JPS63136219A - Control system for display of redrawn area - Google Patents

Abstract

PURPOSE:To prevent flickering of a picture by limiting the redrawing processing range set when the mutual relation has a change among those windows to be displayed only to a redrawn area which is detected newly when said mutual relation of window is changed. CONSTITUTION:A redrawing processing range is limited to a range (E1, E2, D2, F2, F1, D1) that is detected newly owing to a fact that the mutual relation is changed among positions, sizes, etc., of windows WD1 and WD2. Then no redrawing processing is carried out to a range (P, E1, D1, F1, R, S) of the window WD2 which requires no redrawing processing. Thus it is possible to improve the redrawing processing efficiency and also to prevent the picture from flickering since no double display is applied to the area of the window WD2 so far displayed. Then the display picture quality is improved.

Description

[Detailed Description of the Invention] [Summary] In a bitmap display device that performs display using a multi-window method, the range of redrawing processing when the mutual relationship between each window changes is determined based on the change in the mutual relationship between each window. It is now limited to the newly revealed drawing area. Thereby, the redrawing process can be performed efficiently, and the image quality can be improved by preventing screen flickering.

[Industrial application field]

The present invention is an improved bitmap display device that performs display using a multi-window method, so that redrawing processing can be efficiently performed when the mutual relationship between each multi-window changes and the drawing area of each window changes. Redraw Area Display Control Method [Prior Art] As shown in FIG. 6, a multi-window display displays a plurality of windows WD, WD2, etc. on a display screen 5CRN of one display. Each window displays a different image. The user is
One window is treated as one display device, and data processing such as graphic processing and document processing is performed interactively via this window. The user can freely generate, move, and disappear windows.

Further, as shown in the figure, it is possible to display a plurality of windows in an overlapping manner. In this case, each window is assigned a priority, and a window with a lower priority is masked by a window with a higher priority.

In the case of FIG. 6, the area of window WD is (A,.

B,,C,,D,), and the area of WD2 is (P.

Q, R, S), so the windows WD and W D
In the two overlapping regions (B+, Q, B+, D+), the image of the window WD+ is displayed, and the image of the window WD is masked and not displayed.

The bitmap display device is equipped with a memory corresponding to each display point on the display screen 5CRN, and has on/off information for each display point.
Since it can be turned off, it is used as a multi-window display device.

In the state shown in FIG. 6, the window W D + is larger than the area (A2°B
2, C2, D2), the area of window WD2 (E
, ,B2. D2. F2. Since the parts Fl, Dl) are exposed, this exposed area (B+, B2).

The area of window WD2 including (D2, F2, B+, D+) (P, B2, D+, F2, R, S
) is necessary.

In such a case, conventionally, the areas (P, B+, D+) that were previously displayed on the display screen 5CRN.

F, , R, S) containing region (P, B2, D2
, F2, R, S: areas indicated by diagonal lines) were all redrawn.

[Problem that the invention seeks to solve]

In the conventional redraw area display control method, when a new area that requires redrawing is revealed, the redrawing process is performed to include the area that was previously displayed on the display screen in addition to the revealed area. was going on.

For this reason, drawing processing requires a lot of time, so in the conventional method, redrawing processing takes a lot of time, and
There was a problem in that the previous display screen and the redrawn screen overlapped, causing flickering on the screen and degrading the image quality.

The present invention provides a redrawing area display control method that efficiently performs redrawing processing and redraws a flicker-free, high-quality screen by limiting the redrawing processing area to a new revealed area. The purpose is to

[Means for solving problems]

The solution taken by the present invention will be explained with reference to the principle explanatory diagram of FIG.

In FIG. 1, 10 is a bitmap display device, 5CRN is a display screen, and WD and WD2 are windows. It is assumed that windows WD, have a higher priority than WD2. Therefore, window WD2 (P, Q, R
, S) region (B+, Q.

B+, D+) is the window WD+ (At
B+C+D,) are masked and not displayed.

In this state, window WD+ (At B+ C
+D+) is the area (A2, B2, C2, D2)
When you move to the position, the area of window WD2 (El, B2, D2
.

The parts F,,F,,D,) are exposed.

The present invention provides the window W displayed on the display screen in this way.
When the mutual relationship such as the position and size of D + and WD2 changes, the redrawing processing range is
The drawing area is limited to the newly revealed drawing area E, E2 D2 F2 FIDl due to the change in the mutual relationship of D2.

[For production]

In the present invention, the range of redrawing processing is set to the window W.
A newly revealed area (E, , B2
, D2, F2. F, , D, ).

In this way, the redrawing process is not performed for the areas (P, E, DI, F, , R, S) of the window WD that do not require drawing processing, and the revealed area (El) is not redrawn.

E2. D2. F2. Since the redrawing process is performed only for the range (Fl, DI), the redrawing process range is narrower than in the conventional method, and the redrawing process can be performed efficiently. Furthermore, since there is no overlapping display of the areas PED, F, and R3 of the window WD2 that had been displayed up to that point, flickering of the screen can be prevented and the image quality can be improved.

Note that the present invention is not limited to the case where there are two windows. That is, in general, when the mutual relationship between a plurality of windows changes and new exposed areas appear at multiple locations, the redrawing processing range is limited to those new exposed areas.

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 2 to 5. FIG. 2 is an explanatory diagram of an example of a bitmap display device implementing the present invention, FIG. 3 is an explanatory diagram of redrawing area extraction processing in the embodiment of the present invention, and FIG. 4 is a flowchart of the same redrawing area information creation process. FIG. 5 is an explanatory diagram of the arrangement of each rectangular area information on the window table in the same embodiment.

(A) Configuration of Bitmap Display Apparatus In the bitmap display apparatus 10 shown in FIG. 2, 11 is a window drawing processing section which performs multi-window display using various known multi-window display control methods.

12 is a mapping memory, inside which each window (WD
+, WD2) are provided with window memories 121, 122, etc., in which image information of WD2) is stored in bitmap format.

13 is a window management table, each window WD,
, WD2, and the like are provided. The figure illustrates the contents of the window table 132 of the window WD2. When the drawing area of window WD2 is composed of four rectangular areas a to d, the area information of each rectangular area is as follows:
As shown in the figure, various information such as the upper left X coordinate of the rectangle, the upper left Y coordinate of the rectangle, the width of the rectangle, the height of the rectangle, and link information linking to the area information of the next rectangle are stored. Since extraction of these rectangular areas is performed by known clipping processing, the rectangular area information is also called clipping information. Also, since the new revealed area is determined from the difference between the new and old clipping information, it is also called a differential clip.

Reference numeral 14 denotes a window area information processing unit that performs processes such as generating, changing, and storing rectangular area information, that is, clipping information, for each window table in the window management table 13.

A display 15 displays the contents of each window WD, WD2, etc. in the mapping memory 12 in a multi-window format.

(B) Operation of the Embodiment Now, assuming that multi-window display is performed using windows WD, WD2, etc., drawing data for multi-window display is manually input to the window drawing processing unit 11 from a host, keyboard, etc. (not shown). . The drawing data includes data such as window priority, display position on the display, and the position and size of each window.

The window drawing processing unit 11 refers to the window memories 121 and 122 and the window tables 131 and 132 based on the input drawing data, and extracts the image data portions of the window memories 121 and 122 within the areas indicated by the window tables 131 and 132. is extracted and multi-window display is performed using various known methods.

Multi-window display methods include, for example: ■ A method in which images from each window are combined on a frame memory to create a display screen image, and then displayed on a display; ■
When displaying images on the display, scanning addresses of the mapping memory are generated at high speed by taking into consideration the priority of each window, the position of each window on the mapping memory, the position of each window on the display screen, etc. There are methods of combining signals.

Now, in this state, due to the change in the mutual relationship of windows WD, WD2, etc., a,
Assume that the areas indicated by b and C have been newly revealed and need to be redrawn. d is the area that has been displayed up to that point.

The window drawing processing unit 11 sends area information such as the position and size of each window in the drawing data to the window area information processing unit 14.

The window area information processing unit 14 compares the manually generated area information of each window WD and WD with the area information of the corresponding window tables 131 and 132, and if there is a change in the area information, changes the area information of the redraw area. Perform extraction processing.

Next, a general method of redrawing area extraction processing will be explained with reference to FIGS. 3 and 4.

In FIG. 3(a), it is assumed that the diagonally shaded area between rectangle 1 and rectangle 2 is the redrawing area RDP. In addition, tl (x, y)
and c+(x, y) are the upper left and lower right coordinates of rectangle 1, and t2 (x, y) and C, (x, y) are the upper left and lower right coordinates of rectangle 2.

This redrawing area RDP is divided into 4 areas as shown in FIG. 3(b).
The area is divided into rectangular areas REC, -REC, and area information for each rectangle is created. FIG. 4 is a flowchart showing this rectangular area information creation process.

■ It is determined whether rectangle 1 and rectangle 2 overlap. This is the coordinates t+ (
x, y) and t2 (x, y), C+(x, y) and C
2(x, y) (step S, )).

If rectangle 1 and rectangle 2 do not overlap, rectangle area information regarding rectangle 1 and rectangle 2 is created by clipping processing, respectively (step S2).

■ If rectangle 1 and rectangle 2 overlap, compare the magnitude relationship between the upper left y coordinates t+ (y) and t2 (y) of rectangle 1 and rectangle 2 to determine the positional relationship between the upper sides of both rectangles. (Step S3).

When t+ (y)>t2 (y), that is, rectangle 1
When the upper side is below the upper side of rectangle 2, the rectangular area R
Since FC, exists, area information of rectangular area RFC, is created based on the area information of rectangle 1 and rectangle 2 (step S4).

■ Upper left X coordinate t of rectangle 1 and rectangle 2, (X) and t
+ (y) is compared to determine the positional relationship between the left sides of both rectangles (step S5).

When t+ (x)>tz (x), that is, when the left side of rectangle 1 is on the right side of the left side of rectangle 2, rectangular area RE C2 exists, so the area information of rectangle 1 and rectangle 2 Area information of the rectangular area REC is created based on (step S6).

■ Lower right X coordinates of rectangle 1 and rectangle 2 C1 (x) and C2 (
X) is compared to determine the positional relationship between the right sides of both rectangles (step St>).

When C+ (x)<C2(x), that is, when the right side of rectangle 1 is on the left side of the right side of rectangle 2, the rectangular area RE
Since C3 exists, area information of rectangular area REC3 is created based on the area information of rectangle 1 and rectangle 2 (step S8).

■ Lower right y coordinates Cl (y) and C of rectangle 1 and rectangle 2
2(y) to determine the positional relationship between the lower sides of both rectangles (step 39).

When C+ (y)<C2(y), that is, when the lower side of rectangle 1 is on the right side of the lower side of rectangle 2, the rectangular area RE
Since C, exists, create area information of rectangular area REC, based on the area information of rectangle 1 and rectangle 2 (Step 5IQ) 0 Apply the rectangular area creation process of ■ to ■ above. Accordingly, the area information of the rectangular areas a, b, and C of the redrawing area in FIG. 2 can be created. That is, the area information of rectangle a can be created by the process ``■'', the area information of the rectangle ``su'' can be created by the process ``■'', and the area information of the rectangle C can be created by the process ``■''.

The area information of the new rectangles a, b, and C of the window WD2 created in this way is stored in the window table 132 together with predetermined link information. FIG. 5 shows the arrangement of each rectangular area information on the window table 132. Note that since each area information of each rectangular area a to C is created by clipping processing, the area information of each rectangle is expressed as "clipping information" in FIG. 5. Further, the area information of rectangle d has already been stored. In the manner described above, the redrawing processing range can be limited to the newly revealed area (a-C).

Since window WD has a higher priority than window WD, new area information for window WD can be created by rewriting the upper left and lower right coordinates from old coordinates to new coordinates.

Window WD1 by window area information processing unit 14
and WD, new area information and window table 1
31 and 132, the window drawing processing unit 11 stores the window table 131 as in the conventional method.
．． 132 and corresponding window memories 121, 122
, the image data portions of the window memories 121 and 122 within the areas indicated by the window tables 131 and 132 are retrieved, and multi-window display is performed using various known methods.

In the case of window WD2, drawing processing is performed for each rectangular area, and by drawing in the order of a→b-+C-+d based on the link information, the window WD including the new redrawn area (a-c) is created. A desired area (a-d) of , is drawn.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment.

For example, when extracting a new redrawn area, in addition to dividing it into horizontal rectangular areas (a to C) as shown in Figures 3 and 4, it is also divided into vertical rectangular areas and extracted. You can also do it like this.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be obtained.

(a) Since the redrawing process is performed only on areas that are newly revealed due to changes in the mutual relationship between the windows, the redrawing process range becomes narrower, and the redrawing process can be performed efficiently.

(Mouth) Since the same area is no longer displayed overlappingly, screen flickering is prevented and image quality can be improved.

[Brief explanation of the drawing]

Figure 1: An explanatory diagram of the principle of the present invention. Figure 2: An explanatory diagram of an example of a bitmap display device implementing the present invention. Figure 3: Redraw area extraction processing in an embodiment of the present invention. FIG. 4: A flowchart of the redrawing area information creation process in the embodiment of the present invention. FIG. 5: An explanatory diagram of the arrangement of each rectangular area information on the window table in the embodiment of the present invention. FIG. 6: An explanatory diagram of a conventional redraw area display control method. 1 and 2, 10... bit map display device, 11...
Window drawing processing unit, 12...mapping memory,
13... Window management table, 14... Window area information processing unit, 15... Display, 121
゜122... Window memory, 131, 132...
・Window table WD, WD2-...Window, 5CRN...Display screen.

Claims (1)

[Claims] Re-drawing area display control when the mutual relationship between windows displayed on a bitmap display device (10) that performs multi-window display changes and the drawing area of each window changes. In this method, the range of redrawing processing when the mutual relationship between windows displayed on the display screen of the bitmap display device (10) changes, A redraw area display control method characterized by being limited only to an area.