Curve-drawing device, curve-drawing method, curve-drawing program, and integrated circuit

Abstract

The present invention provides a curve-drawing device in which the need to perform further approximation on a curve approximation result can be decided by a simpler technique than in the past. A curve-drawing device (1) is intended for a straight-line approximation of a curved contour line defined by a line width and a center line, and comprises: a path division unit (10) for calculating a plurality of division points on the center line which divide the center line; a contour point calculation unit (12) for calculating two separation points located at equal distances from the division points along a normal to the center line through the division points; a decision unit (13) for calculating the respective distances between two separation points located on the same side relative to a straight line passing through the two division points out of four separation points calculated for two neighboring division points, and determining whether a ratio for a case based on the shorter of the two distances is greater than a predetermined value; and a curve formation unit (16) for approximating the longer of partial contour lines, which are parts sandwiched between the normals that pass through the two division points on the contour line, by more segments than the shorter of the partial contour lines when the ratio has been determined to be greater than the predetermined value.

Description

technical field [0001] The present invention relates to a curve drawing technique for approximately drawing a curved portion of an outline of a character or figure with a plurality of line segments. Background technique [0002] In recent years, vector drawing technology has been used in the drawing of characters such as fonts, or curve parts in graphics, etc. The inside of the outline represented by the line segment is filled. The quality of characters or graphics approximated by this technique is affected by the degree of smoothness of the junction of line segments used for the approximation (hereinafter referred to as edge). Therefore, when rough approximation processing results in insufficient edge smoothness, further approximation is performed using line segments in order to add swelling to the edge. In this way, judging for each edge whether further approximation of the edge is necessary can be said to be a process that is executed very frequently. For judging wheth...

AI Technical Summary

Problems solved by technology

[0009] However, the above-mentioned technique has a problem that although it is possible to determine whether approximation is necessary, it is necessary to calculate the angle of the two line segments constituting each edge, and complex calculations such as inverse trigonometric functions are required to calculate the angle.

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