JPS62100786A - Multiwindow display system - 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 Industrial Application] The present invention relates to a multi-window display method, particularly to a method for developing each window data into a bitmap.

[Conventional technology]

In multi-window display, different small screens are displayed on a part of the screen (display surface) of a CRT display, for example, and the number of small screens (windows) may be one or multiple. In the latter case, the multiple windows are not necessarily separated from each other and may overlap,
In an overlapping area, only one is displayed, and the other is not displayed because it is hidden behind the other and cannot be seen.

Conventionally, when multiple windows overlap each other, the upper window is displayed and the lower window is not displayed.The firmware calculates the positional relationship of each window, and in the overlapping area, the window is displayed in priority order. The system uses a method in which the data is divided into invisible parts (those with the highest priority are not visible), and the firmware writes only the data of the visible parts to the bitmap.

[Problem that the invention sought to solve]

However, this method has the drawback that complicated processing is required, such as managing each window, calculating positional relationships, and developing character patterns up to (or from) the middle.

To explain it with drawings, FIG. 2 shows an outline of the display system, where IO is a system bus connected to a central processing unit (CPU), etc. not shown, 12 is a write control circuit, 14 is a bitmap memory, and 16 is a CRT display. It is. The bitmap memory 14 is connected to the display 16
The image data to be displayed on the screen (display surface) of the CRT is stored, and is read out in synchronization with the scanning of the CRT to supply a video signal. Image data to bitmap memory 14 is sent through system bus 10 and written to memory 14 by write control circuit 12. If the screen is text, the character code is stored in a code buffer (not shown but connected to the system bus 10), read out, and rearranged into character pattern data by a character generator (CG). , the character pattern data is written to a predetermined address of the bitmap memory 14 by the write control circuit 12. The address may be stored in correspondence with each character code in the code buffer, or the display screen may be divided into n characters horizontally and m lines vertically, and the character code in the code buffer is stored according to this character code. They are stored in order (space codes are used where there are no characters),
Addressing may also be done by sequentially reading the code buffer. In the case of a graphic pattern, a memory (not shown but also connected to the system bus 10) is provided to store the pattern, and the memory is read and written to the bitmap memory 14.

The same goes for window screen data; if it's a character screen, it's stored in the character code buffer, and if it's a graphic screen, it's stored in the pattern memory. Normally, this data is for one screen or more, and only a part of it (the part displayed in the window) is written to the bitmap memory 14, and if there is overlap in multi-windows, the above-mentioned judgment is made. , only visible data is written.

To explain in FIG. 3, 20 is the screen of the display 16, 2
2.24 is a multi-window among them, and these windows partially overlap, and window 22 has a higher priority, so data in the overlapping part of window 24 is not displayed. Store screen data like this in bitmap memory 1.
To expand to 4, write to the memory 14 in the raster direction, monitor the write address, and first write the data of the original screen (the screen that is the bank of the multi-window) and set the write address. (When the starting point X+, Y+ of the window 22 is reached, the data is switched to that of the window 22, and when the X coordinate reaches the end point X2.Y2 of the window, the data is switched again to the data of the original screen, and the above process is repeated. The write address will eventually become the start end of window 24, X:l, Y3, but since window 24 has a lower priority, the write data will not be changed as the screen data of window 22, and
The coordinates become X2 and the screen data of window 24,
When the X coordinate reaches X4, the data is switched to the original screen data and the above process is repeated. When the write address exceeds Y2, the write data consists of original screen data and window 24 data, and when it exceeds Y4, only the original screen data is written.

As described above, writing multi-window screen data to the bitmap memory is troublesome as it requires address comparison and priority order determination. Furthermore, in the case of a character screen, one character is represented by 7 x 14 or 22 x 22 (dots or bits), and has a certain width both vertically and horizontally, but if the window address is not an integral multiple of this width, The process starts from , and ends midway through, making the process cumbersome.

The present invention is an attempt to improve the above-mentioned problems and to make it possible to easily write data for a multi-window screen into a bitmap memory, thereby reducing the load on firmware.

[Means for solving the problem] The present invention writes image data of a multi-window screen in a bitmap memory, reads out the memory, and displays the image data on a display screen. It is characterized in that it writes to the region of the window in the bitmap memory, and in the overlapping area of the windows, the image data of the window with higher priority is left and the data of the window with lower priority is erased.

[Effect]

When writing the image data of the multi-window screen to the bitmap memory, starting with the window with the lowest priority,
In the window overlap area, low-priority image data is erased by high-priority image data written later or by clearing processing performed before writing, and in the window overlap area, the high-priority window is visible, and the low-priority window is erased. You can easily get a multi-window screen hidden underneath.

〔Example〕

To explain with drawings, in Figure 1 (al) 20 is the aforementioned display screen, 22, 24, and 26 are multi-windows,
As for the priority, 22 is the highest, 24 is medium, and 26 is the lowest. In order to write such multi-screen data to the bitmap memory 14 (represented by the screen 20 here), the present invention first writes the data of the window 26 with the lowest priority as shown in FIG. 1(b). Write to memory 14. In this case, it is assumed that the data of the original screen has already been written to the memory 14, and the data of the window 26 will be overwritten on the data of the original screen (since it is a memory, overwriting will change the stored data to the latest data. updated).

Next, as shown in FIG. 1(C), the area 24a of the window 24 with the second priority is cleared (for example, all 0s are written to that area of the memory 14), and then the first
As shown in Figure (d), the data of the window 24 is written into the area 24a. Note that to clear the area 24a,
This is to eliminate residual data. That is, when the original screen 20 is a graphic screen, there is image data on the entire surface (all bits), but on a character screen, the spaces between characters and lines are blank, so if you simply overwrite the data in the window 24, which is a character screen, There is a risk that the graphic image on the screen 20 will appear between the lines. If all bits are cleared, there will be no such fear. Note that if the window 26 is also a text screen, it is better to clear that part once before writing.

Next, the image data of window 22, which has the highest priority, is written. This is also shown in window 2 as shown in Figure 1(e).
Then, the image data of the window 22 is written in the area 22a as shown in FIG. 1 <r>.

In this way, the image data of the relevant window is simply written to the bitmap memory starting from the one with the lowest priority, without comparing addresses or determining the priority order. those with high priority) are visible, and those on the lower side (low priority)
can display a hidden multi-window screen. Furthermore, even if the window is a character screen, writing is performed only within the start and end coordinates (XIYl, X2Y2, etc.), thereby easily displaying a screen that starts and ends in the middle of a character.

Various methods can be used to write the image data of a window 22, for example, into the bitmap memory 14.
Assuming that the size is the same as that of , the addresses of these memories are generated using a rask scan method, the memory 22M is read out, the memory 14 is read out (inoperable) or written, and the write control circuit 12 is provided with a clip control function to set the addresses. The read data of the memory 22M is not given to the memory 14 until the address reaches X+, Y+, and the memory 14 is kept continuous or inactive. When the address reaches X+, Y+, the memory 22M
A method is adopted in which the read data of M is given to the memory 14, the memory 14 is put into the write mode, and writing is performed, and such processing is performed in the range of XIY1, X2Y2. When clearing the window area, the write control circuit 12 prepares data O and sets the address to X + Y.
＋.

The data O is supplied to the memory 14 in the range of X 2 Y 2 and the memory 14 is placed in write mode.

The address is window address X + Y + ””
It is also possible to generate only X2Y2, etc., but in this case a special address generation circuit is required. In this respect, the above-mentioned rask scan method is suitable because it can utilize the rask scan function in the bitmap memory 14 as is.

When changing the image data of window 24 in the state shown in FIG. 1(f), the changed data of window 24 is written in area 24a, and then
rewrite the data. As a result, a multi-window screen is obtained in which the priority order is the same as before and the data in the window 24 is updated.

〔Effect of the invention〕

As explained above, according to the present invention, multi-windows that are displayed in priority order can be created by simply writing the image data of a low-priority window to a bitmap without calculating the overlap between each window. screen is obtained and is extremely effective.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing an overview of a display system, and FIG. 3 is an explanatory diagram of a memory writing procedure. In the drawing, 20 is the screen, 22 is the high priority window, 2
4.26 is a medium or low priority window.

Claims (2)

[Claims] (1) In a method in which image data of a multi-window screen is written to a bitmap memory, and the memory is read out and displayed on a display screen, the image data of the window with the lowest priority is written to the area of the window in the bitmap memory in order, A multi-window display method that is characterized by leaving the image data of a window with a high priority in the overlapping area of windows, and erasing the data of a window with a low priority. (2) The multi-window display method according to claim 1, wherein the window area is cleared before writing the image data of the window.