JPS6232568A - Graphic processor - Google Patents

Abstract

PURPOSE:To avoid the generation, transmission, and execution of a useless command and thereby to improve the speed of graphic processing by providing a command-to-draw generating part that transmits to a graphic generating part a command-to-draw which includes only one among device coordinates in case they consecutively coincide with each other. CONSTITUTION:The command-to-draw generating part 11 generates the command-to-draw based on the designation of the kind of the drawing and that of the coordinate received from the keyboard via a keyboard interface part 14, and transmits it to the graphic generating part 12. The part 12 generates the graphic based on the said command from the part 11, and writes it in the screen inside a frame memory 2. A display control part 13, according to a command received from the keyboard 5 via the keyboard interface part 14, displays a picture on the said screen in the frame memory 2 on a CRT 6 via the CRT interface part 4. Also, the part 13, executes the exchange between the screen in the frame memory 2 and that in a picture file 3 and a scrolling pictures in accordance with a command from the keyboard 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to graphics processing devices used in computer graphics systems.

2. Description of the Related Art Computer graphics systems that perform processing such as the creation of graphics and 2wR collections in an interactive manner with a computer are becoming popular.

One type of graphic processing device used in such a computer graphics system is one that performs graphic processing while converting the coordinates of graphic elements specified by the user into coordinates on the device.

In other words, the user sets the coordinates of the upper left corner and the lower right corner of the screen to be drawn, for example, (0, 0), respectively.
(N, M), and then input the specified coordinates on the screen to the graphics processing device.The graphics processing device stores the input coordinates in the screen memory and image file. This is a format in which graphic processing is performed by automatically converting to coordinates on the device determined by units or sizes such as pixels.

Problems to be Solved by the Invention In the above-mentioned graphic processing device with automatic coordinate conversion, when a user instructs to draw a minute pattern that exceeds the resolution within the screen of the device, degeneracy occurs for multiple input coordinates. A meaningless drawing command consisting of the same coordinate values on the device and a command to connect these same coordinate values with a line segment is created and executed.

Creating and executing such meaningless drawing commands reduces the processing speed of the graphics processing device.

Means for Solving the Constituent Problems of the Invention The graphic processing device of the present invention, which solves the problems of the prior art described above, processes only one of the converted coordinates on the device when they match consecutively. It includes a drawing command creation section that passes the included drawing commands to the figure generation section, and is configured to avoid the creation and execution of meaningless commands.

Hereinafter, the operation of the present invention will be explained in detail together with examples.

Embodiment FIG. 1 is a functional block diagram showing the configuration of a computer graphics system including a graphic processing device according to an embodiment of the present invention.

This computer graphics system includes a graphic processing device 1. Frame memory 29 image file 3. CRT interface section 4. It is equipped with a keyboard 5 and a CRT 6.

The graphic processing device 1 includes a drawing command creation section 11.degree. graphic generation section 121, a display control section 13, and a keyboard interface section 14.

The drawing command creation section 11 creates a drawing command based on the designation of the drawing type and the designation of the coordinates received from the keyboard via the keyboard interface section 14, and passes this to the graphic generation section 12. The figure generating section 12 generates a figure based on the drawing command received from the drawing command generating section 11, and writes this on the screen in the frame memory 2.

The display control section 13 has a keyboard interface section 14.
In accordance with a display command received from the keyboard 5 via the CRT interface section 4, the screen in the frame memory 2 is displayed on the CRT 6 via the CRT interface section 4. In addition, the display control unit 1
3 performs swapping and scrolling of the screen in the frame memory 2 and the screen in the image file 3 according to commands from the keyboard 5.

The operation of the drawing command creation section 11 when the user instructs the creation of a figure by connecting a plurality of coordinate points (polyline drawing) from the keyboard 5 will be explained with reference to the flowchart in FIG.

When the drawing command generation unit 11 receives a command to draw a polyline from the keyboard 5, in a first step 21, it waits for the input of the coordinates of the first vertex, and upon receiving the input, proceeds to the next step 22.

In step 22, the drawing command creation unit 11 calculates the coordinates used by the user (hereinafter referred to as "world coordinates").
The coordinates of the first vertex inputted in are converted into coordinates on the device (hereinafter referred to as " (referred to as "device coordinates").

In the next step 23, the drawing command creation unit 11 determines whether the new device coordinates converted from the newly input world coordinates match the previous device coordinates converted from the world coordinates input immediately before. judge. The device coordinates immediately before the first input world coordinates are set to coordinates outside the device screen, so
The determination result is no match, and the process proceeds to step 24.

The drawing command creation unit 11 saves the latest device coordinates as drawing data, and in the next step 25 updates the immediately previous device coordinates with the latest device coordinates.

The drawing command creation unit 11 determines whether all world coordinates have been input from the keyboard 5. This coordinate input ends when a drawing execution command issued from the keyboard 5 is detected after all world coordinates have been input, or when the number of world coordinates input becomes equal to the number of vertices specified when commanding polyline drawing. Detected based on factors such as

If the input of world coordinates has not been completed for all vertices, the drawing command creation unit 11 returns to step 21, waits for input of the world coordinates of the next vertex, and then repeats the operations from step 22 to step 26.

If the drawing command creation unit 11 detects in step 23 that the new device coordinates match the immediately previous device coordinates, it saves the new device coordinates in step 24 and saves the immediately previous device coordinates in step 25. The process skips updating the device coordinates and immediately proceeds to step 26.

When the drawing command generation unit 11 determines in step 26 that the input of world coordinates is completed, the process proceeds to step 27, passes the polyline drawing command along with all saved device coordinates to the figure generation unit 12, and then proceeds to the next step 28. After setting the previous device coordinate value to a coordinate value outside the screen, based on a polyline drawing command from the keyboard 5 (the drawing command creation process is finished).

The figure generator 12, which has received the drawing data from the draw command generator 11, writes into the frame memory 2 a polyline figure that connects the received device coordinates.

FIG. 3 is a conceptual diagram showing an example of the above-mentioned polyline drawing command creation process.

Following the polyline drawing command, the world coordinates A, B, C, of vertices to be connected by line segments are input from the keyboard 5.
D, E and F are input sequentially.

In this case, since the interval between the device coordinates corresponding to the adjacent world coordinates is less than the minimum pixel size, the drawing command creation unit 11 converts the world coordinates into the corresponding device coordinates a and a in step 22 of FIG. , b, b, c,
Convert to c.

At the same time, the drawing command creation unit 11 detects in step 23 of FIG. Skip update, a
A drawing command containing only three device coordinates, , b, and c as drawing data is created and passed to the graphic generation section 12 .

As shown in FIG. 3, a line segment connecting pixels at device coordinates a, b, and c is displayed on the CRT screen. All device coordinates a, a, b, b converted from world coordinates as in the conventional method.

The figures that are created and displayed when c and c are passed to the figure generator 12 are exactly the same. Therefore, in the graphic processing apparatus of the present invention, unnecessary creation, transfer, and execution of drawing data can be avoided.

As illustrated in Figure 4, the world coordinates A of six vertices
The same applies when inputting -F to draw a polygon and the corresponding device coordinates are the same.

The case where two device coordinates match has been illustrated above, but if three or more device coordinates match consecutively, only one of them is saved as drawing data.

In addition, although we have illustrated the case of drawing in which adjacent world coordinates are connected by a line segment, when drawing a rectangle by specifying the world coordinates of two opposing corners, when the device coordinates of the two corresponding corners match, The effects of the apparatus of the present invention are also exhibited when the device coordinates of the two corresponding ends match when a diamond is removed by specifying the top end and right end.

Furthermore, in the drawing command generation section, after all device coordinates are set, they are passed to the figure generation section in one go. It can also be configured to be passed to

Effects of the Invention As explained in detail above, the graphic processing device of the present invention has the following effects:
Since it is equipped with a drawing command creation section that passes a drawing command containing only one of them to the figure generation section when the device coordinates match consecutively, it eliminates the creation of useless commands.
Transfer and execution are avoided, and the graphic processing speed is improved.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the configuration of a computer graphics system including a graphics processing device according to an embodiment of the present invention, and FIG. A flowchart for explaining an example, and FIGS. 3 and 4 are conceptual diagrams for explaining the present invention in detail. 1...Graphic processing device, 11...Drawing command generation unit, 1
2...Graphic generator, 13...Display control unit. 14...Keyboard interface section.

Claims (1)

[Claims] In a graphic processing device that performs graphic processing while converting the coordinates of a graphic element specified by a user into coordinates on the device, if the converted coordinates on the device match continuously, 1. A graphics processing device comprising: a drawing command creation section that passes a drawing command containing only one of the following to a graphics generation section.