JPS62247475A - Graphic display method - Google Patents

Abstract

PURPOSE:To easily obtain an optional shape at a high speed just by adding a view port area memory by synthesizing the display data causing a clipping operation and the data showing the area prescribed the view port area memory and writing this synthetic data to a display refresh memory. CONSTITUTION:The inside and outside area values of a view port area memory A14 are set at '1' and '0' respectively and stored previously in a view port area memory A13 in the form of the information equivalent to the shape of the port A14. While a view point area memory B15 stores the information equivalent to the shape of a view port B16 in the same way. In such a way, a picture is obtained by clipping the synthetic display data of both display data A and B via both view ports 14 and 16 having a synthetic shape of both view port area memories A and B and displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a graphic display method, and particularly to a graphic display method suitable for clipping operations.

[Conventional technology]

Clipping operations in conventional graphic processing require a clipping algorithm to be executed by a microprogram in software or hardware in order to determine whether or not a graphic is within the viewport area. Shape clipping processing is complicated and difficult to process at high speed, and there are few prospects for realizing it.

This type of system is described, for example, in ``Graphic processing engineering using computer displays'' Nikkan Kogyo Shimbun series (1981).

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, the clipping processing algorithm is executed by a program including a microprogram.

For this purpose, dedicated hardware is also added, which leads to the complexity of the hardware, and there is a problem in that high speed cannot be expected due to program processing, resulting in a decrease in performance. Also.

Since the processing involved in both hardware and software is complex, the amount of development man-hours required increases.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to solve the above-mentioned problems in conventional graphic display methods, and to create graphics that can quickly and easily realize arbitrary shapes in clipping operations. The objective is to provide a display method.

[Means for solving problems]

The above-mentioned object of the present invention is to provide a graphics display device using a rusk scan type display, which is equipped with a display refresh memory that stores display data, and which includes a plurality of viewport area memories that store viewport areas of arbitrary shapes. This is achieved by a graphical display method characterized in that display data accompanied by a clipping operation and data indicating an area defined by the viewport area memory are combined and written to the display refresh memory. be done.

[Operation] The present invention eliminates the coordinate calculation process performed by software or hardware in conventional clipping operations, and provides multiple viewport area memories equivalent to display refresh memories.
Viewport information of arbitrary different shapes is written in each of the viewport area memories in advance.

Here, the area "1"' is set as the viewport area, and the multiple viewport area memories mentioned above store individual viewport areas, and when read out, a viewport with a composite shape is also formed. can.

When writing display data to display refresh memory,
By simultaneously reading the contents of the corresponding viewport area memory and writing only the relevant display data whose read value is ``1'' to the display refresh memory,
Clipping operations using multiple viewport areas can be easily and quickly achieved.

In other words, by providing multiple viewport area memories that are equivalent to display refresh memories, multiple processing of different viewport areas becomes possible, and the contents of the viewport area memories themselves are dot-compatible and can be stored within the area. Since it is information on whether or not the image is displayed, a clipped figure is obtained by taking an AND condition between the display data and the contents of the viewport area memory.

Therefore, clipping operations can be achieved by simply adding memory, which eliminates the need for complicated hardware or software.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 2 is a diagram showing an overview of the present invention. Here, the display data is stored in two display buffer memories, and the viewport area memory is stored in two of the multiple display buffer memories.
This diagram illustrates the configuration of a single sheet.

That is, in the figure, 11 is a display buffer memory (A) that stores display data (A), and 12 is a display buffer memory (A) that stores display data (A).
13 is a viewport area memory (A) for setting the viewport (A) 14, 15 is a viewport area memory (B) for setting the viewport (B) 16. ), 17 indicates a display refresh memory. Each of the above-mentioned memories has a full dot configuration and has the same capacity.

In the viewport area memory (A) 13, in advance, as information corresponding to the shape of the viewport (A) 14, the value of the area within the viewport (A) 14 is set to 1'', and the value of the area within the viewport (A) 14 is set to 1'', (A) Value of area outside 14 is “O”
Similarly, the viewport area memory (B) 15 also stores information corresponding to the shape of the viewport (B) 16.

Here, when writing the display data obtained by combining the display data (A) and the display data (B) into the display refresh memory 17, at the same time, the viewport area memory (
A) 13 and the contents of the viewport area memory (B) 15 are combined and read, and the dots of the display data to be written are displayed in the viewport (A) 14 and viewport (B) 16. By determining whether or not the area is within the combined area and writing the result to the display refresh memory 17, the display data can be changed to a combined viewport of the viewport (A) 14 and viewport (B) 16. This means that it was clipped.

FIG. 1 is a control block diagram within the display device.

In the figure, symbols 11 to 13, 15, and 17 indicate the same components as shown in FIG.
TL) is shown. Further, 22 to 28, 30.31 are signal lines, 29 is an AND gate, 32 is a parallel/serial conversion circuit, and 33 is a display.

The operation of this embodiment is such that the control circuit 21 controls the data line 22 . The data is written to the viewport area memory (A) 13 or the viewport area memory (B) 15 via the address line 23 and write control lines 24,25.

In addition, the display data is display data (A) and display data (
When displaying the composite data of B), the first display data (A) is displayed on the data line 22. The address line 23 and write control line 26 allow the display buffer memory (A) to
Similarly, the second display data (B) is also written to data line 22.11. The address line 23 and write control line 27 control the display buffer memory (B) 12.
written to.

When displaying, the viewport area memory (A) 1 is
3. Viewport area memory (B) 15° Display buffer memory (A) 11 and display buffer memory (B)
12 contents are read simultaneously.

At this time, the viewport area memory (A) 13 and
The output of the viewport area memory CB) 15 is wired-ORed and output as combined viewport area information, and the display data is also output to the display buffer memory (A) 11 and the display buffer memory (B) 12. The output of is wired-ORed and becomes the synthesized display data, and the value of this display data is subjected to an AND condition using the above-mentioned synthesized viewport area information and the AND gate 29, and is input to the display refresh memory 17. , the display refresh memory 17 by the write control line 30.
written to.

The display refresh memory 17 is sequentially read out via a read control line 31, and the read values are displayed on a raster scan display 33 via a parallel/serial conversion circuit 32.

As mentioned above, display data (A) and display data (B)
The synthesized display data of the viewport area memory (A) and the viewport area memory (B) can display a figure clipped in the viewport of the synthesized shape.

In this way, by having the viewport area memory (A) and the viewport area memory (B) coexist, clipping operations can be performed by overlapping different arbitrary shapes, and the viewport area memory (A) and viewport area memory (B) can be used together. The effect is that clipping operations can be easily and quickly realized simply by adding memory.

〔Effect of the invention〕

As described above, according to the present invention, in a graphic display device that uses a raster scan type display and is equipped with a display refresh memory that stores display data, a viewport area that stores a viewport area of an arbitrary shape. A plurality of memories are provided, and the display data that involves clipping operations and the data indicating the area defined by the viewport area memory are combined and written to the display refresh memory, so that the view By simply adding a port area memory, there is a remarkable effect in that a graphic display method that can quickly and easily realize an arbitrary shape in a clipping operation can be realized.

[Brief explanation of drawings]

FIG. 1 is a control block diagram within the display device, and FIG. 2 is a diagram showing an overview of this system. 11.12: Display buffer memory, 13, 15: Viewport area memory, 14, 16: Viewport,
17: Display refresh memory, 21: Control circuit, 2
2: Data line, 23 Near address line, 24, 25
゜26.27,30: Write control line, 28,31:
Read control line. 29: AND gate, 32: Parallel/serial conversion circuit, 1st
Figure 2

Claims (1)

[Claims] 1. In a graphics display device using a raster scan display and equipped with a display refresh memory that stores display data, a plurality of viewport area memories that store viewport areas of arbitrary shapes are provided,
A graphic display method characterized in that display data accompanied by a clipping operation and data indicating an area defined by the viewport area memory are combined and written to the display refresh memory.