JPH0395592A - Cursor display control system - Google Patents

Abstract

PURPOSE:To eliminate the need of executing applications to a cursor display screen for erasure and display and to plot images without damaging a cursor for a screen by providing areas storing the AND and XOR patterns of screen images and the cursor, respectively. CONSTITUTION:When a cursor display request is issued, the screen images of a VRAM 1 are copied to the storing area 2 with the pointer of a cursor position area 5, the images of a screen musk area 3 are made AND in the VRAM 1, the images of the cursor musk area 4 are made XOR therein, and they are displayed. At the time of plotting characters and pictures in a cursor display part, plot data is written into the area 2, and then into the VRAM 1 in a way the same as above-mentioned. As for the movement of the cursor, the images plotted in the cursor display can be returned by restoring the images of the area 2 in the VRAM 1. Thus, the cursor is not disappeared nor destroyed in the middle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Field of Industrial Application) The present invention relates to a cursor display control method suitable for use when displaying a mouse cursor or the like on a graphic screen of a personal computer or the like.

(Prior Art) Conventionally, when displaying a mouse cursor or system cursor on a graphic screen of a personal computer, etc., the screen image of the part where the cursor is displayed is saved in a separate memory, and a screen mask (AN
The cursor was displayed by applying a cursor mask (XOR pattern) and a cursor mask (XOR pattern).

When drawing characters or pictures on the graphics screen, temporarily erase the cursor (restore the saved screen image)
However, after drawing, the cursor needs to be displayed again. In other words, when drawing on a graphics screen, the application program must erase/display the cursor.

(Problem to be Solved by the Invention) If characters or pictures are drawn on a graphic screen without erasing the cursor while the cursor is displayed, the cursor may disappear or be destroyed, and when the cursor is moved, There were problems such as the previously drawn part disappearing.

This invention provides a cursor display control method that does not break the cursor or disrupt the screen even when an application draws characters or pictures on a graphic screen without being aware of the 1-millimeter distance due to the presence of the cursor. The purpose is to

[Structure of the Invention] (Means for Solving the Problem) The present invention provides a method for displaying a cursor of a pointing device such as a mouse or a system cursor indicating the position of a character on a graphic screen of a personal computer, etc. After drawing characters or pictures on the cursor, we provide a cursor display control method that can correctly display the previously drawn image even if the cursor is moved, and the screen image of the part where the cursor is displayed is stored in VRAM.
In a graphic display that displays a cursor by applying a screen mask and a cursor mask to the screen area, second and third memories that store the respective mask calculation images;
When a character or picture is drawn on the cursor display area, the data is drawn in the above-mentioned memory, and a memory write control circuit is provided that writes the results of logical operations using each of the above-mentioned mask patterns onto the VRAM, and when the cursor is moved. ■VRAM the first memory image above! ．． : Characterized by restoration.

(Function) In the above configuration, there is an area A that stores the screen image of the part where the cursor is displayed, an area B that stores the screen mask of the cursor (AND pattern), and an area that stores the cursor mask (XOR pattern) of the cursor. By providing B.C, when you try to draw a character or picture in the cursor display area, it will be drawn in area A and will appear in area B.
By drawing in consideration of the C pattern, a cursor display is realized without the cursor disappearing or being destroyed, and without disturbing the screen when the cursor is moved.

As a result, when the cursor is displayed on the graphic screen, it is possible to draw the screen without destroying the cursor screen, even if the application does not erase or display the cursor.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail using the drawings. In the figure, code 1 is VRAM (video RAM)
This is a memory area in which display data to be displayed on a graphic screen is stored. When supporting color, multiple planes of memory with the same capacity exist. code 2
is the storage area, and the VRAM where the cursor is displayed
This is an area to save images. When supporting color, multiple planes exist, similar to VRAM. Reference numeral 3 is a screen mask area, which is an area for storing a cursor screen mask (AND pattern data). When supporting color, multiple planes exist, similar to VRAM. Reference numeral 4 is a cursor mask area, which is an area for storing a full cursor mask (XOR pattern). When supporting color, multiple brains exist, similar to VRAM. Reference numeral 5 is a cursor position area, which is an area for storing the position where the cursor is displayed. Reference numeral 6 is a size area, which is an area for storing the size of the cursor. Reference numeral 7 indicates a control unit including a CPU and a display processor that controls drawing and display.

Hereinafter, the operation of the embodiment of the present invention will be explained in detail. When displaying a cursor, first import the cursor size into the size area 6, save area 2, and screen mask area 4.
determine the size of Next, the screen mask and cursor mask are taken into areas 3 and 4, respectively, and the cursor position is stored in cursor position area 5.

When a cursor display request occurs, the cursor position area 5
The cursor is displayed by copying the screen image of VRAMI to the storage area 2 from the pointer indicated by , ANDLing the image of screen mask area 3 to VRAMI, and performing 6 X O R (exelusive OR) of the image of cursor mask area 4 to VRAMI. be done.

Here, when attempting to draw characters or pictures in the cursor display area, drawing data is written into the storage area 2.

Furthermore, on the VRAMI, the drawing data is ANDed with the screen mask area 3, XORLed with the cursor mask area 4, and then written to the VRAMI.

To move the cursor, move the image in storage area 2 to V
By restoring to RAMI, the image drawn on the cursor display can be restored.

In this way, there is an area A that stores the screen image of the part where the cursor is displayed, and a screen mask (AN) for the cursor.
By providing area B that stores the cursor mask (XOR pattern) and area C that stores the cursor mask (XOR pattern), when you try to draw characters or pictures in the cursor display area, it will be drawn in area A and displayed on the screen. has area B. To achieve a cursor display in which the cursor does not disappear or be destroyed, and the screen is not disturbed when the cursor is moved, by drawing in consideration of the C pattern.

[Effects of the Invention] As explained above, according to the present invention, when a cursor is displayed on a graphic screen, it is possible to draw the screen without damaging the cursor or the screen even if the application does not erase or display the cursor. becomes possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. 1...VRAM, 2...Save area, 3...Screen mask area, 4...Cursor mask area, 5...
- Force-sol position area, 6... size area, 6... control section.

Claims (1)

[Scope of Claims] A graphic display in which a screen image of a portion where a cursor is displayed is stored in a first memory separate from VRAM, and a screen mask and a cursor mask are applied to the screen area to display a cursor. 2nd and 3rd memories that store mask calculation images, and when characters or pictures are drawn on the cursor display area,
A memory write control circuit is provided for drawing the data in the memory and writing the results of logical operations using each of the mask patterns on the VRAM, and restoring the first memory image to the VRAM when the cursor is moved. A cursor display control method featuring: