JP2879831B2 - Graphic element extraction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a graphic element for designating a part of various graphic elements such as a straight line, an arc, and a coordinate point constituting drawing data as an edit target or an output target. Regarding the designation method.

2. Description of the Related Art In a system that handles drawing data such as a CAD (Computer Aided Design) system, a specific graphic element in created drawing data or read drawing data is designated to delete, move, enlarge, and delete. Editing processing such as rotation is frequently performed. Further, it is also performed to instruct only a specific graphic element and output it to a drawing device such as a plotter.

In such a case, a graphic element designating process for specifying an edit target or an output target is required.

Conventionally, as this type of graphic element designation method, a method using a pointing device such as a mouse is often used. One method is to target graphic elements included in a rectangular area specified by the mouse as target elements, and the other method is to specify target graphic elements one by one using the mouse. It is a method.

[Problems to be Solved by the Invention] However, in the former method, the area that can be specified is limited to a rectangular area surrounded by outlines extending in the horizontal and vertical directions. However, there are inconveniences such as designating graphic elements that do not need to be designated, and leaving unspecified parts.

Further, in the latter method, although the degree of freedom in specifying graphic elements is high, there is a drawback that the specification operation is troublesome because graphic elements must be specified one by one.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a graphic element specifying method capable of easily specifying an arbitrary graphic element of any shape in a free form.

[Means for Solving the Problems] A graphic element designating method according to the present invention provides an area setting means for inputting an arbitrary outline defining an area from which a graphic element is to be extracted, and each drawing constituting drawing data. It is characterized in that it comprises an in-area element extracting means for judging whether or not an element is included in the area surrounded by the outline and extracting the element when the element is included in the area.

[Operation] In the present invention, when an area by an arbitrary outline is set by the area setting means, the in-area element extracting means
It is determined whether each graphic element is included in the area surrounded by the outline, and only the graphic elements included in the area are extracted. Therefore, by arbitrarily specifying the shape of the outline, it is possible to specify an area of any shape as the specified area. Can do
Graphic elements can be specified very easily.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a functional block diagram showing a configuration of a graphic element designating apparatus according to an embodiment of the present invention. This device is based on a hardware configuration of a general CAD system including an input device, a display device, a CPU, a memory, an external storage device, and an output device, and a program for causing the hardware configuration to execute processing described later. In particular, only a portion for executing a process of designating a graphic element is extracted and expressed as a functional block.

In FIG. 1, an area setting means 1 includes a coordinate input means such as a mouse, a keyboard or a joystick, and graphic data composed of line segments such as straight lines and arcs whose end points input by the coordinate input means are designated by an operator. A closed graphic is generated by connecting with each other, and an area from which a graphic element is to be extracted is set. The area data set by the area setting means 1 is stored in the area data storage means 2.

The area data stored in the area data storage means 2 is supplied to the in-area element extraction means 3. The in-area element extraction means 3 is supplied with graphic elements such as coordinate points, straight lines, and arcs to be edited, which are stored in the graphic element storage means 4.

The in-area element extracting means 3 fetches the graphic elements one by one, determines whether or not the fetched graphic elements are included in the area defined by the area data, and determines the graphic elements included in the area and the graphic elements included in the area. The part included in the area is extracted as an element in the area. The extracted intra-area element is stored in the intra-area element storage means 5. The in-region elements stored in the in-region element storage unit 5 are supplied to the in-region element output unit 6 and are output via a drawing device such as a plotter (not shown).

Next, the operation of the graphic element designating apparatus according to the present embodiment thus configured will be described.

When the operator inputs, for example, a straight line indicated by a broken line in FIG. 2 using the area setting means 1, an area S1 surrounded by the input is set as a specified area. At this time, the area data storage means 2 stores the area S1 in FIG.
Coordinates (ax, ay), (bx, by), of the outline points A, B, C, D, E, F of
.., (Fx, fy) are stored. Note that this is an example in which the designated area is surrounded by a straight line. For example, when an arc or the like is used, the end point coordinates, the center coordinates, the radius, and the like are stored in the area data storage unit 2. Absent.

When the designated area S1 is set by the area setting means 1,
The intra-region element extraction means 3 extracts the intra-region elements according to the procedure shown in FIG.

That is, first, one graphic element is read from the graphic element storage means 4 (S1). Next, the type of the graphic element is checked (S
2) If the graphic element is a coordinate point, perform an in-region discrimination process (S3) of the coordinate point; if it is a straight line, perform a scissoring process of the straight line (S4); A scissor link process is performed (S5). When a part of the graphic element is included in the specified area, the entire graphic element may be extracted. However, here, only the part included in the specified area is extracted by the scissoring process. Like that.

When the determination of all the graphic elements is completed, the in-region element extraction processing ends (S6).

FIG. 4 is a diagram showing further details of the in-region discrimination process of coordinate points (S3) in the process of FIG.

That is, when the read graphic element is a coordinate point, first, as shown in FIG. 5, a line segment between the coordinate point G1 or G2 and each of the outline points A to E is obtained (S11). Next, each line segment AG
The angles formed by 1, B−G1,... Are added (S12). However, the fifth
Assuming that the counterclockwise direction is the positive direction in the figure, if the angle formed by the line segment exceeds 180 °, the addition process is performed on the assumption that the angle formed by the line segment is the negative direction. When such addition processing is performed, for example, when the coordinate point G1 is included in the designated area S1 as shown in FIG. 5A, the addition result from the contour point A to the contour point E is just obtained. 360 ゜. On the other hand, when the coordinate point G2 is not included in the designated area S1, as shown in FIG. 3B, the contour points A to C are in the positive direction, the contour points C to F are in the negative direction, Since the contour points F to A are in the positive direction, the addition result is 0 °. Therefore, the addition result
When it becomes 360 °, it is determined that the coordinate point G1 is an element in the designated area, and the coordinate point G1 is extracted as an element in the area. On the other hand, if the addition result does not become 360 °, it is determined that the coordinate point G2 is an element outside the area.

FIG. 6 shows a scissoring process (S
It is a figure which shows the further detail of 4).

That is, if the read graphic element is a straight line,
First, the intersection between the straight line and the outline point is calculated (S21). If there is no intersection (S22), the in-region discrimination is performed for the coordinates of the start point and end point of the straight line by the same processing as in FIG. 4 (S23). If the coordinates of the start and end are included in the designated area (S24), the straight line is also included in the designated area, and the straight line is extracted as an element in the area (S25). If it is determined that any one of the start and end coordinates is outside the designated area (S24), it is determined that the entire straight line does not exist within the designated area, and the processing of the next element is performed. I do.

On the other hand, if there is an intersection (S22), as shown in FIG. 7, the straight line L is divided into line segments P1-P3, P3-P4, P4-P2 by intersections P3 and P4 of the straight line L and the outline. (S2
6). Next, the midpoints O1, O2, O3 of the respective line segments are obtained, and it is determined whether or not these midpoints O1 to O3 are respectively included in the designated area (S27). Then, a line segment whose midpoint exists in the designated area is extracted as an element in the area.

In these processes, the in-region discriminating process of the start and end points and the middle point (S23, S27) is performed by the in-region discriminating process of the coordinate points in FIG.

By such processing, for example, as shown in FIG. 8, when the graphic elements are examined in the order of line segments L1, L2, L3,.
Ultimately, only the line segments LP1 and LP2 included in the designated area S1 are scissored and extracted.

As described above, according to the apparatus of the present embodiment, the extraction region of the graphic element can be set by an arbitrary graphic. Therefore, even for a graphic element having a complicated shape, the graphic element can be specified by a simple procedure. Can be.

In the above embodiment, the specified graphic element is output. However, when the specified graphic element is to be edited and processing such as deletion, enlargement, reduction, rotation, and movement is performed, the area In-area element editing means may be provided instead of the in-element output means 6. Also in this case, needless to say, the effects of the present invention can be obtained.

[Effects of the Invention] As described above, according to the present invention, it is possible to specify an extraction region of a graphic element by an arbitrary outline, and therefore, even if the graphic element is deformed in any way, It is possible to easily set an area surrounding this, and it is possible to easily specify a graphic element.

[Brief description of the drawings]

1 to 8 are views for explaining a graphic element designating apparatus according to an embodiment of the present invention. FIG. 1 is a functional block diagram of the apparatus, FIG. 2 is a schematic diagram showing area data, and FIG. FIG. 3 is a flowchart of an in-region element extraction process, FIG. 4 is a flowchart of a coordinate point in-region determination process, FIG. 5 is a schematic diagram for explaining the same process, FIG. 6 is a flowchart of a straight line scissoring process, FIG. 7 is a schematic diagram for explaining the same process, and FIG. 8 is a schematic diagram for explaining the in-region discrimination process. 1 ... Area setting means, 2 ... Area data storage means, 3 ...
... Element extracting means in area, 4... Graphic element extracting means, 5.
... area element storage means, 6 ... area element output means.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06F 15/62 G06F 15/72

Claims (1)

(57) [Claims] 1. An area setting means for setting an area from which a graphic element is to be extracted by area data comprising a graphic element defining an outline of the area, and an area for storing the area data set by the area setting means. A data storage unit for determining whether or not each graphic element consisting of a point and a line segment element constituting the drawing data is included in the area, and determining whether or not the graphic element is included in the area, An element extracting unit, wherein, when the graphic element forming the drawing data is a point, the in-region element extracting unit extracts when the point exists inside the region data, and extracts the drawing data. If the graphic element that constitutes is a line element, the intersection between the line element and the area data is calculated, and the end point of the line element having no intersection with the area data is calculated as the end point. Extracted when it exists inside the data, and for a line segment element having an intersection with the area data, the line element is divided by the intersection, and each of the divided line elements is divided into the area data by the middle point. A graphic element extraction method characterized in that the graphic element is extracted when it exists inside the image.