JPS60100266A - Shading system - Google Patents

Abstract

PURPOSE:To enable the titled system to reduce work memory by depicting a shading pattern between the start point and the end point in pair on the work memory and by modifying the shading pattern on the work memory according to frame information. CONSTITUTION:A graphic processor 102 reads a command from a graphic process command buffer 101, depicts the pattern of a frame line on a display memory 104, and depicts patterns of shading start and end points on a work memory 103 to store the frame information in a frame information memory 105. After executing necessary modification to the shading patterns according to the frame information, the processor writes the modified shading patterns in the display memory 104.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a graphic shading processing method in an image processing apparatus.

[Background of the invention]

Shading processing is part of image processing, and conventional image processing apparatuses perform this shading processing in the following manner.

First, according to the frame information (vertex coordinates of the closed figure to be shaded, type of frame line of the closed figure, etc.).

The frame line pattern is drawn on the display memory and work memory a, the inverted frame line pattern is drawn on the work memory b, and the shading start and end point patterns are drawn on the work memory (2).

Next, for each line (for example, a vertical line) that is a unit of shading processing, a shading pattern is drawn in the display memory by making a run in the work memory C, but the starting and ending points are not always appropriate. It may not be. This is because in the case of circular shapes, etc., the start and end point patterns are drawn by tracing the frame line in a certain direction, so the positions of the start and end points may shift up and down, and the frame line is a continuous line (solid line). ), the two innermost points of the intersection of the frame line pattern and each line can be used as the start and end points, whereas if the frame line is a discontinuous line such as a broken line, the part where the line is This is the same as in the case of a solid line, but there are problems such as the center of the inverted pattern of the frame line must be set as the starting point or ending point in a portion without a line. Therefore, the frame line pattern of the start point and end point portion detected by scanning the work memory C and its inverted pattern are read from the work memories a and b, and appropriate start and end points are determined.

A shading pattern is drawn on the display memory between the start point and end point determined in this way. By repeating the above processing, a shading figure is obtained in the display memory.

Although the dual shading processing method is capable of high-speed processing, it has the disadvantage of requiring three levels of work memory. Note that the reason why the frame line pattern is drawn in work memory a separately from the display memory is because the display memory often contains patterns such as characters other than frame lines, and the frame line pattern on the display memory is used to determine the starting and ending points. This is because it is not desirable to use it for

[Purpose of the invention]

An object of the present invention is to provide a shading processing method that can reduce work memory.

[Summary of the invention]

The shading processing method of the present invention reduces the work memory to 1
First, the frame line pattern is drawn on the display memory according to the frame information, the pattern of the start and end points of the shape ink is drawn on the work memory 1-, and then the corresponding pattern is drawn on the work memory. After drawing a shading pattern between the starting point and the ending point forming the shading pattern, necessary corrections are made to this shading pattern according to the frame information in the work menu, and the corrected shading pattern is written on the display screen. That is.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram showing one embodiment of the present invention. In this figure, 101 is a graphics processing command buffer, 1.02 is a graphics processor, 103 is a work memory, 104 is a display memory, 10.5 is a frame information memory, 10
6 is a display device.

FIG. 2 is a flowchart 1- showing the flow of shading processing by the graphic processor 102.

The details of the shading process will be explained according to this figure.

First, the graphic processor 102 reads one command from the graphic processing command buffer 101 (■), and determines whether the command is a shading start command (■). If the determination result is No, the command is a frame information command.

In accordance with the frame information, the graphic processor 102 draws a frame line pattern on the display memory 104 (■), draws a shading start point and end point pattern on the work memory 103 (■), and writes the frame information (code information) in the display memory 104 (■). ■), return to step ■, and read the next command.

If the shading start command is read and the determination result in step ■ is YES, the graphic processor 102
starts the actual shading process. This process is
This is done for each line that crosses the figure to be shaded.

First, the graphic processor 102 scans the work memory 103 for the first grain line, and sets the position where the start and end point patterns are first detected as the start point, and the position where the last point pattern is detected as the end point.
Draw a shading pattern in work memory 1.03 J2 between the start and end points (■). The graphic processor 102 reads frame information from the frame information memory 105 (■
), determine the presence or absence of a frame line from this frame information■), and if there is no frame line, calculate two points corresponding to the center point of the frame line pattern on the relevant line from the frame information, and calculate the two points (corrected The shape ink pattern drawn in the work memory 103 is extended to the starting point and ending point (■). If there is a frame line, the graphic processor 102 determines whether there is a frame line pattern at the position of the line (■); if not, executes step 0 to extend the shape ink pattern, and if there is a frame line pattern, The portion of the shading pattern drawn in the work memory 103 that overlaps with the frame line pattern is erased (4!I)).

The graphic processor 102 determines whether the above processing has been performed up to the last line (■), and if there are unprocessed lines remaining, it returns to step ■ and starts processing the next line. The obtained shading pattern and the pattern on the display memory 104 are logically summed, and the shading pattern is written in the display memory 104 (0).

FIG. 3 shows the method for selecting the starting point and ending point in step (2) in the form of a truth table. It is determined whether the point P is to be the starting point or the ending point according to the conditions of the displacement ΔX in the X direction of the point P and the point P, -1, -, and the displacement ΔX in the direction of P and the point Pi++. A point P denoted as 1 is selected as a starting point or an end point, and a point P denoted as 0 is not selected.

Note that if there is no frame line (however, the shading range corresponding to the frame line is specified by the frame information), nothing is written to the display memory 104 in step (3). Frame information memory 10
5 does not need to be an independent memory; for example, an empty area of the work memory +03 or the display memory 104 may be used. Moreover, processing such as step [phase] may be executed by hardware.

〔Effect of the invention〕

As described in detail above, according to the present invention, the work memory that conventionally required three areas can be used for shading processing, but now only one area can be used, and the hardware cost for shading processing can be significantly reduced. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing one embodiment of the present invention, and FIG.
The figure is a flowchart showing the flow of shape ink processing by the 1.1 type processor, and Figure 3 is an explanatory diagram of how to select the start and end points of shape ink.
...Graphic processor, 1.03...Work memory, 1
04... Display memory, 105... Frame information memory. Figure 1 Figure 3 Figure 2

Claims (1)

[Claims] (1) After drawing a frame line pattern and shading start and end point patterns on the display memory and work memory, respectively, according to the frame information, and drawing a shading pattern between the paired start and end points on the work memory. , a shading processing method characterized in that the shading pattern is subjected to necessary modification on the work memory according to the frame information, and the modified shading pattern is written to the display memory.