JPH06149533A - Segment quick plotting system for reducing plotting processing for segment outside display area - Google Patents

Abstract

PURPOSE:To enable a quick plotting processing by omitting a processing for one of the buffers of a segment out of a display area in a segment plotting system provided with double buffers. CONSTITUTION:A plotting means 1 alternately writes segment data included in the display area to frame buffers 2 and 2' and displays the contents of one of the frame buffers at a display device 3 while writing the data to the other frame buffer. At the time of the plotting processing to the first frame buffer 2, when the segment data are included in the display area and the data are written in the frame buffer 2, the flag of a buffer write flag holding means 4 is raised. At the time of the plotting processing to the second frame buffer 2', a buffer write flag is referred to and when the flag is not raised, the plotting processing to the second frame buffer 2' is omitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed drawing method in a graphic display device, and more particularly, the present invention reduces the drawing processing of a segment outside the display area.
The present invention relates to a segment high-speed drawing method capable of high-speed drawing.

[0002]

2. Description of the Related Art FIG.
It is a block diagram of a control system of a display device,
In the figure, 11 is an interface control processor for interfacing between the graphic display device and the host computer, 12 is a graphics data memory for storing graphics data, and each segment of the graphics data memory 12 Each element of graphic data (for example, each element of a graphic such as a circle or a triangle) is stored as a coordinate value.

Reference numeral 13 is a graphic processor for processing graphic data, 14 is an image data generation processor for generating image data from the graphic data processed by the graphic processor, and 15 and 16 are image data memory (for storing image data). The image data memories 15 and 16 constitute a double buffer as shown in the figure, and when data is being written in one of the image data memories, the other image data An image is displayed on a display device such as a CRT according to the image data stored in the memory (hereinafter, the image data memory 15 is called an A buffer and the image data memory 16 is called a B buffer).

Reference numeral 17 is a CRT control processor for displaying an image on a display device such as a CRT. 6 and 7 are schematic flow charts of the conventional segment drawing processing, and FIG. 6 shows the processing in the graphic processor.
FIG. 7 shows the processing in the image data generation processor.

The conventional segment drawing processing control will be described with reference to FIGS. In step S61 of FIG. 6, when a display area for the display device is designated, the graphic processing processor 13 notifies the display area to the image data generation processor 14. Next, the graphic processor 13
In step S62, the remaining number of segments to be processed is determined. If the remaining number is not 0, step S62
At 63, the segment pointer is obtained by referring to the segment management table storing the start address of each segment.

In step S64, a buffer swap command is sent to the image data generation processor 14 to swap the frame buffers (A buffer and B buffer). When the buffer swap command is issued, the image data generation processor 14 swaps the frame buffers in step S71 of FIG. That is, the A buffer is set to the data writable state, and the contents of the B buffer are displayed on the display device.

Then, in step S65 of FIG.
From the address specified by the segment pointer,
Reads the graphic data stored in the corresponding segment, processes the elements in the segment such as adding the coordinate value that is the reference of the display position to the coordinate value of the read graphic data, and sends the drawing command etc. to the image data generation processor. send. When the drawing command is issued and the processing result by the graphic processor is passed, the image data generation processor 1
Reference numeral 4 determines whether or not the graphic data processed by the graphic processor 13 is applied to the previously notified display area, and when the graphic data is applied to the display area, the image data is written in the A buffer (step S72 in FIG. 7). .

In step S66 of FIG. 6, the graphic processor 13 sends a buffer swap command to the image data generation processor 14 in order to swap the A buffer and the B buffer. , Step S73 of FIG.
At, the frame buffer is swapped, the contents of the A buffer are displayed on the display device, and the B buffer is set to the data writable state.

Then, in the same manner as described above, the graphic processor 13 processes the elements in the segment in step S67 and issues a drawing command or the like. When the drawing command is issued, the image data generation processor 14 writes the processing result of the graphic processor 13 in the B buffer in step S74 of FIG. 7, as described above.

When the remaining number of segments to be processed becomes 0 by repeating the above processing, the process goes to END from step S62 and ends. As described above, in the control system shown in FIG. 5, the frame buffer is a double buffer, and while writing data in one buffer,
When the contents of the other buffer are displayed on the display device and the writing of data to one buffer is finished, the buffers are swapped and the same data as the data written to one buffer is written to the other buffer. ,
The contents of both buffers are controlled so that they are always the same so that the data can be displayed even while the data is being written.

[0011]

By the way, the graphic processor 13 in the above-mentioned control system processes the segment outside the display area in the same manner as the segment in the display area and displays the processing result as image data. The image data generation processor 14 writes only the image data concerning the display area notified in advance in the A buffer and the B buffer among the processing results by the graphic processor 13.

Therefore, when there are many segments,
The graphic processor 13 requires a lot of processing time to process the non-displayed segments. In particular, as described above, in the system having the double buffer, the segment outside the display area is processed for each of the A buffer and the B buffer, which causes a problem that the processing time becomes long. .

The present invention has been made to solve the above-mentioned problems of the prior art. In the segment drawing system having a double buffer, the processing for one buffer of a segment outside the display area is omitted. Accordingly, it is an object of the present invention to provide a segment high-speed drawing method that enables high-speed drawing processing.

[0014]

FIG. 1 is a block diagram showing the principle of the present invention. In the figure, 1 is a drawing means for alternately writing the segment data included in the display area to the first and second frame buffers, and 2 and 2'are first and second holding images to be displayed on the display device. 3 is a display device for displaying an image written in the first or second frame buffer, and 4 is a buffer write flag holding means.

In order to solve the above-mentioned problems, the present invention, as shown in FIG. 1, displays the contents of the other frame buffer while writing the data in the other frame buffer. Frame buffer 2,
In the segment high-speed drawing method for displaying an image on the display device 3 by alternately writing the segment data included in the display area into the first and second frame buffers 2 and 2 ′, A buffer write flag holding means 4 for holding a buffer write flag indicating whether or not segment data has been written in the frame buffer 2 is provided.

After drawing the segment data to the first frame buffer 2, the first frame buffer 2 is referred to with reference to the buffer write flag.
It is determined whether or not writing to the first frame buffer 2 has not been performed.
By omitting the drawing process for the second frame buffer 2 ', the drawing process for the segment outside the display area is reduced.

[0017]

Operation: First and second frame buffers 2, 2 '
When writing graphic data to a segment, if it is known before the drawing process of the segment whether the segment is out of the display area, a series of drawing processing is not necessary for the segment out of the display area. Become.

However, the state inside or outside the display area changes due to movement or enlargement / reduction of the display area, movement of segments, addition / deletion of elements, etc., and the segment to be drawn is displayed before the segment drawing processing. It is difficult to determine whether or not it is completely out of the area. For this reason, the drawing process for the first frame buffer cannot be omitted, but since the drawing process has already been performed for the first frame buffer when the drawing process for the second frame buffer is performed, Whether or not the drawing process for the second frame buffer is necessary can be easily determined.

Based on the above principle, the present invention sets a buffer write flag when writing to the first frame buffer, and refers to the above flag during drawing processing on the second frame buffer. However, when the buffer write flag is not set, the drawing process for the second frame buffer is omitted.

With the above arrangement, in the present invention, the drawing processing of the segment outside the display area can be reduced to about half, and the processing speed for the screen including many segments outside the display area can be reduced. It can be significantly improved. At the same time, it is possible to update the screen including many segments outside the display area at a higher speed.

[0021]

2 and 3 are schematic flow charts of an embodiment of the present invention, FIG. 2 shows a process in a graphic processor, and FIG. 3 shows a process in an image data generation processor. In FIG. 2, “interface” is an interface provided between the graphic processor and the image data generation processor, and a buffer write flag indicating whether or not data has been written to the A buffer is provided on this interface. A flag register for storing is provided.

FIG. 4 shows the image data generation processor 1
4 is a flowchart showing the processing in 4. The segment drawing processing of the embodiment of the present invention will be described with reference to FIGS. 2, 3 and 4. In step S21 of FIG.
When the display area is designated, the graphic processing processor 13 notifies the image data generation processor 14 of the display area. Then, in step S22, the remaining number of segments to be processed is determined, and if the remaining number is not 0,
In step S23, the segment pointer is obtained by referring to the segment management table storing the start address of each segment.

In step S24, a buffer swap command is sent to the image data generation processor 14 to swap the frame buffers (A buffer and B buffer). When the buffer swap command is issued, the image data generation processor 14 swaps the frame buffers in step S31 of FIG. That is, the A buffer is set to the data writable state, and the contents of the B buffer are displayed on the display device.

That is, when the buffer swap command is issued, the image data generation processor switches the states of the A buffer and the B buffer in step S41 of FIG. In step S25 of FIG. 2, the buffer write flag of the flag register provided on the interface between the graphic processor and the image data generation processor is reset.

Then, in step S26 of FIG.
Similar to the above, the elements in the segment are processed, and a drawing command or the like is sent to the image data generation processor 14. In the image data generation processor 14, when the drawing command is issued, when the graphic data processed by the graphic processing processor 13 reaches the notified display area, the image data is written in the A buffer (step of FIG. 3). S32).

Further, the image data generation processor 14 is A
Each time writing to the buffer, an ON signal is sent to the buffer write flag of the flag register provided on the interface, and this is OR-processed by the flag register. That is, in the image data generation processor 14, when the drawing command is issued in step S42 of FIG. 4, it is determined whether or not the command data is for the display area, and the command data is for the display area. In this case, the data is written in the A buffer and the buffer write flag on the interface is ORed. As a result, the buffer write flag is turned on when the segment data is written to the A buffer, but the buffer write flag is turned on when the segment data is not written to the A buffer outside the display area. Remains off.

In step S27 in FIG. 2, the graphic processor 13 sends a buffer swap command to the image data generation processor 14 in order to swap the A buffer and the B buffer. , Step S33 of FIG.
At, the frame buffer is swapped, the contents of the A buffer are displayed on the display device, and the B buffer is set to the data writable state.

In step S28 of FIG. 2, the graphic processor 13 refers to the flag register on the interface to determine whether or not data has been written to the frame buffer during the A buffer processing, and the frame buffer is checked. If the data is written in, the process goes to step S29 to process the elements in the segment in the same manner as described above, and sends the drawing command and the like. If no data is written in the frame buffer, the above process is not performed and the process returns to step S22 to repeat the above process.

As described above, in the above embodiment, A
At the time of buffer processing, the buffer write flag provided on the interface is OR-processed every time there is writing to the frame buffer (every time there is drawing on the display area). By simply referring to it, it is possible to know whether or not the segment to be drawn covers the display area, and it is possible to omit the drawing processing for the B buffer of the segment that does not cover the display area.

[0030]

As is apparent from the above description,
In the present invention, in the segment drawing method having the double buffer, when the segment data is outside the display area and the segment data has not been written to one buffer, the writing to the other buffer is omitted. By doing so, the drawing processing of the segment outside the display area can be reduced to about half, and the processing speed for the screen including many segments outside the display area can be significantly improved. At the same time, it is possible to update the screen including many segments outside the display area at a higher speed.

[Brief description of drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a flowchart of an embodiment of the present invention.

FIG. 3 is a flowchart (continuation) of the embodiment of the present invention.

FIG. 4 is a flowchart in the image data generation processor.

FIG. 5 is a block diagram of a segment drawing method which is a premise of the present invention.

FIG. 6 is a flowchart of a conventional example.

FIG. 7 is a flowchart (continuation) of a conventional example.

[Explanation of symbols]

 11 Interface Control Processor 12 Graphic Data Memory 13 Graphic Processing Processor 14 Image Data Generation Processor 15, 16 Image Data Memory 17 CRT Control Processor

Claims (1)

[Claims] 1. A first and second frame buffer (2.) that displays the contents of the other frame buffer while writing data to one frame buffer.
2 ') and the segment high-speed drawing method for displaying an image on the display device (3) by alternately writing the segment data contained in the display area to the first and second frame buffers (2.2') A buffer write flag holding means (4) for holding a buffer write flag indicating whether or not segment data has been written in one frame buffer (2) is provided, and the first frame buffer (2 ) Is drawn, it is determined whether or not writing to the first frame buffer (2) is performed by referring to the buffer write flag, and the first frame buffer (2) is determined.
The high-speed segment drawing method is characterized in that the drawing processing of the segment outside the display area is reduced by omitting the drawing processing for the second frame buffer (2 ') when the writing to the second frame buffer (2') is not performed.