JPH08147482A - Method and device for plotting dash line - Google Patents

Abstract

PURPOSE: To uniformly distribute a dash line on a curved line like a circle and a circular arc, etc., so as to equalize the shape of the dash line at the junction point of a beginning point and an ending point. CONSTITUTION: Plotting data inputted from an input device 1 is sent to an interpolation processing part 6 through a plotting data processing part 4, and the interpolation processing part 6 interpolates the plotting data. In the case where the plotting data is the curved line such as the circular arc, the circle and an ellipse, etc., a circular circumference calculating part 7 calculates circumferential distance L from the beginning point to the ending point of the interpolated data. An interpolation mode calculating part 8 determines the number ns of new cycles from the circumferential distance L and the designated cycle length s1 of the dash line stored in a cycle table 5, and further, determines new cycle length s1' and each new pitch length Pk' in one cycle. A dash line control part 9 delivers dash line data to an output control part 10 so as to let it start plotting from a position shifted by the half portion of a new first pitch length Pi, and besides, let it end the plotting at the position shifted by the half portion of the first pitch length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for drawing a figure including an arc, an ellipse, etc., and more specifically, when drawing a curve such as an arc, an ellipse, etc. with a dash line such as a broken line or a dash-dot line. The present invention relates to a dash line drawing method and device capable of adjusting the dash line end.

[0002]

2. Description of the Related Art When a figure output device such as a plotter is used to draw a figure including a dash line such as a broken line or a dash-dot line, a pen-down and a pen-ab are usually repeated at regular intervals to draw a desired figure. Therefore, when drawing a curve such as an arc or an ellipse, depending on the length of the curve, the drawing ends in a pen-up state, as shown in FIG.
The position of the curve at the end may become unclear as shown in FIG. 7B, or the shape of the dash line at the end (starting point) may become uneven as shown in FIG.

Conventionally, it has been attempted to adjust the end of a straight line so that the end of the straight line ends in a pen-down state, but the above-mentioned end adjustment is not performed for a curved line such as an arc or an ellipse. It was

[0004]

As described above, in the prior art, when a curved line such as an arc or an ellipse is drawn by a dash line, there are the following problems. (1) When a curved line such as a circular arc is drawn on a dash line, the end point may be pen-up, and a correct drawing result cannot be obtained. (2) In the case of a figure where the start point and end point match, such as a full circle,
The shape of the dash line does not match at the junction of the start point and the end point, resulting in a non-uniform figure.

The present invention has been made in order to solve the above-mentioned problems of the prior art. An object of the present invention is to draw a dash line evenly on a curved line when drawing a curved line such as an arc. It is an object of the present invention to provide a method and a device for drawing a dash line that can be distributed to each other and can match the shape of the dash line at the joining point of the start point and the end point.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is such that when drawing a curve such as a circle, an ellipse, an arc, an elliptic arc, etc. by a figure output device with a dash line, the above-mentioned drawing Calculate the circumference of the dash line part of the curve to be compared, calculate the new cycle length by comparing the cycle length of the preset dash line and the above circumference,
The new cycle length obtained and the preset cycle length above,
Also, the new pitch length in the cycle is calculated from the preset pitch length of the dash line, and 1/2 of the initial pitch length of the obtained new pitch is shifted to obtain a point of 1/2 of the initial pitch. Start drawing the dash line from, and in the last cycle of the dash line, the initial pitch length is 1
The drawing of the dash line is ended at the point of / 2.

According to a second aspect of the present invention, in a drawing device for drawing a curve such as a circle, an ellipse, an arc, an elliptic arc, etc., which includes a dash line at least in part, the cycle length and pitch length of various dash lines are set. A new cycle length is calculated by comparing the cycle table and the means for determining the circumference of the dash line part of the curve such as circle, ellipse, arc, elliptic arc, etc. and the cycle length of the dash line set in the above cycle table and the above circumference. , A means for calculating a new pitch length in a cycle from the obtained new cycle length and the cycle length and pitch length set in the cycle table, and a curve including a dash line based on the new cycle length and the new pitch length. A control means for controlling drawing is provided, and when the control means outputs a curve including a dash line, the control should be performed at the new pitch obtained. The drawing of the dash line is started from the point of 1/2 of the initial pitch, and the drawing of the dash line is ended at the point of 1/2 of the initial pitch length in the last cycle of the dash line. .

[0008]

According to the first and second aspects of the present invention, when a curve such as a circle, an ellipse, an arc, an elliptic arc, etc. including a dash line at least in part is drawn, the cycle length of the dash line set in advance is set. The new cycle length is calculated by comparing the circumference of the dash line part of the curve to be drawn with the new cycle length, and the new pitch in the cycle is calculated from the calculated new cycle length and the preset cycle length and preset dash line pitch length. The length is calculated, and the dash line is drawn by shifting half the initial pitch length of the calculated new pitch, so the dash line cycle can be made uniform and the dash line can be accurately displayed. Can be drawn.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an embodiment of a drawing apparatus of the present invention, and FIG. 1 shows an embodiment in which a figure is drawn by a plotter. In the figure, 1 is an input device for inputting drawing data, 2 is an output device such as a plotter, 3 is a processing device, and the processing device 3 is a drawing data processing unit 4 for processing the input drawing data, and a dashboard. A cycle table 5 that stores the line shape, an interpolation processing unit 6 that interpolates the input drawing data to generate drawing data of straight lines and curves, and a circumference that calculates the length of a curve such as an arc to be drawn. A calculation unit 7, an interpolation mode calculation unit 8 that adjusts the end of the dash line, a dash line control unit 9 that controls drawing of the dash line according to the result of the interpolation mode calculation unit 8, and an output that controls the output device 2. Control unit 10
It has and.

The cycle table 5 has a cycle length s1 (hereinafter referred to as a designated cycle length) of a dash line such as a dashed line, a one-dot chain line, a two-dot chain line, an arbitrary chain line and the pitch length within one cycle. This is a table for storing PK (hereinafter referred to as designated pitch length: an example of the designated cycle length and designated pitch length is shown by the chain double-dashed line in FIG. 4), and the initial value is set in advance and will be described later. As described above, the cycle length and the pitch length are changed according to the drawing data.

2 and 3 are flowcharts showing the processing in the processing unit 3 shown in FIG. 1. The drawing processing of the dash line in this embodiment will be described with reference to the same drawings. In FIG. 1, when drawing data is input from the input device 1, the drawing data is processed by the drawing data processing unit 4 and sent to the interpolation processing unit 6. The interpolation processing unit 6 determines whether the input drawing data is a straight line (step 10 in FIG. 2).
0), if the drawing data is a straight line, linear interpolation is performed (step 101). If the drawing data is a circle or an ellipse, the circle or the ellipse is interpolated (step 102). In addition,
As the interpolation method, various well-known methods can be used and will not be described in detail here.

Next, it is judged whether the dash line mode is the start mode or the dash line is in progress (step 10
3) In the case of the start mode of the dash line mode, the circumference calculation unit 7 determines the circumference distance L from the start point to the end point of the dash line for the interpolation curve data generated by the interpolation processing unit 6.
Is calculated (step 104). Interpolation mode calculator 8
Is the circumference distance L calculated by the circumference calculation unit 7 and the cycle
The new cycle number ns is calculated from the specified cycle length s1 of the dash line stored in the table 5 by the following equations (1) to (3). Further, the new cycle length s1 'and each new pitch length Pk' within one cycle are obtained from the equations (4) and (5) (step 105). (L / s1) = n remainder ... m m = 0 when n s = n (1) When m <ΔL ns = n (2) When m ≧ ΔL ns = n + 1 (3) Note that ΔL is in the following range It can be adjusted as needed.

0 <ΔL <(first pitch length P1 / 2) (L / ns) = new cycle length s1 '(4) new kth pitch length Pk' = designated kth pitch length Pk * (s1 '/ s1) ) (5) Is.

FIG. 5 is a diagram for explaining the relationship between the designated cycle length and the new cycle length, which shows the case where the dash line is a broken line. In the figure, (a) shows the pitch lengths P1 and P2 of the dash lines (broken lines) stored in the cycle table 5, (b) shows the designated cycle length s1, and (c) shows the new cycle length s1 '. Further, (d) shows the new pitch lengths P1 'and P2'.

When the above equations (2) and (3) are satisfied,
As shown in the figure, the specified cycle length s1> the new cycle length s1 ', and the new pitch lengths P1' and P2 are obtained by multiplying the specified pitch lengths P1 and P2 by (new cycle length s1 '/ specified cycle length s1). 'Is calculated. When the new cycle length s1 'and the new pitch length Pk' are calculated in the interpolation mode calculation unit 8, the dash line control unit 9 performs the dash line interpolation processing based on the new cycle length s1 'and the new pitch length Pk'. Then, the dash line data is passed to the output control unit 10 to start drawing the dash line (steps 106 and 10).
7). At that time, the dash line control unit 9 is shown in FIG.
As shown in, drawing is started from a position shifted by 1/2 of the new first pitch length P1, and 1 / pitch of the first pitch length.
The drawing is finished at the position shifted by 2 minutes.

Until the drawing of the dash line is completed, the dash line interpolation processing is repeated while setting the dash line data of the next pitch, and the output control unit 1
0 to draw a dash line (step 10 in FIG. 3)
9, 108, 106, 107 in FIG. 2). After that, it is determined whether the output graphic is a curved line such as an arc or an ellipse (step 110 in FIG. 3), and if it is not a curved line such as an arc, the process ends.
In the case of a curved line such as a circular arc, it is determined in step 111 of FIG. 3 whether or not the drawing of the curved line or the like is completed, and similarly to the above, the processing from step 102 to step 111 is performed until the drawing of the circular arc or the like is completed. repeat.

As a result, it is possible to draw a figure in which the end point is always in the pen-down state, and in the case of an arc or a full circle, the end point is changed as shown in FIGS. 1 and 6 (b) (c). It is possible to draw a complete circle with a clear arc or dash line. In the above embodiment, the case where the figure is output by the plotter has been shown, but the present invention is not limited to the above embodiment.
The present invention can be applied to various well-known graphic output devices such as when a graphic is output to a display device such as a display.

[0018]

As described above, according to the present invention, when a curve such as a circle, an ellipse, an arc, and an elliptic arc is output as a dash line, the cycle length of a preset dash line and the circumference of the curve to be output are set. The new cycle length in the cycle is calculated from the calculated new cycle length, the preset cycle length and the preset pitch length of the dash line, and the initial value of the calculated new pitch is calculated. Since the drawing of the dash line is started by shifting the length of 1/2 of the pitch length, the dash line cycle can be equalized.

Therefore, when a figure including a dash line is output by a plotter or the like, it is possible to draw an accurate and attractive drawing.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a drawing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 3 is a flowchart (continuation) showing the operation of the embodiment of the present invention.

FIG. 4 is a diagram illustrating a relationship between a designated cycle length and a designated pitch length.

FIG. 5 is a diagram illustrating a relationship among a designated cycle length, a new cycle length, and a new pitch length.

FIG. 6 is a diagram showing a result of drawing a dash line according to the embodiment of the present invention.

FIG. 7 is a diagram showing a result of drawing a conventional dash line.

[Explanation of symbols]

 1 Input Device 2 Output Device 3 Processing Device 4 Drawing Data Processing Section 5 Cycle Table 6 Interpolation Processing Section 7 Circumference Calculation Section 8 Interpolation Mode Calculation Section 9 Dash Line Control Section 10 Output Control Section

Claims (2)

[Claims] 1. When drawing a curve such as a circle, an ellipse, an arc or an elliptic arc with a dash line by a figure output device, the circumference of the dash line portion of the curve to be drawn is calculated, and the preset cycle length of the dash line is obtained. Then, the new cycle length is calculated by comparing the above-mentioned circumference with the above-mentioned circumference, and the new cycle length within the cycle is calculated from the calculated new cycle length, the preset cycle length, and the preset dash line pitch length. Shift the calculated initial pitch length of the new pitch by 1/2, start drawing the dash line from the point of 1/2 of the initial pitch, and set the initial pitch in the last cycle of the dash line. A method of drawing a dash line, characterized in that drawing of the dash line is finished at a point of 1/2 of the length. 2. A plotting apparatus for plotting a curve such as a circle, an ellipse, an arc, an elliptic arc including a dash line at least in part, and a cycle table for setting cycle lengths and pitch lengths of various dash lines, and a circle, an ellipse, A means for obtaining the perimeter of the dash line portion of a curve such as an arc, an elliptic arc, etc. and a new cycle length obtained by comparing the perimeter with the cycle length of the dash line set in the above cycle table and the new cycle length obtained, A means for calculating a new pitch length in the cycle from the cycle length and the pitch length set in the cycle table, and a control means for controlling the drawing of a curve including a dash line based on the new cycle length and the new pitch length. The control means, when outputting a curve including a dash line, has a half of the initial pitch in the obtained new pitch. From to initiate the drawing of the dashed line, in the last cycle of dashed lines, drawing and wherein the to finish drawing the dashed line in terms of 1/2 of the initial pitch length.