JPH04262472A - Graphic display device - Google Patents

Abstract

PURPOSE:To enhance the display speed of a graphic display device and to decrease the amount used of segment buffer. CONSTITUTION:The content of a command stored in a segment buffer 10 is read out, and only if the read content does not coincide with the content (represents drawing primitive, attributive, etc.) that was read previously, the content that was read secondly is stored in the optimizing buffer 24. Data that is sequentially and temporarily stored in the optimizing buffer 24 is stored in a segment buffer read control section 20 by a segment buffer writing control section 26. As a result, a twice registered section in a segment buffer 10 is deleted. A period of time for transfer of graphic data from segment buffer 10 to frame buffer 14 is shortened, and the amount used of segment buffer 10 is decreased.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic display device that transfers graphic data from a segment buffer to a frame buffer to display graphics on a screen such as a CRT, and more particularly to a means for rewriting the contents of a segment buffer.

0002

2. Description of the Related Art Graphic display devices as output devices for computers have become increasingly important as the amount of information output from computers has increased in recent years. Especially recently,
There is a significant need to improve display speed.

Generally, a graphic display device called a graphic display device is composed of a CRT display, a plurality of storage elements, and a processor. FIG. 4 shows a block diagram of the configuration of a graphic display device according to a conventional example. The graphics display device shown in this figure is comprised of a segment buffer 10, a graphics processor 12, a frame buffer 14, a video generator 16, and a CRT display 18. The segment buffer 10 is a buffer that stores graphic data, and stores the graphic data using a logical coordinate system called a world coordinate system. Graphic data registered in the segment buffer 10 by a command from a graphics application or a user is supplied to a subsequent graphics processor 12. The graphics processor 12 has a function of bit-expanding the graphic data from the segment buffer 10 onto the frame buffer 14, but in performing this expansion, the world coordinate system in the segment buffer 10 is converted into a physical coordinate system. That is, in the frame buffer 14, graphic data is expanded and stored using physical coordinates corresponding to addresses. When the graphic data is bit-developed into the frame buffer 14, a video signal corresponding to this graphic data is generated by the video generator 16. The video signal is CRT
The data is supplied to the display 18, and a corresponding figure is thereby displayed on the screen of the CRT. in this way,
Conventionally, graphics have been displayed on the screen of the CRT display 18 by sequentially transferring graphic data from the segment buffer 10.

0004

However, in the conventional graphic display device, there is a problem in that the overlap of graphic data registered in the segment buffer 10 imposes a certain limit on the improvement of display speed. This problem arises due to the following reasons.

[0005] A segment buffer stores a graphic set composed of a plurality of graphic data. Each graphic data consists of graphic primitives called segments and their attributes. Here, the graphic primitives refer to straight lines, circles, characters, etc., and the attributes refer to colors, line types, character sizes, etc. These graphic primitives and attributes are registered in the segment buffer in order according to instructions from the host computer, for example. Therefore, even when the same graphic primitive or attribute is repeated, for example, the same graphic primitive or attribute is registered for the number of repetitions.

For example, when trying to draw 1,000 vectors of red dashed lines on the screen of a CRT display, an attribute indicating ``red'', an attribute indicating ``dashed line'', and an attribute indicating ``vector'' are each divided into 1,000 segments. Must be registered on the buffer.

As a result of such redundant registration to the segment buffer, there is a certain limit to the supply speed of graphic data from the segment buffer to the graphic processor, and therefore there is a certain limit to the display speed of the graphic display device as a whole. A problem has arisen in which the

The present invention has been made with the aim of solving these problems, and by analyzing the graphic data stored on the segment buffer and eliminating duplicate registration, the segment buffer can be updated. The purpose is to save storage capacity and improve display speed.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the graphic display device of the present invention has the following features:
a segment buffer read control unit that reads the storage contents of the segment buffer; an optimization processing control unit that deletes duplicate portions included in the storage contents of the segment buffer;
It has an optimization buffer that temporarily stores data obtained by the optimization processing control unit and from which duplicated portions have been deleted, and a segment buffer write control unit that writes the contents of the optimization buffer to the segment buffer. Shape primitives or /
It is characterized by deleting duplicate parts of attributes.

0010

[Operation] In the present invention, duplicately registered portions of graphic data stored in the segment buffer are deleted. That is, the segment buffer read control unit reads out the storage contents of the segment buffer,
Duplicate portions included in the read content are deleted by the optimization processing control unit. The graphic data from which the overlapping portion has been deleted is temporarily stored in the optimization buffer, and then written to the segment buffer by the segment buffer write control unit. Therefore, among the graphic data written to the segment buffer, overlapping parts related to repetition of the same graphic primitive or repetition of the same attribute are deleted, and as a result, the amount of graphics supplied from the segment buffer to the graphics processor is reduced. Become. Therefore, the display speed of the graphic display device is improved, and the storage capacity of the segment buffer can be reduced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the same components as those of the conventional example shown in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows a block diagram of the configuration of a graphic display device according to an embodiment of the present invention. As shown in this figure, this embodiment
In addition to the conventional example shown in FIG.
and a segment buffer write control section 26.

The segment buffer read control unit 20 is a processor that reads graphic primitives or attributes related to control in the optimization processing control unit 22 from the segment buffer 10. The optimization processing control unit 22 has a function of deleting overlapping parts, which is a feature of the present invention. That is, it analyzes the contents stored in the segment buffer 10 and performs control to delete duplicate parts. Optimized buffer 2
Reference numeral 4 denotes a buffer that temporarily stores data related to graphic primitives or attributes whose duplicate parts have been deleted by the optimization processing control unit 22. It has a function of writing the storage contents of the optimization buffer 24 to the segment buffer 10 when the optimization process is completed or when the optimization process is completed.

Furthermore, in this embodiment, optimization control flag setting means 28 is provided. This optimization control flag setting means 28 is a means for setting an optimization control flag, and when this flag is set on, the optimization processing control unit 22 executes the optimization processing. is set to off, the optimization process by the optimization process control unit 22 is prohibited.

Next, the operation of this embodiment will be explained.

Optimization processing control unit 22 in this embodiment
executes optimization of graphic primitives and attributes stored in the segment buffer 10. In the case of optimization of graphic primitives, the graphic primitives are sequentially read from the segment buffer 10, and if the graphic primitives read earlier and the graphic primitives read later overlap, the latter The operation is to delete the . For example, a command to draw a vector is usually set so that N (N: plural) consecutive vectors can be drawn. However, when a user actually uses a graphic display device, N vectors consisting of a starting point and an ending point are drawn.
Possible usage modes are as follows. That is, following a certain vector symbol, the next vector symbol is drawn, and then the next vector is drawn. In such a case, compare the end point of the previous vector symbol drawn and the starting point of the vector symbol you are currently drawing, and if they are the same point, delete the duplicate points and create a continuous vector. It is intended to be drawn as follows. Also,
Attribute optimization is an operation of deleting any duplicately set attributes among the attributes registered in the segment buffer 10 that were set later. For example, if the color of a figure is set to "red" at a certain point, and the same content "red" is subsequently set, the latter will be deleted.

FIGS. 2 and 3 show the flow of operation of this embodiment. The operations shown in these figures are particularly related to the optimization of color attributes.

First, the color attribute optimization operation is started (
100), and the read start address of the segment buffer 10 is set in the segment buffer read control unit 20 (102). That is, segment buffer 10
It is determined from which address reading is to be started. Subsequently, a write address to the optimization buffer 24 is set (104). That is, it is set from which address in the optimization buffer 24 data should be written. Note that the segment buffer read start address in step 102 is determined according to the parameters of the command given by the graphic application or the user.

Subsequently, an initial flag is set to 1 (106). The initial flag is a flag indicating whether or not the readout from the segment buffer 10 that is about to be performed is the first time. When the initial flag is set to 1, it indicates that the reading from the segment buffer 10 is the first time, and when it is set to 0, it indicates that it is the second or subsequent time.

Next, a command is read from the segment buffer 10 (108). The command referred to here is the memory content of the segment buffer 10, and is C
It contains graphic primitives and attribute values to be stored in the RT display 18. Therefore, by referring to the contents of this command, the contents of the color, which is the attribute set in the command, becomes clear.

In the following step 110, it is determined whether the command extracted in step 108 includes segment data (data related to graphic primitives). If it is determined that the content of the optimization buffer 24 is not included, it can be assumed that the optimization process has been completed for all the graphic data written in the segment buffer 10, so the process moves to step 112, and the contents of the optimization buffer 24 are transferred to the segment buffer. It will be written into the segment buffer 10 by the write control unit 26. In addition, Figure 2
The operations shown in FIG. 3 may be executed by an optimization command given from a host computer, and in this case, the content of the determination in step 110 is usually based on the area of the segment buffer included in the optimization command. It may be determined whether the optimization process has been executed for all specified values.

[0022] If it is determined in step 110 that segment data is included, an optimization process according to a feature of the present invention is executed. That is, in this example, since the attribute "color" is optimized, first a determination 112 is performed as to whether or not it is a color command. If the result of this determination 112 is that it is a color command, a determination 114 is executed to determine whether the initial flag is 1, and if it is 1, that is, this is the first read from the segment buffer 10. If so, the color indicated by the command (current color) is set in the current color area (116). Here, the current color area is a storage area secured inside the optimization processing control section 22. After this, the initial flag is set to 0 (118), and the process moves to step 120.

In step 120, step 10
The contents of the command read in step 8 are written to the optimization buffer 24. That is, when a command is extracted from the segment buffer 10 for the first time, the extracted command is stored as is in the optimization buffer 24. Thereafter, in decision 122 it is determined whether optimization buffer 24 is full. When the extraction from the segment buffer 10 is the first time, the optimization buffer 24 is not full, so
The process moves to step 108 described above, and the next retrieval is performed.

Regarding the operation after the second extraction from the segment buffer 10, since it is determined in determination 114 that the initial flag is not 0,
Decision 124 is performed. In this determination 124,
It is determined whether the content currently stored in the color area matches the color attribute included in the command extracted this time. If they match, it is recognized that they are so-called overlapping parts, and the process returns to step 108. Therefore, only if there is no match, the optimization buffer 2
Step 120 relating to writing to 4 is executed. That is, the deleted data for the portion where the contents of the current color area match the current color is stored in the optimization buffer 24. Subsequently, a determination 122 is performed, and if it is determined that the optimization buffer 24 is not full, the process returns to step 108 and the same operation is repeated.

However, when the extraction of commands from the segment buffer 10 and the writing of data to the optimization buffer 24 are repeated a predetermined number of times, the optimization buffer 24
is in a full state, and the full condition in decision 122 is satisfied. In this case, the optimization processing control unit 22 sets the address to the segment buffer 10 in the segment buffer write control unit 26, and the segment buffer write control unit 26 writes the optimization buffer 10 using the set address as the start address. The contents of are written to the segment buffer 10 (125). After the segment buffer write control unit 26 executes the write, the optimization processing control unit 22 resets the write address to the optimization buffer (126).
, return to step 108.

As a result of such operations, if the color attribute optimization process has been completed for all commands stored in the segment buffer 10, step 112 described above is completed.
will be executed. Note that, as described above, step 112 may be executed after the optimization process has been executed for all targets on the segment buffer 10 specified by the optimization command from the host computer.

[0027] The above explanation is only about the optimization processing for color attributes, but it can be easily applied to other attributes as well. That is, the content of the determination in step 112 may be replaced with a determination regarding another attribute instead of a determination regarding the color attribute, or a determination regarding an arbitrary graphic primitive. Further, such change settings can also be realized by parameter settings of an optimization command supplied from the host computer.

Through such operations, according to this embodiment, the amount of usage of the segment buffer 10 is reduced and the time required to transfer graphic data from the segment buffer 10 to the frame buffer 14 is shortened.

For example, if you want to draw 1,000 red, broken line vectors in succession, the vector command is 20.
bytes, 8 bytes for color commands, 8 bytes for line type commands
If it is a byte, then (20+8+8
) × 1000 = 36000 bytes of usage is required, but if optimization is performed, it will be 8 + 8 + 20 × 1000 =
The usage amount of 20016 bytes is sufficient. Furthermore,
If 1,000 vectors are consecutive (i.e. 2000
If the book vectors are drawn continuously), it is sufficient to add 8+8+4+1001×8=8028 bytes after optimization. As described above, according to this embodiment, the usage amount of the segment buffer 10 required for drawing can be reduced, and the effect is more noticeable when the number of repetitions of processing with many overlapping parts is large. Become something.

Regarding the transfer time of graphic data from the segment buffer 10 to the frame buffer 14,
For example, if the vector command is 10 μs, the color command is 5 μs, and the line type command is 5 μs, if you are trying to draw 1,000 red, broken line vectors in succession, the number of times (10 + 5 + 5) × 1000 = 20000μs
was required, but after optimization it became 5+5+10×100
0=10010 μs. That is, in this example, the graphic data can be transferred in about half the time.

[0031]

[Effects of the Invention] As explained above, according to the present invention,
Since the contents stored in the segment buffer 10 are analyzed and duplicate registrations are eliminated, it is possible to display quickly and reduce the usage of the segment buffer. This results in a graphic display device that is less expensive and easier to use.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a graphic display device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the flow of the color attribute optimization operation in this embodiment, particularly the first half thereof.

FIG. 3 is a flowchart showing the flow of the color attribute optimization operation in this embodiment, especially the latter half.

FIG. 4 is a block diagram showing the configuration of a graphic display device according to a conventional example.

[Explanation of symbols]

10 Segment buffer 12 Graphic processor 14 Frame buffer 16 Video generator 18 CRT display 20 Segment buffer read control section 22 Optimization processing control section 24 Optimization buffer

Claims (1)

[Claims] Claims 1: A segment buffer that stores graphic data in logical coordinates; a graphics processor that converts graphic data from logical coordinates to physical coordinates; a frame buffer in which graphic data in physical coordinates is bit-developed; In a graphic display device comprising a video generator that generates a video signal related to graphic data, and a display device that displays a graphic on a screen according to the video signal, a segment buffer read control unit that reads the storage contents of the segment buffer; An optimization processing control unit that deletes duplicate parts included in memory contents, an optimization buffer that temporarily stores data from which duplicate parts have been deleted by the optimization processing control unit, and a segment that writes the contents of the optimization buffer to a segment buffer. 1. A graphic display device, comprising: a buffer write control unit, and configured to delete overlapping portions of graphic primitives and/or attributes of graphic data stored in a segment buffer.