JPS63213090A - Control instruction string development system for line segment plotting - Google Patents

Abstract

PURPOSE:To develop a line segment string including a dot such as an alternate long and short dash line, an alternate long and two short dashes line and a dotted line outputted by a device to make the line segment which has a fixed line width by developing the line segment including the dot when a line has width, so that the dot becomes the line segment string having the fixed line width on the device coordinate. CONSTITUTION:In a control instruction string storing means 1 for line segment plotting a control instruction string for line segment plotting to be developed for the aggregate representation of the dots on the device co-ordinate is stored. By a control instruction developing and processing means 2 for the line segment plotting the control instruction string for the line segments plotting stored in the means 1 is fetched one instruction by one and developed as the aggregation of the dots on the device co-ordinate. Then required information is supplied to a lie segment plotting instruction analysis means 3 through a register 5. By the means 3, a co-ordinate value representing the dot in the line segment plotting instruction is developed to the co-ordinate value on the device co-ordinate based on that information and the developed device co-ordinate value is returned to the means 2. By the mean 2, image data developed as the aggregation of the dots on the device co-ordinate is transmitted to a graphic output device 4 when all the processing of the control instruction for the line segment plotting is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a line drawing system that expands a line segment drawing control command sequence into a set representation of points on device coordinates and outputs it to a graphic output device such as a CRT or Japanese printer. This invention relates to a control instruction sequence expansion method for minute drawing.

BACKGROUND ART Conventionally, when the line segment to be developed has a width (thickness) and the VI1 type of the line segment includes a point, such as a dashed-dotted line, this type of line segment drawing control command sequence has been developed. As shown in Figures 5(a) and (b), the method for developing the point on the device coordinates is as follows:
It was developed as a line segment with a length equal to the thickness of a line parallel to either the axial direction or the Y-axis direction.

Figure 3 (a) shows an example in which points are developed as line segments with the thickness of the line in the Y-axis direction, and Figure 5 (b) shows a line segment with points in the X-axis direction with the thickness of the line. An example expanded as follows is shown.

Problems to be Solved by the Invention However, in the conventional line segment expansion method described above, when the line segment includes a point and has a width, such as a dashed-dotted line, the point is defined as a line segment with a length equal to the line width. Since it is only mechanically expanded in a fixed direction, either the axial direction or the Y-axis direction, the line segments containing points such as one-dot chain line, two-dot chain line, two-dot chain line, dotted line, etc. output to the device have a constant line width. The drawback is that it didn't seem like it was there.

The present invention has been made in view of the above-mentioned conventional circumstances, and
Therefore, the object of the present invention is to solve the problem of a dashed-dotted line when the line has a width.
The purpose of this method is to develop line segments including points such as two-dot chain lines and dotted lines so that they become a line segment array with a constant line width on the device coordinates.

Means for Solving the Problems In order to achieve the above objective f, the line segment drawing control instruction sequence expansion method according to the present invention expands the line segment drawing control instruction sequence into a set representation of points on the device coordinates. A line segment drawing control instruction string storage means stores a line segment drawing control instruction string to be developed, and a line segment drawing control instruction string is stored from the line segment drawing control instruction string storage means. Line segment drawing control command expansion processing means that inputs a command string and expands it into a set representation of points on device coordinates; and a line segment drawing command analysis means for analyzing an expansion method when expanding into a set of points, and the device is configured to be used when the width of the line is equal to or larger than a codot and coordinate values representing the point are input. It is characterized in that the expanded coordinate values on the coordinates are determined based on both the coordinate values representing the points input as a line segment drawing command and the coordinate values appearing at the beginning of the next command.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

Referring to FIG. 1, the reference number / is line segment drawing control command string storage means, ko is line segment drawing control command expansion processing means, 3
denotes a line segment drawing command analysis means, da denotes a graphic output device, and S denotes a register.

Here, the line segment drawing control command string storage means 1 is set, for example, on the main storage device, and stores a line segment drawing control command string to be developed into a set representation of points on the device coordinates. The line segment drawing control command expansion processing means takes out the line segment drawing control command sequence stored in the line segment drawing control command sequence storage means l, one by one, and expands it as a set of points on the device coordinates. Then, if necessary, necessary information is passed to the line segment drawing command analysis means 3 via the register 3, and based on this information, the line segment drawing command analysis means 3 expresses the points in the line segment drawing command. The coordinate values are expanded into coordinate values on the device coordinates, and the expanded device coordinate values are returned to the line segment drawing control command expansion means. When all the line segment drawing control commands have been processed, the line segment drawing control command expansion means sends the image data developed as a set of points on the device coordinates to the graphic output device trtyc. The graphic output device is composed of, for example, a CRT, and decodes and displays the image data received from the line segment drawing control command development processing means.

The above is an outline of the operation of this embodiment. Next, the flowchart in FIG. The operation of this embodiment will be explained in more detail with reference to the flowchart in FIG. As shown in the figure, the command sequence stored in the line segment drawing control command sequence storage means 1 includes a line width attribute command representing the line width and a line segment drawing command for drawing the line segment. . There is no regularity in the order in which a single command appears. The line width attribute command stores a value representing the line width. In the line segment drawing command, coordinate values representing the vertices of the polygonal line are stored as many sets as the number of vertices, with the X coordinate value and the X coordinate value being one set. Also, locus 11 values (Xl, Yl)
, (X2. Y2 )・(Xn, Yn) is always continuous, and at least (Xl, Yl
), (X2. Y2 ) always exists.

And (Xl, Yl), (X2. Y2)...
- It is assumed that there is a condition that the coordinate values of (Xn, Yn) may overlap.

In FIG. 1, a line segment drawing control instruction string generated by an application program or the like is stored in a line segment drawing control instruction string storage means, and then a line segment drawing control instruction expansion processing means is activated. .

When the line segment drawing control command development processing means is activated, it starts the process shown in FIG. 2, and determines whether all one line segment drawing command has the same X and Y coordinate values. A point coordinate detection flag for this purpose is initially set to θ (S10).

Next, a command is taken out from the line segment drawing control command string storage means (S20). I want to judge whether all commands have been processed or not? θ), and when the processing of all commands is completed, the expanded data is output to the graphic output device (522).
o.) 1. End the expansion process. If all commands have not been processed yet, determine the command type, and if it is a line width attribute command, store the current value of the line width in the work area (S/ZA), and then Process of reading instructions (S〃
). If the input command type is a line segment drawing command,
Input the l coordinate point that exists in that command and put it in the work area (
Xp.

Yp) is stored (SSO). Here, (Xp, Yp) means the nearest input l coordinate point. Next, determine whether input of all coordinate points in the l instruction has been completed by checking whether all commands have been completed or by detecting the next instruction code (S + θ), and if so, the first coordinate value in the l instruction ( Xs,
Compare Ys) with the input coordinate values (Xo, Yo) read last in the l command (S/90), and if they are not equal, manually write the next command (S20). If they are equal, it means that a command to express a point has been input, so the point coordinate detection flag is set to l (S-〇〇). Then, the coordinate values representing the point are stored in the work area as (X-1, Y-1), and the next command is input (S). If input of all coordinate points in the l instruction is not completed, determine whether it is the first coordinate point in the l instruction (S to ), and if so, convert (, Xp, Yp) to (Xs
, Ys) to the work area where it is stored.
), then (Xp, Yp) is transferred to the work area where (Xo, Yo) is stored (5tso), and the process moves to inputting the l coordinate point (S, tO). If it is not the first coordinate point in the l command, it is determined whether the point coordinate detection flag is "/" (5g0), otherwise the process moves to 5720. If so, in order to develop the coordinate values representing the point based on one point (Xo, Yo), (x-1, Y-s), the current value of the line width m, (Xo, Yo), (X -1,
Each point of Y-1) is set in the register 5, and the line segment drawing command analysis means J is called (Sqo). Then, the coordinate values representing the point returned to the register S by the line segment drawing command analysis means 3 are expanded (x-1', Y-1') and (
Draw a line segment connecting points B'p and B" of is reset to “o” (SIlo). Next, point (Xp, Yp) and point (
To determine whether Xo, Yo) are equal or not, E3/:10),
If so, there is no need to draw a line segment, and the process moves to inputting the next coordinate point (SyO). Point (Xp.

If Yp) and the point (Xo, Yo) are not equal, draw a line segment connecting the points with the current line width value (S/3o)
.

Next, in order to store the seven input coordinate values before the current one, (Xp, Yp) is transferred to the work area where (Xo, Yo) is stored (S/, tO). Then, the process moves to inputting the next l coordinate point into the work area where (Xp, Yp) is stored (S, tO).

Through the processing described above, the line segment drawing control command string inputted from the line segment drawing control command string storage means 1 is developed into an image data that is a set representation of points on the device coordinates, and is output to the graphic output device. Ru.

Next, the flowchart of FIG. 3 shows an example of the processing of the line segment drawing command analysis means 3, and the flowchart of FIG. A method for developing coordinates representing points into line segments will be explained in detail with reference to FIG. The line segment drawing command analysis means 3 receives a command (Xo,
Yo).

Based on the A2 and 8 points expressed by the coordinate values of (X-1, Y-1) and the line width m, point B is set to the coordinate values (X-1',
Y-1') (x-1'', Y-1'') point B'
and point B" into a line segment that connects point A (X
o, Yo) and point B (X-1, Y-1'), draw a line that intersects Jt: 1 m to M angle and passes through point B, and draw two lines that are ψ apart from point B. The point requires B
'<X-1',Y-11'), B// (X-1
", Y-+") and the following procedure.

As shown in Figure 3, if we calculate the slope θ of the line segment with respect to the X axis based on points A and B on the device coordinates, θ is θ = sin
'(Yo-Yl)/ (Xo-X 1)'+(
Yo-Y 3)' --- (obtained by C (FIO)
. Next, draw a line that passes through point B and is inclined by θ + qo0 with respect to the X-axis of the device coordinates, and if the line width is m, the coordinate value B representing the point is the coordinate value of point B' and point B'' (X- 1', Y-1
'), (X呵", Y-1"), it is expanded to (F〃).

The device coordinate values of the points B'p and B'' obtained by this process are returned to the line segment drawing control command expansion processing means via the register 3, and the coordinate values expressed by the points are converted to the line segment. Finish the expansion process.

Figure 6 shows the case where points are developed as line segments with a line width m based on the above-mentioned processing, and Figure 7 shows an enlarged view of the part indicated by K in Figure 6 (inside the circle). FIG. That is, as mentioned above, point A (Xo, Yo) and point B (X-1, Y-1
) Draw a line that intersects the line connecting at right angles and passes through point B, and draw a point of m/2 each from point B as B'
(X-1', Y-1'), B"(x-1",
Y-1"), the line segment connecting points B' and B" becomes the line segment to be sought.

As described in detail, according to the present invention, in the process of expanding a line segment drawing control instruction string stored in the line segment drawing control instruction string storage means into a set representation of points on device coordinates, When the line width is codot or more and the coordinate value representing a point is input, the method of expansion on the device coordinates is the coordinate value representing the input point as a line segment drawing command, and the coordinate value representing the input point appears at the beginning of the next command. By determining based on both the coordinate values and the line width, line segments that include points such as one-dot chain lines, two-dot chain lines, 10-dot lines, etc., can be treated as line segments with a constant line width on the device coordinates. The effect is that it can be expanded to be visible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
FIG. 3 is a flowchart showing an example of the operation of the line segment drawing control command analysis means 3, and FIG. /[
A diagram showing the state in which line width attribute commands and line segment drawing commands are stored and the format of the commands. Figures S (a) and (b) are
FIG. 12 is a diagram showing an example of a case where a point is expanded as a line segment of the thickness of the line in the Y-axis direction and a point is expanded as a line segment of the thickness of the line in the Y-axis direction. (Figure 1 can showing an example)
6 is a diagram showing an example in which a point ゛ is developed as a line segment with a line width of m in the X-axis direction, and FIG. FIG. 7 is an enlarged view of a portion (inside the circle) of FIG. 6. l... Control command string storage means for line segment drawing, C... Control command expansion processing means for line segment drawing, 3... Line segment drawing command analysis means, D... Figure output device FIG.

Claims (1)

[Claims] A line segment drawing control command sequence is defined as one dot (pixel) on the device coordinates.
In the process of drawing a developed image on the device by expanding it into a set representation of points that are "on" (corresponding dots are filled) or "off" (corresponding dots are not filled), the line segment drawing control command to be developed is a line segment drawing control instruction string storage means for storing line segment drawing control instruction strings, and a process of inputting a line segment drawing control instruction string from the line segment drawing control instruction string storage means and expanding it into a set representation of points on device coordinates. a line segment drawing control instruction expansion processing means for performing line segment drawing control instruction expansion processing means; and a line segment drawing instruction that is called from the line segment drawing control instruction expansion processing means and performs analysis processing when expanding the line segment into a set representation of points on the device coordinates. analysis means, and the width of the line is 2.
If a coordinate value that is larger than a dot and represents a point is input, the expanded coordinate value on the device coordinates is the coordinate value that represents the point input as a line segment drawing command and the coordinate that appears at the beginning of the next command. A control instruction string expansion method for line segment drawing that is characterized by determining based on both values and values.