text attribute structure; and using the Skia rendering engine to render the text onto a display screen based on the obtained glyph list information, font outline information, and resolution parameters.
[0009] According to the cross-platform consistency printed text content display method of this application embodiment, firstly, a unified text object description protocol, DPI settings for the inkjet printer and PC host computer software are established, text is shaped using HarfBuzz, font outlines are obtained using FreeType, a unified text measurement method is used, and text is drawn using Skia; thereby, it is ensured that the measurement and drawing results of text by the inkjet printer and host computer on different platforms are highly consistent, and the cross-platform text display error problem is solved.
[0010] In addition, the method for displaying printed text content based on cross-platform consistency proposed in the above embodiments of this application may also have the following additional technical features:
[0011] Optionally, during display, the process includes: determining whether the device to be displayed is a PC host computer or an inkjet printer; if it is a PC host computer, the character list information, font outline information, and resolution parameters are submitted to Skia rasterization via a customized Flutter engine, and then sent to the Flutter rendering pipeline to complete anti-aliasing and layer compositing before being displayed on the screen; if it is an inkjet printer, the character list information, font outline information, and resolution parameters are directly sent to the embedded Skia for rasterization and written to the LCD controller's display memory.
[0012] Optionally, to make the resolution of the PC host computer consistent with the resolution of the inkjet printer printhead according to the resolution of the inkjet printer printhead, the method includes: reading the current physical first DPI value from the device EEPROM or printhead driver register; and setting a second DPI value of the PC host computer according to the first DPI value, wherein the first DPI value is equal to the second DPI value.
[0013] Optionally, obtaining the pixel width and height of the entire line of text based on the glyph list information and the font outline information includes: converting the glyph list information into floating-point device pixels to obtain the step and offset of each glyph in the DPI coordinate system; adding the font outline information to the same offset to calculate the pixel extreme value actually occupied by the character; accumulating the pixel extreme values along the line direction and adding the letter_spacing set by the text attribute structure to obtain the cumulative width of the entire line of text; comparing all y_bearing and y_offset vertical drift values along the vertical direction, taking the difference between the top and bottom values and adding the underline thickness to obtain the cumulative height of the entire line of text; and outputting the cumulative width and cumulative height as the pixel width and height of the entire line of text.
[0014] To achieve the above objectives, a second aspect of this application provides a computer-readable storage medium storing a cross-platform consistent print text content display program, which, when executed by a processor, implements the cross-platform consistent print text content display method described above.
[0015] To achieve the above objectives, a third aspect of this application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, when the processor executes the program, it implements the above-described method for displaying printed text content based on cross-platform consistency.
[0016] To achieve the above objectives, a fourth aspect of this application proposes a cross-platform consistent printed text content display device, comprising: a definition module, used to acquire the string to be printed and a defined text object description protocol, and obtain a text attribute structure according to the defined text object description protocol; a setting module, used to acquire the resolution of the inkjet printer head, and make the resolution of the PC host computer consistent with the resolution of the inkjet printer head according to the resolution of the inkjet printer head; a text shaping module, used to use a text shaping engine to obtain corresponding glyph list information according to the text attribute structure; an extraction module, used to use a font rasterization engine to obtain corresponding font outline information according to the glyph list information and the text attribute structure; a measurement module, used to obtain the pixel width and height of the entire line of text according to the glyph list information and the font outline information; and a display module, used to draw the obtained glyph list information, font outline information and resolution parameters onto the display screen using the Skia rendering engine. Attached Figure Description
[0017] Figure 1 This is a flowchart illustrating a method for displaying printed text content based on cross-platform consistency according to an embodiment of this application;
[0018] Figure 2This is a block diagram of a cross-platform consistent printed text content display device according to an embodiment of this application. Detailed Implementation
[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.
[0020] To better understand the above technical solutions, exemplary embodiments of this application will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.
[0021] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.
[0022] Figure 1 This is a flowchart illustrating a method for displaying printed text content based on cross-platform consistency according to an embodiment of this application. The method includes the following steps:
[0023] S101, obtain the string to be printed and the defined text object description protocol, and obtain the text attribute structure according to the defined text object description protocol.
[0024] It should be noted that the string to be printed is obtained from the original printable text content entered by the user on the PC host computer or inkjet printer interface.
[0025] Specifically, a unified text object description protocol is established as follows:
[0026]
[0027] The above protocol describes the font, font size, x and y starting coordinates for drawing, character spacing, character width ratio, bold, italics, underline, and other information used in the text. The inkjet printer and the PC host computer software obtain the text attribute structure through a unified protocol.
[0028] S102, obtain the resolution of the inkjet printer head, and make the resolution of the PC host computer consistent with the resolution of the inkjet printer head according to the resolution of the inkjet printer head.
[0029] In other words, the DPI settings of the inkjet printer and the PC host computer software should be standardized.
[0030] As one embodiment, to make the resolution of the PC host computer consistent with the resolution of the inkjet printer printhead, the method includes: reading the current physical first DPI value from the device EEPROM or printhead driver register; and setting a second DPI value of the PC host computer according to the first DPI value, wherein the first DPI value is equal to the second DPI value.
[0031] It should be noted that different inkjet printers may have different printhead resolutions (DPI), such as 300, 600, and 1200. Therefore, the PC software needs to dynamically obtain the DPI information from the inkjet printer and use the same DPI setting to ensure consistent display position information during measurement and drawing.
[0032] S103 uses a text shaping engine to obtain the corresponding glyph list information based on the text attribute structure.
[0033] In other words, the text shaping engine (HarfBuzz) analyzes the language and context of each Unicode character, processes rules such as ligatures and hyphens, queries font information, and performs glyph replacement and positioning.
[0034] Specifically, with the same HarfBuzz parameters set, some of the shaping methods are as follows:
[0035]
[0036] S104 uses a font rasterization engine to obtain the corresponding font outline information based on the glyph list information and text attribute structure.
[0037] In other words, the font rasterization engine (FreeType) obtains the font outline path from the font file using the glyph list information returned by HarfBuzz. The font outline path is used for subsequent font drawing.
[0038] S105: Obtain the pixel width and height of the entire line of text based on the glyph list information and font outline information.
[0039] As an example, the pixel width and height of the entire line of text are obtained based on the glyph list information and font outline information, including: converting the glyph list information into floating-point device pixels to obtain the step and offset of each glyph in the DPI coordinate system; adding the font outline information to the same offset to calculate the pixel extreme value actually occupied by the character; accumulating the pixel extreme values along the line direction and adding the letter_spacing set by the text attribute structure to obtain the cumulative width of the entire line of text; comparing all y_bearing and y_offset vertical drift values along the vertical direction, taking the difference between the top and bottom values and adding the underline thickness to obtain the cumulative height of the entire line of text; and outputting the cumulative width and cumulative height as the pixel width and height of the entire line of text.
[0040] In other words, after shaping the text using HarfBuzz, the width and height of the text are calculated using a unified calculation method based on the returned glyph list information. Specifically, some of the calculation methods are as follows:
[0041]
[0042]
[0043] In summary, by iterating through each glyph step and offset returned by HarfBuzz, the total horizontal width of the entire line is obtained. At the same time, by combining the upper and lower extreme values and vertical drift of the outline bounding box given by FreeType, the precise height of the entire line of text in the device pixel coordinate system is calculated. Italic protrusion compensation and character spacing correction are added, and finally, the tight pixel width and height corresponding one-to-one with the nozzle DPI are output, providing a zero-error positioning benchmark for subsequent Skia rendering.
[0044] S106: Based on the obtained glyph list information, font outline information, and resolution parameters, the Skia rendering engine is used to draw the image onto the display screen.
[0045] In other words, by using the unified Skia rendering engine, the glyph list information obtained through HarfBuzz and the font outline information obtained through FreeType are drawn and output to the display screen. Specifically, some of the drawing methods are as follows:
[0046]
[0047]
[0048]
[0049] In addition, during the display process, the following steps are taken: determining whether the device to be displayed is a PC host computer or an inkjet printer; if it is a PC host computer, the character list information, font outline information, and resolution parameters are submitted to Skia rasterization via a customized Flutter engine, and then sent to the Flutter rendering pipeline to complete anti-aliasing and layer compositing before being displayed on the screen; if it is an inkjet printer, the character list information, font outline information, and resolution parameters are directly sent to the embedded Skia for rasterization and written to the LCD controller's display memory.
[0050] In other words, the PC host computer software extends the Flutter engine through customized modifications to achieve text measurement and drawing functions, thus achieving cross-platform measurement and drawing consistency with the inkjet printer equipment.
[0051] It should be noted that on the PC side, the host computer software is developed based on the Flutter platform. The `TextPainter.computeLineMetrics()` method in the Flutter engine includes reserved blank areas on the top, bottom, left, and right sides when measuring text, making it impossible to directly obtain the tight bounding box information that strictly encloses the text outline. To solve this problem, a custom modification was made to the Flutter engine, adding a custom text measurement method that can obtain the minimum boundary size of the text. This solution ensures that the measurement results of the host computer software are consistent with the measurement method on the inkjet printer device, thus achieving consistency in text drawing and layout across platforms.
[0052] In summary, the cross-platform consistent method for displaying printed text content in this application obtains the string to be printed and a defined text object description protocol, and obtains the text attribute structure according to the defined text object description protocol; obtains the resolution of the inkjet printer head, and ensures that the resolution of the PC host computer is consistent with the resolution of the inkjet printer head; uses a text shaping engine to obtain the corresponding glyph list information based on the text attribute structure; uses a font rasterization engine to obtain the corresponding font outline information based on the glyph list information and the text attribute structure; obtains the pixel width and height of the entire line of text based on the glyph list information and the font outline information; and uses the Skia rendering engine to draw the text onto the display screen based on the obtained glyph list information, font outline information, and resolution parameters; thereby achieving cross-platform consistency in measuring and drawing inkjet printer text content.
[0053] To implement the above embodiments, this application proposes a computer-readable storage medium storing a cross-platform consistent print text content display program. When the cross-platform consistent print text content display program is executed by a processor, it implements the cross-platform consistent print text content display method as described above.
[0054] To implement the above embodiments, this application proposes a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The device is characterized in that, when the processor executes the program, it implements the above-described method for displaying printed text content based on cross-platform consistency.
[0055] To achieve the above embodiments, such as Figure 2 As shown in the figure, this application proposes a printable text content display device based on cross-platform consistency, including: a definition module 10, a setting module 20, a text shaping module 30, an extraction module 40, a measurement module 50, and a display module 60.
[0056] The system comprises the following modules: Definition Module 10, which acquires the string to be printed and the defined text object description protocol, and obtains the text attribute structure based on the defined text object description protocol; Setting Module 20, which acquires the resolution of the inkjet printer head and ensures that the resolution of the PC is consistent with the resolution of the inkjet printer head; Text Shaping Module 30, which uses a text shaping engine to obtain the corresponding glyph list information based on the text attribute structure; Extraction Module 40, which uses a font rasterization engine to obtain the corresponding font outline information based on the glyph list information and the text attribute structure; Measurement Module 50, which uses the glyph list information and font outline information to obtain the pixel width and height of the entire line of text; and Display Module 60, which uses the Skia rendering engine to draw the text onto the display screen based on the obtained glyph list information, font outline information, and resolution parameters.
[0057] It should be noted that the above regarding Figure 1 The description of the cross-platform consistency-based printed text content display method also applies to this cross-platform consistency-based printed text content display device, and will not be repeated here.
[0058] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0059] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0060] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0061] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0062] It should be noted that any reference signs placed between parentheses in the claims should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. This application can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.
[0063] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
[0064] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
[0065] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0066] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0067] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0068] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0069] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.
Claims
1. A method for displaying printed text content based on cross-platform consistency, characterized in that, The method, which applies to both a PC host computer and an inkjet printer, includes the following steps: Obtain the string to be printed and the defined text object description protocol, and obtain the text attribute structure according to the defined text object description protocol; Obtain the resolution of the inkjet printer head, and make the resolution of the PC host computer consistent with the resolution of the inkjet printer head according to the resolution of the inkjet printer head; A text shaping engine is used to obtain the corresponding glyph list information based on the text attribute structure; The font rasterization engine is used to obtain the corresponding font outline information based on the glyph list information and the text attribute structure; The pixel width and height of the entire line of text are obtained based on the glyph list information and the font outline information; Based on the obtained glyph list information, font outline information, and resolution parameters, the image is drawn onto the display screen using the Skia rendering engine.
2. The method for displaying printed text content based on cross-platform consistency as described in claim 1, characterized in that, When displaying, it includes: Determine whether the device to be displayed is a PC host computer or an inkjet printer; If it is a PC host computer, the glyph list information, font outline information and resolution parameters are submitted to Skia rasterization in one go through the customized Flutter engine, and then sent to the Flutter rendering pipeline to complete anti-aliasing and layer compositing before being displayed on the screen; If it is an inkjet printer, the character list information, font outline information and resolution parameters are directly sent to the embedded Skia for rasterization and written to the LCD controller's display memory.
3. The method for displaying printed text content based on cross-platform consistency as described in claim 1, characterized in that, To ensure that the resolution of the PC is consistent with the resolution of the inkjet printer head, the following steps are taken: Read the current physical first DPI value from the device EEPROM or nozzle driver register; The second DPI value of the PC host computer is set according to the first DPI value, wherein the first DPI value is equal to the second DPI value.
4. The method for displaying printed text content based on cross-platform consistency as described in claim 3, characterized in that, The pixel width and height of the entire line of text are obtained based on the glyph list information and the font outline information, including: The glyph list information is converted into floating-point device pixels to obtain the step and offset of each glyph in the DPI coordinate system; Add the font outline information to the same offset to calculate the extreme value of pixels actually occupied by the character; The cumulative pixel extreme values are added along the line direction and the letter_spacing set by the text attribute structure is added to obtain the cumulative width of the entire line of text. Compare all the vertical shift values of y_bearing and y_offset, take the difference between the top and bottom values and add the underline thickness to get the cumulative height of the entire line of text; The cumulative width and cumulative height are used as the pixel width and height of the entire line of text for output.
5. A computer-readable storage medium, characterized in that, It stores a cross-platform consistent print text content display program, which, when executed by the processor, implements the cross-platform consistent print text content display method as described in any one of claims 1-4.
6. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method for displaying printed text content based on cross-platform consistency as described in any one of claims 1-4.
7. A printable text content display device based on cross-platform consistency, characterized in that, include: The definition module is used to obtain the string to be printed and the defined text object description protocol, and to obtain the text attribute structure according to the defined text object description protocol; The setting module is used to obtain the resolution of the inkjet printer head and make the resolution of the PC host computer consistent with the resolution of the inkjet printer head according to the resolution of the inkjet printer head. The text shaping module is used to obtain the corresponding glyph list information based on the text attribute structure using the text shaping engine; The extraction module is used to obtain the corresponding font outline information based on the glyph list information and the text attribute structure using a font rasterization engine; The measurement module is used to obtain the pixel width and height of the entire line of text based on the glyph list information and the font outline information; The display module is used to draw the glyphs onto the display screen using the Skia rendering engine, based on the obtained glyph list information, font outline information, and resolution parameters.