JPS6359683A - Graphic drawing system - Google Patents

Abstract

PURPOSE:To execute an effective picture processing by examining the state of the overlap of a screen and other window, selecting a proper processing method and processing. CONSTITUTION:A position relation identification part 12 obtains information relating to the window from a window information holding part 10, information relating to a minimum rectangle R surrounding a graphic applied from a rectangle R forming part 11 and identifies whether the relation thereof corresponds to a type of respective types and informs to a drawing method decision part 14. According to the drawing of a method 1, the intersection point of the graphic to be drawn and the window W is obtained to form a graphic to be newly drawn and execute the drawing by a system consisting of an intersection point search part 15, a graphic forming part 17 and a drawing part 19 and according to the method 2, whether the graphic is situated within the window W for every picture element or not is inspected by a system consisting of a picture element position search part 16, a decision part 18, and the drawing part 19, only when the graphic is decided that it is situated within the window W, drawing is executed.

Description

[Detailed Description of the Invention] [Summary] When controlling a multi-window screen that displays multiple virtual display screens on a single display screen, when displaying windows in an overlapping manner, the figures, etc. in the window may overlap with those of other windows. If it is in the shadow of a window, you need to hide that part.

Conventionally, when processing such images, there were problems in that the processing took a long time, and depending on the overlap between the image and other windows, the processing became extremely inefficient. In order to solve these conventional problems, the present invention discloses a technology that can perform efficient image processing by examining the state of overlap between the screen and the pond window and selecting an appropriate processing method. are doing.

[Industrial Field of Application] The present invention relates to image processing by an information processing device, and in particular, in a multi-window screen display, some of the figures to be displayed are hidden behind other windows. This relates to a control method when drawing only a portion.

[Prior Art] When displaying figures on a display, a method called multi-window is sometimes used.

As shown in Figure 4(a), this has several virtual display screens on the display (50, 51, 5 in the figure).
2) It acts as if there are multiple displays.

By the way, when a number of windows are displayed on the display in this way, the windows may overlap. (b) shows a case where two windows overlap.

At this time, you may want to display a figure in the lower window 54, but when drawing, you are not allowed to rewrite the contents of the upper window 53, and you must draw only the part excluding the area of the upper window. Must be.

Conventionally, when drawing a figure under the condition that only the area to be displayed is drawn and not outside of that area, the figure must be redrawn by finding the intersection between the figure and the area to be displayed. Either one of two methods was used: configuring the shape and drawing the newly created shape, or checking whether the shape is inside the area to be displayed when writing the shape to frame memory, etc., and then drawing it. .

To further explain these methods using drawings, the former method involves finding the intersection between the figure and the window, reconstructing the figure, and drawing a new figure. When filling in the triangle 55, find the intersection points P, Q, and R of the sides of the triangle 55 and the window 57, and from this find a new quadrilateral 56 configured as A, P, Q, and R, and fill it in. It is.

Also, when writing the latter figure to frame memory etc., the method of checking whether it is inside the window and drawing it is as follows.
For example, when filling out a triangle DEF as shown in FIG. 6, by managing the area of the window 58, between ST' and U→
This is a control method in which drawing is performed in the range U→■' in the range indicated by V, but not drawn in other sections in the same range and in the sections indicated by reference marks W to X and thereafter.

[Problems to be Solved by the Invention] Among the conventional drawing methods described above, the former method involves finding the intersection between the figure and the area to be displayed, reconstructing the figure, and drawing the newly created figure. There is a problem in that a lot of processing time is required to reconstruct the figure. On the other hand, in the latter method of drawing by checking whether or not it is inside the area to be displayed when writing the figure to a frame memory etc., for example, as shown in FIG. Even if only a small part of the figure 59 (the part indicated by 61 in the figure) is actually drawn, it is necessary to check each time whether or not the entire figure 59 is to be drawn. The problem was that the efficiency was very low.

In view of these conventional problems, the present invention draws figures etc. efficiently and at high speed under the condition that drawings are made only within a specified window and not outside of that window. The purpose of the present invention is to provide an image processing device that can perform the following functions.

[Means for Solving the Problems] According to the present invention, the above-mentioned object is achieved as described in the claims, in which, in processing an image by an image drawing device, a figure to be drawn is divided between the figure and the display screen. A method that draws only the part that overlaps with a specific area of
means for generating a minimum rectangle R surrounding a given figure;
means for holding information regarding a region W of a window to be drawn for the overlapping portion when it overlaps with a figure or a part thereof;
means for identifying the positional relationship between the R and W, and means for comparing the area of the R and the area of the W;
A method of generating and drawing a new figure to be drawn by finding the intersection of the figure to be drawn and W according to the positional relationship between R and the area of W. When a figure is written to the frame memory, the figure drawing method is characterized in that, for each pixel, it is drawn by checking whether it is located within W or not. achieved.

[Embodiment] As described above, the present invention can draw figures efficiently and at high speed under the condition that only the inside of the window should be drawn and the outside should not be drawn. According to the rflj relationship between the figure and the window, the first method is to find the intersection between the figure and the window, reconstruct the figure, draw the newly created figure, and write the figure to a frame memory, etc. In this method, the second method of drawing is performed by checking whether or not the object is inside the window.

An example of the drawing procedure according to the present invention will be described below.

■Find the smallest rectangle R that completely encloses the given figure. This rectangle R can be found relatively easily.For example, in the case of a polygon, it can be found from the maximum and minimum values of the coordinates of all vertices, and in the case of a circle, it is a square whose side length is equal to the diameter. becomes.

■The area of the window is SW, the area of the rectangle R is SR1, and the area of the intersection of both is SI.

■There are four types of positional relationships between the window and the rectangle R, as shown in FIG. That is, in Fig. 3, l indicates the window, 2 indicates the minimum rectangle R that completely surrounds the given figure 3, and (a) shows the case where window 1 and rectangle R are far apart (this is type L(b) is when window 1 and rectangle R intersect (this is called type ■); (c) is when window 1 includes rectangle R, this is called type m), (d> is the case where window 1 is included in rectangle R (this is assumed to be type ■).

(2) Let T1 be the time required to find the intersection between the figure and the window, reconstruct the figure, and create a new figure. Tl
is proportional to the number of sides.

The time required to write the figure to the frame memory is T2
shall be. T2 is proportional to R.

■Approximate results using the first method (hereinafter referred to as method 1) and the second method (hereinafter referred to as method 2) for each of the four types shown in (a) to (d) in Figure 3. The opening during drawing is shown in Table 1.

Table 1: Based on the above conditions, actual drawing is performed using the following device configuration and its control.

FIG. 1 is a block diagram of one embodiment of the present invention, showing the configuration of the drawing section of the window of the image drawing device and the overlapping part of the image, where 1o generates and holds f* information of the window W. 1 is a window information holding unit; 11 is a rectangle R generation unit; 12 is an inter-position gA identification unit; 13 is a comparison unit; 14 is a drawing method determination unit; 1
Reference numeral 5 represents an intersection search section, 16 a pixel position investigation section, 17 a figure generation section, 18 a determination section, and 19 a drawing section.

Furthermore, Fig. 2 shows the flow section showing the υ control.

In FIG. 1, the positional relationship identification unit 12 obtains information related to windows from the window information storage unit 10, and information related to the smallest rectangle R surrounding a given figure from the rectangle R generation unit, and calculates the relationship between them. out of the types shown in FIG. 3 and informs the drawing method determining unit 14 of the type.

The drawing method determining section 14 determines a drawing method for each type as shown below, and arranges it to each section, thereby performing drawing.

If it is type (2), Tl and T2 are calculated, and if T1 is smaller than T2, method 1 is used, and if it is larger, method 2 is used to draw.

If it is mouth, type ■, find T1 and T2 and compare part 1.
Find the ratio of SI and SR from 3 and obtain T1+72・(SI/S
If R) is smaller than T2, method 1 is used, and if it is larger, method 2 is used for drawing.

C. If it is type H, use method 2 to draw.

2. If type ■, find Tl, T2, SI, SR, and T
If 1+72·(SI/SR) is smaller than T2, method 1 is used, and if it is larger, method 2 is used for drawing.

Note that in the drawing method 1 described above, a system including the intersection search unit 15, figure generation unit 17, and drawing unit 19 finds the intersection between the figure to be drawn and the window W, and generates a new figure to be drawn. On the other hand, in the case of method 2, a system including a pixel position investigation section 16, a determination section 18, and a drawing section 19 inspects each pixel to see if it is located within the window W. , is drawn only when it is determined that it is within the window W.

[Effects of the Invention] As explained above, according to the present invention, all figures can be drawn efficiently and at high speed under the condition that drawing is only done within the window and not outside of the window. .

In addition, the drawing time for large figures can be kept below a certain value. This constant value is T1+ (time to draw the entire window).

Furthermore, by using method 2 when the figure is small, the drawing time can be brought closer to zero as the figure is made smaller.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a flowchart showing control of one embodiment of the present invention, FIG. 3 is a diagram explaining the relationship between a window and a rectangle surrounding a figure, and FIG. The figure explains a multi-window type display, Figure 5 explains how to find the intersection between a figure and a window, reconstruct the figure and draw it, and Figure 6 shows whether the figure is inside a window. Diagram explaining how to check and draw, 7th
The figure is a diagram illustrating drawing when most of the figure is hidden behind other windows.

Claims (1)

[Scope of Claims] A method of drawing only a portion of a figure to be drawn where the figure overlaps with a specific area within a display screen in processing an image by an image drawing device, the method comprising: A means for generating the smallest enclosing rectangle R, a means for holding information regarding a region W of a window to be drawn for the overlapping portion when it overlaps with a figure or a part thereof, and identifying a positional relationship between the above-mentioned R and W. and a means for comparing the area of said R and the area of said W, and the object to be drawn is provided according to the positional relationship between R and W and the relationship between the area of R and the area of W. How to generate and draw a new figure to be drawn by finding the intersection of the figure and W, and when writing the figure to the frame memory.
A graphic drawing method characterized in that for each pixel, drawing is performed by selecting one of two methods: checking whether the pixel is located within W and drawing.