JPH0340127A - Multi-window display device and window priority deciding device - Google Patents

Abstract

PURPOSE:To attain the switch of the display windows for each picture element by selecting the window data having the highest priority out of those data which are successively outputted from the storage means separated for each window synchronizing with the signal showing a scanning position on a display screen. CONSTITUTION:A window image writing means 17 outputs the window images stored in the window buffers 10a - 10c to a selection circuit 15 via the data lines 11a - 11c independently of each window and synchronizing with a signal 5 showing a scanning position on a CRT. At the same time, a window priority deciding means 12 outputs a selection signal 14 for the window to be displayed to the circuit 15 based on the signal 5 and the window information given previously from a writing means 13. The circuit 15 uses the data on the window selected by the signal 14 out of those data 11a - 11c received from each window and synthesizes a multi-window image to display this image on a CRT 2. As a result, the windows can be changed for each picture element.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a multi-window display in which multiple images (generally rectangular areas) are displayed in a superimposed manner on a display screen. The present invention relates to a multi-window display device and a window priority determination device.

2. Prior Art A conventional multi-window display device is shown in, for example, "Hardware Configuration of a Multi-Window System" by Maejima, ``Multi-Window System'', IEICE ILIE 84-100.

FIG. 3 shows a block diagram of this conventional multi-window display device, in which 1 is a window buffer that stores a plurality of window images (A, B, etc.). 2 is a CRT, and 3 is a CRT control device which generates a synchronizing signal 4 for the CRT 2 and a signal 5 indicating a scanning position on the CRT. Reference numeral 6 denotes a window priority determining device which generates an address 8 of a window image to be displayed from a signal 5 indicating the scanning position on the CRT and window information previously given by the writing means 7. Reference numeral 9 denotes means for writing an image into the window buffer l; 91 a multiplexer which selectively supplies the read address 8 for writing and displaying the window image to the window buffer l;

In the conventional multi-window display device configured as described above, the image writing means 9 reads out the window image developed in the window buffer L to the window display position in synchronization with rask scanning, and synthesizes the multi-window image onto the L CRT 2. indicate.

Inventiveness<%7f Problems to be SolvedHowever, in the configuration described in 2, the display contents are changed by changing the read address 8 to window buffer 1 for display, so window buffer 1
The present invention has the problems that the window opening position on the display screen is limited by the memory cycle time of the memory cycle time, and the display content is limited by the word, which is the unit of memory access, and the degree of freedom in window display is low. In view of this, an object of the present invention is to provide a multi-window display device that is fast and has a high degree of freedom in window display.

Means for Solving the Problems The present invention provides independent memory means for each window for storing image data, means for writing an image into the memory means, and means for writing the image data into the memory means in synchronization with a signal indicating a scanning position on a display screen. Means for sequentially outputting the contents of each independent storage means for each window, and inter-window priority determination indicating which window contents are displayed on each display pixel in synchronization with a signal indicating the scanning position on the display screen. and a selection means for outputting data from the outputting means which is independent for each window manually, and outputting data from a window indicated by a signal from the inter-window priority determining means. be.

According to the above-described configuration, the present invention selects the highest priority window data from the data group sequentially output from the storage means separated for each window in synchronization with the signal indicating the scanning position on the display screen. It is now possible to switch display windows in units, allowing for multi-window display with a high degree of freedom.

Embodiment FIG. 1 shows a block diagram of a multi-window display device in an embodiment of the present invention.

In FIG. 1, 2 is a CRT, and 3 is a CRT control device that generates a synchronizing signal 4 for the CRT 2 and a signal 5 indicating a scanning position on the CRT, and the above structure is the same as that in FIG. 3.

10a to 10c are window buffers that store window images of n windows, and unlike window buffer 1 in FIG.
The stored data is output to data lines 11a to 11c in synchronization with signal 5 indicating the scanning position on T. 12 is a window priority determination device; a signal 5 indicating the scanning position of the CRT l;
A selection signal 14 for selecting a window to be displayed is generated from the window information given in advance by the writing means 13. 15 is a selection circuit which outputs to 16 the data selected by the selection signal 14 from among the data lines 118-lie.

17 is a window image writing means for window buffer] 0a to 10c.

The operation of the multi-window display device of this embodiment configured as described above will be described below.

The window image writing means 17 outputs the window image stored in the window buffers 10a to 10c+1 to the selection circuit 15 independently for each window via the data lines 11a to Ilc in synchronization with the signal 5 indicating the scanning position on the CRT.

On the other hand, the window priority determination device 12i outputs to the selection circuit 15 a selection signal 14 for selecting a window to be displayed based on the signal 5 indicating the scanning position on the CRT and the window information previously given by the writing means 13. Selection circuit 15
A multi-window image is synthesized by using the data of the window selected by the selection signal 14 among the data Ila to llc from each window as display data.
Display on CRT2.

As described above, according to this embodiment, physically separated window buffers 10a to 10c are provided for each window.
By determining display data from la to Ilc according to the selection signal 14, the window can be changed pixel by pixel.

In the embodiment, window image writing means 1
7 is a common claw; it may be provided for each window.

Also window buffers 10a to 10c I;)-
, an image writing port (corresponding to the window image writing means 17 in the embodiment) and a display data reading port (corresponding to the output data lla to llc in the embodiment)
It is more efficient to configure it with separate dual-port memory.

FIG. 2 is a block diagram of a window priority determination device in one embodiment of the present invention. In the same figure, 5 is C
A signal indicating the scanning position on the RT; 13 is window information writing means; 14 is a selection signal indicating the highest priority window; the above structure is similar to that shown in FIG. 18
is the signal line 1 to the corresponding dual port memory described later according to the window information from the window information writing means 13.
device for writing the shape of the window via 9, 20a~
20C is a dual port memory that stores the window shape of each window number and outputs the stored data to ports 21a to 21c in synchronization with signal 5 indicating the scanning position on the CRT; 22 is a dual port memory that outputs the stored data to ports 21a to 21c; This is a priority encoder that inputs data and outputs a selection signal I4.

The operation of the window priority ranking determination device of this embodiment configured as described above will be described below.

When a new window is generated, the window shape writing device 18 writes data (logic '1'') for the window forming part corresponding to the display screen into the dual port memory of that window number. When erased, all 9 bits of the dual port memory of the corresponding window number are set to logic "0". For example, when a new window with window number 2 is created on the display screen, the bit of the window formation component corresponding to the display screen is set to logic "in the dual baud) memory 20b, and the window with window number 1 is created on the display screen. When the data is deleted (all bits of the dual port memory 20a are set to logic 'O').

Dual port memories 20a to 20c store window shape data (currently opened window shape data) 21a to 21a stored in synchronization with signal 5 indicating the scanning position on the CRT.
2] Priority encoder 22 via the port of c
Output to. This pig shows the window opening status at each scan location on the CRT. Priority encoder 2
2 obtains a window number by encoding the n-bit data inputted in conjunction with the CRT scanning position by prioritizing the data from 21a as the highest priority.

As described above, according to this embodiment, a memory that stores the opening position of each window on the display screen in the form of a shape is set up independently for each window (this shape is used) to determine the window priority order. By doing this, it is possible to determine the priority order of windows not only in rectangular shapes but also in shapes such as circles and triangles on a pixel-by-pixel basis.

In some embodiments, the window shape writing device 18 may be provided for each window.

As described in detail, according to the present invention, a plurality of windows can be displayed quickly and flexibly, and its practical effects are great.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a multi-window display device according to an embodiment of the present invention @ Fig. 2 is a block diagram of a window priority determination device according to an embodiment of another invention @ Fig. 3 is a block diagram of a conventional multi-window display device It is a diagram. 2...CRT, 3...CRT control device 4...C
RT synchronization signal, 5... Signal indicating scanning position on CRT, 10a to 10c... Window buffer, 12
...Window priority determination device 13...Window information 1 information writing means, 14...Selection signal, 15...Selection cycle 17...Window image writing means, 18
...Window shape writing device, 20'a~20b...
・Dual port memory, 22...priority encoder

Claims (3)

[Claims] (1) storage means independent for each window for storing image data; means for writing images into the storage means;
Means for sequentially outputting the contents of each of the independent storage means for each window in synchronization with a signal indicating the scanning position on the display screen; An inter-window priority determining means for indicating whether or not to display the contents of a window, and data from the output means independent for each window are input, and data from the window indicated by a signal from the inter-window priority determining means is input. A multi-window display device comprising a selection means for outputting data, and using the output from the selection means as display data. (2) An independent storage means for each window number consisting of a window number indicating display priority among multiple windows and a bit corresponding to a pixel position on the display screen, and when a window is generated on the display screen. All bits corresponding to the display position of the storage means of the corresponding window number are set to logic 1, and all bits of the storage means of the corresponding window number are set to logic 0 when the window disappears from the screen. data writing means; means for sequentially outputting the contents of each independent storage means for each window number in synchronization with a signal indicating a scanning position on the display screen; A window priority order determining device, comprising a priority order determining means for inputting and outputting the highest priority window number, and outputting the highest priority window number for each pixel. (3) The inter-window priority determining means according to claim 2
2. The multi-window display device according to claim 1, wherein the multi-window display device is the window priority order determining device according to the above.