JPH0310294A - Image display device - Google Patents

Abstract

PURPOSE:To speedily generate image data and to improve processability by providing a specific means deciding the image data as data in an window and a writing means writing the decided image data in image memory. CONSTITUTION:A square area writing circuit 3 compares a square area 101 sent from a display processor 1 with a display address 103 sent from a line generating circuit 2. When the display address 103 is contained in the square area 101, a writing permission signal 105 is outputted to an AND gate 4. The AND gate 4 takes the logical product of a writing signal 104 from the line generating circuit 2 and the writing permission signal 105 from the square area writing circuit 3, and outputs obtained value as a writing signal 106 to an image memory 5. In the image memory 5, the image data generated on the line generating circuit 2 is written by display color data 102 sent from the line generating circuit 2, the display address 103 and the writing signal 106 sent from the AND gate 4. Thus, image data generation is speedily performed and processability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an image display device, and more particularly to a multi-window display method for an image display device.

Prior Art Conventionally, in an image display device, coordinates of two points, a start point and an end point, are given to a straight line generation circuit to generate straight line data.
The straight line data is displayed on a display screen.

In the straight line generation circuit, when the coordinates of two points, a starting point and an ending point, are given, the closest point to the straight line connecting these two points is found, and data for that straight line is generated using those points.

Also, when performing multi-window display on the display screen, one window may overlap with another window, resulting in a window that is partially hidden by the other windows. There is.

In this case, in order to display the straight line data within that window, even if you give the straight line generation circuit the coordinates of the two points, the starting point and the ending point, the straight line generating circuit will not be able to display the straight line data that is generated from the coordinates of these two points. It was not possible to determine whether points were hidden by other windows or visible.

Therefore, in the case of multi-window display on display screen 2, where a part of one window is hidden by another window, it is not possible to use a straight line generation circuit. The image data in the window was generated under program control of the display processor and written into the image memory.

That is, in the display processor, a program generates straight line data from the coordinates of two points, the starting point and the ending point,
For each point of this straight line data, determine whether it is hidden by another window or visible,
Only the visible points were written into the image memory.

In such conventional image display devices, when performing multi-window display, the display processor generates image data by a program, and each point of the image data is either hidden by other windows or visible. I judged whether it was a point and wrote it to the image memory, so
This process requires a large amount of time and has the disadvantage that processing performance is significantly reduced.

Purpose of the Invention The present invention was made in order to eliminate the above-mentioned drawbacks of the conventional devices, and its purpose is to provide an image display device that can generate image data at high speed and improve processing performance. shall be.

Structure of the Invention An image display device according to the present invention is an image display device that displays image data generated by a straight line generation circuit on a display screen, and when multi-window display is performed on the display screen, the straight line determining means for determining whether the image data generated by the generating circuit is data within the own window that does not overlap with other windows; and storing the image data determined by the determining means as data within the own window into an image memory. It is characterized by having a writing means for writing.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, when display data 100 is given from the display processing processor to the linear generation circuit 2, the linear generation circuit 2 generates image data based on the display data 100 from the display processing processor, and converts display color data 102 into the image. A display address 103 is output to the memory 5, a display address 103 is output to the rectangular area write circuit 3 and the image memory 5, and a write signal 104 is output to the anime games 1 and 4, respectively.

The rectangular area writing circuit 3 compares the rectangular area 101 sent from the display processing processor with the display address 103 sent from the straight line generation circuit 2, and determines the display address 10.
3 is included in the rectangular area 101, a write permission signal 105 is output to the AND gate 4.

AND gate 4 is write signal 10 from straight line generation circuit 2
4 and a write enable signal 105 from the rectangular area write circuit 3
and outputs the result to the image memory 5 as a write signal 106.

Display color data 1 from the straight line generation circuit 2 is stored in the image memory 5.
02, display address 103, and write signal 106 from Antogate 4, a straight line generation circuit is generated. 2, the generated image data is written.

That is, image data is written into the image memory 5 using the display address 103 from the straight line generation circuit 2 that is determined by the rectangular area writing circuit 3 to be included in the rectangular area 101.

On the other hand, when the rectangular area writing circuit 3 determines that the rectangular area is not included in the rectangular area 101, the rectangular area writing circuit 3 does not output the write permission signal 105. The write signal 104 is suppressed, and no image data is written to the image memory 5.

Therefore, the image data generated by the straight line generation circuit 2 is written into the image memory 5 only in the rectangular area specified by the display processing processor 1, and is then sent to the display device 6 as image data 107 to be displayed.

FIG. 2 is a diagram for explaining the operation of one embodiment of the present invention. In these figures, 7 indicates the display area of the display device 6, A and B indicate windows (when multi-window display is performed), and A1 and A2 indicate the rectangular area set in the rectangular area writing circuit 3. ing.

The operation of an embodiment of the present invention will be explained using FIG. 1 and FIG. 2.

As shown in FIG. 2(a), the display processor 1 performs window switching when a part of window A is hidden under window B when performing multi-window display on the display device 6. The area of window A excluding the portion hidden by B is divided into two rectangular areas AI and A2 as shown in FIGS. 2(b) and 2(c) and set in the rectangular area writing circuit 3, respectively.

At this time, three coordinates (a, b
), (c, d), and (e, f) are also partially hidden by window B [see Figure 2 (a)], and the hidden parts are indicated by broken lines. It is shown in

First, when a rectangular area A1 is set in the rectangular area writing circuit 3, the display processing processor] writes three coordinates (a.

b), (c, d), (e, f) are given.

In the straight line generation circuit 2, three coordinates (a, b) are generated based on the display data I00 from the display processing processor.

Triangular image data represented by (c, d) and (e, f) is generated, and this image data is used as display color data 102, display address 103. It is output as a write signal 104.

On the other hand, the rectangular area writing circuit 3 determines whether the display addresses 103 sequentially output from the straight line generation circuit 2 are within the rectangular area AI, and writes only when the display address 103 determined to be within the rectangular area Al. A permission signal 105 is output to the AND gate 4.

Therefore, image data as shown in FIG. 2(b) is written in an area corresponding to the display area 7 of the image memory 5.

Further, when the rectangular area A2 is set in the rectangular area writing circuit 3, the rectangular area writing circuit 3
The display address 10 is sequentially output from the straight line generation circuit 2.
3 is within the rectangular area A2, and the write permission signal 105 is output to the AND gate 4 only when the display address 103 is determined to be within the rectangular area A2. In the area corresponding to 7, image data as shown in FIG. 2(C) is written.

Therefore, the image memory 5 stores the image shown in FIG. 2(b).

A combination of the image data shown in FIG. 2(c), that is, the image data in window A shown in FIG. 2(a), is written, and the image data is displayed on the display device 6.

In this way, when one window A is hidden by the other window B when performing multi-window display on the display device 6, the image data generated by the straight line generation circuit 2 is displayed within the rectangular areas Al and A2. The rectangular area writing circuit 3 determines whether or not the data is the data of the rectangular area At, A2.
By writing the image data determined to be within the range into the image memory 5, the straight line generation circuit 2 can be used even when part of one window A is hidden by the other window B. image data can be generated at high speed.

Therefore, unlike in the past, there is no need for the program to judge whether each point of image data is hidden by the other window B, so multi-window display can be performed at high speed, and processing performance can be improved. It is possible to direct the

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, when multi-window display is performed on a display screen, it is determined whether or not image data generated by a straight line generation circuit is hidden by another window, and By writing image data that is determined not to be
This has the advantage that image data can be generated at high speed and processing performance can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operation of the embodiment of the present invention. Explanation of symbols of main parts 1... Display processing processor] 0 2... Line generation circuit 3... Rectangular area writing circuit 4... Anime game 1, 5・・・・・・Image memory

Claims (1)

[Claims] (1) An image display device that displays image data generated by a straight line generation circuit on a display screen, and when multi-window display is performed on the display screen, the image data generated by the straight line generation circuit is and a writing means for writing image data determined by the determining means to be data within the own window into an image memory. image display device.