JPS6373478A - Multi-window display system by display map - Google Patents

Abstract

PURPOSE:To attain the window display of an arbitrary shape by providing a display map memory to designate at a pixel unit which contents of a frame memory are displayed. CONSTITUTION:The system is constituted of plural frame memories 1-4 to store the data with the bit map form of respective windows, a display map memory 5 to store a selecting signal to designate to a pixel (picture element) unit which data of the frame memory of respective windows are displayed on a display screen 6, a selector 8 to select the picture element data of frame memories 1-4 by a selecting signal with the memory 5 and a display screen 6 to display the data selected by the selector 8. Thus, the change of the window frame of the screen and the change of a display priority come to be satisfactory when the frame memories 1-4 are not changed and the memory 5 only is changed, and the control of the multi-window becomes be easier.

Description

[Detailed Description of the Invention] [Summary] The present invention provides a multi-frame display H having a frame memory.
In the window display method, by providing a plurality of frame memories that store bit images for each window and a display map memory that specifies which of those frame memories is to be displayed on a pixel-by-pixel basis,
This makes it easy to control the visibility/invisibility of windows by overlapping each other, change window priorities, display contents, and sizes, and make it possible to form windows into arbitrary shapes.

[Industrial application field]

The present invention relates to a multi-window display method for a display device having a frame memory, and more particularly to a multi-window display method that facilitates high-speed control of multi-window display and can display windows of arbitrary shapes.

[Conventional technology]

In recent years, multi-function devices have been developed to improve man-machine interface
The number of window display type display devices is increasing.

FIG. 3 is a block diagram showing a typical example of this, and shows an example in which a rectangular bitmap area is copied by a rask operation. In FIG. 3, the display device consists of frame buffers 1, 2, and 3°4.5" that store bitmaps of the same size as the screen, a display screen 6, and a rask operation circuit 7. , 2.3.4 store a bitmap for each window, a frame buffer 5'' holds an image exactly the same as the display screen 6, and a frame buffer 1.2.3.4 stores a bitmap for each window. 2. 3. 4 to 12 multi-window screens are stored. The method is to determine the visible portion of each window, divide the visible portion into rectangular areas, and sequentially transfer each rectangular area to the frame buffer 5' by the rask operation circuit 7.

There are various rask operations, but one example is to write the lowest clock image from frame buffer 4 to frame buffer 5, and then write "ABCD..." to frame buffer 5.・Write from buffer 2. In frame buffer 5'', the overlapping portion of the two images is naturally erased from the clock image that was written first.Similarly, when ``Aiu...'' is subsequently written from frame buffer 3, "Hl" of the written image in the frame buffer 2 is erased, and a display screen as shown in FIG. 3 is completed.

[Problem that the invention seeks to solve]

In the above conventional technology, the size of each window is X and Y.
Given the minimum and maximum values in each direction, their management,
Dividing the visible part into rectangular 'pM areas and starting the rask operation are performed by a microprogram (firmware), etc., but when editing a multi-window screen, it is necessary to determine the visible part of multiple frame memories and to start the rask operation. It is necessary to perform division processing, which takes time and requires an extra operation called a rask operation.

Further, the shape of the window is limited to a rectangle or a set of rectangles.

The present invention was devised in view of these problems, and provides a multi-window display that facilitates control of multi-window display, enables high-speed response, and also enables window display of arbitrary shapes. The purpose is to provide a method.

[Means for solving problems]

FIG. 1 is a block diagram showing the principle of the present invention.

In the present invention, what are the measures taken to solve the above problems? In a display device having a 1B frame memory 1, 2° 3.4, which frame memory 1, 2,
3.4 is provided with a table map memory 5 for specifying on a pixel-by-pixel basis whether or not the contents of 4 are to be displayed, and employs a multi-window display method using a display map that performs multi-window display of an arbitrary shape.

[Effect]

The display program uses multiple frame memories 1゜2.3.
Compared to 4, it is possible to store the entire image of each window without having to be aware of window overlap, so it is easy to change the display contents, and the window frame configuration and screen collection can be changed using a single display map. This simplifies the process of determining visible and invisible areas based on overlapping windows, dividing the visible area, etc., making it easier to control multi-window display, and enabling high-speed response. Furthermore, since the display area can be designated in pixel units, it is possible to display a window of arbitrary shape.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to examples and drawings.

Basic Configuration of the Present Invention (FIG. 1) FIG. 1 is a block diagram showing the principle of the present invention as well as one embodiment of the basic configuration. In FIG. 1, a multi-window display device embodying the present invention includes a plurality of frame memories 1, 2, and 3 that store bitmaps of each window.
．． 4, a display map memory 5 for specifying which of them to display in pixel units, and a display screen 6.
and a selector 8.

The frame memories 1, 2, 3.4 may be the same as conventional frame buffers, but the display map memory 5 is
This is a table memory in which a control code is written for each dot, with pixels corresponding to each frame memory and display screen. That is, a control code is written in each dot, for example, a code (■) specifying frame memory 1 is written in the blank area, and a circle with a part missing in the clock pixel specifies frame memory 4. A code (2) to specify the frame memory 2 is written in the pixel "ABCD . . .", and a code (2) to specify the frame memory 2 is written in a partially missing rectangle in the pixel "ABCD...". The overlapping portion of these windows is overlaid by a window with a higher priority, for example, by using firmware to allocate a control code that designates a frame memory to a window area in the order of the windows with lower priority. Therefore, in the above case, the determination of visible and invisible areas, division processing, etc. need only be performed on the display map memory 5, which simplifies the process and enables high-speed response. The above control code is sent to the selector 8 as a selection signal, and the selector 8 selects from each frame memory according to this control code when scanning pixels.
Since only the image information is read, the processing speed does not slow down.

Here, when adding or changing the contents of the window, for example, when it became necessary to add 'E' in frame memory 2, conventionally the rask operation had to be restarted from the beginning, but in this embodiment, As long as the frame memory 2 is rewritten without being aware of the visible area, the pixels in the visible area are directly selected by the selector 8, so the display screen 6 can be automatically rewritten.Also, "ABCD..." Conventionally, when it was decided to display the window above the "Ai-Dou" window, the program would display the contents of frame memory 2 above the contents of frame memory 3. In addition, it was necessary to restart the rask operation from the beginning, but in this embodiment, the display map memory 5 can be set to "HI" simply by changing the control code of each dot in the area where the windows overlap from ■ to ■. and its window frame are selected instead of "Ai" and its window frame, and it appears as if the windows have been replaced on the display screen 6.

Example of the present invention (Figure 2) FIG. 2 is a block diagram showing another embodiment of the invention.

In FIG. 2, a main access circuit 22 is connected to a bus 21 such as a CPU (not shown), and the main access circuit 2
2 buffers 23, 24.2 as frame memory
5.26 and the display knob memory 27 are connected. This example shows the case where ■ 16 colors are displayed with 4 bits per pixel, the number of windows is 4, and the buffer 2
3 to 26 are dual port memories that store images for each window. One graphic character, an image, etc. are written into the buffers 23 to 26 from the bus 21. Of course, it is also possible to use a configuration in which writing is performed from a vector generation circuit or a character generation circuit. Display map memory 27 stores a code indicating which buffer to display for each pixel, as explained in FIG.

Each of the buffers 23, 24, 25, 26 is connected to the selector 28 via the sub-access circuits 23a to 26a, and the display map memory 27 also has its own sub-access circuit 27.
A select signal is input to the selector 28 via a. A display control circuit 29 is connected to the selector 28 and performs data D/A conversion and scanning control. A rask scan address generation circuit 30 is interposed between each of the sub-access circuits 23a to 27a and the display control circuit 29.
And when reading data from the display map memory 27, the access position is controlled.

The selector 28 selects read data from the buffers 23 to 26 pixel by pixel based on the control code from the display map memory 27, and sequentially outputs the data to the display control circuit 29. The display control circuit 29 outputs image data to a display section or the like according to the created bitmap.

〔Effect of the invention〕

As described above, according to the present invention, when changing the window frame of the screen or changing the display priority of each window, that is, the visible/invisible area, etc., only the display map memory can be used without changing each frame memory. There is no need to transfer extra data such as changes that need to be made, and the need to be aware of window overlap is only when creating a display map, so high-speed response is possible. Furthermore, there is no need for display screen generation processing by a raster operation circuit, and the overlapping of windows, display priority of each window, etc. can be controlled on a single display map, so the circuit and control can be simplified. Furthermore, since the display area can be specified in units of pixels, it is possible to display windows of arbitrary shapes.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of the present invention, FIG. 2 is a configuration diagram of an embodiment of the present invention, and FIG. 3 is a configuration diagram of a conventional example. In the figure, 1 to 4, 23 to 26; frame memory 5. 27; display map memory; 6; display screen; 7; raster operation circuit; 8. 28; selector; 19; display control circuit; 30; raster scan・It is an address generation circuit. Figure 2 of the actual clothing example of the multi-fin rip dog water span between the throats.

Claims (1)

[Claims] In a display device having a plurality of frame memories (1, 2, 3, 4), specifying in units of pixels which frame memory (1, 2, 3, 4) contents are to be displayed. Display map memory (
5), a multi-window display method using a display map, which is characterized by displaying multi-windows of arbitrary shapes.