JP5885827B2 - Drawing control apparatus and drawing control program - Google Patents

Description

  The present invention relates to a drawing control apparatus and a drawing control program for drawing a figure in a plurality of scissor areas.

2. Description of the Related Art Conventionally, there has been proposed a graphics system corresponding to scissoring of a plurality of areas in which only a figure portion existing in an area where a plurality of areas are combined is drawn when a figure is drawn.
For example, in Patent Document 1 below, a pixel value is written for each scissoring region (hereinafter referred to as “scissor region”), and the scissor value of the pixel in each scissor region is updated, thereby allowing an arbitrary number of pixels. A drawing control apparatus that employs a scissoring method that sequentially executes scissoring on a scissor area is disclosed.
Note that a drawing allowable range defined by the maximum value and the minimum value is set for each scissor area, and is included in the figure to determine whether or not to write a pixel to the scissor area. A comparator for determining whether or not the coordinate value of the pixel to be included is included in the drawing allowable range of the scissor area is provided for each scissor area.

Japanese Translation of PCT International Publication No. 2010-510608 (paragraphs [0005] to [0007])

  Since the conventional drawing control apparatus is configured as described above, when a part of the scissor area is not used, the comparator of the scissor area is not used. However, an unused comparator is used for other purposes (for example, whether or not the color value or alpha value (transparency) of a pixel included in the figure is included in the drawing allowable range of the scissor area). Therefore, there is a problem that resources cannot be used effectively and resources cannot be effectively used.

  The present invention has been made to solve the above-described problems, and provides a drawing control apparatus and a drawing control program capable of using resources in the apparatus for various purposes and effectively utilizing the resources. The purpose is to obtain.

The drawing control apparatus according to the present invention includes a coordinate value / pixel value calculating unit for calculating a pixel coordinate value and a pixel value included in the figure according to setting information of the figure to be drawn in a plurality of scissor areas, The storage means for storing the drawing allowable range of the scissor area and the coordinate value or pixel value of the pixel included in the figure calculated by the coordinate value / pixel value calculation means is set as the comparison target value and included in the figure. Each of the pixels to be compared includes a drawing allowable range determination unit that determines whether the comparison target value of the pixel is included in the drawing allowable range of the scissor area stored by the storage unit, and a drawing allowable range determination unit A drawing target pixel discriminating unit for discriminating a drawing target pixel from pixels included in the figure based on the determination result, and a coordinate value / pixel value calculating unit based on the discrimination result of the drawing target pixel discriminating unit By The pixel values of the pixels contained within the calculated figure provided a frame buffer update means for writing into the frame buffer, drawing allowable range judging means, selects a coordinate value calculated by the coordinate value, the pixel value calculation unit If the selection information indicating that the coordinate value is set as the comparison target value and the pixel value calculated by the coordinate value / pixel value calculating means is selected, the pixel value is input. Is set as a comparison target value.

According to this invention, the coordinate value or pixel value of the pixel included in the figure calculated by the coordinate value / pixel value calculating means is set as the comparison target value, and for each pixel included in the figure, the pixel comparison object value is a drawing tolerance in the determining means for determining whether or not included in the drawing tolerance of the stored sheet-user area by memorize means, based on the determination result of the drawing allowable range judging means The figure calculated by the coordinate value / pixel value calculating means based on the determination result of the drawing target pixel determining means for determining the pixel to be drawn from the pixels included in the figure and the drawing target pixel determining means the pixel values of pixels included therein is provided a frame buffer update means for writing the frame buffer, drawing allowable range judging means, indicating to select the coordinate value calculated by the coordinate value, the pixel value calculation unit If the selection information is input, the coordinate value is set as the comparison target value, and the selection information indicating that the pixel value calculated by the coordinate value / pixel value calculation means is selected is input. Since it is configured to set the value, not only the coordinate value calculated by the coordinate value / pixel value calculating means but also the pixel value can be set as the comparison target value and the drawing allowable range determining means can be used. Therefore, there is an effect that the resources can be effectively used.

It is a block diagram which shows the drawing control apparatus by Embodiment 1 of this invention. It is a flowchart which shows the processing content of the drawing control apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows an example of the figure of drawing object. It is explanatory drawing which shows an example of the pixel of drawing object. It is explanatory drawing which shows the case where an icon is expanded with a bilinear filter.

Hereinafter, in order to describe the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a drawing control apparatus according to Embodiment 1 of the present invention.
In FIG. 1, a CPU (Central Processing Unit) 1 is connected to a drawing control device 2 via a CPU bus 3, and when drawing of a figure to a plurality of scissor areas is started, the setting information of the figure (for example, Then, a process of outputting a drawing command including the coordinates of the figure (for example, the coordinates of the vertex of the figure) and information indicating the drawing color to the drawing control apparatus 2 is performed.
Further, when the CPU 1 outputs a drawing command to the drawing control device 2, the maximum / minimum information indicating the maximum value and the minimum value that define the drawing allowable range of each scissor area, the setting flag of each scissor area (use of the scissor area) A flag indicating whether or not each scissor area is judged (a flag indicating whether the inside of the scissor area is “valid” or “external is valid”), and a setting mode for specifying the comparison target data ( A process of outputting the selection information) to the drawing control apparatus 2 is performed.
Note that the CPU 1 may output these flags and information by including them in a drawing command.

  The drawing processing unit 11 of the drawing control device 2 is composed of, for example, a semiconductor integrated circuit in which an MPU (Micro Processing Unit) is mounted or a one-chip microcomputer, and is included in a drawing command output from the CPU 1. In accordance with the graphic setting information, a process of calculating the coordinate values (x, y) of the pixels included in the graphic and the pixel values such as the color value and the α value (transparency) is performed. The drawing processing unit 11 constitutes coordinate value / pixel value calculation means.

The drawing target pixel discriminating unit 12 performs processing for discriminating a drawing target pixel from among pixels included in the figure based on the coordinate value (x, y), the color value and the like calculated by the drawing processing unit 11. carry out.
The maximum / minimum value setting register 13 of the drawing target pixel discriminating unit 12 is prepared for each scissor area, and is a memory for storing the maximum value and the minimum value indicated by the maximum / minimum information output from the CPU 1. The maximum value / minimum value setting register 13 constitutes maximum value / minimum value storage means.

The setting flag register 14 is prepared for each scissor area, and is a memory for storing a setting flag for the scissor area output from the CPU 1.
The condition determination flag register 15 is prepared for each scissor area, and is a memory for storing a condition determination flag for the scissor area output from the CPU 1.

The comparator 16 is prepared for each scissor area and includes a selector 16a and a comparison processing unit 16b.
If the setting mode output from the CPU 1 indicates that the coordinate value is selected as the comparison target value of the scissor area, the selector 16a of the comparator 16 indicates the coordinate value (x, If y) is set as a comparison target value and output to the comparison processing unit 16b to indicate that a color value is selected as the comparison target value of the scissor area, the color value calculated by the drawing processing unit 11 is used. If the comparison target value is set and output to the comparison processing unit 16b and indicates that the α value is selected as the comparison target value of the scissor area, the α value calculated by the drawing processing unit 11 is used as the comparison target value. To output to the comparison processing unit 16b.
For each pixel included in the figure to be drawn, the comparison processing unit 16b draws the scissor area in which the comparison target value of the pixel is defined by the maximum value and the minimum value stored in the maximum value / minimum value setting register 13. A process of determining whether or not it is within the allowable range is performed.
The comparator 16 constitutes a drawing allowable range determining means.

The drawing target pixel discrimination processing unit 17 is composed of, for example, a semiconductor integrated circuit in which an MPU is mounted, a one-chip microcomputer, or the like. Based on the determination result of the comparator 16, the pixel to be included in the figure is determined. From this, a process of discriminating a pixel to be drawn is performed.
For example, the setting flag stored in the setting flag register 14 indicates that all scissor areas are used, and the condition determination flag stored in the condition determination flag register 15 indicates that all scissor areas In the case where “effective” is indicated, the pixel determined by the comparator 16 that the comparison target value is included in the drawing allowable range of all scissor areas among the pixels included in the figure. And the pixel is determined to be a pixel to be drawn.
When the condition determination flags stored by the condition determination flag register 15 indicate that all scissor areas are “internally valid”, the setting flags stored by the setting flag register 14 are not If the area indicates that the area is not used, the comparator 16 identifies a pixel for which the comparison target value is determined to be included in the drawing allowable range of all scissor areas except the unused scissor area. The pixel is determined to be a pixel to be drawn.

Further, when the condition determination flag stored by the condition determination flag register 15 indicates that the scissor area “internally valid” and the scissor area “externally valid” are mixed, the comparator With reference to the determination result of 16, for the scissor area where “inside is valid”, the condition that the comparison target value is included in the drawing allowable range is satisfied, and “outside area” is valid. For the scissor region, a pixel that satisfies the condition that the comparison target value is not included in the drawing allowable range is specified, and the pixel is determined to be the drawing target pixel.
The drawing target pixel discrimination processing unit 17 constitutes a drawing target pixel discrimination means.

  The memory control unit 18 is composed of, for example, a semiconductor integrated circuit in which an MPU is mounted, a one-chip microcomputer, or the like. The pixel value (color value, pixel value) of a pixel included in the figure calculated by the drawing processing unit 11 Among the α values, the processing for writing only the pixel values of the drawing target pixels determined by the drawing target pixel determination processing unit 17 into the frame buffer 19 is performed. The memory control unit 18 constitutes a frame buffer update unit.

In the example of FIG. 1, the drawing processing unit 11, the maximum value / minimum value setting register 13, the setting flag register 14, the condition determination flag register 15, the comparator 16, and the drawing target pixel determination processing unit 17 that are components of the drawing control apparatus. It is assumed that each of the memory control unit 18 and the memory control unit 18 is configured by dedicated hardware. However, the drawing control apparatus executes a drawing control program described later in addition to a computer (for example, in addition to a personal computer. Mobile phones, portable information terminals, car navigation devices, and the like are also included.
When the drawing control device is configured by a computer, the maximum value / minimum value setting register 13, the setting flag register 14, and the condition determination flag register 15 are configured on the memory of the computer, and the drawing processing unit 11, the comparator 16, the drawing A drawing control program in which the processing contents of the target pixel discrimination processing unit 17 and the memory control unit 18 are described is stored in the memory of the computer, and the CPU of the computer executes the drawing control program stored in the memory. You can do it.
FIG. 2 is a flowchart showing the processing contents of the drawing control apparatus according to Embodiment 1 of the present invention.

Next, the operation will be described.
First, when the CPU 1 starts drawing a figure for a plurality of scissor areas, the CPU 1 outputs a drawing command including setting information for the figure to the drawing control apparatus 2.
The graphic setting information includes, for example, information indicating the coordinates of the graphic (for example, the coordinates of the vertex of the graphic) and the drawing color.
For example, if the figure to be drawn is a triangle, the coordinates of the three vertices of the triangle are included in the setting information, and the color information, α value (transparency), etc. are included in the setting information as the drawing color of the three vertices It is.

Further, when the CPU 1 outputs a drawing command to the drawing control device 2, the maximum / minimum information of each scissor area, each scissor area setting flag, each scissor area condition determination flag, and each scissor area setting mode. Are output to the drawing control apparatus 2.
Here, the maximum / minimum information is information indicating the maximum value and the minimum value of the drawing allowable range in the scissor area. If the drawing allowable range is related to the coordinate value, the drawing allowable range is, for example, the value x of the X coordinate. Is within the range of x1 <x <x2 and the Y coordinate value y is within the range of y1 <y <y2.
Further, if the drawing allowable range relates to the pixel value, the drawing allowable range is a range for drawing only pixels whose pixel value c is in the range of c1 <c <c2, for example.
In this case, x1, y1, c1, etc. are the minimum values of the drawing allowable range, and x2, y2, c2, etc. are the maximum values of the drawing allowable range.
The drawing allowable range may be set for each scissor area, the drawing allowable range related to the coordinate value may be set for a certain scissor area, and the drawing allowable range related to the pixel value may be set for a certain scissor area. Needless to say, a similar drawing allowable range (for example, a drawing allowable range related to coordinate values) may be set for all scissor areas.

The scissor area setting flag is a flag indicating whether or not the scissor area is used. The scissor area indicating that this flag is “not used” is not handled as a scissor area.
For example, when there are N scissor areas, the setting flags for the N-2 scissor areas indicate “use” and the setting flags for the remaining two scissor areas indicate “not use”. Thus, the remaining two scissor areas are not handled as scissor areas, and a graphic drawing process is performed on N-2 scissor areas.

The scissor area condition determination flag is a flag indicating whether “inside is valid” or “outside is valid” of the scissor area. For a scissor area where “inside is valid”, the scissor area For the scissor area in which drawing of the figure is permitted and “external is valid”, drawing of the figure is permitted to the outside of the scissor area.
The setting mode is selection information indicating whether the selector 16a of the comparator 16 selects a coordinate value, a color value, or an α value as comparison target data. For the scissor area where the minimum value is set, a setting mode indicating that the coordinate value is selected is given as comparison target data, and for the scissor area where the maximum value and minimum value of the drawing allowable range regarding the color value are set. A setting mode indicating that a color value is selected is given as comparison target data.

Note that the maximum value and the minimum value of the drawing allowable range in the scissor area indicated by the maximum / minimum information output from the CPU 1 are stored in the maximum value / minimum value setting register 13 prepared for each scissor area.
The scissor area setting flag output from the CPU 1 is stored in a setting flag register 14 prepared for each scissor area.
The scissor area condition determination flag output from the CPU 1 is stored in a condition determination flag register 15 prepared for each scissor area.

When the drawing processing unit 11 receives a drawing command from the CPU 1 (step ST1 in FIG. 2), according to the setting information of the graphic contained in the drawing command, the coordinate values (x, y) and pixel values such as color values and α values (transparency) are calculated (step ST2).
For example, if the figure to be drawn is a triangle, as shown in FIG. 3, the coordinates (x1, y1), (x2, y2), (x3, y3) of the three vertices P1, P2, P3 of the triangle are the figures. Therefore, using these coordinates, line segments L1, L2, and L3 connecting the vertices are obtained, and an area (triangle) surrounded by the three line segments L1, L2, and L3 is obtained. By specifying, the coordinate value (x, y) of each pixel included in the inside of the triangle is calculated.
For example, the line segment L1 can be obtained by substituting the coordinates (x1, y1) and (x2, y2) of the vertices P1, P2 into the simultaneous equations shown below.
y1 = a · x1 + b
y2 = a · x2 + b
Here, a is the slope of the line segment L1, and b is a constant.

Regarding the color value and α value, for example, if the figure to be drawn is a triangle, the color values of the three vertices P1, P2, and P3 of the triangle are included in the figure setting information. In the case of a color value of a pixel located in the middle of the vertex P2, an intermediate value between the color value of the vertex P1 and the color value of the vertex P2 is calculated as the color value of the pixel. The same applies to the α value.
However, when the pixel located between the vertex P1 and the vertex P2 is not the midpoint of the vertex P1 and the vertex P2, but the distance to the vertex P1 and the distance to the vertex P2 are different, the vertex P1 to the vertex P2 The color value and the like are calculated in consideration of the distance so that the color value and the like gradually change (gradation).

When the drawing processing unit 11 calculates the coordinate value (x, y), color value, α value, and the like of the pixel included in the figure, the drawing target pixel determination unit 12 calculates the pixel coordinate value (x, y) and color. Based on the value or the like, the drawing target pixel is determined from the pixels included in the figure.
Specifically, it is as follows.

The drawing target pixel determination unit 12 uses only the comparator 16 corresponding to the “use” scissor area among the comparators 16 prepared for each scissor area, and performs the comparison corresponding to the “not used” scissor area. In order not to use the device 16, each scissor area is referred to by referring to a setting flag (setting flag for the scissor area output from the CPU 1) stored in the setting flag register 14 corresponding to each scissor area. It is determined whether or not the scissor area is “used” (step ST3).
When the “used” scissor area is specified, the drawing target pixel determination unit 12 activates the comparator 16 corresponding to the scissor area (step ST4).

If the setting mode output from the CPU 1 indicates that the coordinate value is selected as the comparison target value of the scissor area, the selector 16a of the activated comparator 16 draws the drawing calculated by the drawing processing unit 11. The coordinate value (x, y) of the pixel included in the target graphic is set as the comparison target value, and the comparison target value is output to the comparison processing unit 16b (step ST5).
If the setting mode output from the CPU 1 indicates that the color value is selected as the comparison target value of the scissor area, the selector 16a is included in the drawing target figure calculated by the drawing processing unit 11. If the color value of the pixel to be compared is set as the comparison target value, the comparison target value is output to the comparison processing unit 16b, and the α value is selected as the comparison target value of the scissor area, the drawing process The α value of the pixel included in the drawing target graphic calculated by the unit 11 is set as a comparison target value, and the comparison target value is output to the comparison processing unit 16b (step ST5).

When the comparison processing unit 16b of the activated comparator 16 receives the comparison target value from the selector 16a, the comparison processing unit 16b acquires the maximum value and the minimum value stored in the maximum value / minimum value setting register 13, and in the scissor area. Specify the allowable drawing range.
When the drawing allowable range in the scissor area is specified, the comparison processing unit 16b determines whether the comparison target value of the pixel is included in the drawing allowable range for each pixel included in the figure to be drawn. (Step ST6).

When the drawing target pixel determination processing unit 17 determines whether the comparison target value of the pixel is included in the drawing allowable range for each pixel included in the figure, the drawing target pixel determination processing unit 17 displays the determination result. Based on the pixel included in the figure, the drawing target pixel is determined.
That is, the drawing target pixel determination processing unit 17 applies each scissor region condition determination flag (stored in the condition determination flag register 15) for pixels for which it is determined that the comparison target value is included in the drawing allowable range. Referring to the scissor area condition determination flag corresponding to the “use” scissor area, it is determined whether each scissor area is a scissor area of “internally valid” (step ST7).
Then, the drawing target pixel determination processing unit 17 sets the “passable area” scissor area “internally valid” (step ST8), and sets the “externally valid” scissor area “fail area” (step ST8). ST9).

In addition, the drawing target pixel determination processing unit 17 sets each scissor region condition determination flag (stored in the condition determination flag register 15) for pixels for which it is determined that the comparison target value is not included in the drawing allowable range. With reference to the scissor area condition determination flag corresponding to the “used” scissor area, it is determined whether each scissor area is a scissor area of “external valid” (step ST10).
Then, the drawing target pixel discrimination processing unit 17 sets the “externally valid” scissor area to the “Pass area” (step ST8), and sets the “internally valid” scissor area to the “Fail area” (step ST8). ST9).
Note that the scissor area whose setting flag stored in the setting flag register 14 indicates “not used” is not handled as a scissor area as described above, and therefore this scissor area is set as a “Pass area”. Set.

The drawing target pixel discrimination processing unit 17 determines, for each pixel included in the figure, whether or not all scissor areas for the pixel are “pass areas” (step ST11). If it is “Pass region”, it is determined that the pixel is a pixel to be drawn (step ST12).
On the other hand, if any one of the scissor areas for the pixel is a “Fail area”, it is determined that the pixel is not a pixel to be rendered (step ST13).

Note that the processing in steps ST5 to ST13 is performed for each pixel, and if there remains a pixel for which it is not yet determined whether or not it is a drawing target pixel, the processing returns to step ST5, and step ST5 is performed. To ST13 are repeatedly performed (step ST14).
When it is determined whether all the pixels included in the drawing target graphic are the drawing target pixels, the process proceeds to step ST15.

Here, FIG. 4 is an explanatory diagram illustrating an example of a drawing target pixel.
FIG. 4A shows an example in which there are three scissor areas A, B, and C whose “inside is valid”. Therefore, only the pixels included in all three scissor areas A, B, and C among the pixels in the triangle that is the drawing target graphic are set as the drawing target pixels. For example, the scissor area Pixels that are included in A and C but not included in the scissor area B are not set as drawing target pixels.
In the example of FIG. 4B, the scissor areas A and B are “internally valid”, but the scissor area C is “externally valid”. For this reason, only the pixels included in the scissor areas A and B and not included in the scissor area C among the pixels in the triangle that is the drawing target graphic are set as the drawing target pixels.

  When the drawing target pixel determination processing unit 17 determines the drawing target pixel, the memory control unit 18 determines the pixel value (color value, α value, etc.) of the pixel included in the drawing target graphic calculated by the drawing processing unit 11. Among these, a process of writing only the pixel value of the drawing target pixel into the frame buffer 19 is performed (step ST15).

  As apparent from the above, according to the first embodiment, the coordinate value or pixel value (color value, α value, etc.) of the pixel included in the figure calculated by the drawing processing unit 11 is used as the comparison target value. For each pixel included in the figure, the comparison target value of the pixel is within the drawing allowable range of each scissor area defined by the maximum value and the minimum value stored by the maximum value / minimum value setting register 13. And a drawing target pixel discrimination processing unit 17 for discriminating a drawing target pixel from among pixels included in the figure based on the judgment result of the comparator 16. The memory control unit 18 frames only the pixel value of the drawing target pixel among the pixel values (color value, α value, etc.) of the pixel included in the drawing target figure calculated by the drawing processing unit 11. Write to buffer 19 Thus, the comparator 16 can be used by setting not only the coordinate value calculated by the drawing processing unit 11 but also the pixel value (color value, α value, etc.) as a comparison target value. Therefore, there is an effect that the resources can be effectively used.

That is, the comparator 16 prepared for each scissor area is composed of a selector 16a and a comparison processing unit 16b, and the coordinate values and color values calculated by the drawing processing unit 11 in accordance with the setting mode output from the CPU 1. Since the comparison target value is selected from the value, α value, etc., when performing general scissor processing using the coordinate value as the comparison target value, the maximum value / minimum value of the coordinate value is maximized. The coordinate value stored in the value / minimum value setting register 13 and selected by the selector 16a may be selected.
On the other hand, a maximum value / minimum value such as a color value or an α value is stored in the maximum value / minimum value setting register 13 so that the selector 16a selects a color value, an α value, or the like calculated by the drawing processing unit 11. Thus, not only a general scissor process but also a scissor process using a color value, an α value or the like as a comparison target value can be performed.
Therefore, since the comparator 16 can be used for other than general scissor processing, it is possible to effectively use resources.

Note that the following uses are conceivable as application examples of the drawing control apparatus of the first embodiment.
For example, as shown in FIG. 5, when enlarging an icon with a bilinear filter, an intermediate color between the icon color and the transparent color is mixed in the boundary (contour) portion of the icon, so normally one transparent color is designated. It is not possible to make it transparent through just doing.
On the other hand, when the drawing control apparatus of FIG. 1 is used, it is possible to set a drawing allowable range (maximum value, minimum value) relating to color values and transmit only the color values within the drawing allowable range. Even when the icon is enlarged with a bilinear filter, it can be transmitted clearly.
Also, in a drawing processing system that can superimpose a graphics window and a video window, by sharing the scissor area setting register and the video window area setting register, the circuit size can be reduced. Applicable.

  In the present invention, any constituent element of the embodiment can be modified or any constituent element of the embodiment can be omitted within the scope of the invention.

  The drawing control apparatus according to the present invention can be applied to, for example, a control panel for consumer / industrial equipment.

  DESCRIPTION OF SYMBOLS 1 CPU, 2 Drawing control apparatus, 3 CPU bus, 11 Drawing process part (coordinate value / pixel value calculation means), 12 Drawing object pixel discrimination part, 13 Maximum value / minimum value setting register (maximum value / minimum value storage means) , 14 setting flag register, 15 condition determination flag register, 16 comparator (rendering allowable range determination unit), 16a selector, 16b comparison processing unit, 17 rendering target pixel discrimination processing unit (rendering target pixel discrimination unit), 18 memory control Part (frame buffer updating means), 19 frame buffer.

Claims (5)

Coordinate values and pixel value calculating means for calculating pixel coordinate values and pixel values included in the figure according to setting information of the figure to be drawn in a plurality of scissor areas;
Storage means for storing a drawing allowable range of each scissor area;
The coordinate value or pixel value of the pixel included in the figure calculated by the coordinate value / pixel value calculation means is set as the comparison target value, and the comparison target value of the pixel is set for each pixel included in the figure. A drawing allowable range determination means for determining whether or not is included within the drawing allowable range of the scissor area stored by the storage means;
Based on the determination result of the drawing allowable range determination unit, a drawing target pixel determining unit that determines a pixel to be drawn from among pixels included in the figure;
A frame buffer update unit that writes the pixel value of the pixel included in the figure calculated by the coordinate value / pixel value calculation unit to the frame buffer based on the determination result of the drawing target pixel determination unit;
When the selection information indicating that the coordinate value calculated by the coordinate value / pixel value calculation unit is selected is input, the drawing allowable range determination unit sets the coordinate value as a comparison target value, and A drawing control apparatus, wherein selection information indicating that a pixel value calculated by a value / pixel value calculation unit is selected is set as a comparison target value.   The drawing target pixel determining means determines that the comparison target value is included in the drawing allowable range of all scissor areas by the drawing allowable range determining means from the pixels included in the figure. The drawing control apparatus according to claim 1, wherein a pixel is specified and the pixel is determined as a drawing target pixel.   When a scissor area that is not used is set, the drawing target pixel determining means excludes a scissor area whose comparison target value is not used by the drawing allowable range determining means from among pixels included in the figure. 2. The drawing control apparatus according to claim 1, wherein a pixel determined to be included in a drawing allowable range of all scissor areas is specified, and the pixel is determined to be a drawing target pixel.   When there is a scissor area whose inside is effective and a scissor area where the outside is effective, the drawing target pixel determining means refers to the determination result of the drawing allowable range determining means and the inside is effective For the scissor area, the comparison target value is included in the drawing allowable range, and the comparison target value is not included in the drawing allowable range for the scissor area that is valid outside. The drawing control apparatus according to claim 1, wherein a pixel satisfying a condition is specified, and the pixel is determined as a drawing target pixel. A coordinate value / pixel value calculation means for calculating a coordinate value and a pixel value of a pixel included in the graphic in accordance with setting information of the graphic to be drawn in a plurality of scissor areas;
A storage processing procedure for storing a drawing allowable range of each scissor area;
When selection information indicating that the drawing allowable range determination unit selects the coordinate value is input, the coordinate value is set as a comparison target value and selection information indicating that the pixel value is selected is input. The pixel value is set as a comparison target value, and for each pixel included in the graphic, the comparison target value of the pixel is included in the drawing allowable range of the scissor area stored by the storage unit. A drawing allowable range determination processing procedure for determining whether or not
A drawing target pixel determining unit for determining a drawing target pixel from among pixels included in the figure based on a determination result of the drawing allowable range determining unit;
Frame buffer update processing in which the frame buffer update unit writes the pixel values of the pixels included in the figure calculated by the coordinate value / pixel value calculation unit to the frame buffer based on the determination result of the drawing target pixel determination unit A drawing control program for causing a computer to execute procedures and.

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