JPH02121071A - Superimposed graphics display system - Google Patents

Abstract

PURPOSE:To display superimposed graphics at high speed when the superimposed state of the parts of graphics to be superimposed is changed, and the superimposed graphics are displayed after that by arbitrarily changing the size of the parts of the graphics to be superimposed and after that displaying the superimposed graphics. CONSTITUTION:A control means 7 writes respective separate graphics to planes 2 and 3, recognizes the superimposed state of both the instructed graphics, instructs a plane control means 12 to separately read the graphics respectively recorded in the planes 2 and 3, and superimposes the graphics when the graphics are sent to a display part 6. Consequently, the superimposed state of both the graphics can be displayed according to the designation. Thus, a display speed can be increased when the superimposed state of the graphics is changed, and the superimposed graphics are displayed after that.

Description

[Detailed Description of the Invention] [Summary] A superimposed figure that improves display speed when displaying a plurality of figures in a superimposed manner by changing the positional relationship between the figures in a display device that displays figures. Regarding the display method, in order to display the graphics at high speed and eliminate the need to memorize the original graphics, the graphics are written to a bitmap memory consisting of multiple planes, and the planes are raster scanned to create the bitmap. In a display device that reads figures written in a memory and displays the read figures, independent figures are written to each of a plurality of planes, and when reading figures written to the planes, each A control means for instructing a raster scan start position for each plane, and an address for starting raster scan for each plane based on instructions from the control means, and raster scans for each plane are simultaneously started from different address positions. A plane control means is provided, and the figures written in each plane are individually read out by performing rask scanning from the address specified by the plane control means, so that the relative positional relationship of the plurality of figures read out can be arbitrarily determined. The configuration is such that it is changed to and displayed.

[Industrial application field]

The present invention relates to a display device that displays figures, and particularly to a display method for superimposed figures that improves display speed when displaying a plurality of figures in a superimposed manner by changing the positional relationship between the figures.

A plurality of figures are displayed in a superimposed manner on the same display screen of a display device, but when the overlapping state of the overlapping portions is changed and displayed, it is necessary to switch the display contents at high speed.

[Conventional technology]

FIG. 4 is a block diagram illustrating the conventional technique, and FIG. 5 is a diagram illustrating the operation of FIG. 4.

The CRT control circuit 1 sends an address for rask scanning on the planes 2 and 3 constituting the bitmap memory, reads out the data of each pixel of the figure written on the planes 2 and 3, and reads out the data of each pixel of the figure written on the planes 2 and 3. send it to

Color information corresponding to the data of each pixel is read out from the look amplifier table 4, converted into a video signal by the D/A conversion circuit 5, and sent to the display section 6. Display section 6 is CRT
Under the control of the control circuit 1, the display screen is scanned in synchronization with the rask scanning of planes 2 and 3, and the video signal sent out by the D/A conversion circuit 5 is displayed.

Therefore, on the display screen of the display unit 6, as shown in FIG. 5, for example, the figures ■ and ■ are displayed, and the figures ■ and the overlapping portion ■ of the figures ■ are displayed in different colors, respectively.

As shown in FIG. 5, when parts of figures ■ and ■ are displayed in an overlapping manner, figures ■ and ■ are written on planes 2 and 3, respectively, as shown in FIG. plane 2
When 3 and 3 are rask-scanned, for example, 2 of figure 2, which is a combination of 1-bit data successively read from figure 2 on plane 2 and 1-bit data read from figure 3 on plane 3, is scanned. The bit data is sent as an address for reading out the color information of each pixel in the lookup table 4.

Therefore, the data of each pixel of figure ■ on plane 2 is set to “0”.
“, and the data of each pixel of the figure ■ on plane 3 is “1”.
'', "01" is sent to the lookup table 4. Also, the data of each pixel of the figure ■ on the plane 2 is set to "1", and the data of each pixel of the figure ■ on the plane 3 is set to "1". 0”, lookup table 4 contains “10”.
” is sent out. Then, “11” is sent out from the superimposed portion (3).

Therefore, the color information sent by the lookup table 4 is
Assuming that the color is green when the address is "01", red when the address is "10", and blue when the address is "11", the fifth
As shown in the figure, the figure ■ is displayed in green, the figure ■ is displayed in red, and the overlapping portion ■ is displayed in blue.

[Problem to be solved by the invention]

The overlapping state of the overlapping part ■ of figures ■ and ■ shown in FIG. The situation needs to change.

In this case, the figure conventionally written in planes 2 and 3 ■
This is achieved by once erasing the and ■ and rewriting the figure with a different overlapping state.

For this reason, conventionally, rewriting time was required to erase and rewrite the figures ■ and ■, and when changing the overlapping state, the display speed decreased and it was necessary to memorize the figures ■ and ■. There's a problem.

In view of such problems, the present invention writes figures ■ and ■ independently in planes 2 and 3, respectively, and
When reading out the figure's and The purpose is to enable high-speed display without performing a writing operation, and to eliminate the need to memorize the figures ``■'' and ``■''.

[Means to solve the problem]

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

The control means 7 writes, for example, the figure 2 shown in FIG. 5 in the plane 2 of the bitmap memory 15, and the figure 2 in the plane 3, respectively.

Then, the control means 7 determines the overlapping state of the specified figures ■ and ■, and sends them to the planes 2 and 3 from the addresses of the figures ■ and ■ written in the planes 2 and 3 at the beginning of raster scanning. Determine the address and plane control means 12
to determine the start address of the raster scan to be sent to plane 2 and the start address of the raster scan to be sent to plane 3, and cause planes 2 and 3 to perform raster scan, respectively.

Therefore, planes 2 and 3 have different addresses at the start of raster scanning, and the figure ■ written on plane 2 and the figure ■ written on plane 3 are in an overlapping state of the specified figures ■ and ■. The information is read out accordingly and sent to the display section 6 for display.

[Effect]

With the above configuration, the control means 7 causes the planes 2 and 3 to write separate figures ■ and ■, respectively, recognizes the overlapping state of the instructed figures ■ and ■, and instructs the plane control means 12. The overlapping state of the figures ■ and ■ is displayed as specified by reading the figures ■ and ■ recorded in the planes 2 and 3 separately and superimposing them when sending them to the display section 6. Therefore, it is possible to increase the display speed when displaying by changing the overlapping state, and it is also possible to eliminate the need to memorize the figures (1) and (2).

〔Example〕

FIG. 2 is a block diagram of a circuit showing an embodiment of the present invention.
FIG. 3 is a diagram illustrating the operation of FIG. 2.

The processor 13 temporarily stores graphic data sent from the host device via the interface circuit 8 in the RAM 10,
This graphic data is instructed to the drawing processor 11 to be written independently into planes 2 and 3, respectively. At this time, the processor 13 determines that the given figure is in the range shown by "1" in FIGS. 2 and 3, that is, as shown in
Assuming that the vertical direction is a rectangle with four dots, for example, drawing is performed at the center of plane 2 and plane 3, respectively. Therefore, "θ" is written in the remaining areas of planes 2 and 3.

If there is no instruction from the processor 13, the CRT control circuit 14 performs raster scanning from the leading areas of planes 2 and 3 to read data and send it to the look amplifier table 4 as in the conventional case. The color information read from the look amplifier table 4 is sent to the display section 6 via the D/A conversion circuit 5, and rectangles ``■'' and ``2'' are displayed in a superimposed manner.

When the processor 13 receives an instruction to move the rectangle ■ from the mouse 9, it determines the overlapping state of the rectangles based on the amount of movement, and from the addresses of the rectangles written in planes 2 and 3, creates a raster to be sent to planes 2 and 3. The first address at the start of scanning is determined, and the CRT control circuit 14 is instructed to determine the first address of the raster scan sent to plane 2 and the first address of raster scan sent to plane 3, and the first address of the raster scan sent to plane 3 is determined. Each raster scan is performed at the same time.

That is, when displaying as shown in FIG. 361, the raster scanning start address for plane 2 is as follows, assuming that the main scanning direction is in the direction of arrow A and the sub-scanning direction is in the direction of arrow B.
The position shown in (2) is taken as the raster scan start address, and the raster scan start address of plane 3 is taken as the position shown in (2).

Therefore, from plane 2, the same content as shown in FIG. 3 is read, and from plane 3, two rows of "0" are added in the sub-scanning direction at the beginning of the state shown in FIG. 3. The rectangular position is shifted by 1 dot in the main scanning direction and 2 dots in the sub-scanning direction. Ru.

In the look amplifier table 4, as shown in FIG. 3, when the address is 00'', there is no color specification, and the display screen of the display unit 6 does not emit light. Therefore, black is displayed on the display screen.

The address “01” is green, and the address “10” is green.
” is red and address “11” is blue.
The data in the head area of the rectangle that is first read from plane 2 is 1'', and 0'' can be read from plane 3, so the address sent to lookup table 4 is 1''.
0”.

Therefore, as shown in FIG. 361, the color information of the first pixel read from the look amplifier table 4 is red, and the D/
The A conversion circuit 5 converts the signal into a video signal, and sends it to the display section 6 to display red.

In this way, the data of each pixel sequentially read out from planes 2 and 3 in response to rask scanning is such that the rectangular data read out from plane 3 is shifted by 2 dots in the sub-scanning direction, and Since there is a one-dot shift in the direction, four dots are displayed in blue on the display screen of the display unit 6, as shown in 61, where the rectangle read from plane 2 and the rectangle read from plane 3 overlap. The remaining portion of the rectangle read from plane 2 is displayed in red, and the remaining portion of the rectangle read from plane 3 is displayed in green.

Since the remaining pixels do not emit light, they are all black.

Furthermore, if the rask scan start address of plane 2 is set to the position shown in Figure 3 (■), and the rask scan start address of plane 3 is set to the position shown in Figure 3 (■), then the rectangle read from plane 3 will be read from plane 2. Since the data is read out with a deviation of two dots in the main scanning direction and one dot in the sub-scanning direction with respect to the rectangle, the three superimposed dots are displayed in blue, as shown in FIG. 362.

(Effects of the Invention) As explained above, the present invention allows the CRT control circuit to read out a figure written on each plane by shifting an arbitrary number of dots in the main scanning direction and the sub-scanning direction according to instructions from the processor. Therefore, it is possible to arbitrarily change the size of the overlapping part of the figure and display it, and there is no need to erase and rewrite the figure drawn on the plane, so it can be displayed at high speed. At the same time, since there is no need to continue storing figures written on the plane, the memory area can be used effectively.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of a circuit showing an embodiment of the present invention, Fig. 3 is a diagram explaining the operation of Fig. 2, and Fig. 4 is a diagram showing the conventional technology. FIG. 5 is a block diagram for explaining the operation of FIG. 4. In the figure, 1.14 is a CRT control circuit, 2.3 is a plane, 4 is a look-up table, 5 is a D/A conversion circuit, 6 is a display section, 7 is a control means, 8 is an interface circuit, 9
is a mouse, 10 is a RAM, 11 is a drawing processor, 12 is a plane control means, 13 is a processor, (N)

Claims (1)

[Claims] A figure is written in a bitmap memory (15) composed of a plurality of planes (2) (3), and the planes (2) (3) are
) in a display device that raster-scans a graphics field, reads graphics written in the bitmap memory (15), and displays the graphics that have been read out; a control means (7) for instructing a raster scan start position for each plane (2) (3) when writing and reading figures written on the plane (2) (3); Based on the instructions from the control means (7), each plane (2) (
Plane control means (12) that determines the address at which raster scanning is to be started for each plane (2) and (3) and simultaneously starts raster scanning from a different address position for each plane (2) and (3).
).