JPH08147463A - Figure generating device - Google Patents

Abstract

PURPOSE: To accurately and efficiently connect segments by specifying an area including a segment and a connection part to be connected and newly drawing a segment which has the coordinate values of the intersection of the segment of this area as coordinate values of a connection-side end point. CONSTITUTION: An input interface 3 inputs an editing instruction inputted from a keyboard 1 and the coordinate values of two points indicated with a mouse 2 to a CPU 4. The CPU 4 starts a program for segment connection stored in a program part 52 of a memory 5 with the inputted editing command. Then the area in a specific range including the connection-side end point of a segment connecting with another segment and the intersection of this segment and the other segment connecting this segment is specified. The segment having its end point included in the area among segments included in the specified area is selected as a segment to be connected to the other segment, the coordinate values of the intersection of the segments are calculated, and the coordinate values of the connection-side end point of the selected segment are replaced with the coordinate values of the intersection to newly draw a segment by extending or shortening the segment, thereby connecting the segment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer having a graphics function for connecting discontinuous line segments,
The present invention relates to a graphic device such as a CAD device.

[0002]

2. Description of the Related Art There are roughly two methods of connecting discontinuous line segments in a conventional figure forming device. (1) Using a pointing device such as a mouse Enlarge the part to be connected on the CRT screen and select the line segment extension / shortening edit menu to select the end point of the line segment to be connected. After selecting with the mouse by eye measurement, move the graphics cursor from the end point to extend or shorten the line segment, and set the line segment to be connected to the end point of another line segment or the connection point on the line other than the end point. Connect and visually check the connection status.

(2) Method of changing line segment attributes The attributes (coordinate value, line width, inclination angle, central angle, etc.) relating to drawing of line segments to be connected are displayed on the screen of the CRT. The user calculates the coordinate value of the connecting point, the central angle, etc. from these attribute values and changes the attribute value displayed on the screen, so that the line segment is extended or shortened and connected to another line segment.

[0004]

In the above-described conventional figure forming apparatus, when connecting line segments using a pointing device such as a mouse, the end point is selected by visual observation to move the graphics cursor, The end points or connection points of other line segments that should be connection points are visually selected to connect the line segments, and the connection state is visually checked, resulting in lack of accuracy and low processing efficiency, and the accuracy of the pointing device. Is low and the graphics cursor movement pitch is coarser than the drawing pitch of the figure, there is a case in which the end points or the connection points cannot be accurately selected and the connection cannot be performed. Further, in the method of changing the attribute value of a line segment, it is necessary to calculate the coordinate value of the connecting point, the central angle, etc., so that the operation is complicated.

The present invention has been made to solve such a problem, and when an area including a line segment to be connected and a connected portion is designated, an intersection of the line segments included in this area is specified. Calculate the coordinate values of and draw a new line segment with the coordinate value of this intersection as the coordinate value of the end point on the connecting side to accurately and efficiently connect the line segments and create a figure that is easy to connect. The purpose is to provide a device.

[0006]

SUMMARY OF THE INVENTION A graphic creating apparatus according to the present invention relates to drawing of drawn line segments including coordinate values of end points in a graphic creating apparatus for connecting drawn discontinuous line segments. Means for storing the attribute value, means for designating an area of a predetermined range including an end point on the connecting side of a line segment to be connected to another line segment, and an intersection of the line segment and the other line segment, Means for selecting, as a line segment to be connected to the other line segment, a line segment whose endpoint is included in the line segment included in the area of the predetermined range designated by the means, and the coordinate value of the intersection point And a means for replacing the coordinate value of the end point on the connecting side of the selected line segment with the coordinate value of the intersection point, and the coordinate value replaced by the means as the coordinate value of the end point on the connecting side. ,
And a means for newly drawing a line segment obtained by extending or shortening the selected line segment.

[0007]

The graphic creation apparatus of the present invention has a predetermined range including an end point on the connecting side of a line segment to be connected to another line segment and an intersection of this line segment and another line segment to which this line segment is to be connected. When the area of is specified, the line segment whose end point is included in this area is selected as the line segment that should be connected to other line segments, and the coordinate value of the intersection of the line segments is selected. Calculate and replace the coordinate value of the end point on the connecting side of the selected line segment with the coordinate value of the intersection point,
A line segment obtained by extending or shortening this line segment is newly drawn to connect the line segments. Therefore, the line segments are accurately and efficiently connected, and the connecting operation is easy.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing its embodiments. FIG. 1 is a block diagram showing the configuration of the graphic creation apparatus of the present invention. In the figure, 1 is a keyboard for inputting editing commands such as line segment connection, 6 is a monitor for displaying graphics, 2 is a rectangular area including the end points of the line segments to be connected and the intersections of the line segments. 6 is a mouse that designates two vertices on a diagonal of a rectangle to be designated on the screen. The input interface 3 is an editing command input from the keyboard 1,
And the coordinate values of the two points designated by the mouse 2 are input to the CPU 4. The CPU 4 activates the line segment connecting program stored in the program section 52 of the memory 5 by the edit command input through the input interface 3, and the coordinate values of the two points designated by the mouse 2 Is stored in a register or the like (not shown) of the memory 5, and a rectangle having two points designated by the mouse 2 as two vertices on a diagonal line is displayed on the monitor 6 by using a screen display program that has already been activated.

The memory 5 includes a system section 51 for storing an operating system, a program section 52 for storing various application programs such as a line segment connecting program and a screen display program, and coordinate values of created line segment end points. Is roughly divided into a data section 53 for storing attribute values and the like including.

Next, the procedure of connecting the line segments by the graphic forming apparatus of the present invention will be described with reference to the flowchart shown in FIG. 2 and the diagram specifically showing the process of connecting the line segments shown in FIG. Incidentally, the two line segments L _1, L _2, the line segment L _1, L ₂ of the start point, respectively P _1s, P _2s, each P _1e of the end point, P _2e, the intersection of the line segment L ₁ and L ₂ ( Let P ₀ be the intersection on extension). The rectangular range D ₀ including the end points on the connection side of the connection target line segments and the intersections of the line segments to be the connection points is designated with the mouse 2 (S1). It is determined whether all four endpoints are within the rectangular range D ₀ (S2), and all four endpoints are within the rectangular range D _0.
Since when present within is a specified error rectangular area D _0, and the like to display a reassignment message rectangular area D _0, the flow returns to step S1.

When there are three or less endpoints within the rectangular range D ₀ , it is determined whether all four endpoints are outside the rectangular range D ₀ (S3), and all four endpoints are within the rectangular range D _0. If it exists outside, it is a designation error, so that a message for redesignating the rectangular range D ₀ is displayed and the process returns to step S1. Steps S2, S3 is determined in the case endpoint present in the rectangular area D ₀ is to three one to determine the line segment L ₁ and L ₂ of the two in the rectangular area D ₀ is intersected (S4).

When the two line segments L ₁ and L ₂ do not intersect within the rectangular range D ₀ (FIGS. 3A and 3B), one or both of the _two line segments L ₁ and L ₂ Rectangle range D by extension of
_It is determined whether or not they intersect within ₀ (S5). Two line segments L ₁ and L
_{If 2} do not intersect in the rectangular area D ₀ is the rectangular area D ₀
Since this is an error in the specification of No. _2, a redesignation message for the rectangular range D ₀ is displayed, and the process returns to step S1.

As a result of the judgment in step S5, the two line segments L ₁
And L ₂ intersect in the rectangular range D ₀ by one or both extensions, the end points on the connecting side (starting point) and the opposite end points (starting point) of the line segments L ₁ and L ₂ are the rectangular range. D ₀
As described below, the coordinate value of the intersection point P ₀ of the line segments L ₁ and L _{2 is set to} a new end point (start point) of one or both of the line segments L ₁ and L ₂ depending on whether or not the line segments L ₁ and L ₂ exist. A new line segment to be the coordinate value of is determined (S6).

That is, the starting _points P _1s and P _{1 of} the line segments L ₁ and L _2
2s are both within the rectangular range D ₀ and end points P _1e and P _2e
To but if both are outside the rectangular area D ₀ (FIG. 3 (a)), the intersection point P ₀ on the extension of the line segment L ₁ and L ₂ and the new start point P _1s and P _2s of the line segment L ₁ and L ₂ . Also, one line segment L ₁
Is outside the rectangular range D ₀ and only the starting point P _2s of the other line segment L ₂ is within the rectangular range D ₀ (FIG. 3b),
The new starting point P of the intersection P ₀ on the extension of the line segment L ₂ line segment L _2
2s .

On the other hand, as a result of the determination in step S4, when the two line segments L ₁ and L ₂ intersect within the rectangular range D ₀ , the end points of the line segments L ₁ and L _{2 on} the connecting side (start point and Depending on whether or not the end point (referred to as the end point) on the opposite side of the line segment exists within the rectangular range D ₀ , as described below, line segments L ₁ and L
A new line segment having the coordinate value of the intersection point of ₂ as the coordinate value of the new end point (start point) of one or both of the line segments L ₁ and L ₂ is determined (S7).

That is, the starting _points P _1s and P _{1 of} the line segments L ₁ and L _2
2s are both within the rectangular range D ₀ and end points P _1e and P _2e
If is together outside the rectangular area D ₀ (FIG. 3 (c)), the intersection point P ₀ of the line segment L ₂ and the new start point P _1s and P _2s of the line segment L ₁ and L _2. If both ends of _one line segment L ₁ are outside the rectangular range D ₀ and only the starting point P _2s of the other line segment L ₂ is within the rectangular range D ₀ (FIG. 3 (d)), the line the point of intersection P ₀ of the minute L ₂ be a new starting point P _2s of the line segment L _2. With the coordinate value of the end point of the new line segment determined in step S6 or S7 as the coordinate value of the start point, a line segment that is an extension or a contraction of the old line segment is newly drawn (S8).

In the above embodiment, the connection of straight lines has been described. However, straight lines and spline curves or Bezier curves, spline curves or bezier curves, etc., can be represented by a quadratic curve or an nth degree polynomial. Even in the case of extension and connection, processing can be performed in the same manner as in the case of a straight line by extending the domain of the curve or performing interpolation maintaining the curvature. FIG. 4 is a diagram specifically showing a connecting process when connecting curves.

[0018]

As described above, when the area including the line segment to be connected and the connected portion is designated, the graphic creation apparatus of the present invention obtains the coordinate value of the intersection of the line segments included in this area. ,
Since a line segment having the coordinate value of the intersection as the coordinate value of the end point on the connection side is newly drawn, the line segments are accurately and efficiently connected, and the connection operation is easy.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a graphic creation apparatus of the present invention.

FIG. 2 is a flow chart showing a procedure for connecting line segments by the graphic creation device of the present invention.

FIG. 3 is a diagram specifically showing a process of connecting line segments in the case of a straight line by the graphic creation device of the present invention.

FIG. 4 is a diagram specifically showing a process of connecting line segments in the case of a curve by the graphic creation device of the present invention.

[Explanation of symbols]

 1 keyboard 2 mouse 3 input interface 4 CPU 5 memory 6 monitor 51 system section 52 program section 53 data section

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location 9365-5H G06F 15/62 320 K 9365-5H 322 C

Claims (4)

[Claims] 1. A graphic creation apparatus for connecting drawn discontinuous line segments to each other, a means for storing attribute values related to drawing including the coordinate values of end points of the drawn line segments, and another line segment. And a means for designating a region of a predetermined range including an end point on the coupling side of the line segment to be connected to the line segment and an intersection of the line segment and the other line segment, and a line included in the region of the predetermined range designated by the means. Of the segments, means for selecting a line segment whose end point is included in the region as a line segment to be connected to the other line segment, means for calculating the coordinate value of the intersection, and the selected line segment Means for replacing the coordinate value of the end point on the connection side with the coordinate value of the intersection point, and extending or shortening the selected line segment by using the coordinate value replaced by the means as the coordinate value of the end point on the connection side. A graphic creation apparatus comprising: means for newly drawing a line segment. 2. The figure creating device according to claim 1, wherein the line segment is an n-th order curve (where n is an integer of 1 or more). 3. The figure creating device according to claim 1, wherein the line segment is a spline curve. 4. The figure creating device according to claim 1, wherein the line segment is a Bezier curve.