JPS61109094A - Cursor display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cursor display device, and more particularly to a cursor display device for displaying a cursor on a raster scan display device.

BACKGROUND OF THE INVENTION Raster scan display devices have traditionally been used as man-machine interfaces for graphic processing systems. This raster scan display device has multiple frames (e.g. several frames to several + frames).
Some have an image memory of 1 frame, and others have an image memory of 1 frame.

When displaying a cursor on a display device having multiple frames of image memory, for example, graphic image data is stored in a first frame memory, and a position specified by a position input device such as a trackball is stored in a second frame memory. Stores the cursor image data to direct. 1st
and the second frame memory, and generates composite image data in which a cursor image is superimposed on a graphic image by calculating both image data.

A display device having a plurality of frames of image memory as described above can make the cursor on the screen follow the movement of the position input device at high speed, but is very expensive. For this reason, low-cost image processing systems use display devices having one frame of image memory.

A display device having one frame of image memory is
When displaying a cursor, graphic image data is stored in the image memory. When a position is specified by the position input device, first, the graphic image data of a predetermined area corresponding to the cursor display in the image memory is saved to the -H work area, etc., and then the generated cursor image data and the above-mentioned graphic image data are calculated. The composite image data is written in the predetermined area of the image memory, and the graphic image data that was saved when the cursor was moved or erased is polished back to the predetermined area of the image memory.

Problems to be Solved by the Invention The above-mentioned image memory cursor replacement process is performed during the vertical blanking period of the display device. but,
In a display device having one frame of image memory, in order to display a cursor, it is necessary to save graphic image data, write 1 composite image data, and write back the saved graphic image data, and the time required for cursor display is multiple times. This is at least three times as large as a frame image memory. Therefore, a display device having one frame of image memory requires several vertical blanking periods for one cursor rewriting process in the image memory, has a slow cursor display speed, and is sensitive to positional manual movements such as trackballs. There were problems such as not being able to follow up quickly and the cursor flickering.

Therefore, the present invention provides the following features: a cursor memory, an address generation means, an input means, and a first and second writing means.
It is an object of the present invention to provide a cursor display device that solves the above problems.

Means for Solving the Problems FIG. 1 shows the overall structure of the present invention. In the figure, graphic image data is transferred from an image memory 7 to a cursor memory 3 which can be accessed at high speed.

The address generating means generates cursor display unit addresses for the image memory 7 and the cursor memory 3 from the position data from the position input device 4. Further, the calculation means B generates cursor image data from the position data, and generates composite image data from this cursor image data and the graphic image data from the cursor memory. This synthesis! ! ii
The image data is written to the cursor display section address of the image memory 7 by the tenth writing means C. The second 8-input means writes the graphic image data read from the cursor display section address of the cursor memory 3 to the cursor display section address of the image memory 7 in response to changes in position data.

Operation In the present invention, the graphic image data in the image memory is transferred to the cursor memory 3 which can be accessed at high speed,
graphic image data for generating composite image data;
Graphic image data for erasing the cursor is read from the cursor memory 3. Further, this access to the cursor memory 3 is also performed during periods other than the vertical blanking period of the display device 5.

Embodiment FIG. 2 shows a block diagram of an embodiment of a system to which the present invention is applied. In the figure, a cursor display device 1 is composed of a processor 2 and a cursor memory 3, and displays a cursor on the display screen of a display device 5 in accordance with position data supplied from a position input device 4. The position input device M4 is, for example, in the X-axis direction of the rotary ball.

It is a device such as a trackball, a mouse, or a digitizer that detects each rotation in the Y-axis direction and outputs position data, and this position data is supplied to the processor 2 of the cursor display device 1.

The display device 5 includes a control processor 6 and an image memory 7.
, a video signal generation device 8, and a CRT 9, the control processor 6 stores one screen worth of graphic image data supplied from a host computer (not shown) in one frame of image memory 7, and also stores the graphic image data for one frame in the image memory 7. 7
The graphic image data is sequentially read out and supplied to the video generation device 8. The video signal generation device 8 generates a video signal from the synchronization signal and the graphic image data, supplies it to the CRT 9, and causes the CRT 9 to display an image. A vertical synchronization signal output from the video signal generation device 8 is supplied to the processor 2 of the cursor display device 1. Further, the cursor memory 3 has the same storage capacity as the image memory 7 for one frame, and can be accessed at high speed.

Next, the processing executed by the processor 2 will be explained using the flowchart shown in FIG. Processor 2 is CRT9
Selecting a menu displayed on the screen or specifying an area on the screen, etc.
If cursor display is requested, execution of the process shown in the third diagram is started.

First, the processor 2 sequentially writes the graphic image data read out from the image memory 7 of the display device 5 into the cursor memory 3 to perform an entire copy (step 20). Next, the position data in the X-axis direction and Y-axis direction supplied from the position input device 4 is taken in (step 21
). The processor 2 generates an address for the cursor display area in the image memory 7 from the captured position data and stores it in a predetermined storage area (hereinafter this storage area will be referred to as the "first address register") (step 22), and the above-mentioned Generates the address of the cursor display part in the cursor memory 3 from the position data and stores it in another predetermined storage area (hereinafter this storage area will be referred to as the "second address register").
Step 23).

By the way, one screen as shown in Figure 4 is 1024 degrees horizontally and 1 vertically.
The image data represented by 024 dots is stored in cursor memory 3.
and is stored in the image memory 7, and the memory 3.7 is 1
It stores 2 bytes (-16 dots) of data at an address, and assumes that the starting addresses of the cursor memory 3 and the image memory 7 are m, .no. Here, when position data specifying point P in FIG. 4 is supplied, the first
The address register contains a group of addresses (for example, n+Q, n+Q+1) that indicates the cursor display crab surrounded by broken lines to form the cross-shaped cursor 10 (the first address of this crab is Q).゜n＋Q
+ 2, n+ Q + 64, n10
+ 65, n+Q+66, n+Q+ 128
．． ...) are stored, and similarly, the second address register contains a group of addresses (m+Q, m+Q+1. m+2. i+) that specify the cursor display area (■)
Q+64. -=-) is stored.

The pattern for displaying the cursor 10 after generation of the addresses of the image memory 7 and the cursor memory 3, that is, the first. Cursor image data corresponding to each address stored in the second address register is generated; Second
The data is stored in a storage area different from the address register (hereinafter, this storage area will be referred to as "data register J") (step 24). Thereafter, the cursor memory 3 is accessed at high speed using the address stored in the second address register, and the graphic image data in the part (2) surrounded by the broken line in FIG. 4 is read out (step 25). The data is subjected to an OR operation (or exclusive OR operation) with the crab image data from the data register corresponding to K, and the result of the operation, that is, the composite image data, is sequentially stored in the data register (
Step 26).

Thereafter, the processor 2 determines from the vertical synchronization signal supplied from the video signal generator [8] whether or not it is a vertical blanking period in which the image memory 7 is not being accessed by the control processor 6 (step 27). If it is a blanking period, the process moves to step 28. This step 2
8, the addresses of the image memory 7 and the composite image data are sequentially retrieved from the first address register and the data register, respectively, and the image memory 7 is accessed using these addresses, and the portion (3) of the image memory 7 shown in the fourth figure is read. Write composite image data.

After writing, the position data supplied from the position input device 4 is taken in (step 29), and this position data is compared with the previously taken position data (step 30), and when they are the same, the process moves to step 29 and .3
Repeat 0. Of course, during this time, the control processor 6 sequentially reads the image data from the image memory 7, and the image including the cursor is displayed on the CRT 9.

If the position data changes from the previous position data and cursor movement is instructed, the process moves to step 31, where the cursor memory 3 is accessed at high speed according to the address of the second address register, and the graphic image of the part Data is retrieved and stored in the data register. Next, it is determined whether or not it is a vertical blanking period (step 32), and if it is a vertical blanking period, the process moves to step 33. In step 33, the image memory 7 is input from each of the first address register and data register.
The addresses and the graphic image data are respectively taken out sequentially, the image memory 7 is accessed using these addresses, and the graphic image data is written back into the section of the image memory 7.

Thereafter, the process moves to step 22 and the above process is repeatedly executed.

As described above, a memory having a storage capacity of one frame and capable of high-speed access is used as the cursor memory 3, and steps 22 to 26 and 31 are performed during steps 22 to 26 and 31 when the image memory 7 is accessed by the control processor 7. It can be executed during the period. Therefore, the cursor rewriting process in the image memory 7 can be executed within one or two vertical blanking periods, the cursor display speed is fast, and the cursor display can quickly follow the movement of the position input device. The cursor on the screen does not flicker.

Note that if it is determined in step 32 that it is not the vertical blanking period, substantially the same processing as in steps 22 to 26 is performed, and the newly generated image memory address and cursor memory address are respectively transferred to the third. The data is stored in each of the fourth address registers, and the graphic data and composite image data are stored in the second data register.

After this, when the vertical planking period begins, step 33
Execute 3rd. the fourth address register and the second
The contents of each data register in the first. Transfer to the second address register and data register respectively・Step 2
7, and is not limited to the above embodiment.

Note that although the device of the present invention is suitable for application to a display device having an image memory of one frame, it may be applied to a display device having an image memory of a plurality of frames, and is not limited to the above embodiment.

Effects of the Invention As described above, the cursor display device according to the present invention includes a cursor memory, address generation means, and calculation means.

Since the first and second writing means are used, the access time of the cursor memory is shortened, and the processing for obtaining composite image data and the processing for accessing the cursor memory can be performed during the vertical blanking period of the display device. The cursor display speed is fast, the cursor display can follow the movement of the position input device at high speed, and the cursor display on the screen does not flicker.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the overall configuration of the present invention, FIG. 2 is a block diagram of an embodiment of the device of the present invention, and FIG. 3 is a flowchart of an embodiment of the processing executed by the processor shown in FIG.
FIG. 4 is a diagram for explaining the CRT screen and memory addresses. DESCRIPTION OF SYMBOLS 1... Cursor display device, 2... Processor, 3.
...Cursor memory, 4...Position input device, 5...
・Display device, 7...image memory, 9...C
RT. 10...Cursor, 20-33...Step, A.
. . . address generation means, B . . . arithmetic means, C . . . first writing means, D . . . second writing means.

Claims (1)

[Claims] A cursor display device that displays a cursor on a raster scan display device according to position data supplied from a position input device, and is a high-speed cursor display device that transfers and stores one frame of graphic image data from the image memory of the display device. an accessible cursor memory, an address generating means for generating cursor display part addresses of the image memory and the cursor memory corresponding to the position data, and generating cursor image data corresponding to the position data and generating the cursor image. arithmetic means for generating composite image data by performing a logical operation on the data and graphic image data read from the cursor memory at a cursor display unit address; a first writing means for writing to the address; and a second writing means for writing the graphic image data read from the cursor memory at the cursor display address to the cursor display address of the image memory in response to a change in the position data. What is claimed is: 1. A cursor display device comprising: a cursor display device;