WO2017203675A1

WO2017203675A1 - Graphics rendering apparatus, graphics rendering method, display system, and graphics rendering program

Info

Publication number: WO2017203675A1
Application number: PCT/JP2016/065663
Authority: WO
Inventors: 鳥居　晃
Original assignee: 三菱電機株式会社
Priority date: 2016-05-27
Filing date: 2016-05-27
Publication date: 2017-11-30

Abstract

A graphics rendering apparatus (10) is provided with: an intermediate data generation unit (12) that generates intermediate data (23a) from graphic data (22a) and a rendering list (21a) and stores the intermediate data in an external memory (20); an intermediate data scanning unit (13) that detects a graphic having a portion included in a tile region from the intermediate data (23a); a built-in frame buffer (15); a graphic rendering processing unit (14) that generates and renders, in the built-in frame buffer (15), a tile region image (15a) corresponding to the tile region from pixel data of the graphic detected by the intermediate data scanning unit (13); a write control unit (16) that writes, into a frame buffer (24), a rendering image obtained by rotating the rendered tile region image (15a) in accordance with a specified rotation angle; and a rendering control unit (11) that controls each configuration so that a rendering image of one screen is rendered in the frame buffer (24).

Description

Graphics drawing apparatus, graphics drawing method, display system, and graphics drawing program

The present invention relates to a graphics drawing device and a graphics drawing method for drawing a drawing image in a frame buffer, a display system including the graphics drawing device and a display device, and a computer for executing a process for drawing a drawing image in a frame buffer. The present invention relates to a graphics drawing program.

When a graphics drawing device displays a graphics screen on a display device such as a liquid crystal display (LCD), pixel data of the graphics (drawing image) drawn in the frame buffer on the memory is read and read. Pixel data is output to a display device. The display device displays a graphics screen corresponding to the graphics drawn in the frame buffer.

When displaying a horizontally long graphics screen on the display panel of the display device, install the display device so that the display panel has a horizontally long shape. The graphics drawing device draws horizontally long graphics (writes pixel data) in the frame buffer, reads pixel data of the drawn graphics sequentially from the frame buffer in the horizontal direction (reading direction) of the graphics, Pixel data is output to a display device. A display device having a horizontally long display panel displays a horizontally long graphics screen corresponding to the graphics drawn in the frame buffer by scanning the display panel in the horizontal direction based on the received pixel data. To do.

When displaying a vertically long graphics screen on the display panel unit of the display device, for example, the display panel unit is rotated 90 degrees and the display device is installed so that the display panel unit has a vertically long shape. The graphics drawing device draws a vertically long graphic in the frame buffer, sequentially reads the drawn pixel data of the graphics from the frame buffer in the vertical direction (reading direction) of the graphics, and sends the pixel data to the display device. Output. A display device having a vertically long display panel unit performs a vertical scan in the display panel unit based on the received pixel data, thereby generating a vertically long graphics screen corresponding to the graphic drawn in the frame buffer. indicate. However, when pixel data is sequentially read from the frame buffer on the memory, which is a DRAM, in the vertical direction of the graphics, overhead such as precharging frequently occurs, so that access efficiency to the memory is lowered.

In order to improve the access efficiency, a horizontally long drawing image obtained by rotating the vertically long graphics drawn in the frame buffer by 90 degrees is created, and the pixel data of this drawing image is sequentially read in the horizontal direction (reading direction). A method of outputting the read pixel data to a display device (a method of creating a horizontally long image on a frame buffer) can be considered.

Also, when rendering graphics in the frame buffer, a method of creating a horizontally long image rotated by 90 degrees by performing address conversion of pixel data on the frame buffer (a method of converting the address when writing to the frame buffer) Is also conceivable (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 7-325753

However, the method of creating a horizontally long image on the frame buffer has the problems that the required memory capacity increases, the required memory bandwidth (transfer speed) increases, and the processing time also increases.

Also, the method of converting the address when writing to the frame buffer requires a multi-port memory as a frame buffer, so that there is a problem that it cannot be applied to a system using a normal DRAM as a frame buffer.

The present invention has been made in order to solve the above-described problems, and a special function is not required for the memory used as the frame buffer, and without increasing the memory capacity, the memory bandwidth, and the processing time. Graphics display device and graphics display method capable of displaying vertically long graphics screen on display device, display system including graphics drawing device and display device, and graphics drawing for causing computer to execute graphics drawing method The purpose is to provide a program.

A graphics drawing apparatus according to an aspect of the present invention is a graphics drawing apparatus that draws a drawing image in a frame buffer, and stores graphic data indicating a figure to be drawn, which is stored in a first storage area, and A drawing list that defines the drawing contents of the graphic data stored in the storage area 2, a pointer indicating the graphic data, conversion information indicating coordinate conversion processing of the graphic to be drawn, and the graphic to be drawn An intermediate data generation unit that generates intermediate data including drawing range information indicating a drawing range and stores the intermediate data in a third storage area; and a portion included in the tile area to be processed from the intermediate data. An intermediate data scanning unit for detecting the graphic, a built-in frame buffer in which a drawing image of the tile area is drawn, and the intermediate data scanning unit A graphic drawing processing unit for generating a first image corresponding to the tile area to be processed from the pixel data of the graphic that has been output, and drawing the first image in the internal frame buffer; and the internal frame buffer A writing control unit that writes a second image obtained by rotating the first image drawn in accordance with a designated rotation angle to the frame buffer, and the writing of the second image is repeated, thereby A drawing control unit for controlling the intermediate data scanning unit, the graphic drawing processing unit, and the writing control unit so that the drawing image of one screen is drawn in the frame buffer;

A graphics drawing method according to another aspect of the present invention is a graphics drawing method for drawing a drawing image in a frame buffer, the figure data indicating a figure to be drawn stored in a first storage area, From the drawing list that defines the drawing contents of the graphic data stored in the second storage area, the pointer indicating the graphic data and the conversion information indicating the coordinate conversion processing of the graphic to be drawn and the graphic to be drawn Generating intermediate data including drawing range information indicating the drawing range of the image, and storing the intermediate data in a third storage area; and a portion included in the tile area to be processed from the intermediate data. From the intermediate data scanning step for detecting the graphic having, and from the pixel data of the graphic detected in the intermediate data scanning step, Generate a first image corresponding to the tile area to be processed, and draw the first image in a built-in frame buffer, and specify the first image drawn in the built-in frame buffer The frame buffer by repeating the writing control step of writing the second image rotated according to the rotated angle to the frame buffer, the intermediate data scanning step, the graphic drawing processing step, and the writing control step. A drawing control step of drawing the drawing image of one screen.

A display system according to still another aspect of the present invention includes the graphics drawing device that draws a drawing image in a frame buffer, and a display device that displays an image based on the drawing image drawn in the frame buffer. It is.

According to the graphics drawing device, the graphics drawing method, and the graphics drawing display program according to the present invention, no special function is required for the memory used as the frame buffer, and the memory capacity, the memory bandwidth, and the processing A vertically long graphics screen can be displayed on the display device without increasing the time.

Further, according to the display system of the present invention, a special function is not required for a memory used as a frame buffer, and a vertically long graphics screen is obtained without increasing memory capacity, memory bandwidth, and processing time. Can be displayed.

1 is a block diagram showing a schematic configuration of a display system (including a graphics drawing device and a display device) according to Embodiment 1 of the present invention. FIG. 2 is a diagram illustrating an example of a vertically long graphics screen displayed on a vertically long display panel unit of the display device of FIG. 1. (A) is a figure which shows an example of the vector figure data as figure data stored in a figure data storage area, (b) is a figure which shows an example of the vector figure according to the vector figure data of Fig.3 (a) It is. (A) is a figure which shows an example of the bit map image data as figure data stored in a figure data storage area, (b) is an example of the bit map figure according to the bit map image data of Fig.4 (a). FIG. It is a figure which shows the example of the structure of the drawing list stored in a drawing list storage area. It is a figure which shows the example of the structure of the intermediate data stored in an intermediate data storage area by an intermediate data production | generation part. 3 is a flowchart showing an operation (graphics drawing method) of the graphics drawing apparatus according to the first embodiment. (A) to (c) are tile areas to be processed by the graphics drawing apparatus according to the first embodiment (first selected tile area), tile area images drawn in the built-in frame buffer, and built-in frames. It is a figure which shows the drawing image read from the buffer and written in the frame buffer. (A) to (c) are tile areas to be processed by the graphics drawing apparatus according to the first embodiment (second selected tile area), tile area images drawn in the built-in frame buffer, and built-in frames. It is a figure which shows the drawing image read from the buffer and written in the frame buffer. (A) to (c) are tile areas to be processed (the tile area selected last) by the graphics rendering apparatus according to the first embodiment, tile area images drawn in the built-in frame buffer, and built-in frame buffer. It is a figure which shows the drawing image read from and written in the frame buffer. (A) And (b) is a figure which shows the reading direction of the drawing image in a frame buffer, and the scanning direction in a display panel part regarding the graphics drawing apparatus which concerns on Embodiment 1. FIG. (A) And (b) is a figure which shows the reading direction of the drawing image in a frame buffer, and the scanning direction in a display panel part regarding a comparative example. (A) And (b) is a figure which shows the scanning direction in the conversion method of the drawing image in a frame buffer, and a display panel part regarding another comparative example. It is a figure which shows the other example of the drawing list | wrist shown by FIG. It is a hardware block diagram which shows the graphics drawing apparatus of a modification.

<< 1 >> Embodiment 1
<< 1-1 >> Configuration FIG. 1 is a block diagram showing a schematic configuration of a display system according to Embodiment 1 of the present invention. As shown in FIG. 1, the display system according to the first embodiment includes a graphics drawing device 10 that draws a drawing image (graphics) 24 a in a frame buffer 24, and a drawing image 24 a that is drawn in the frame buffer 24. And a display device 40 for displaying an image based thereon. The display system according to the first embodiment also includes an external memory 20 as a storage device and a CPU (Central Processing Unit) 30 as a central control unit that controls the graphics drawing device 10 and the external memory 20. Good.

The graphics drawing device 10 is a device capable of executing the graphics drawing method according to the first embodiment, and draws a single screen drawing image 24 a in a frame buffer 24 provided on the external memory 20. In FIG. 1, each of the graphics drawing device 10, the external memory 20, the CPU 30, and the display device 40 is shown as an independent configuration. Computer)). The CPU 30, the external memory 20, and the graphics drawing device 10 may be provided in one control device (for example, a PC), and the graphics drawing device 10 and the display device 40 may be connected by a cable.

The display device 40 includes a display panel unit 41 such as an LCD. FIG. 1 shows a display device 40 in which the display panel unit 41 is in a vertically long state (vertically long rectangular shape). However, the display device 40 rotates the display panel unit 41 (for example, when the user rotates the display panel unit 41 by 90 degrees to the right or 90 degrees to the left), thereby causing the display panel unit 41 to be in the horizontally long state or the vertically long state. You may provide the mechanism which can be switched to either.

The external memory 20 is, for example, a DRAM (Dynamic Random Access Memory). The external memory 20 includes a drawing list storage area (second storage area) 21 in which a drawing list 21a is stored, a graphic data storage area (first storage area) 22 in which graphic data 22a is stored, and intermediate data 23a. Are stored in an intermediate data storage area (third storage area) 23 and a frame buffer 24 in which one frame of image data (one screen drawing image) is stored. FIG. 1 shows a case where one external memory 20 has a drawing list storage area 21, a graphic data storage area 22, an intermediate data storage area 23, and a frame buffer 24. A plurality of memories (a plurality of storage devices) may be provided separately. The external memory 20 may have two frame buffers 24. In this case, the frame buffer in which the drawing image is written (the frame buffer being written) and the frame buffer from which the drawing image is being read (the frame buffer being read) are periodically switched.

The graphics drawing device 10 includes a drawing control unit 11 that controls the overall operation of the graphics drawing device 10, an intermediate data generation unit 12, an intermediate data scanning unit 13, a graphic drawing processing unit 14, a built-in frame buffer 15, A writing control unit 16 for drawing the drawing image 24a in the frame buffer 24 (that is, writing pixel data). The graphics drawing apparatus 10 reads pixel data of a drawing image (graphics) 24a of one screen drawn in the frame buffer 24 in a predetermined reading direction (a horizontal direction indicated by a broken line 24b in FIG. 11A described later). ) And a display reading unit 17 for outputting the read pixel data.

The intermediate data generation unit 12 generates intermediate data 23a from the drawing list 21a stored in the drawing list storage area 21 and the graphic data 22a stored in the graphic data storage area 22, and the intermediate data 23a is externally generated. The data is stored in the intermediate data storage area 23 in the memory 20. The generation of the intermediate data 23a by the intermediate data generation unit 12 is repeated until the last item in the drawing list 21a is read (details will be described in steps S1 to S5 in FIG. 7 described later).

The intermediate data scanning unit 13 detects a figure having a portion included in a tile area which is an image data area to be processed from the intermediate data 23a stored in the intermediate data storage area 23, and detects a figure indicating the detected figure. Information (detection result information) is given to the graphic drawing processing unit 14. The size of the tile area is determined in advance, and is, for example, the same size (number of pixels) as that of the built-in frame buffer 15.

The graphic drawing processing unit 14 generates pixel data for the graphic indicated by the graphic detection information received from the intermediate data scanning unit 13 by using the graphic data 22a stored in the graphic data storage area 22, and uses the pixel data from the pixel data. A drawing image (tile area image) of the tile area is stored in the built-in frame buffer 15. The built-in frame buffer 15 is composed of, for example, an SRAM (Static Random Access Memory).

The write control unit 16 reads the tile area image 15a stored in the built-in frame buffer 15, and stores (writes) the tile area image in an area corresponding to the tile area in the frame buffer 24.

Detection of a graphic in the tile area by the intermediate data scanning unit 13, storage of the tile area image 15a in the built-in frame buffer 15 by the graphic drawing processing unit 14, and writing of the tile area image 15a in the frame buffer 24 by the write control unit 16 are as follows. The process is repeated until drawing of one frame of graphics (drawing image of one screen) is completed in the frame buffer 24 (details will be described in steps S6 to S14 in FIG. 7 described later).

When the drawing of one frame of drawing image (graphics) is completed, the display reading unit 17 sequentially reads out the pixel data of the drawing image 24a stored in the frame buffer 24 in a predetermined reading direction, and the read pixels. Data is output to the display device 40.

<< 1-2 >> Operation FIG. 2 is a diagram illustrating an example of a vertically long graphics screen displayed on the vertically long display panel unit 41 of the display device 40. The graphics screen illustrated in FIG. 2 includes a graphic I1, a graphic I2, a graphic I3, a graphic I4, a graphic I5, and a graphic I6. In the following, the graphics drawing device 10, the external memory 20, and the CPU 30 enlarge, reduce, rotate, and move the plurality of figures I1, I2, I3, I4, I5, and I6 to display the display panel unit of the display device 40. An operation for displaying a graphics screen as shown in FIG.

First, the CPU 30 stores graphic data 22 a of a graphic to be drawn in the graphic data storage area 22. The graphic data 22a is, for example, vector graphic data or bitmap image data.

3A shows an example of vector graphic data as graphic data 22a stored in the graphic data storage area 22, and FIG. 3B shows a vector according to the vector graphic data of FIG. 3A. It is a figure which shows an example of a figure. The vector graphic data shown in FIG. 3A includes commands (for example, “MoveTo”, “LineTo”, and “CurveTo”) and coordinates of the vertices of the vector graphic in the XY coordinate system as data defining the graphic contour. (X0, Y0), (X1, Y1), and (X2, Y2) and the coordinates (X3, Y3) of the control point are included. Also, the vector graphic data shown in FIG. 3A can include data “drawing color” that specifies the color of the graphic. As shown in FIG. 3 (b), the vector figure according to the vector figure data of FIG. 3 (a) has its figure outline composed of two straight lines and one Bezier curve. However, the vector graphic data as the graphic data 22a stored in the graphic data storage area 22 is not limited to the example shown in FIGS. 3 (a) and 3 (b).

4A is a diagram showing an example of bitmap image data as the graphic data 22a stored in the graphic data storage area 22, and FIG. 4B is a diagram of the bitmap image data of FIG. 4A. It is a figure which shows an example of the bitmap figure according to. In the bitmap image data shown in FIG. 4A, the graphic contour of the bitmap image is rectangular, the size of the bitmap image (width Width and height Height), and the color value for each pixel of the bitmap image ( For example, RGBA value). In FIG. 4A, “pixel 0 (RGBA)” indicates the RGBA value in the 0th pixel, “pixel 1 (RGBA)” indicates the RGBA value in the 1st pixel, and “pixel N “(RGBA)” indicates an RGBA value in the Nth pixel (N is a positive integer). The RGBA value is a value obtained by expressing the color value of a pixel by a value of three primary colors of red (R), green (G), and blue (B) and an alpha value indicating transparency (A).

In addition, the CPU 30 stores in the drawing list storage area 21 of the external memory 20 in advance a drawing list 21 a that is used by the graphics drawing apparatus 10 to draw one frame of drawing image (one screen of graphics) in the frame buffer 24. Store.

FIG. 5 is a diagram showing an example of the structure of the drawing list 21 a stored in the drawing list storage area 21. The drawing list 21a defines how to draw each of the figures (vector figures or bitmap images) I1, I2, I3, I4, I5, and I6 stored as the figure data 22a (the figure data 22a This is data that defines the drawing content to be used. Which of the plurality of graphic data 22a stored in the graphic data storage area 22 is to be drawn depends on the pointer 22a1 (graphics I1, I2, I3, I4, I5, FIG. 5) of the graphic data 22a shown in FIG. The drawing information (conversion information indicating the coordinate conversion processing of the drawn figure) designated by I6) and indicating how to draw the designated figure is designated by the conversion matrix 21a2. The conversion matrix 21a2 is, for example, a 2-by-3 conversion matrix (1) shown below, in which A to F are components (matrix elements).

The transformation matrix (1) is used for the XY coordinates of the vertices (corner portions) of the vector graphic as the graphic data 22a and the XY coordinates of the control points, or the XY coordinates of the bitmap image as the graphic data 22a. By applying the following equation (2), the figure indicated by the coordinates (X, Y) before the coordinate conversion is enlarged, reduced, rotated, translated, etc., and the coordinates (Xn, Yn) after the coordinate conversion are indicated. Can be converted into a figure. Note that the coordinate transformation using the following equation (2) is an affine transformation, and a technique itself for enlarging, reducing, rotating, and translating a figure by affine transformation is known.

The drawing list 21a includes the drawing contents of the entire frame. In the example of FIG. 2, the drawing contents include drawing of six figures I1, I2, I3, I4, I5, and I6. Therefore, the drawing list 21a for performing this drawing is the figure I1, shown in FIG. The pointer 21a1 (graphics I1, I2, I3, I4, I5, and I6 in FIG. 5) indicating I2, I3, I4, I5, and I6 and a conversion matrix 21a2. The graphics I1, I2, I3, I4, I5, and I6 are drawn in order from the top of the drawing list 21a (the top row in FIG. 5) downward. For example, the item in the top line of the drawing list 21a shown in FIG. 5 indicates that the pointer 21a1 indicates the graphic I1 and the coordinate conversion is performed by the following equation (3).

The CPU 30 instructs the graphics drawing apparatus 10 to start drawing when the graphic data 22a and the drawing list 21a necessary for drawing are stored in the graphic data storage area 22 and the drawing list storage area 21 of the external memory 20, respectively. . Thereby, the graphics drawing apparatus 10 starts a process of drawing the drawing image 24 a for one frame in the frame buffer 24. First, the drawing control unit 11 instructs the intermediate data generation unit 12 to start processing.

FIG. 6 is a diagram illustrating an example of the structure of the intermediate data 23a stored in the intermediate data storage area 23 by the intermediate data generation unit 12. FIG. 7 is a flowchart showing the operation (graphics drawing method) of the graphics drawing apparatus 10 according to the first embodiment.

When the intermediate data generation unit 12 receives an instruction to start the drawing process from the drawing control unit 11, the intermediate data generation unit 12 reads the drawing list 21a (FIG. 5) stored in the drawing list storage area 21 from the top (step S1).

The intermediate data generation unit 12 reads the graphic data 22a designated in the drawing list 21a from the graphic data storage area 22, and draws the graphic list 21a with respect to the XY coordinates of the vertices and control points of the graphic indicated by the read graphic data. Coordinate conversion processing is performed using the conversion matrix 21a2 and coordinate conversion formulas (formulas (2), (3), etc.) specified in FIG. That is, the coordinate conversion process is performed on the XY coordinates of the vertex and the control point of the graphic data (vector graphic data) 22a of the graphic I1 by the equation (3) using the conversion matrix (AI1 to FI1). At this time, the intermediate data generation unit 12 determines the minimum value and the maximum value of the XY coordinates (Xn, Yn) after the coordinate conversion, and holds them as drawing range information (FIG. 6) (step S2). The drawing range information is expressed by, for example, the maximum value and minimum value of Xn and the maximum value and minimum value of Yn.

When the coordinate conversion processing for all the vertices and control points of the figure I1 is completed, the pointer 21a1 to the figure I1, the conversion matrix 21a2 specified by the drawing list 21a, and the drawing range information (the converted coordinates Xn Are written in the external memory 20 as intermediate data 23a (FIG. 6) (step S3).

Next, the intermediate data generation unit 12 determines whether the last item in the drawing list 21a has been read (step S4). If the last item has not been read (NO in step S4), the intermediate data generation unit 12 determines whether the next item in the drawing list 21a has been read. Are read (step S5). In the example of FIG. 5, the intermediate data generation unit 12 performs the same processing as in the case of the graphic I1 for the next item (the graphic I2 specified next) in the drawing list 21a. That is, the intermediate data generation unit 12 reads the graphic data 22a of the graphic I2 from the graphic data storage area 22, and converts the transformation matrix (AI2 to FI2) for the vertices of the graphic and the XY coordinates of the control points indicated by the graphic data 22a. Use it to perform coordinate transformation processing. Then, when the coordinate conversion process is completed for all the vertices and control points of the graphic I2 (YES in step S4), the intermediate data generation unit 12 converts the pointer to the graphic I2 and the conversion matrix specified by the drawing list 21a ( AI2 to FI2) and drawing range information (maximum value and minimum value of coordinate Xn after conversion, maximum value and minimum value of coordinate Yn after conversion) are stored in intermediate data storage area 23 of external memory 20 as intermediate data 23a. Write.

The intermediate data generation unit 12 repeats the same processing, reads up to the last item in the drawing list 21a, and registers information about all graphic data 22a that needs to be drawn in one frame as shown in FIG. The intermediate data 23 a is created in the intermediate data storage area 23 of the external memory 20.

Next, the drawing control unit 11 instructs the intermediate data scanning unit 13 to start processing. First, the drawing control unit 11 instructs the intermediate data scanning unit 13 to set the tile area in the upper left corner on the screen as a drawing target (step S6). 8A to 8C show a tile area (first selected tile area) 13a to be processed by the graphics drawing apparatus 10, a tile area image 15a drawn in the built-in frame buffer 15, and a built-in frame. It is a figure which shows the drawing image 16a read from the buffer 15 and written in the frame buffer 24. Here, the size (size) of the tile area is the same as that of the built-in frame buffer 15. The size of the tile area is determined in advance, and is a small area such as 32 pixels × 32 pixels or 64 pixels × 64 pixels, for example.

When the intermediate data scanning unit 13 receives an instruction from the drawing control unit 11, the intermediate data scanning unit 13 reads the intermediate data 23a from the intermediate data storage area 23 of the external memory 20 (step S7), and refers to the drawing range information of the intermediate data 23a (FIG. 6). Then, it is determined whether or not the graphic data 22a has a portion included in the tile area 13a to be processed (step S8). If the referenced graphic data 22a has a portion included in the processing target tile area 13a (YES in step S8), the intermediate data scanning unit 13 instructs the graphic drawing processing unit 14 to point to the graphic data 22a. Then, a transformation matrix is output and drawing is instructed. In the example of FIGS. 8A to 8C, since the graphic I2 has a portion included in the tile area 13a to be processed, the intermediate data scanning unit 13 instructs the graphic drawing processing unit 14 to draw the graphic I2. And give instructions.

When receiving a drawing instruction from the intermediate data scanning unit 13, the figure drawing processing unit 14 reads the figure data 22 a from the figure data storage area 22 of the external memory 20, and the vertices of the figure indicated by the figure data 22 a and the XY coordinates of the control points Next, after performing a coordinate transformation process using the designated transformation matrix to deform the figure, pixel data is generated for the tile area to be processed and rendered in the built-in frame buffer 15 (step S9). The method of generating pixel data from the graphic data 22a is a known technique.

The intermediate data scanning unit 13 determines whether the intermediate data 23a of all the figures has been scanned (step S10). If the intermediate data 23a has not been scanned to the last item (graphic information) (NO in step S10). ), The next item (graphic information) in the intermediate data 23a is scanned (step S11), and the same processing is performed.

The intermediate data scanning unit 13 scans the intermediate data 23a of all the figures, and all the figure data 22a having a portion included in the tile area to be processed (in the example of FIGS. 8A to 8C, the figure I2 (Only) is completed, the creation of the image for the tile area to be processed is completed in the built-in frame buffer 15.

Next, the drawing control unit 11 instructs the write control unit 16 to write pixel data corresponding to the tile area into the frame buffer 24. The writing control unit 16 calculates the writing position of the frame buffer 24 on the external memory 20 from the rotation angle and the position of the tile area, and rotates the tile area image 15a of the built-in frame buffer 15 to the drawing image 16a in the frame buffer 24. (Step S12). At this time, as indicated by an arrow 62 in FIG. 8C, writing is performed in the horizontal direction (long side direction) with respect to the frame buffer 24 of the external memory 20, as indicated by an arrow 61 in FIG. As shown, the built-in frame buffer 15 is read in the vertical direction. The built-in frame buffer 15 is preferably composed of SRAM. In this case, there is no overhead such as precharge even if the vertical reading is performed, so that the vertical reading can be performed efficiently. it can. Further, since the memory capacity required for the built-in frame buffer 15 is very small, it is considered that the influence on the product price is small even when the built-in frame buffer 15 is a relatively expensive SRAM.

Next, the drawing control unit 11 determines whether or not the processing has been completed for all tile areas on the screen of one frame to be drawn (step S13). In this example, next, the drawing control unit 11 instructs the intermediate data scanning unit 13 to set the tile area adjacent to the right of the upper left corner on the screen as a drawing target (step S14). FIGS. 9A to 9C show a tile area (second tile area selected) 13a to be processed by the graphics drawing apparatus 10, a tile area image 15a drawn in the built-in frame buffer 15, and a built-in frame. FIG. 4 is a diagram showing a drawing image read from the buffer 15 and written to the frame buffer 24.

When the intermediate data scanning unit 13 receives an instruction from the drawing control unit 11, the intermediate data scanning unit 13 reads the intermediate data 23a from the intermediate data storage area 23 of the external memory 20, and refers to the drawing range information of the intermediate data 23a to process the graphic data 22a. It is determined whether or not there is a part included in the tile area. When the intermediate data scanning unit 13 includes a portion included in the tile area to be processed, the intermediate data scanning unit 13 outputs a pointer and a conversion matrix to the graphic data 22a to the graphic drawing processing unit 14 to instruct drawing. In the example of FIGS. 9A to 9C, since the figure I2 and the figure I4 have a portion included in the tile area to be processed, the intermediate data scanning unit 13 draws the figure I2 and the figure I4. An instruction is issued to the drawing processing unit 14.

Upon receiving an instruction from the intermediate data scanning unit 13, the graphic drawing processing unit 14 reads the graphic data 22 a from the graphic data storage area 22 of the external memory 20, and the vertexes and control points of the graphic indicated by the read graphic data 22 a are read. After transformation by performing a coordinate transformation process using a transformation matrix designated for the XY coordinates, pixel data is generated for the tile area to be processed and rendered in the built-in frame buffer 15.

The intermediate data scanning unit 13 scans the intermediate data 23a of all the figures, and all the figure data 22a having a portion included in the tile area to be processed (in the example of FIGS. 9A to 9C, the figure I2 When the drawing of the graphic I4) is completed, the tile area image 15a to be processed is completed in the built-in frame buffer 15.

Thereafter, the drawing control unit 11 instructs the write control unit 16 to write pixel data corresponding to the tile area into the frame buffer 24. The writing control unit 16 calculates the writing position of the frame buffer 24 on the external memory 20 from the rotation angle and the position of the tile area, and rotates the tile area image 15a of the built-in frame buffer 15 (for example, rotates left by 90 degrees). Write to frame buffer 24.

Similarly, processing is performed for all tile areas on the screen. FIGS. 10A to 10C are diagrams for explaining processing for the last tile area (the lowermost right on the screen). Similarly, the intermediate data scanning unit 13 reads the intermediate data 23a from the external memory 20, and refers to the drawing range information to determine whether or not the graphic data 22a has a portion included in the tile area to be processed. FIGS. 10A to 10C show the tile area to be processed by the graphics drawing apparatus 10 (the tile area selected last), the tile area image drawn in the built-in frame buffer 15, and the built-in frame buffer 15. It is a figure which shows the drawing image read and written in the frame buffer.

Upon receiving an instruction from the intermediate data scanning unit 13, the graphic drawing processing unit 14 reads the graphic data 22 a from the external memory 20, and performs a transformation process by performing a coordinate conversion process using the conversion matrix specified for the XY coordinates of the vertices and control points. After that, pixel data is generated for the tile area to be processed and drawn in the built-in frame buffer 15.

Thus, for each tile area, the intermediate data 23a is scanned to detect a graphic having a portion included in the tile area to be processed, and the graphic data 22a is read out and drawn in the built-in frame buffer 15, and the built-in frame By rotating and writing the tile area image 15a of the buffer 15 to the frame buffer 24 on the external memory 20, a rotated drawing image is obtained.

FIGS. 11A and 11B relate to the graphics drawing apparatus 10 according to the first embodiment. FIG. 11A shows the drawing direction of the drawing image 24a in the frame buffer 24 (the normal reading direction in the external memory 20). ) 24b shows a state of reading, and FIG. 11B is a diagram showing a scanning direction 41a in the display panel 41. The reading direction 24b of the drawing image 24a and the scanning direction 41a in the display panel unit 41 correspond to each other. When the processing is completed for all tile areas on one screen, the display reading unit 17 completes reading of the one-screen drawing image 24 a stored in the frame buffer 24 on the external memory 20. The display device 40 displays an image on the display panel unit 41 based on the data received from the display reading unit 17. In the first embodiment, at this time, the frame buffer 24 may read in the horizontal direction, which is a predetermined reading direction. For this reason, even if the external memory 20 is a DRAM, the access efficiency does not decrease.

FIGS. 12A and 12B relate to a comparative example, and FIG. 12A shows the drawing image reading direction in the frame buffer 241 in the direction different from the vertical direction of the external memory (the horizontal direction which is a predetermined reading direction). ), And FIG. 12B is a diagram showing the scanning direction in the display panel unit 41. In this case, since the pixel data is sequentially read from the frame buffer 241 on the external memory, which is a DRAM, in the vertical direction of the graphics, overhead such as precharging frequently occurs, and the access efficiency to the memory is reduced. There is.

FIGS. 13A and 13B relate to another comparative example, and FIG. 13A shows a drawing image 242b that is generated by rotating the vertically drawn image 242a 90 ° counterclockwise in the frame buffer 242. FIG. 13B shows a state in which the reading direction of 242b is read in the horizontal direction, which is a predetermined reading direction of the external memory, and FIG. In this case, although the overhead such as precharge does not increase, there is a problem that the necessary memory capacity increases, the necessary memory bandwidth (transfer rate) increases, and the processing time also increases.

<< 1-3 >> Effect According to the graphics rendering apparatus 10 according to the first embodiment described above, a tile area image is obtained for each of the plurality of tile areas 13a obtained by dividing the image data area of one screen. 15a is generated, the generated tile area image 15a is stored in the built-in frame buffer 15, the tile area image is rotated in a specified direction (for example, 90 degrees) and in a specified direction, and the rotated image 16a is rotated. Drawing in the frame buffer 24. By such processing, when writing to the frame buffer 24 on the external memory 20, as shown by the arrow 62 in FIG. 8C, FIG. 9C, and FIG. Writing is performed in the horizontal direction in the frame buffer 24, and when reading, the reading is performed in the horizontal direction in the frame buffer 24 as indicated by an arrow 24b in FIG. For this reason, even if the external memory 20 is a DRAM, the access efficiency is not lowered, and the degradation of the image display performance can be prevented.

<< 2 >> Modification 1
In the first embodiment, the drawing list 21a stored in the external memory 20 has the structure shown in FIG. However, the drawing list may have a hierarchical structure as indicated by reference numeral 50 in FIG. The drawing list may have a format that defines a series of drawing commands, such as a display list of OpenGL (Graphics Library), which is a three-dimensional graphics API (Application Program Interface).

As shown in FIG. 14, when the drawing list has a hierarchical structure 50, when the upper drawing list 51 refers to the lower drawing lists 52 and 54, the drawing list 52 further refers to the lower drawing list 53. At this time, the designated transformation matrix (for example, transformation matrix 512) is multiplied by the transformation matrix (for example, transformation matrix 522, 542) designated for each figure in the lower drawing list, and the multiplication result The coordinate transformation process is performed on the XY coordinates of the vertex and the control point of the graphic data 22a using the transformation matrix.

<< 3 >> Modification 2
In the first embodiment, the case where the built-in frame buffer 15 has a storage area corresponding to one tile area has been described. However, the built-in frame buffer has a double buffer configuration (that is, has a storage area corresponding to two tile areas), and the writing control unit 16 writes an image from the built-in frame buffer to the frame buffer 24 and a graphics drawing process. The unit 14 may execute the process of drawing an image of the next tile area in the built-in frame buffer in parallel. In this case, it is possible to reduce the time required to draw a drawing image of one screen in the frame buffer 24.

<< 4 >> Modification 3
FIG. 15 is a hardware configuration diagram showing a configuration of a modified example of the graphics drawing apparatus 10. A graphics drawing apparatus 10 shown in FIG. 1 includes a memory 91 as a storage device that stores a program (graphics drawing program) as software, and a processor 92 as an information processing unit that executes the program stored in the memory 91. (For example, by a computer). In this case, the drawing control unit 11, the intermediate data generation unit 12, the intermediate data scanning unit 13, the graphic drawing processing unit 14, the writing control unit 16, and the display reading unit 17 in FIG. Equivalent to. Note that a part of the graphics drawing apparatus 10 shown in FIG. 1 can be realized by the memory 91 shown in FIG. 15 and the processor 92 that executes a program.

<< 5 >> Modification 4
In the first embodiment, the display device 40 is in a vertically long state in which the display panel unit 41 is rotated 90 degrees to the right (the tile area image 15a of the built-in frame buffer 15 is rotated 90 degrees to the left, Explained). However, the display device 40 includes posture detection means (panel state detection means) for detecting the rotation direction and rotation angle of the display panel unit 41, and the graphics drawing device includes means for receiving a detection signal of the posture detection means. The control unit 11 may control the writing control unit 16 based on the detection signal of the attitude detection unit. For example, the drawing control unit 11 sets the rotation angle and the rotation direction of the tile area image 15a according to the rotation direction and the rotation angle of the display panel unit 41, and the frame buffer 24 matches the rotation angle and the rotation direction. The writing position may be calculated (determined).

The present invention can be applied to a device or system connected to or including a display device such as a PC. Further, the present invention is applicable to an electronic signboard (digital signage) or the like.

10 graphics drawing device, 11 drawing control unit, 12 intermediate data generation unit, 13 intermediate data scanning unit, 14 figure drawing processing unit, 15 built-in frame buffer, 15a tile area image, 16 write control unit, 17 display reading unit, 20 External memory, 21a, 50 drawing list, 21 drawing list storage area (second storage area), 22 figure data storage area (first storage area), 22a figure data, 23 intermediate data storage area (third storage area) ), 23a intermediate data, 24 frame buffer, 24a drawing image (graphics), 24b reading direction, 30 CPU, 40 display device, 41 display panel section, 41a scanning direction.

Claims

A graphics drawing device for drawing a drawing image in a frame buffer,
A pointer indicating the graphic data from graphic data indicating a graphic to be drawn stored in the first storage area and a drawing list defining the drawing content of the graphic data stored in the second storage area Generating intermediate data including conversion information indicating coordinate conversion processing of the figure to be drawn and drawing range information indicating a drawing range of the figure to be drawn, and storing the intermediate data in a third storage area A data generator;
From the intermediate data, an intermediate data scanning unit for detecting the graphic having a portion included in the tile area to be processed;
A built-in frame buffer in which a drawing image of the tile area is drawn;
A graphic drawing processing unit for generating a first image corresponding to the tile area to be processed from pixel data of the graphic detected by the intermediate data scanning unit and drawing the first image in the built-in frame buffer When,
A writing control unit for writing, into the frame buffer, a second image obtained by rotating the first image drawn in the built-in frame buffer according to a specified rotation angle;
Drawing for controlling the intermediate data scanning unit, the graphic drawing processing unit, and the writing control unit so that the drawing image of one screen is drawn in the frame buffer by repeating the writing of the second image. A graphics drawing device comprising: a control unit;
Each time the drawing image of one screen is stored in the frame buffer, the pixel data of the drawing image in the frame buffer is sequentially read in a predetermined direction in the frame buffer, and the read pixel data is read out. The graphics drawing device according to claim 1, further comprising a display reading unit for outputting.
The graphics drawing apparatus according to claim 1, wherein the first storage area, the second storage area, the third storage area, and the frame buffer are different storage areas in one external memory. .
The graphics drawing device according to any one of claims 1 to 3, wherein the conversion information indicating a coordinate conversion process of the figure is a conversion matrix.
The graphics drawing apparatus according to any one of claims 1 to 4, wherein the graphic data includes at least one of vector graphic data and bitmap image data.
6. The graphics drawing apparatus according to claim 1, wherein the built-in frame buffer is an SRAM.
The graphics drawing device according to any one of claims 1 to 6, wherein the frame buffer is a DRAM.
The graphics drawing apparatus according to any one of claims 1 to 7, wherein the specified rotation angle is 90 degree right rotation or 90 degree left rotation.
The graphics drawing device according to any one of claims 1 to 8, wherein the built-in frame buffer has a storage area having a size equal to a shape of the tile area or a size twice the shape of the tile area.
A graphics drawing method for drawing a drawing image in a frame buffer,
A pointer indicating the graphic data from graphic data indicating a graphic to be drawn stored in the first storage area and a drawing list defining the drawing content of the graphic data stored in the second storage area Generating intermediate data including conversion information indicating coordinate conversion processing of the figure to be drawn and drawing range information indicating a drawing range of the figure to be drawn, and storing the intermediate data in a third storage area A data generation step;
An intermediate data scanning step of detecting the graphic having a portion included in the tile area to be processed from the intermediate data;
A graphic drawing processing step of generating a first image corresponding to the tile area to be processed from pixel data of the graphic detected in the intermediate data scanning step and drawing the first image in a built-in frame buffer; ,
A write control step of writing, into the frame buffer, a second image obtained by rotating the first image drawn in the built-in frame buffer according to a specified rotation angle;
A graphics drawing method comprising: a drawing control step of drawing the drawing image of one screen in the frame buffer by repeating the intermediate data scanning step, the graphic drawing processing step, and the writing control step.
The graphics drawing apparatus according to any one of claims 1 to 9, which draws a drawing image in a frame buffer;
A display device for displaying an image based on the drawn image drawn in the frame buffer;
Display system with.
A pointer indicating the graphic data from graphic data indicating a graphic to be drawn stored in the first storage area and a drawing list defining the drawing content of the graphic data stored in the second storage area Generating intermediate data including conversion information indicating coordinate conversion processing of the figure to be drawn and drawing range information indicating a drawing range of the figure to be drawn, and storing the intermediate data in a third storage area Data generation process,
An intermediate data scanning process for detecting the graphic having a portion included in the tile area to be processed from the intermediate data;
A graphic drawing process for generating a first image corresponding to the tile area to be processed from pixel data of the graphic detected in the intermediate data scanning process, and drawing the first image in a built-in frame buffer;
A writing control process for writing, in a frame buffer, a second image obtained by rotating the first image drawn in the built-in frame buffer according to a specified rotation angle;
A graphics drawing program for causing a computer to execute a drawing control process for drawing a drawing image of one screen in the frame buffer by repeating the intermediate data scanning process, the graphic drawing process, and the writing control process.