JPH0578852B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for converting output from an electronic computer into
It relates to a display device that displays characters, images, graphs, etc. on the display screen of a CRT (cathode ray tube), that is, a cathode ray tube.

[Conventional technology]

Prior art to this invention is JP-A-59-162588 filed by the same applicant as the applicant of this invention.
There is an invention that was published in the publication No. No. (hereinafter referred to as the earlier application).

FIG. 2 is a block diagram showing a display device corresponding to FIG. 7 of the earlier application, in which numeral 1 denotes a bitmap memory section as a first memory section;
For example, a plurality of various rectangular image patterns are held. Reference numeral 2 denotes a display control unit to which the positions and sizes of the plurality of rectangular image patterns in the bitmap memory unit 1, display priorities for overlapping display, and the plurality of rectangular image patterns are transferred. The position on the screen memory section 3 is held as display control information. Reference numeral 3 denotes a screen memory section as a second memory section, in which image patterns corresponding to dots on the display screen of a cathode ray tube (hereinafter abbreviated as CRT) 7 are stored. Reference numeral 4 denotes an area discriminating unit which determines the area that needs to be changed in the screen memory unit 3 according to the display control information and change type in the display control unit 2, and the bitmap memory unit 1 corresponding to the area.
It identifies the area within the area and instructs the direct memory access controller unit 5 (hereinafter abbreviated as DMAC) to perform an image pattern transfer operation for the identified area.

The DMAC 5 follows instructions from the area determination unit 4,
Data is transferred from the bitmap memory section 1 to the screen memory section 3, and a predetermined area in the screen memory section 3 is partially filled in. A video control section 6 generates a video signal corresponding to the image pattern to be displayed read out from the screen memory section 3 in accordance with a predetermined scanning timing.

Figure 3 shows, for example, three rectangular image patterns.
This is an explanatory diagram illustrating a state in which IP1, IP2, and IP3 are held in the bit map memory section 1, and each of these rectangular image patterns
Assuming that the position of the top left corner vertex of IPi (i = 1, 2, 3) in bitmap memory unit 1 is (xi, yi), this represents the position of rectangular image pattern IPi in bitmap memory unit 1. do.
In addition, the above rectangular image pattern IPi (i=1,
The x-direction size of 2 and 3) is represented by hi, and the y-direction size is represented by vi, and using these, the size of the rectangular image pattern IPi is represented by hi and vi. Furthermore, in the case of overlapping display, the display priority of each rectangular image pattern IPi is set as PRi. When PRi<PRj, the rectangular image pattern IPi is displayed below IPj, and as a result, a part of the rectangular image pattern IPi is displayed as if it were hidden by IPj.
It goes without saying that if i≠j, then PRi≠PRj.

Next, FIG. 4 shows that the rectangular image patterns IP1, IP2, and IP3 explained in FIG.
Explanation showing the state of the screen memory section 3 that can be obtained as a result of transferring the rectangular image patterns IP1, IP2, and IP3 to a specific position in the screen memory section 3 when the display priority is PR2<PR3. It is a drawing. Here, the position of the top left corner vertex of each rectangular image pattern IPi in the screen memory section 3 is defined as (αi, βi), and this is defined as the position of the rectangular image pattern IPi in the screen memory section 3.

Next, FIG. 5 shows the state of the screen memory section 3 held by the display control section 2 in order to generate the state of the screen memory section 3 shown in FIG. 4 from the state of the bitmap memory section 1 shown in FIG. 3 above. 7 is a diagram specifically displaying display control information.

Next, the display control section 2 generates the state of the screen memory section 3 shown in FIG. 4 from the state of the bitmap memory section 1 shown in FIG.
The operations of the area discriminator 4 and DMAC 5 will be explained.

First, the area determination section 4 receives display control information from the display control section 2, and uses it to minimize the amount of data transferred between the bitmap memory section 1 and the screen memory section 3 when the display screen is changed. As shown in FIG. 6, the screen memory section 3 is divided into small rectangular areas that do not overlap each other using the extension lines of each side of each image pattern, and the position and size of each small rectangular area are maintained. .

Next, the area determination unit 4 receives an instruction from the display control unit 2 to display the rectangular image pattern IP1. At this time, the area determination unit 4
Using the display control information in and the position and size of the small rectangular area, small rectangular areas m1 to m4 in the screen memory section 3 that are not hidden by the other rectangular image patterns IP2 and IP3 of the rectangular image pattern IP1 are created. identify Then, the following operation is performed only on these small rectangular areas m1 to m4. That is, the bitmap memory unit 1 instructs the DMAC 5 to transfer the portions of the rectangular image pattern IP1 corresponding to the respective small rectangular areas m1 to m4 to the corresponding small rectangular areas m1 to m4.

Subsequently, the area determination unit 4 performs the same operation as in the case of displaying the rectangular image pattern IP1 described above in accordance with instructions from the display control unit 2 for each of the rectangular image patterns IP2 and IP3. That is, the area discriminator 4 detects a rectangular image pattern.
Regarding IP2, the DMAC 5 transfers the portions of the rectangular image pattern IP2 corresponding to the small rectangular areas m5 to m11 in the screen memory section 3 from the bitmap memory section 1 to the corresponding small rectangular areas m5 to m11. give instructions to Also,
Regarding the rectangular image pattern IP3, portions of the rectangular image pattern IP3 corresponding to the small rectangular areas m12 to m17 in the screen memory unit 3 are transferred from the bitmap memory unit 1 to the corresponding small rectangular areas m12 to m17, respectively. Instruct the DMAC5 to: As a result, the state of the screen memory section 3 as shown in FIG. 4 is generated.

[Problem that the invention seeks to solve]

Since the conventional display device of this type was configured as described above, the rectangular image pattern shown in FIG.
Even when changing the display of a rectangular image pattern that is not hidden by another rectangular image pattern in the screen memory unit 3, as in IP3, the area discriminating unit 4 divides the rectangular image pattern into small rectangular areas. Since it is necessary to instruct the DMAC 5 to transfer data from the bitmap memory unit 1 to the screen memory unit 3 in units of each of these small rectangular areas, there is a problem that display changes regarding the rectangular images are delayed.

This invention has been made to solve the above-mentioned problems, and for rectangular image patterns that do not need to be divided into small rectangular areas to change the display, the operation of the area discriminator 4 is changed. The object of the present invention is to obtain a display device that can change the display without changing the display.

[Means for solving problems]

The display device of the present invention includes a first memory section (bitmap memory section 1) that holds data of a plurality of image patterns, and a second memory section (bitmap memory section 1) that holds data of display patterns corresponding to dots on a display screen. a screen memory section 3), a data transfer section (direct memory access control section 5) that transfers the data held in the first memory section to the second memory section, and a screen memory section 3) necessary for displaying the image pattern. a display control unit 2 that holds display control information such as the position and size of the image pattern in the first memory unit and the second memory unit, and display priority for superimposed display;
Then, the second memory section is divided into small rectangular areas that do not overlap each other using extension lines of each side of each image pattern based on display instructions from the display control section, and each small rectangular area is divided into an area determining unit 4 that holds the position and size and identifies an area that needs to be changed in the second memory unit and an area in the first memory unit that corresponds to the area in divided units; When transferring image pattern data in the memory section to the second memory section, it is determined whether or not one image pattern overlaps with another image pattern based on display control information held in the display control section; If it is determined that the image patterns do not overlap, instruct the data transfer unit to transfer data of the image patterns from the first memory unit to the second memory unit, and if it is determined that the image patterns overlap, Activate the area discrimination unit to identify an area of the image pattern that is not hidden by another image pattern, and transfer data of the area that is not hidden from the first memory unit to the second memory unit. The present invention is characterized in that it includes a processing determining section 8 that instructs the data transfer section to transfer data.

[Effect]

The processing determination unit 8 determines whether a certain image pattern overlaps with another image pattern based on display control information from the display control unit 2,
If it is determined that they do not overlap, that is, for image patterns that do not need to be divided into small rectangular areas to change their display, data is stored from the first memory section to the second memory section.
Instructs the data transfer unit to transfer data to the memory unit. In addition, if an image pattern overlaps with another image pattern, the area discrimination unit divides the image pattern into small rectangular areas, and the data transfer unit transfers the data in the area that is not hidden by other image patterns. instruct.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, the same reference numerals as in FIG. 2 indicate the same or corresponding parts, and 8 indicates a processing discrimination section. Based on the display control information held by the display control unit 2 and the change type, the processing determination unit 8 determines that a certain rectangular image pattern is partially hidden by another rectangular image pattern and the screen memory unit 3 serves as a second memory unit. Determine whether or not it is held. Then, the area discriminating unit 4 is instructed to extract each small rectangular area of the screen memory unit 3 from the bitmap memory unit 1 and transfer it to the screen memory unit 3, or
The rectangular image pattern is transferred from the bitmap memory section to the screen memory section in one transfer operation without directly instructing the DMAC 5 to take out each small rectangular area from the bitmap memory section and transfer it to the screen memory section.

Next, the bitmap memory section 1 in FIG.
The operations of the display control section 2, area discriminating section 4, DMAC 5, and processing discriminating section 8 for generating the state of the screen memory section 3 shown in FIG. 4 from the state shown in FIG. 4 will be explained.

First, the area determination section 4 receives display control information from the display control section 2, and uses it to minimize the amount of data transferred between the bitmap memory section 1 and the screen memory section 3 when the display screen is changed. As shown in FIG. 6, the screen memory section 3 is divided into small rectangular areas that do not overlap each other using the extension lines of each side of each image pattern, and the position and size of each small rectangular area are maintained. .

Next, the processing determination unit 8 receives an instruction from the display control unit 2 to display the rectangular image pattern IP1. At this time, the processing determination unit 8 identifies from the display control information in the display control unit 2 that the rectangular image pattern IP1 is hidden in the rectangular image pattern IP2 in the screen memory unit 3,
As a result, the area determination unit 4 is instructed to perform a display operation regarding the rectangular image pattern IP1. Subsequently, the processing determination unit 8 identifies that the rectangular image pattern IP2 is hidden in the rectangular image pattern IP3 based on the instruction from the display control unit 2, and performs a display operation regarding the rectangular image pattern IP2. The area discriminator 4 is instructed to do so.

Next, when the processing determination unit 8 receives an instruction to display the rectangular image pattern IP3 from the display control unit 2,
From the display control information in the display control section 2, it is identified in the screen memory section 3 that the rectangular image pattern IP3 is not hidden by other rectangular image patterns, that is, rectangular image patterns IP1 and IP2. In this case, the processing determination unit 8
does not instruct the area discrimination unit 4, but directly transfers the rectangular image pattern IP3 in the bitmap memory unit 1 to a predetermined position in the screen memory unit 3 without dividing it into small rectangular areas.
Instruct DMAC5. Therefore, the rectangular image pattern IP3 can be generated in the screen memory section 3 by operating the DMAC 5 only once.

As another example of the operation of the processing determining section 8, the processing determining section 8 deletes the rectangular image pattern IP3 from the state of the screen memory section 3 shown in FIG. 4 and generates the state of the screen memory section 3 shown in FIG. Explain the operation.

At this time, the processing determination unit 8 determines whether the rectangular image pattern IP3 is different from another rectangular image pattern in the screen memory unit 3 based on the display control information from the display control unit 2.
i.e. rectangular image patterns IP1 and IP2
identify that it is not in a state hidden by
However, the change type is "erase" and rectangular image pattern IP2 is rectangular image pattern IP
3, when erasing, it is necessary to restore the part of the rectangular image pattern IP2 that is hidden by the rectangular image pattern IP3 to the image pattern of the rectangular image pattern IP2. In this case, the processing determining section 8 instructs the area determining section 4 to erase IP3 in the screen memory section 3. Upon receiving the instruction, the area determination unit 4 determines the IP3 in FIG.
m ₁₃ , m ₁₅ , m ₁₆ , and m ₁₇ are filled in as a background pattern, and m ₁₂ and m ₁₄ of IP2 are restored.

As still another example of the operation of the processing determining unit 8, the eighth
The operation of the process determining unit 8 when erasing the rectangular image pattern IP3 in the state of the screen memory unit 3 shown in the figure will be described.

At this time, the processing determination unit 8 determines whether the rectangular image pattern IP3 is different from another rectangular image pattern within the screen memory unit 3 based on the display control information within the display control unit 2.
i.e. rectangular image patterns IP1 and IP2
and the rectangular image pattern IP3 is not hidden by the rectangular image pattern IP1.
It is determined that neither of the rectangular image patterns of IP2 and IP2 is hidden. Therefore, although the change identification is "erase", the process determining unit 8 does not instruct the area determining unit 4 to delete the rectangular image pattern IP3, and the process determining unit 8 does not instruct the area determining unit 4 to delete the rectangular image pattern IP3 in the screen memory unit 3. Directly instructs DMAC5 to fill the area with the background pattern. Therefore, the rectangular image pattern IP3 in the screen memory section 3 can be erased by operating the DMAC 5 only once.

〔Effect of the invention〕

As described above, according to the display device of the present invention, when the image pattern overlaps with another image pattern, the display change is performed in units of small rectangular areas, and when the image patterns do not overlap, the display is changed in small rectangular areas. Since the image pattern is configured to be changed in units of the entire image pattern without being divided, display changes related to the image pattern can be made at high speed because the display changes related to the image pattern are performed in units of small rectangular areas. Since the number of areas to be managed is reduced, the memory capacity can be reduced and the write process becomes easier.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a conventional display device of this type, and FIG. 3 shows three rectangular image patterns held in a bitmap memory section. Figure 4 is an explanatory diagram showing the state in which 3
FIG. 5 is an explanatory diagram showing a state in which rectangular image patterns are held. FIG. 5 is an explanatory diagram specifically expressing display control information held in the display control unit. FIG. An explanatory diagram showing the state of the divided screen memory section, FIG. 7 is an explanatory diagram of the screen memory section when one of the three rectangular image patterns is erased, and FIG. 8 is an explanatory diagram showing the state of the screen memory section when one of the three rectangular image patterns is erased. FIG. 2 is an explanatory diagram showing a state in which three rectangular image patterns with different arrangements are held in the screen memory unit. In the drawing, 1 is a bitmap memory section (first memory section), 2 is a display control section, 3 is a screen memory section (second memory section), 4 is an area discrimination section, 5 is a direct memory access controller section, 6 is a video control section, 7 is a cathode ray tube, and 8 is a processing discrimination section. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A first memory section that holds data of a plurality of image patterns; a second memory section that holds data of display patterns corresponding to dots on a display screen; and the first memory section. a data transfer section that transfers data held in the image pattern to the second memory section; a position of the image pattern in the first memory section and the second memory section necessary for displaying the image pattern; A display control unit that holds display control information such as size and display priority for overlapping display, and a second memory unit that extends each side of each image pattern based on display instructions from the display control unit. The area is divided into small rectangular areas that do not overlap each other using lines, and the position and size of each small rectangular area are maintained, and the areas that need to be changed in the second memory section are identified in each divided unit. an area determination unit that identifies an area in the first memory unit with respect to the area; and a display held in the display control unit when transferring image pattern data in the first memory unit to the second memory unit; Determining whether or not an image pattern and another image pattern overlap based on the control information, and when determining that they do not overlap, transmitting data of the image pattern from the first memory section to the second memory section. Instructs the data transfer unit to transfer the data, and if it is determined that the image patterns overlap, activates the area determination unit to identify areas of the image pattern that are not hidden by other image patterns; A display device comprising: a processing determination unit that instructs the data transfer unit to transfer data of the area from the first memory unit to the second memory unit.