JPH05282387A - Graphic overlapping recognizing method - Google Patents

Abstract

PURPOSE:To recognize the overlapping of graphics at a high speed by performing a simple coordinate calculation without using any graphic logical operation. CONSTITUTION:It is decided whether two input horizontal and vertical polygoanl graphics A and B are partly overlapping with each other or not, whether the graphic A is included on the graphic B or not, and whether both graphics A and B are not overlapping at all with each other or not. Under such conditions, an apex P1 (X1, Y1) of the graphic A is noted and the intersecting points (P2-P5) are obtained between a straight line l (Y=Y1:Y1 showing the Y coordinate value of P1 and the graphic B. These intersecting points are arranged in the order of smaller X coordinate values, that is P2, P1, P3, P4 and P5. It is decided that P1 is included in the graphic B is P1 has an even order number. This processing is carried out to each apex of the graphic A. Then the graphic A is included in the graphic B as long as all apexes of the graphic A are included in the graphic B. If no apex of the graphic A is included in the graphic B, both graphics A and B are not overlapping with each other. Otherwise both graphics are partly overlapping with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recognizing overlapping figures in a CAD system.

[0002]

2. Description of the Related Art Conventionally, graphic logic operation has been used as a means for recognizing the overlap of graphics. FIG. 5 is a block diagram of a conventional figure overlap recognition method. In step 1, two polygon figures A and B as shown in FIG. 3 or 4 are input. In 2, the AND of the two figures (the figure of the overlapping portion of the two figures A and B) is obtained.
In 3, the overlapping is determined based on the relationship between the overlapping figure obtained in 2 and the input figures A and B.

Without the AND figure, the two figures do not overlap at all (FIG. 4). If the AND graphic is equal to one graphic, the graphic is included in the other graphic. If the AND figures are not equal to either of the two figures, they partially overlap (Fig. 3).

The slit logic method is an example of the graphic logic operation method 2. In this case, as shown in FIG. 6, it is divided into elongated sections orthogonal to the X or Y axis. Next, an operation is performed between the slits at the edges that pass through the slits, and all slits are repeatedly processed to obtain the desired result. The overlapping state of the figures in each slit can be judged by the order relation of each edge at the lower end of the slit. An AND figure (a figure in the overlapping portion of two figures) is obtained by this method.
(For details, see Nishide et al. "One method of logical operation processing of LSI artwork data", Shin-Gakken CTS78-126, Yoshida et al. "One method of logical operation processing of figures" S54 Information Processing Society of Japan P587)

[0005]

However, in the above-mentioned configuration, since the graphic logic operation is performed, there is a problem that the algorithm is complicated and a very long time is required for the operation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide means and apparatus for recognizing graphic overlap at high speed.

[0007]

In order to achieve the above-mentioned object, the present invention performs overlapping recognition of horizontal and vertical polygon figures by a method as shown in FIGS. That is, first,
A slit is cut at each apex of the figure B to find an intersection with the figure A. Then, the overlap is determined based on the positional relationship between the intersections and the vertices.

[0008]

According to the present invention, with the above-mentioned configuration, the overlapping of the horizontal and vertical polygon figures is determined by simple coordinate calculation. Since this judging means is realized by an algorithm simpler than the graphic logic operation, it has a smaller number of processing points than the slit method, and it is possible to judge the overlap of the graphics at high speed.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of the method for recognizing overlapping shapes of the present invention.
FIG. 1 as shown in FIG. 3 or FIG.
Two horizontal and vertical polygon figures A and B are input. 2 is
Whether the two input figures A and B partially overlap,
Is graphic A included in graphic B?
It is a means to determine whether they do not overlap at all. The movement
The work will be described with reference to FIG. First, the vertex P of A₁(X₁，
y₁) And pay attention to the straight line 1 (y = y₁: Y₁Is P₁Y coordinate of
Value) and B intersection (P₂~ P_Five). P₁~ P_FiveTo
Order from the smallest x-coordinate value. In FIG. 2, P
₂, P₁, P₃, P _Four, P_FiveBecomes P₁Is an even number
If P₁Is in graphic B.

The above processing is performed for each vertex of A. If all the vertices are in the figure B, the figure A is included in the figure B. If no vertex is in the figure B, the figure A overlaps the figure B. Not not. In other cases, a part of the two figures overlap. In the case of FIG. 2, since all the vertices of the figure A are in the figure B, A is included in B. In the case of FIG. 3, since P ₁ is in B but the other vertices are not in B, A and B are partially overlapped. In the case of FIG. 4, since all the vertices are not in B, A and B do not overlap at all.

With the above-mentioned judging means, it is possible to judge overlapping of figures at high speed without using the figure logical operation which requires a complicated algorithm.

[0013]

As described above, according to the present invention, overlapping of figures can be recognized at high speed by performing simple coordinate calculation without using figure logical operation.

[Brief description of drawings]

FIG. 1 is a flowchart of a method of recognizing overlapping shapes in an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the overlap determination method in the embodiment.

FIG. 3 is a diagram showing an overlap determination figure in the same embodiment.

FIG. 4 is a diagram showing an overlap determination figure in the same embodiment.

FIG. 5 is a flowchart of a conventional figure overlap recognition method.

FIG. 6 is a diagram for explaining the operation of a conventional overlap determination method.

Claims (2)

[Claims] 1. A method of recognizing the overlap of horizontal and vertical polygon figures, wherein the figure overlap is determined by coordinate calculation. 2. A slit is cut at each vertex of one figure to obtain an intersection with another figure, and the coordinates of the obtained intersection are compared with the coordinates of each vertex, and each vertex has the other points. 2. The method for recognizing overlapping of figures according to claim 1, wherein the overlapping of figures is determined based on whether or not the figures are included in the figure.