JPH0896149A - Graphic plotting device - Google Patents

Abstract

PURPOSE: To plot graphics fast by changing a side direction stored after color code switching information has been into the direction of a side to be processed unless the direction of the side to be processed that a CPU decides is parallel to a scanning direction. CONSTITUTION: The CPU 101 sets the color code switching information in a RAM 103 corresponding to the display position of the start point of the side to be processed when the direction of the side to be processed is not parallel to the scanning direction and the direction and a side direction stored in a direction storage register have specific side direction relation. Further, the CPU 101 sets the color code switching information at storage positions in the RAM 103 corresponding to respective display positions when the respective display positions on the side to be processed other than the display positions of both the ends of the side to be processed change from display positions as last process objects to a direction orthogonal to the scanning direction. The side direction stored in the direction storage register is changed into the direction of the side to be processed after the 1st color code switching information is set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic drawing apparatus having a function of filling a closed contour line.

[0002]

2. Description of the Related Art In a device for outputting an image on a display device such as a CRT or LCD such as a personal computer or a TV game, or a device for outputting an image on a paper such as a word processor, the amount of data is reduced. For the purpose of compressing, the graphic data is often drawn by the process of drawing the contour line and the process of filling the area surrounded by the contour line with a predetermined color.

In this case, as a general method known in the related art for the process of filling the inside of the area surrounded by the closed contour, there are two methods classified into two large categories called seed fill and scan conversion. is there. The basic ideas of both parties will be explained below.

First, in the seed fill, one point (seed) existing within a closed contour line is given, and it is judged whether or not a point adjacent to the point is within the contour line.
If the point lies within the contour line, the adjacent point is examined as a new seed. By repeating this operation, it is determined whether or not all the points within the outline should be filled, and the filling process is executed.

However, in this method, seeds must be preset in all contour lines to be filled, and when a large area is filled, the number of times of access to points within the contour lines is increased. Moreover, the number of determinations becomes enormous, and it is unsuitable as a means for painting a figure adopted in a TV game or the like that requires high-speed rewriting of the display screen.

On the other hand, in scan conversion, a contour line is first drawn. Then, a scan is performed along the raster in the region that contains the contour, and the pixels inside the contour (between the odd and even intersections of the contour and the scan points) are colored. The outer pixels (between the even-numbered intersections and the odd-numbered intersections between the contour line and the scanning points) are not painted, so that the figure is filled. For example, with respect to the figure shown in FIG. 17, in scanning, the area between the first intersection A and the next intersection B is filled.

However, in the scan in the example of FIG. 17, according to the algorithm in which no countermeasure is taken, the filling will start after the intersection E following the intersections C and D. Therefore, at the maximum point and the minimum point, it is necessary to take a measure to continue the process that has been executed immediately before. As a specific algorithm, the maximum point and the minimum point are extracted in advance, the intersection point obtained at the time of scanning and the previously extracted pole point are compared at any time, and if they match each other, the processing executed immediately before Can be continued.
That is, if the process that has been executed up to immediately before is a process that does not perform the filling, the filling is not performed even after the extreme point,
If the process executed up to immediately before is the filling process, the filling process is continued even after the extreme point.

In this scan conversion method, the memory access can be performed at high speed by adopting the scan processing in one direction. However, it is necessary to perform a process of extracting a maximum point / a minimum point from the contour line in advance and a process of determining whether or not the intersection of the scan line and the contour line is the pole point. Therefore, when this method is applied to a complicated figure (with many poles), there is a problem that the processing time increases.

As a method for improving the problems of the above-described general scan conversion method, Japanese Patent Laid-Open No. 62-192
There is a known example disclosed in 878. In the technique disclosed by this known example, while the contour line is developed in the display memory, at the same time, the color-painting control information is written in a separately secured work memory area of the same size according to a predetermined rule, and all the contour lines are written. After being expanded, the working memory area is sequentially scanned, and color data is expanded into the corresponding dots of the display memory while switching between performing / not performing the paint every time the color control information appears.
Therefore, this method has an advantage that it is not necessary to perform processing such as extraction of a pole point after the contour line is developed and determination of an intersection point during scanning.

However, in this method, as a rule for setting the color painting control information, the polarities of the inclination of the side showing the contour line drawn immediately before and the inclination of the side showing the contour line to be drawn next are respectively set. Change is determined, so that, for example, the contour line on the display memory can be seen at the locations of and in FIG. 18 (b) corresponding to the basic picture as shown in FIG. 18 (a). When processing is performed on consecutive sides with a horizontal side between them, when processing is performed on the next side of the horizontal side, the polarity depends on the connection with the side processed before the horizontal side. The exception processing must be performed by retroactively processing the starting point of the horizontal side only when the two differ. In the example shown in FIG. 18 (b), it is only necessary to go back one horizontal side in the processing of the part in the case of, but in the case where a plurality of horizontal sides are connected by the transformation processing such that this figure is compressed in the vertical direction, , Processing to trace back to the beginning of the horizontal side is required (see FIG. 18 (c)). Therefore, this method has a problem in that the continuity of processing is interrupted depending on the shape to be drawn, and the processing time becomes long and the processing algorithm becomes complicated, which is disadvantageous in programming. ing.

On the other hand, for example, when graphic data such as a portrait using an animation image is drawn by a process of drawing the contour line and a process of filling a range surrounded by the contour line with a predetermined color, For example, a person's face is divided into multiple parts to increase variations. For example, as shown in FIG. 19, bangs, hair, face outline,
Graphic data is held by being divided into parts such as ears, eyes, nose, and mouth, and these are arranged at appropriate positions to form one face.

However, in such a system, if the same black contour line as the lower side of the part exists, for example, in the seam of the upper part of the individual bangs with the upper hair,
When the part is connected to the hair part, FIG.
As shown in (a), the boundary between these two parts can be seen, resulting in a strange picture.

In order to avoid such an inconvenience, FIG.
As shown in 0 (b), it is conceivable to eliminate the upper contour line of the bangs part. However, in this case, since it is impossible to fill the inside of the figure whose contour line is not closed, it is not possible to retain such figure with only a little information such as the contour line data and the internal color code. However, there is a problem in that the figure needs to be represented by a color code for each dot in a bitmap format, which leads to an increase in data amount. Further, the graphic operation processing such as enlargement or reduction of the bitmap data requires a lot of data processing, which is disadvantageous in view of drawing speed.

An object of the present invention is to make it possible to draw any figure at high speed by simple processing without exception.

[0015]

According to the present invention, a color code switching information storage means (color code setting area) corresponding to each display position on the display means (display means 104) is arranged along a predetermined scanning direction. A figure for drawing a figure by reading color code switching information (color code switching flag) from each storage position and setting a plurality of predetermined color codes at each display position on the display means while switching according to the color code switching information. A drawing device is assumed.

First, the contour line information designating means designates information indicating the position of each side on the contour line of the figure. This contour line information designating means is, for example, a start point display position storage means for storing the display position of the start point of each side forming the contour line of the figure (the ROM 10 for storing the start point coordinate data as the drawing figure data.
3) and the display positions of two adjacent start points from the start point display position storage means, and the display position of each interpolation point on the display means corresponding to the side connecting the two start points is calculated. The calculation unit (the CPU 101 that executes step 508 in FIG. 5) is included. Then, the display position of each start point and interpolation point obtained from the start point display position storage means and the interpolation point display position calculation means is output as information indicating the position of each side on the contour line of the graphic.

Next, the side direction storage means (direction storage register) stores the direction of the side. Subsequently, processing target side direction determining means (the CPU 10 that executes step 504 in FIG. 5)
In 1), the direction of the side to be processed, which is the side sequentially designated by the contour line information designating means along the contour line of the figure, is determined.

The first color code switching information setting means (the CPU 1 for executing steps 506 and 513 in FIG. 5)
01) relates to the display position of the starting point of the processing target side, the direction of the processing target side determined by the processing target side direction determining means is not parallel to the scanning direction, and the direction of the processing target side and the side direction storage means are When the stored relationship with the side direction is a predetermined side direction relationship, the color code switching information is set in the storage position in the color code switching information storage unit corresponding to the display position of the starting point of the processing target side. The predetermined edge direction relationship is
For example, when a line segment having the side direction stored in the side direction storage means is assumed with the start point of the processing target side as its end point,
A relationship in which the line segment and the processing target side exist in respective regions that are bisected by a straight line that has a direction parallel to the scanning direction and that passes through the start point of the processing target side (FIGS. 7 to 9).
Say.

Further, the second color code switching information setting means (CPU 101 executing step 510 in FIG. 5) is
Regarding each display position on the processing target side and each display position other than the display positions at both ends of the processing target side, the direction of the processing target side determined by the processing target side direction determining means is not parallel to the scanning direction, and When the display positions other than the display positions at both ends of the processing target side change from the display position that was the processing target last time in the direction orthogonal to the scanning direction, each display position other than the display positions at both ends of the processing target side is changed. Color code switching information is set in a storage position in the color code switching information storage means corresponding to the display position.

Then, the side direction storage control means (the CPU 101 which executes step 507 in FIG. 5) has the first direction when the direction of the processing target side determined by the processing target side direction determining means is not parallel to the scanning direction. After the processing by the color code switching information setting means, the side direction stored in the side direction storage means is changed to the direction of the side to be processed.

In addition to the above-mentioned configuration of the invention, it can be configured to have the following contour line drawing information storage means and contour line drawing means. That is, the contour line drawing information storage unit stores the contour line drawing information that specifies whether or not to draw the contour line of the graphic corresponding to the display position of each start point stored in the start point display position storage unit.

Further, the contour line drawing means has, for each start point, contour line drawing information for designating that the contour line of the figure is drawn at the storage position in the contour line drawing information storage means corresponding to each start point. When stored, a predetermined color code is set at each display position on the display means of the side calculated by the side display position calculation means starting from each starting point, thereby drawing the outline of the figure.

In addition to the above-mentioned additional configuration, it may be configured to have the following contour line drawing information storage means and contour line drawing means. That is, the contour line drawing information storage unit stores the contour line drawing information that specifies the contour line drawing color code corresponding to the display position of each start point stored in the start point display position storage unit.

Further, the contour line drawing means has, for each start point, contour line drawing information for designating that a contour line of a graphic is drawn at a storage position in the contour line drawing information storage means corresponding to each start point. When stored, the contour drawing color code specified by the contour drawing information corresponding to each starting point at each display position on the display means of the side calculated from the respective starting points by the side display position calculating means By setting, the contour line of the figure is drawn.

[0025]

In the present invention, the side direction memory means is provided and
When the direction of the processing target side determined by the processing target side direction determining means is not parallel to the scanning direction, the side direction stored in the side direction storing means after the processing by the first color code switching information setting means is set as the processing target side. By executing the processing for changing the direction to the side direction storage control means, for example, at the time when the processing is performed on the side next to the horizontal side parallel to the scanning direction, the side processed before the horizontal side is processed. Since the direction information is stored, it is not necessary to perform exceptional processing such as tracing back the processing of the starting point of the horizontal side, and the processing algorithm can be simplified.

Then, the first color code switching information setting means establishes a predetermined side direction relationship between the direction of the side to be processed and the side direction stored in the side direction storage means with respect to the display position of the starting point of the side to be processed. By making the determination, the color code switching information can be appropriately set in the color code switching information storage means, and the appropriate filling processing is executed for the figure to be drawn.

In addition to these operations, the contour line drawing information storage means stores the contour line drawing information for designating whether or not to draw the contour line of the figure, and based on this information, the starting side from each starting point By setting a predetermined color code at each display position on the display means of the side calculated by the display position calculation means, it is possible to appropriately control the drawing of the outline of the figure.

Further, the contour line drawing information storing unit stores the contour line drawing information for designating the contour line drawing color code, and based on this information, the display of the side calculated from each start point by the side display position calculating unit is started. By setting an arbitrary color of a plurality of color codes at each display position on the device, the drawing color of the contour line of the figure can be controlled arbitrarily.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Two embodiments of the present invention will be described in detail below with reference to the drawings. <Structure of Embodiment> FIG. 1 is a structure diagram common to the first and second embodiments.

The CPU 101 calculates the coordinates of the straight line corresponding to the contour line connecting the two points given as the contour line information,
The inclination of the straight line is calculated, and the contour drawing flag and the color code switching flag in the RAM 102 are set.

The RAM 102 is used as a work memory when the CPU 101 executes various processes. Also,
In the flag setting area of the RAM 102, a color code switching flag and a contour line drawing flag (see FIG. 4 described later) corresponding to the actual drawing figure are stored. Furthermore, RAM10
In the second color code setting area, for example, in the vertical blanking period, according to the contents of the contour drawing flag and the color code switching flag set in the flag setting area on the same RAM 102 and the contents of the drawing figure data in the ROM 103, The color code is set.

The ROM 103 stores a drawing program data (see FIG. 2 described later) as well as a control program corresponding to an operation flowchart described later. Display means 104
Is composed of, for example, a display. Then, the display means 104 outputs the RGB data to the display while converting the color code set in the color code setting area on the RAM 102 into RGB data or the like during the scanning period other than the vertical blanking period, and outputs the figure. To draw. <Description of Operation of First Embodiment> First, the operation of the first embodiment based on the above configuration will be described in detail. Flag Setting Process First, the process of setting the color code switching flag and the contour drawing flag in the flag setting area of the RAM 102 will be described.

First, the data necessary for the above-mentioned flag setting process is stored in the ROM 103 of FIG. 1 as drawing graphic data. FIG. 2 shows drawing graphic data stored in the ROM 103.

As shown in FIG. 2, the drawing figure data is stored for each figure (# 0, # 1, ... # α, ...). Of the drawing figure data of each figure, the outline color code specifies the color of the outline of each figure. When a color code is set in the color code setting area of the RAM 102 by the color code setting process described later, it corresponds to an address where a contour line drawing flag described later is set in the flag setting area of the RAM 102 by the flag setting process described later. The above-mentioned contour line color code is set to the address (pixel) of the color code setting area.

Next, the internal color code corresponding to each figure is
Specifies the color to be filled inside each shape. When a color code is set in the color code setting area of the RAM 102 by the color code setting processing described later, until just before the address where the color code switching flag described later is set in the flag setting area of the RAM 102 by the flag setting processing described later. When the color code of the background color is set, the above-mentioned internal color code is set to the addresses (pixels) after that address.

In addition, starting point coordinate data (P0.x coordinates, P0.y coordinates), (P1.x coordinates, P1.y coordinates) corresponding to each figure,
(P2.x coordinates, P2.y coordinates), ... Designate the display coordinates of each starting point (vertex) of the outline of each figure. Further, the number data corresponding to each figure specifies the number of starting points of the contour line of each figure. In the line segment coordinate generation process, which is part of the flag setting process described below, the display coordinates of the line segments that form the outline of each figure are calculated based on these coordinate data and the number data.

Next, the flag setting process corresponding to an arbitrary figure for which the above-mentioned drawing figure data is set in the ROM 103 will be described. Here, as an example, the flag setting process when the graphic # α shown in FIG. 2 is drawn will be described.

First, the CPU 101 shown in FIG. 1 calculates the minimum x-coordinate x.min, maximum x-coordinate x.max, minimum y from the coordinate data which is the drawing figure data stored in the ROM 103 corresponding to the drawing figure. Coordinate y.min, maximum y coordinate y.max
Corresponding to these data, for example, FIG. 3 (a)
The flag setting area as shown in FIG. Each address in the secured flag setting area is
It corresponds to each display coordinate (pixel) of the drawn figure. Then, as shown in FIG. 4, a color code switching flag and a contour line drawing flag are stored at each address.

After securing the flag setting area in the RAM 102 as described above, the CPU 101 executes the flag setting processing shown as the operation flowchart of FIG. 5 to draw the color code switching flag and the contour line in the flag setting area. Set flags.

In FIG. 5, in step 501, RA
The values of the color code switching flag and the contour drawing flag of all the addresses in the flag setting area secured in M102 are reset to zero.

At step 502, the value of the number data, which is the drawing figure data stored in the ROM 103 corresponding to the drawing figure, is stored in a predetermined variable (called a loop counter) secured in the RAM 102. It is set as data indicating the number of starting points (vertices) of the contour line. In the example of figure # α shown in FIG. 2, 10 is set as the value of the loop counter. After that, until it is determined in step 512 that the value of the loop counter has been decremented and that value has been reached, that is, until the processing for all the edges forming the contour line of the drawing figure is completed, the processing of steps 503 to 512 Is repeatedly executed.

That is, first, in step 503, contour line drawing flag processing for the start point is executed. At the time when this step 503 is executed for the nth time, RO
Of the plural sets of starting point coordinate data which are drawing figure data stored in M103, the nth starting point coordinate data (Pn-1.x coordinates, Pn-1.y coordinates) are read out and the starting point coordinates are read. The value 1 of the contour drawing flag is set to the address of the flag setting area of the RAM 102 corresponding to the data. The contour line drawing flag is set in this step 503 for all the start points included in the contour line so that the color code of the contour line can be set by the color code setting process described later. For example, at the time when step 503 is executed for the first time, the first start point coordinate data (P0.x coordinate, among the plurality of sets of start point coordinate data that is the drawing figure data stored in the ROM 103,
(P0.y coordinate) is read, and the value 1 of the contour drawing flag is set to the address of the flag setting area of the RAM 102 corresponding to the start point coordinate data.

In step 504, a side direction determination process is executed. At the time when this step 504 is executed for the n-th time, the n-th starting point coordinate data (Pn-1.x coordinates, among the plural sets of starting point coordinate data which are drawing figure data stored in the ROM 103, Pn-1.y coordinate) and the nth
The + 1st start point coordinate data (Pn.x coordinate, Pn.y coordinate) is read. Then, from the nth start point Pn-1 to the n + 1th point
The inclination of the side (hereinafter referred to as the processing target side) forming the contour line toward the th starting point Pn is calculated, and the directions indicated by the inclination are quantized into the eight directions shown in FIG.
The direction of the processing target side is determined as any of the directions 0 to 7 shown in FIG. Here, the process in which the direction of the processing target side is quantized into the eight directions shown in FIG. 6 is realized as a process of selecting the direction closest to the direction of the processing target side among the eight directions shown in FIG. . For example, step 504
Is executed at the first time, the ROM 103
Of the multiple sets of starting point coordinate data that are drawing figure data stored in, the first starting point coordinate data (P0.x coordinate, P0.y coordinate) and the second starting point coordinate data (P1.x coordinate) , P1.y coordinate) is read. Then, the inclinations of the processing target edges forming the contour line from the first start point P0 to the second start point P1 are calculated, and the directions of the inclinations are quantized into the eight directions shown in FIG. The direction of the processing target side is determined as any of the directions 0 to 7 shown in FIG. In the example of the figure # α shown in FIG. 3, the direction of the processing target side from the first start point P0 to the second start point P1 is 2.

In step 505, R in step 503
It is determined whether the starting point coordinate data read from the OM 103 is the first starting point of the closed curve surrounded by the contour line. Only when the step 505 is executed for the first time, the judgment is NO and the step 506 is not executed. In other cases, the judgment is YES and the step 5 is executed.
06 is executed.

In step 506, step 50
3 in which the nth (n ≧
2) The color code switching flag process for the second start point Pn-1 is executed.

The color code switching flag is the RAM 102.
In order to continuously set the internal color code (see FIG. 2), which is the color code for filling, in the color code setting area, which will be described later, the boundary pixels for starting and ending the continuous setting of the internal color code are set. This is a flag for instructing. The setting of the color code switching flag means that the pixel to which the color code switching flag is set divides the drawing figure into the outside and the inside.

As to the starting point P of the contour line, if the starting point P is the maximum point or the minimum point of the figure, as described in the section of "Prior Art and Problems to be Solved by the Invention", immediately before that point. Since it is necessary to continue the color code setting process that has been executed up to now, the R corresponding to the starting point P
The color code switching flag should not be set in the flag setting area on the AM 102. If the starting point P is neither the maximum point nor the minimum point, the starting point P divides the inside and the outside of the figure, so that the starting point P The color code switching flag should be set in the flag setting area on the RAM 102 corresponding to.

Therefore, the following conditions are required as the conditions for setting the color code switching flag for the starting point P. Condition 1-1: The direction of the processing target edge determined in step 504 is not parallel to the scanning direction. That is, in the case of the present embodiment, the direction of the processing target side is neither the direction 3 nor the direction 7.

Condition 1-2: The direction of the processing target side determined in step 504 and the direction indicated by the direction storage register have a predetermined relationship. Specifically, the starting point P of the processing target side
Assuming that a line segment having the direction indicated by the direction storage register as its end point is 2, the line segment and the processing target side have a direction parallel to the scanning direction, and a straight line passing through the start point P of the processing target side There is a relationship that exists in each divided area.

The condition 1-2 is the following condition 1-2-1.
Alternatively, it is satisfied when any of the conditions 1-2-2 is satisfied. Condition 1-2-1: If the direction of the processing target side determined in step 504 is any of the directions 0, 1, and 2 shown in FIG. 6, the direction indicated by the direction storage register is also shown in FIG. The direction is 0, 1, or 2.

Condition 1-2-2: The direction of the side to be processed determined in step 504 is the direction 4, 5, 6 shown in FIG.
In any case, the direction indicated by the direction storage register is also one of the directions 4, 5, and 6 shown in FIG. For example, when the direction of the previous processing target side is neither direction 3 nor 7 (when it is not parallel to the scanning direction), the direction of the processing target side is indicated by the thin solid line arrow in FIG. 7 (a). As shown, in either direction 0, 1, 2, and
The direction indicated by the direction storage register, that is, the direction of the previous processing target side is also the direction 0, as indicated by the broken line arrow in FIG.
In the case of either 1 or 2, the hatched area A and the hatched area B on the scanning line indicated by the thick solid line arrow in FIG.
Since P divides the drawing figure into the inside and the outside, the condition 1-2-1 is satisfied. Therefore, the RAM corresponding to the starting point P
A color code switching flag is set at the address of the flag setting area 102. In the example of the figure # α shown in FIG. 3C, the starting point P1 is applicable. On the other hand, in this case,
The direction indicated by the direction storage register, that is, the direction of the previous processing target side is the direction 4, as indicated by the broken line arrow in FIG.
In the case of either 5 or 6, both the shaded area A and the shaded area B on the scanning line indicated by the thick solid line arrow in FIG. 7C are outside the drawing figure, and the starting point P is the maximum point. Therefore, the condition 1-2-1 is not satisfied. Therefore, R corresponding to the starting point P
The color code switching flag is not set at the address of the flag setting area of the AM 102, and the value of the color code switching flag at that address remains the initial setting value 0. Figure 3
In the example of figure # α shown in (c), the starting points P4 and P8 correspond.

Further, for example, when the previous direction of the processing target side is neither the direction 3 nor the direction 7 (when it is not a direction parallel to the scanning direction), the direction of the processing target side is as shown in FIG.
The direction indicated by the thin solid line arrow in (d) is one of the directions 4, 5, and 6, and the direction indicated by the direction storage register, that is, the direction of the previous processing target side is also the broken line arrow in FIG. 7 (d). If any of the directions 4, 5, and 6 as shown by,
A shaded area A on the scanning line indicated by the thick solid line arrow in FIG.
Since the hatched area B and the shaded area B are divided into the inside and the outside of the drawing figure by the start point P, the condition 1-2-2 is satisfied. Therefore, the color code switching flag is set at the address of the flag setting area of the RAM 102 corresponding to the starting point P. Figure 3 (c)
In the example of the figure # α shown in, the starting point P7 is applicable. On the other hand, in this case, if the direction indicated by the direction storage register, that is, the direction of the previous processing target side is one of the directions 0, 1, and 2 as indicated by the broken line arrow in FIG. The shaded area A and the shaded area B on the scanning line indicated by the thick solid arrow 7 (b) are both outside the drawing figure, and the start point P
Does not satisfy the condition 1-2-2 because it is a minimum point. Therefore, the color code switching flag is not set at the address of the flag setting area of the RAM 102 corresponding to the starting point P, and the value of the color code switching flag at that address remains the initial setting value 0. In the example of the figure # α shown in FIG. 3 (c), the starting point P9 corresponds.

Furthermore, for example, when the direction of the previous processing target side is either the direction 3 or the direction 7 as shown by the one-dot chain line arrow in FIG. 8A or FIG. 9A (parallel to the scanning direction). The direction of the side to be processed is 0, 1, as shown by the thin solid line arrow in FIG. 8 (a) or 9 (a).
8 (a) or 9 (2) and the direction indicated by the direction storage register, that is, the direction of the side opposite to the processing target side across the horizontal side indicated by the one-dot chain line arrow. a)
If the direction is 0, 1, or 2 as indicated by the dashed arrow in Fig. 8A, the shaded area A and the shaded area on the scanning line indicated by the thick solid arrow in Fig. 8A or 9A. Since B is divided into the inside and the outside of the drawing figure by the starting point P, condition 1
Meet 2-1. Therefore, RAM1 corresponding to the starting point P
The color code switching flag is set to the address of the flag setting area 02. On the other hand, in this case, the direction indicated by the direction storage register, that is, the direction of the side opposite to the processing target side across the horizontal side indicated by the one-dot chain line arrow is the broken line in FIG. 8 (c) or 9 (c). If the direction is 4, 5, or 6 as shown by the arrow, then FIG.
Since the shaded area A and the shaded area B on the scanning line indicated by the thick solid line arrow in (c) are both outside the drawing figure, the condition 1-2
-1 is not satisfied. Therefore, RAM1 corresponding to the starting point P
The color code switching flag is not set to the address of the 02 flag setting area, and the value of the color code switching flag of the address remains the initial setting value 0.

Further, for example, when the direction of the previous processing target side is either the direction 3 or the direction 7 as shown by the alternate long and short dash line arrow in FIG. 8D or 9D (parallel to the scanning direction) Direction), the direction of the side to be processed is the direction 4, 5 as shown by the thin solid line arrow in FIG. 8D or 9D.
8 (d) or 9 (6), the direction indicated by the direction storage register, that is, the direction of the side opposite to the side to be processed across the horizontal side indicated by the one-dot chain line arrow. d)
If any one of the directions 4, 5, and 6 as indicated by the broken line arrow in Fig. 8A, the shaded region A and the shaded region on the scanning line indicated by the thick solid line arrow in Fig. 8D or 9D Since B is divided into the inside and the outside of the drawing figure by the starting point P, condition 1
-2-2 is satisfied. Therefore, RAM1 corresponding to the starting point P
The color code switching flag is set to the address of the flag setting area 02. On the other hand, in this case, the direction indicated by the direction storage register, that is, the direction of the side opposite to the processing target side across the horizontal side indicated by the one-dot chain line arrow is the broken line in FIG. 8 (b) or FIG. 9 (b). If the direction is either 0, 1, or 2 as shown by the arrow, then FIG.
Since the shaded area A and the shaded area B on the scanning line indicated by the thick solid line arrow in (b) are both outside the drawing figure, the condition 1-2
-2 is not satisfied. Therefore, RAM1 corresponding to the starting point P
The color code switching flag is not set to the address of the 02 flag setting area, and the value of the color code switching flag of the address remains the initial setting value 0. In the example of the figure # α shown in FIG. 3C, the starting points P3 and P6 correspond.

As still another case, if the direction of the side to be processed determined in step 504 is either direction 3 or 7, that is, if the direction of the side to be processed is parallel to the scanning direction, the condition is satisfied. Since 1-1 is not satisfied, the color code switching flag is not set at the address of the flag setting area of the RAM 102 corresponding to the starting point P of the processing target side, and the value of the color code switching flag at that address is the initial setting value. It remains 0. In the example of the figure # α shown in FIG. 3C, the starting points P2 and P5 correspond.

In the case shown in FIG. 9 (a) or 9 (c), the color code switching flag is set for the starting point P of the side to be processed located at the left end of the horizontal side indicated by the one-dot chain line arrow. It In this case, in the color code setting process to be described later, the color code is switched to the pixel that is first detected after the color code switching flag is not set and the contour drawing flag is not set. That is, the color code is switched on the right side of the horizontal side located immediately after the pixel for which the color code switching flag is set. In this case, the color code switching flag is not set for the start point P 1 of the horizontal side located at the right end of the horizontal side and the interpolation point D (described later) on the horizontal side, so that no problem occurs.

By using the direction storage register updated as described above, for example, at the time when the next side of the horizontal side parallel to the scanning direction is processed, it is processed before the horizontal side. Since the edge direction information is stored, exception processing such as going back to the processing of the start point of the horizontal edge is not necessary, and the processing algorithm can be simplified.

The above-mentioned condition 1-1, condition 1-2-1, and condition 1-2-2 are determined in step 506, and the starting point P of the side to be processed is condition 1-1 and condition 1-2-1. RA corresponding to the starting point P of the side to be processed when the condition 1-1 and the condition 1-2-2 are satisfied.
The value 1 of the color code switching flag is set in the address of the flag setting area of M102.

Next, at step 507, the direction storage register process is executed. Here, when the direction of the side to be processed determined in step 504 is not the direction 3 or the direction 7 which is the direction parallel to the scanning direction among the eight directions shown in FIG. 6, the direction which is a variable on the RAM 102. The direction stored in the storage register is changed to the direction of the processing target side determined in step 504. By using the direction storage register updated in this way, for example, when processing is performed on the next side of the horizontal side parallel to the scanning direction, the direction information of the side processed before the horizontal side is processed. Will be saved.

At step 508, interpolation point coordinate generation processing is executed. At the time when this step 508 is executed for the nth time, the nth start point coordinate data (Pn-1.x coordinate, Pn-1.y coordinate) read from the ROM 103 at step 504 and the n + 1th Starting point coordinate data (P
nx coordinate, Pn.y coordinate) and these two starting points Pn-
The coordinate data of the point on the display pixel (hereinafter referred to as interpolation point D) that most closely approximates the processing target connecting 1 and Pn is calculated. For example, when step 504 is executed for the first time, the first start point coordinate data (P0.x coordinate, P
0.y coordinate) and the second start point coordinate data (P1.x coordinate, P1.x coordinate).
(y coordinate) and the coordinate data of the interpolation point D between these two starting points P0 and P1 is calculated (see FIG. 3 (b)).
As the interpolation point coordinate generation processing described above, integer type Bresenham
Processing based on an algorithm is adopted, and details thereof will be described later.

Subsequently, with respect to the interpolation point D calculated in step 508, steps 509 and 510 are executed until it is determined in step 511 that the end point has been processed.
Is executed.

First, in step 509 which is executed by repeating steps 509 to 511 immediately after the steps 503 to 508 are executed for the nth time, two start points Pn
The contour line drawing flag process is executed for all the interpolation points D 1 calculated in step 508 which form the processing target side between −1 and Pn. Here, all the interpolation points D form a contour line. Therefore, in order to set the color code of the contour line to the interpolation point D by the color code setting process described later, in this step 509, all the above interpolation points D
The value 1 of the contour drawing flag is set to the address of the flag setting area of the RAM 102 corresponding to. For example, in step 509 executed in the repetition of steps 509 to 511 immediately after steps 503 to 508 are executed for the first time, as shown in FIG. 3B, processing between two start points P0 and P1 is performed. The value of the contour line drawing flag is set to 1 at the address of the flag setting area of the RAM 102 corresponding to all the interpolation points D that are included in the target side and calculated in step 508.
Is set.

Next, in step 510 executed in the repetition of steps 509 to 511 immediately after the steps 503 to 508 are executed for the nth time, two start points Pn are set.
The color code switching flag processing is executed for all the interpolation points D 1 calculated in step 508 which form the processing target side between -1 and Pn.

The following two conditions are necessary as the conditions for setting the color code switching flag for the interpolation point D. Condition 2-1: The direction of the processing target side determined in step 504 is not parallel to the scanning direction. That is, in the case of the present embodiment, the direction of the processing target side is neither the direction 3 nor the direction 7.

Condition 2-2: The display position of the interpolation point D has changed from the display position of the starting point P or the interpolation point D, which was the processing target last time, in the direction orthogonal to the scanning direction. That is,
In the case of the present embodiment, the y-coordinate data of the interpolation point D has changed from the y-coordinate data of the starting point P or the interpolation point D that was the processing target last time. If the condition 2-1 and the condition 2-2 described above are determined in step 510 and the interpolation point D to be processed satisfies both of the above two conditions, the flag of the RAM 102 corresponding to the interpolation point D to be processed. The value 1 of the color code switching flag is set to the address of the setting area.

In the example of figure # α shown in FIG. 3C, two starting points are set in step 510 executed in the repetition of steps 509 to 511 immediately after the steps 503 to 508 are executed for the first time. Among the interpolation points D that are included in the processing target side between P0 and P1 and are calculated in step 508, the interpolation points Da and Db shown in FIG. 3C satisfy the above conditions 2-1 and 2-2. Meet together. That is, the direction of the processing target side between the two starting points P0 and P1 is 2 (see FIG. 6). The y-coordinate data of the interpolation point Da or Db is changed from the y-coordinate data of the starting point P0 or the interpolation point Da that was the processing target immediately before them. Therefore, the interpolation point
At the address of the flag setting area of the RAM 102 corresponding to Da and Db, the value 1 of the color code switching flag is set as shown in FIG. 3 (c).

The interpolation point Dc shown in FIG. 3C does not satisfy the above condition 2-2. That is, the interpolation point Dc
The y coordinate data of is the interpolation point that was the processing target immediately before that.
It has not changed from the y-coordinate data of Db. Therefore, the interpolation point
As shown in FIG. 3 (c), the value 1 of the color code switching flag is not set to the address of the flag setting area of the RAM 102 corresponding to Dc, and the value of the color code switching flag at that address is the initial setting value. It remains 0.

Further, in step 510 executed in the repetition of steps 509 to 511 immediately after the steps 503 to 508 are executed the third time, step 508 which constitutes the processing target side between the two starting points P2 and P3. Two (all) interpolation points shown in Fig. 3 (c) calculated by
Dd and De do not satisfy the above condition 2-1. That is, the direction of the processing target side between the two starting points P2 and P3 is 7 (see FIG. 6). Therefore, the address of the flag setting area of the RAM 102 corresponding to the interpolation points Dd and De is shown in FIG.
As shown in (c), the value 1 of the color code switching flag is not set, and the value of the color code switching flag at that address remains the initial setting value 0.

Step 509 and step 5 described above
The process of 10 is performed in step 511 in step 508
The process is executed until it is determined that the process has been performed up to the end point of the interpolation point D 1 calculated in.

When it is determined in step 511 that the processing has been performed up to the end point of the interpolation point D calculated in step 508, the value of the loop counter is decremented in step 512, and as a result, the value of the loop counter becomes zero. If not, that is, if the processing has not been completed for all the edges forming the outline of the drawing figure, the processing of steps 503 to 511 is executed again as the processing of the next processing target edge.

When it is determined in step 512 that the value of the loop counter has become 0 as a result of decrementing the value of the loop counter, finally in step 513, it is the first start point of the closed curve surrounded by the contour line. First starting point
The color code switching flag process for P0 is executed.

Here, the direction determined in step 504 with respect to the processing target side having the first start point P0 as the start point (the side from the start point P0 to P1) (step 504 is the first
Got it the second time) and step 5
Regarding the direction indicated by the direction storage register when 13 is executed (the direction of the side from the starting point P9 to P0 in the example of the figure # α in FIG. 3C), the above-mentioned condition 1-1 and condition 1-
2-1 and condition 1-2-2 are determined in the same manner as in step 506. Then, when the starting point P0 satisfies the condition 1-1 and the condition 1-2-1, or satisfies the condition 1-1 and the condition 1-2-2, the flag of the RAM 102 corresponding to the starting point P0. The value 1 of the color code switching flag is set to the address of the setting area. In other cases, the value 1 of the color code switching flag is not set in the address of the flag setting area of the RAM 102 corresponding to the starting point P0, and the value of the color code switching flag of that address remains the initial setting value 0. Is.

For example, in the example of the figure # α shown in FIG. 3 (c), the side to be processed having the first start point P0 as the start point (start point P0
The direction of the side from P1 to P1 is 2, and the direction of the side from the starting point P9 indicated by the direction storage register to P0 is 4 (see FIG. 6). Therefore, in this case, the condition 1-2
-1 and the condition 1-2-2 are not satisfied, the start point P0
The value 1 of the color code switching flag is not set in the address of the flag setting area of the RAM 102 corresponding to, and the value of the color code switching flag of that address remains the initial setting value 0.

When the processing up to step 513 is completed,
The flag setting process shown in FIG. 5 ends. As a result of the flag setting process described above, for example, for figure # α, FIG.
As shown in (c), the outline drawing flag and the color code switching flag are set in the flag setting area of the RAM 102.

The flag setting process described above is performed by the ROM 1
This is executed every time an arbitrary figure for which the drawing figure data shown in FIG. 2 is set in 03 is drawn. Details of Line Segment Coordinate Generation Processing As in the present embodiment, the contour line is expressed by the coordinate data of the end points of each side forming the contour line, that is, the start point coordinate data, and the coordinate data of the contour line between the start points is set to two adjacent points. The contour line can be efficiently expressed by executing the interpolation calculation on the starting point coordinate data and generating the interpolation calculation. On the other hand, since the position of the display pixel is a quantized position, the interpolation process algorithm for generating the coordinate data of the contour line between the start points is simple interpolation such as linear interpolation for two adjacent start points. It is not enough to execute such an interpolation calculation, and a special algorithm for calculating the interpolation point D 1 on the display pixel that most closely approximates the straight line connecting two adjacent start points is required. As one of such algorithms, the integer Bresenham algorithm widely used as a straight line drawing method in computer graphics is known.

10 and 11 show the step 50 of FIG.
8 is an operational flowchart showing the details of the interpolation point coordinate generation processing of No. 8, which is based on the integer Bresenham algorithm.

Now, the inclination of the processing target side from the n-th starting point Pn-1 to the (n + 1) -th starting point Pn is smaller than 1,
In addition, including the sign, the x-coordinate data Pn.x and the y-coordinate data Pn.y of the (n + 1) th start point Pn are the x-coordinate data Pn-1.x and the y-coordinate data of the n-th start point Pn-1, respectively. It is assumed that it is larger than Pn-1.y.

Under this assumption, in FIG.
A straight line A that connects the n-th starting point Pn-1 (Pn-1.x, Pn-1.y) and the (n + 1) -th starting point Pn (Pn.x, Pn.y) (not shown) is parallel to the y coordinate axis. The y coordinate data E1 at the intersection with the straight line x = Pn-1.x + 1 is the y coordinate data Pn-1.y of the nth start point Pn-1.
By adding the slope m of the straight line A to, E1 = Pn-1.y + m. The value of E1 is the n-th starting point Pn-1.
If Pn-1.y + 1/2 or more with reference to the y-coordinate data Pn-1.y of, the value of x-coordinate data Dx 1 is Pn-1.x + 1 and the first interpolation point D that best approximates the straight line A 1 is the nth starting point
Y obtained by adding +1 to the y coordinate data Pn-1.y of Pn-1
Point having coordinate data Dy 1 = Pn-1.y + 1 (Dx 1, Dy
1) = (Pn-1.x + 1, Pn-1.y + 1). On the contrary, if the value of E1 is smaller than Pn-1.y + 1/2 with reference to the y-coordinate data Pn-1.y of the n-th starting point Pn-1, the x-coordinate data Dx
The value of 1 is Pn-1.x + 1, which best approximates line A
The n-th interpolation point D 1 is a point (Dx 1, Dy 1) = (having the same y-coordinate data Dy 1 = Pn-1.y as the y-coordinate data Pn-1.y of the n-th start point Pn-1. Pn-1.x + 1, Pn-1.y). In the example of FIG. 12, since E1 <Pn-1.y + 1/2, the coordinates of the first interpolation point D1 are (Dx 1, Dy 1) = (Pn-1.x
+1, Pn-1.y).

Then, the y coordinate data E2 at the intersection of the straight line A and the straight line x = Pn-1.x + 2 is obtained by adding the slope m of the straight line A to E1 as E2 = E1 + m. Then, the value of E2 is the y coordinate data Dy 1 of the first interpolation point D 1 calculated in the previous processing.
If it is Dy 1 + 1/2 or more based on, the x coordinate data
The pixel that best approximates the straight line A when the value of Dx 2 is Pn-1.x + 2 is the y-coordinate data Dy 1 of the pixel calculated in the previous process.
Coordinate data obtained by adding +1 to Dy 2 = Dy 1
Pixel having +1 (Dx 2, Dy 2) = (Pn-1.x + 2, D
y 1 +1). On the contrary, the value of E2 is the y coordinate data Dy 1 of the first interpolation point D 1 calculated in the previous processing.
If it is smaller than Dy 1 +1/2 with reference to, the second interpolation point D 2 that best approximates the straight line A with the value of x-coordinate data Dx 2 being Pn-1.x + 2 is calculated in the previous process. Y
The point (Dx 2, Dy 2) having the same y-coordinate data Dy 2 = Dy 1 as the coordinate data Dy 1 is (Pn-1.x + 2, Dy 1). In the example of FIG. 12, E2> Dy1 + 1/2 = Pn-1.y + 1/2
Therefore, (Dx 2, Dy 2) ＝ (Pn-1.x ＋ 2, Dy 1 ＋
1) = (Pn-1.x + 2, Pn-1.y + 1).

Generally, the straight line A and the straight line x = Pn-1.x + i
The y-coordinate data Ei of the intersection point with
It can be calculated by the following formula by adding ay / deltax.

[0081]

[Equation 1] Ei = Ei-1 + deltay / deltax where E0 = Pn-1.y where:

[0082]

## EQU00002 ## deltax = Pn.x-Pn-1.x deltay = Pn.x-Pn-1.y. Also,

[0083]

## EQU00003 ## 1 ≦ i ≦ deltax−1. Then, the value of Ei is the y-coordinate data Dy i-1 of the (i-1) th interpolation point D i-1 calculated in the previous process.
Is smaller than Dy i-1 +1/2 with respect to, that is, the inequality,

[0084]

[Equation 4] If Ei ≧ Dy i-1 +1/2 holds, the value of the x coordinate data Dx i is Pn-1.x +
i-th interpolation point D i that best approximates line A with i
Is the (i-1) th interpolation point D i- calculated in the previous process.
Y obtained by adding +1 to the y coordinate data Dy i-1 of 1
A point having coordinate data Dy i = Dy i-1 +1;

[0085]

## EQU5 ## (Dx i, Dy i) = (Pn-1.x + i, Dy i-1 +1) = (Dx i-1 + 1, Dy i-1 +1). On the contrary, if the formula 4 is not satisfied, the x coordinate data
The value of Dx i is Pn−1.x + i, and the i-th interpolation point D i that best approximates the straight line A is the i-th interpolation point calculated in the previous process.
The same y as the Y coordinate data Dy i-1 of the first interpolation point D i-1
A point having coordinate data Dy i = Dy i-1,

[0086]

## EQU6 ## (Dx i, Dy i) = (Dx i-1 + 1, Dy i-1) In addition,

[0087]

## EQU7 ## Dx 0 = Pn-1.x Dy 0 = Pn-1.y.

From the above consideration, in order to calculate the interpolation point D, basically, while changing the variable i from 1 to deltax−1 (see the equation 3), the error Ei is calculated based on the equation 1. Is calculated sequentially, the i-th interpolation point D i is calculated as Expression 5 if the inequality of Expression 4 is satisfied using the calculation result, and the i-th interpolation point is calculated if the inequality of Expression 4 is not satisfied. point
It suffices to calculate D i as Expression 6.

Here, a modification of the error calculation will be considered. By adding the term (−Dy i−1−1 / 2) to both sides of Equation 4, Equation 4 can be transformed into the following equation.

[0090]

[Equation 8] Ei−Dy i−1 −1/2 ≧ 0 Subsequently, if the error newly obtained by adding the term (−Dy i−1 −1/2) to the error Ei is defined as ei, Equation 8 obtained by modifying Equation 4 can be further transformed into the following equation.

[0091]

[Equation 9] ei ≧ 0 Further, according to the equations 1 and 7, E0 = Pn−1.y = Dy 0, and every time the equation 4 is satisfied, the operation is performed by the equation 5 Dy i = Dy
Focusing on the fact that i−1 +1 is executed, the error ei used in the inequality of the above equation 9 calculated based on the equation 4 is calculated by the following equation obtained by modifying the equation 1. be able to.

[0092]

[Equation 10] ei-1 = ei-1-1 (Only when the equation 9 is satisfied at the i-1th time) ei = ei-1 + deltay / deltax where e0 = E0 + (-Pn-1.y-1 / 2) = Pn-1.y-Pn-1.y-1 / 2 =
By such a modification of the error calculation, the interpolation point D can be calculated by only determining the sign of the error represented by the equation (9). That is, in order to calculate the interpolation point D, the error ei is sequentially calculated based on the equation 10 while changing the variable i from 1 to deltax−1, and the error ei
If the sign of is positive, the i-th interpolation point D i is calculated by the formula 5, and if the sign is negative, the i-th interpolation point D i is calculated by the formula 6.
It may be calculated by a formula.

Here, a further modification of the error calculation will be considered. Even if both sides of Expression 9 are multiplied by 2 * deltax (* is a multiplication symbol, and deltax ≧ 0), the inequality of Expression 9 is established. Then, if the error newly obtained by multiplying the error ei by the term (2 * deltax) is error (i), first,
Expression 9 is transformed into the following expression.

[0094]

## EQU00009 ## error (i) .gtoreq.0 Equation 10 is transformed into the following equation.

[0095]

[Equation 12] error (i-1) = error (i-1) -2 * deltax (only when the equation 11 is satisfied at the i-1th time) error (i) = error (i-1) + 2 * deltay However, error (0) = 2 * deltax * e0 = −deltax Due to such a modification of the error calculation, the floating point calculation deltay / deltax which was necessary in the calculation of Formula 10 becomes unnecessary, and the shift calculation is The error can be calculated only by the multiplication and addition / subtraction that can be used.
The interpolation point D 1 can be calculated by only determining the sign of the error shown in Expression 11. That is, in order to calculate the interpolation point D, while varying the variable i from 1 to deltax−1, the error error (i) is sequentially calculated based on the integer operation and the shift operation of Expression 12, and the code is If it is positive, the i-th interpolation point D i may be calculated by the equation 5, and if the sign is negative, the i-th interpolation point D i may be calculated by the equation 6.

In the operation flow chart of the line segment coordinate generation processing shown in FIGS. 10 and 11, the portion based on the above algorithm is the portion of steps 1018 to 1033 of FIG.

First, step 1018 and step 10
19 corresponds to the operation of the equation 7. Where array data
Dx and Dy and variables px and py are secured in the RAM 102 of FIG.

Next, in step 1020, the first assumption "the inclination of the side to be processed from the nth start point Pn-1 to the (n + 1) th start point Pn is smaller than 1" in the above description, that is, the assumption deltax If> deltay holds, steps 1011 to 1 in FIG.
By 017, sub # delta = deltay, main # delta = de
It is called ltax. Therefore, the calculation of step 1020 erro
r = 2 * sub # delta-main # delta is equal to the operation obtained by substituting the third equation in the equation 12 into the second equation when i = 1.

The loop control processing of steps 1021, 1033 and 1022 corresponds to the condition of the expression (3). Here, if the above-mentioned assumption deltax> deltay holds, main # delta = deltax.

Step 1023 corresponds to the inequality determination processing of the equation (11). Steps 1024-1026
This corresponds to the operation Dy i = Dy i-1 +1 in the equation (5).
That is, when the above-mentioned assumption deltax> deltay is satisfied, flag = TR in step 1014 described later.
Since it is a UE, the value of the variable py is incremented by ratey by one increment unit by executing step 1024 after step 1024. Then, this incremented variable py is arrayed in step 1032.
Substituting Dy i for operation D
The operation corresponding to yi = Dy i-1 +1 is realized. On the other hand, when the determination in step 1023 is NO, the calculation in step 1025 is not executed, and the value of the variable py remains the same as the value when it was executed the last time. Then, the operation in Eq. 6 Dy i
The calculation corresponding to = Dy i-1 is established. The case where step 1026 is executed after step 1024 will be described later.

Step 1027 corresponds to the first expression in Expression 12 executed only when the judgment of Expression 11 executed in Step 1023 is established. Here, if the above-mentioned assumption drax> deltay holds, main
# delta = deltax.

Steps 1028, 1029, and 1030 are the operations in Equation 5 or Equation 6.
This corresponds to Dx i = Dx i-1 +1. That is, when the above-mentioned assumption deltax> deltay is satisfied, flag = TRUE is set in step 1014 described later, and therefore step 1029 is executed after step 1028, so that the value of the variable px increases by one increment. Incremented by ratex. Then, the incremented variable px is substituted into the array Dx i in step 1032, so that the calculation Dx i = Dx i in the formula 5 or the formula 6
The operation corresponding to -1 +1 is realized. The case where step 1030 is executed after step 1028 will be described later.

Step 1031 corresponds to the second equation in the equation (12). Here, when the above-mentioned assumption deltax> deltay is satisfied, sub # delta = deltay. Step 1032 includes steps 1025, 1026,
The values of the variables py and px obtained as a result of the operation of step 1029 or step 1030 are arrayed Dx i and Dy, respectively.
This is the process of substituting for i.

In the above description, the inclination of the processing target side from the n-th starting point Pn-1 to the (n + 1) -th starting point Pn is smaller than 1 (deltax> deltay), and the sign includes the (n + 1) th starting point. The x-coordinate data Pn.x and the y-coordinate data Pn.y of the n-th starting point Pn are respectively the x-coordinate data Pn of the n-th starting point Pn-1.
An explanation will be given of the interpolation point coordinate generation processing when it is assumed that it is larger than -1.x and y coordinate data Pn-1.y. In this case,
In the xy coordinate space shown in 3, the n-th starting point Pn
-1 (Pn-1.x, Pn-1.y) is located at the origin O, the n + 1th starting point Pn (Pn.x, Pn.y) from this origin
This corresponds to the case where the line segment extending in the area exists in the area shown in FIG. Therefore, a process when a line segment extending from the starting point Pn-1 located at the origin to the starting point Pn exists in a region other than the region in the xy coordinate space shown in FIG.

First, in step 1001, an increment gainx of x coordinate data and an increment gainy of y coordinate data from the nth start point Pn-1 to the (n + 1) th start point Pn are calculated based on the following equations.

[0106]

[Mathematical formula-see original document] gainx = Pn.x-Pn-1.x gainy = Pn.y-Pn-1.y x coordinate increment gainx and y coordinate increment ga calculated as a result
iny is stored in the RAM 102 of FIG.

Then, in step 1002 of FIG.
Absolute value deltax of x coordinate increment gainx, and y coordinate increment gain
The absolute value deltay of y is calculated based on the following equation. Here, abs (value) is a function that calculates the absolute value of the value value.

[0108]

[Mathematical formula-see original document] deltax = abs (gainx) deltay = abs (gainy) The x coordinate increment absolute value deltax and the y coordinate increment absolute value deltay calculated as a result are also stored in the RAM 102 of FIG. These values deltax and deltay become the inclination data used in the above-mentioned equation 12 and the like.

Here, if a line segment extending from the starting point Pn-1 located at the origin of the xy coordinate space shown in FIG. 13 to the starting point Pn exists in the region, the inequality de in step 1011 de
Since ltax> deltay holds, the variable main # del stored in the RAM 102 in step 1012 as described above.
The value of the variable deltax is assigned to ta, and the variable de # is stored in the variable sub # delta which is also stored in the RAM 102 in step 1013.
The value of ltay may be substituted, and the above-described interpolation point coordinate generation processing may be applied as it is. In this case, step 1014
The value of the flag flag stored in RAM 102 is "TRUE"
It is said that

On the other hand, when the line segment extending from the starting point Pn-1 located at the origin of the xy coordinate space shown in FIG. 13 to the starting point Pn exists in the area, as compared with the case where the line segment exists in the area,
The only difference is that the magnitude relationship between the slope data deltax and deltay is opposite. Therefore, in this case, the x-coordinate data and the y-coordinate data may be completely exchanged, and then the above-described interpolation point coordinate generation processing may be applied. That is, step 1
Since the inequality deltax> deltay of 011 is not established, the variable ma is changed in step 1015, contrary to the case of the region.
The value of the variable deltay is substituted into in # delta, and step 101
In step 6, the value of the variable deltax is assigned to the variable sub # delta, and then the interpolation point coordinate generation process described above is applied.
In this case, the value of the flag flag stored in the RAM 102 in step 1017 is set to "FALSE". Correspondingly, step 1024 is followed by step 1026 instead of step 1025 described above, so that the value of variable px instead of variable py is increased by one increment.
Incremented by ratex. Step 10
Following step 28, step 1030 is executed instead of step 1029 described above, so that the value of the variable py is incremented by one increment unit ratey instead of the variable px.

The exchange processing of the x-coordinate data and the y-coordinate data in the area described above occurs in the same manner in the case of area and. On the contrary, in the case of the area, and, as in the case of the area, the above-described replacement processing of the x coordinate data and the y coordinate data does not occur.

Next, when a line segment extending from the starting point Pn-1 located at the origin of the xy coordinate space shown in FIG. 13 to the starting point Pn exists in the area, as compared with the case where it exists in the area,
The only difference is that the x coordinate value decreases rather than increases. Therefore, in this case, in step 1003
By the determination that gainx <0, the increment unit ra related to the x coordinate data is increased in step 1006.
The value of tex is set to -1. This process occurs in exactly the same way for regions, and.

On the contrary, with respect to the areas ,,, and, it is determined in step 1003 that gainx> 0, so that the value of the increment unit ratex for the x coordinate data is set to +1 in step 1004.

Furthermore, when the line segment extending from the starting point Pn-1 located at the origin of the xy coordinate space shown in FIG. 13 to the starting point Pn overlaps the y axis, gainx =
When the determination of 0 is made, step 1005
In, the value of the increment unit ratex for the x coordinate data is set to 0.

After the above-described processing of step 1004, 1005, or 1006 is performed, the above-described interpolation point coordinate generation processing is applied. Subsequently, when the line segment extending from the starting point Pn-1 located at the origin of the xy coordinate space shown in FIG. 13 to the starting point Pn exists in the region, the y coordinate value increases as compared with the case where the line segment exists in the region. The only difference is that it does not decrease, but decreases. Therefore, in this case, step 1007
In step 1010, it is determined that gainy <0 in 1
The value of the increment unit ratey is set to -1. This process occurs in exactly the same way for regions, and.

On the contrary, with respect to the areas ,,, and, since gainy> 0 is determined in step 1007, the value of 1 increment unit ratey for the y coordinate data is set to +1 in step 1008.

Further, when the line segment extending from the starting point Pn-1 located at the origin of the xy coordinate space shown in FIG. 13 to the starting point Pn overlaps the x axis, gainy =
When the determination of 0 is made, step 1009
In, the value of the increment unit ratey for the y coordinate data is set to 0.

After the processing of the above step 1008, 1009, or 1010 is performed, the above-described interpolation point coordinate generation processing is applied. As the operation flowcharts of FIGS. 10 and 11 described above, the interpolation point coordinate generation process of step 508 of FIG. 5 is realized. Color code setting processing After the CPU 101 executes the flag setting processing shown in FIG. 5, the color code switching flag and the contour line drawing flag are set in the flag setting area of the RAM 102, and then R
A process of actually setting a color code and drawing a figure in the color code setting area of the AM 102 will be described.

In the color code setting process, the ROM 10
The internal color code and the outline color code of the drawing figure data shown in FIG. The color code setting area on the RAM 102 may be shared with the flag setting area. In this case, the color code switching flag and the outline drawing flag for each pixel on the flag setting area are sequentially overwritten by the color code. Further, the color code setting area may be secured in the display memory area in the display unit 104 of FIG. 1 instead of the RAM 102. In the following description, the RAM 102
The processing when the color code setting area is secured separately from the flag setting area will be described above.

First, a color code setting area corresponding to the flag setting area shown in FIG. 3A on the RAM 102 is secured on the RAM 102. Next, the CPU 101
Alternatively, a color code (00) that becomes transparent at the time of display is set in the paint color code register in the RAM 102.

Next, from the address corresponding to the upper left corner (x.min, y.min) of the display image in the flag setting area to the address corresponding to the right end (x.max, y.min) of the display image. Is incremented and each time one line of processing is completed, the display image is in the downward direction (y direction).
While the address is incremented, the color code switching flag and contour drawing flag are sequentially read from the address corresponding to each pixel up to the address corresponding to the lower right corner (x.max, y.max) of the display image. . Then, the color code set in the paint color code register is set to the address in the color code setting area corresponding to the address where the contour drawing flag is not set. In the example of figure # α shown in FIG. 3 (d), the contents of the address corresponding to the starting point P0 on the outline are first read out.
The color code (00) corresponding to transparency is set.

Next, when the contour drawing flag is first read from the address of the flag setting area corresponding to the starting point P0 (see FIG. 3 (b)), the contour drawing data for the drawing # α on the ROM 103 is drawn. The color code is read (see FIG. 2) and set to the corresponding address in the color code setting area. Further, since the color code switching flag is not read from the address of the flag setting area corresponding to the starting point P0 (see FIG. 3 (c)), the contents of the paint color code register are not changed.

In the scanning of the first line, the contour drawing flag is read again from the address of the flag setting area corresponding to the starting point P8, and the contour color code is set again at the address of the color code setting area corresponding to it. , The transparent color code (00) set in the paint color code register is set in the address of the color code setting area corresponding to the address of the flag setting area in which the other contour drawing flag is not set. go.

In the scanning of the second line, the color code (00) corresponding to transparency is reset in the paint color code register. In the second line, the contour drawing flag is not read from each address of the flag setting area corresponding to the first 4 pixels, but the contour drawing flag is read from the address of the flag setting area corresponding to the fifth pixel (see FIG. Three
(See (b)), and the contour line color code is set at the address of the corresponding color code setting area. At the same time, since the color code switching flag is also read from the address of the flag setting area corresponding to the fifth pixel (see FIG. 3 (c)), the internal color code is read from the drawing figure data for the figure # α on the ROM 103. (See FIG. 2) and set in the paint color code register. After that, the internal color code is set as the paint color code at the address of the color code setting area corresponding to the pixel having no contour line drawing flag. Therefore, the internal color code is set at the address of the color code setting area corresponding to the next pixel. Since the contour drawing flag and the color code switching flag are read from the address of the flag setting area corresponding to the next pixel (seventh pixel on the second line) (see FIGS. 3B and 3C), The outline color code is set in the address of the corresponding color code setting area, and the transparent color code is reset in the paint color code register. Therefore, the transparent color code is set to the address of the color code setting area corresponding to the pixel having no contour line drawing flag thereafter.

In the subsequent scanning of each line (raster), after the color code (00) corresponding to transparency is reset in the paint color code register in the same manner as described above, the color code is read from the flag setting area. Every time the switching flag is read, the contents of the paint color code register are alternately replaced by the transparent color code (00) and the internal color code, and the outline drawing flag is not read to the address of the flag setting area. The color code stored in the paint color code register is set to the address of the corresponding color code setting area (see FIG. 3 (d)).

The color code setting process for the color code setting area is executed, for example, in the vertical blanking period. On the other hand, the display unit 104 displays the color code set in the color code setting area on the RAM 102 during the scanning period other than the vertical blanking period as RG.
While converting into B data or the like, the RGB data is output to a display and a figure is drawn. <Description of Operation of Second Embodiment> Next, an operation of the second embodiment based on the configuration of FIG. 1 will be described.

The second embodiment is different from the first embodiment in that the drawing graphic data stored for each graphic (# 0, # 1, ... # α, ...) is the same as that of the first embodiment. 2 includes not only the contour line color code of one color, but also includes the contour line color codes of eight colors # 1 to # 7 as shown in FIG. Start point coordinate data (P0.x coordinates, P0.y coordinates) that specify the display coordinates of the start point, (P1.x coordinates, P
1.y coordinate), (P2.x coordinate, P2.y coordinate), ...
This is a point including a color number that specifies one of the above-described plurality of contour line color codes for each contour line.

As a result, for example, when the parts of the face shown in FIG. 19 are combined to compose a figure, the color of the contour line of the boundary between the parts can be appropriately controlled.

In order to realize the above-mentioned function, in the second embodiment, a flag setting area secured in the RAM 102 is shown in FIG. 15 instead of the data format of FIG. 4 corresponding to the first embodiment. Has a data format that is That is, in the second embodiment, at the address corresponding to each pixel in the flag setting area, instead of the contour line drawing flag in the first embodiment, for example, a contour line of 8 colors set for each figure is set. It is possible to write 3-bit contour line drawing data that specifies one color of the color code.

The flag setting process of setting the color code switching flag and the contour line drawing data in such a flag setting area is basically the same as the operation flowchart of FIG. 5 in the first embodiment. Steps 503 and 509 are steps 503 'and 5 respectively.
It is different from the case of the first embodiment in that it is replaced with 09 '.

That is, in step 503 ', contour line drawing data processing for the starting point is executed. This step 5
When 03 'is executed for the nth time, the ROM
Of the plural sets of starting point coordinate data which are drawing figure data stored in 103, the n-th starting point coordinate data (Pn
(-1.x coordinate, Pn-1.y coordinate) is read, and the color number stored as drawing figure data together with the starting point coordinate data is read in the address of the flag setting area of the RAM 102 corresponding to the starting point coordinate data. , Contour line drawing data.

On the other hand, in step 509 ', which is executed by repeating steps 509' to 511 immediately after the steps 503 to 508 are executed for the n-th time,
The contour line drawing data processing is executed for all the interpolation points D 1 calculated in step 508 which form the processing target side between the one start points Pn−1 and Pn. Here, all the above interpolation points
At the address of the flag setting area of the RAM 102 corresponding to D, it is stored as drawing graphic data together with the n-th start point coordinate data (Pn-1.x coordinate, Pn-1.y coordinate) stored in the ROM 103. The color number is set as the contour line drawing data.

FIG. 16 shows a figure # α in the second embodiment.
FIG. 15 is a diagram showing a setting example of a flag setting area and a color code setting area corresponding to (FIG. 14), which corresponds to FIG. 3 in the first embodiment. From Figure 16 (b), figure #
It can be seen that each contour line forming α can be set to any color number out of eight colors.

Finally, the color code setting process in the second embodiment will be described. In the first embodiment, as described above, at the address of the color code setting area corresponding to the address of the flag setting area from which the contour line drawing flag is read, one color of the contour line color corresponding to the contour line drawing flag is set. The code was read from the drawing graphic data in the ROM 103 and set.

On the other hand, in the second embodiment, the address of the color code setting area corresponding to the address of the flag setting area from which the contour line drawing data is read is set to the color number indicated by the contour line drawing data. One of the corresponding eight color contour line color codes is read from the drawing graphic data of the ROM 103 and set. As a result, the display color of each contour line forming the figure can be set to any one of the eight contour line color codes set as drawing figure data for the figure. <Other Embodiments> In the first and second embodiments described above, the integer Bresenham shown in the operation flowcharts of FIGS. 10 and 11 is used as the interpolation point coordinate generation processing of step 508 of the flag setting processing of FIG. Although a method based on an algorithm is adopted, the present invention is not limited to this, and various algorithms capable of generating interpolation point coordinates can be adopted. Further, in the above-described embodiment, the position of each side on the contour line of the graphic is represented by the starting point coordinate data which is the drawing graphic data and the interpolation point coordinate data generated by the interpolation point coordinate generation processing. The expression method of may be adopted.

[0136]

According to the present invention, the side direction storage means is provided and the first color code switching information setting is performed when the direction of the side to be processed judged by the side direction judging means to be processed is not parallel to the scanning direction. After the processing by the means, the side-direction storage control means executes the processing for changing the side direction stored in the side-direction storage means to the direction of the side to be processed. At the time of processing, since the direction information of the processed side is stored before the horizontal side, exception processing such as going back to the processing of the starting point of the horizontal side is not necessary, and the processing algorithm is simplified. It becomes possible.

Then, the first color code switching information setting means establishes a predetermined side direction relationship between the direction of the side to be processed and the side direction stored in the side direction storage means with respect to the display position of the starting point of the side to be processed. By making the determination, the color code switching information can be appropriately set in the color code switching information storage means, and it is possible to execute the appropriate filling process on the figure to be drawn.

In addition to these effects, the contour line drawing information storage means stores the contour line drawing information for specifying whether or not to draw the contour line of the figure, and based on this information, the starting side from each starting point By setting a predetermined color code at each display position on the display means of the side calculated by the display position calculation means, it becomes possible to appropriately control the drawing of the outline of the figure.

Further, the contour drawing information storing means stores the contour drawing information for specifying the contour drawing color code, and based on this information, the display of the side calculated by the side display position calculating means starting from each starting point. By setting an arbitrary one of the color codes of a plurality of colors at each display position on the means, it becomes possible to arbitrarily control the drawing color of the contour line of the figure.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing drawing graphic data stored in a ROM 103 in the first embodiment.

FIG. 3 is a diagram showing a setting example of a flag setting area and a color code setting area in the first embodiment.

FIG. 4 is a diagram showing a data format of a flag setting area in the RAM 102 according to the first embodiment.

FIG. 5 is an operation flowchart of a flag setting process.

FIG. 6 is a diagram showing direction classification.

FIG. 7 is an explanatory diagram (Part 1) of the setting operation of the color code switching flag.

FIG. 8 is an explanatory diagram (Part 2) of the setting operation of the color code switching flag.

FIG. 9 is an explanatory diagram (Part 3) of the setting operation of the color code switching flag.

FIG. 10 is an operation flowchart (1) of line segment coordinate generation processing.

FIG. 11 is an operation flowchart (No. 2) of line segment coordinate generation processing.

FIG. 12 is an explanatory diagram (No. 1) of line segment coordinate generation processing.

FIG. 13 is an explanatory diagram (No. 2) of line segment coordinate generation processing.

FIG. 14 is a diagram showing drawing graphic data stored in a ROM 103 in the second embodiment.

FIG. 15 is a diagram showing a data format of a flag setting area in the RAM 102 according to the second embodiment.

FIG. 16 is a diagram showing a setting example of a flag setting area and a color code setting area in the second embodiment.

FIG. 17 is an explanatory diagram (1) of scan conversion.
Is.

FIG. 18 is an explanatory diagram of scan conversion (No. 2).
Is.

FIG. 19 is an explanatory diagram of graphic data divided into a plurality of parts.

FIG. 20 is an explanatory diagram of graphic data synthesized from a plurality of parts.

[Explanation of symbols]

 101 CPU 102 RAM 103 ROM 104 Display Means

Claims (5)

[Claims] 1. A color code switching information is read from each storage position in a color code switching information storage unit corresponding to each display position on a display unit along a predetermined scanning direction, and the display is performed according to the color code switching information. A contour line information designating unit that designates information indicating the position of each side on the contour line of a graphic in a graphic drawing device that draws a graphic by setting a plurality of predetermined color codes at each display position on the device. A side direction storage means for storing the direction of the side, and a processing target side direction determining means for determining the direction of the processing target side which is the side sequentially specified by the contour line information specifying means along the contour line of the figure. A side-direction relation determining means for determining a relation between the direction of the processing-target side determined by the processing-target-side-direction determining means and the side direction stored in the side-direction storing means; Regarding the display position of the starting point of the target side, the direction of the processing target side determined by the processing target side direction determining unit is not parallel to the scanning direction, and the direction of the processing target side and the side direction storage unit store the direction. When the relationship with the defined side direction is a predetermined side direction relationship, the color code switching information is set to a storage position in the color code switching information storage means corresponding to the display position of the starting point of the processing target side. First
The color code switching information setting means, and the display positions on the processing target side other than the display positions at both ends of the processing target side, the processing determined by the processing target side direction determining means The direction of the target side is not parallel to the scanning direction, and each display position other than the display positions at both ends of the processing target side changes from the display position that was the processing target last time to the direction orthogonal to the scanning direction. Second color code switching information setting, the color code switching information is set to a storage position in the color code switching information storage means corresponding to each display position other than the display positions at both ends of the processing target side. Means, and processing by the first color code switching information setting means when the direction of the processing target side determined by the processing target side direction determining means is not parallel to the scanning direction. Later, a graphics-rendering apparatus characterized by having a a side direction storage control means for changing the side direction of the side direction storage means for storing the direction of the processed edge. 2. The predetermined side-direction relationship, when the line segment having the side direction stored in the side-direction storage means is assumed with the start point of the side to be processed as its end point, the line segment and the process The target side is in a state of being present in each region divided into two by a straight line having a direction parallel to the scanning direction and passing through a starting point of the processing target side. 1. The graphic drawing device according to 1. 3. The contour line information designating means stores a start point display position storage means for storing a display position of a start point of each side forming a contour line of a figure, and two adjacent start points from the start point display position storage means. Interpolation point display position calculation means for calculating a display position of each interpolation point on the display means corresponding to an edge connecting the two start points, the start point display position storage means and the interpolation The display position of each of the starting points and the interpolation points obtained from the point display position calculating means is output as information indicating the position of each side on the contour line of the graphic. The graphic drawing device described in. 4. A contour line drawing for storing contour line drawing information for designating whether or not to draw the contour line of the graphic corresponding to the display position of each starting point stored in the starting point display position storage means. Information storage means, and for each of the start points, contour line drawing information for specifying that the contour line of the graphic is to be drawn is stored at a storage position in the contour line drawing information storage means corresponding to each of the start points. In this case, by setting a predetermined color code at each display position on the display means of the side calculated by the side display position calculation means starting from each starting point, a contour for drawing the contour line of the figure is drawn. The graphic drawing apparatus according to claim 3, further comprising: a line drawing unit. 5. A contour line drawing information storage unit for storing contour line drawing information for designating a contour line drawing color code corresponding to a display position of each of the start points stored in the start point display position storage unit, For each start point, when the contour line drawing information designating that the contour line of the graphic is drawn is stored in the storage position in the contour line drawing information storage means corresponding to each start point, The outline drawing color code designated by the outline drawing information corresponding to each vertex is set at each display position of the side calculated by the side display position calculating device on the display device, The graphic drawing apparatus according to claim 3, further comprising: a contour drawing unit that draws a contour of a graphic.