JPH0423179A - Method and device for plotting thick line - Google Patents

Abstract

PURPOSE:To plot a thick line at high speed without necessitating complicated hardware by painting out successively a segment of line area with a rectangular painting-out pattern generated from a terminal point shaped pattern and a plotted segment of line area. CONSTITUTION:A thick line plotting means 8 is provided with a terminal point plotting means 10, an initializing means 11, a deciding means 12, a plotting deciding means 14, a rectangular pattern plotting means 16, a starting point moving means 18, and a correcting means 20. Then, the starting point of a segment of a line is painted out with the terminal point shaped pattern, and at the time of the painting-out in the segment of line area from the starting point to the end point of the segment of a line, the segment of line area is painted out with the rectangular painting-out pattern determined by the terminal point shaped pattern and the segment of line area for every painting-out progress quantity to be determined by the terminal point shaped pattern and the segment of line area, and at the time of arrival at the end point of the segment of a line, the end point is painted out with the terminal point shaped pattern. Thus, since the segment of line area is painted out successively with the rectangular painting-out pattern by which high speed plotting is possible, the thick line can be plotted at high speed, and the complicated hardware is not necessitated.

Description

[Detailed Description of the Invention] [Table of Contents] [Summary] [Field of Industrial Application] [Prior Art] Diagram showing three examples of conventional thick line drawing methods (Fig. 7) [Problems to be Solved by the Invention] ] [Means for Solving the Problems] Principle block diagram of the present invention (Figure 1) [Operation] [Example] Diagram showing an embodiment of the present invention (Figure 2) Showing the processing flow of the present invention (Fig. 3) A diagram showing an example of an end point shape pattern (Fig. 4) A diagram showing an end point shape pattern registration table (Fig. 5) An explanatory diagram of an example of thick line drawing according to the present invention (Fig. 6) [Effects of the invention ] [Summary] The purpose of this paper is to draw thick lines at high speed using inexpensive hardware and simple software, regarding a thick line drawing method and device using an endpoint shape pattern and a rectangular fill pattern. When filling in the line segment area from the start point of the line segment to the end point of the line segment, the end point shape pattern and the line segment are filled in for each filling advance amount determined by the end point shape pattern and the line segment area. A rectangular filling pattern determined by the area is determined, the line segment area is filled with the determined rectangular filling pattern, and when the filling process reaches the end point of the line segment, the end point is filled with the end point shape pattern. , a pattern memory for storing an end point shape pattern, a bit mover, and a thick line drawing control means, the thick line drawing control means having an end point drawing means, an initial setting means, a determining means, a drawing determining means, It consists of a rectangular pattern drawing means, a starting point moving means, and a modifying means.

[Industrial application field]

The present invention relates to a thick line drawing method and apparatus using an end point shape pattern and a rectangular filling pattern depending on the end point shape pattern and a line segment area to be filled.

In recent years, the resolution of display devices has been increasing, and along with this, there is a demand for drawing not only line segments with a line width of one dot but also thick lines. For example, design systems using computers (CAD systems), editing and printing systems (DTP),
systems), there is a high demand for high-speed drawing of thick lines.

[Prior Art] There are several techniques for conventional thick line drawing devices. The drawing of a thick line by any of these thick line drawing devices is defined as a locus when an end point shape pattern is moved from one end point to the other end point of the thick line to be drawn.

A first conventional thick line drawing method will be described below with reference to FIG. 7(A). This first method is based on the position of each dot of a 1-dot line connecting the center of the starting point of the end point shape pattern and the center of the end point of the end point shape pattern for the line segment to be drawn (see Fig. Please refer to ★.

) by a well-known DDA algorithm, and by drawing an endpoint shape pattern at each dot position (for example, "1" is written in each bit occupied by the endpoint shape pattern centered on the determined dot in the frame memory) The process of setting the bit ``) is to draw the thick line you want to draw, and a bit mover is used to sequentially move the end point shape pattern. This bit mover is used by the processor to store the linewidth 1 in the frame memory.
This is a mechanism used to sequentially move the aforementioned end point shape pattern for each dot of the dot line. The second method is to draw each dot in the shape pattern placed at the starting point of the line segment to be drawn, and each dot in the shape pattern placed at the end point (each dot in the shape pattern placed at the starting point). Please refer to the ★ in the dot corresponding to the dot (Figure 7 CB). ) is filled with a 1-dot line between each dot start point and its corresponding dot end point (for example, by filling in each corresponding bit in the frame memory with a 1-dot line). ” bit setting) (Figure 7 (B)
Please refer to the point sequence of and. ) is applied to all of the corresponding dots using a straight line generation mechanism (vector generator), thereby drawing the thick line that is desired. The third method regards the thick line you want to draw as a general polygon, calculates the outline of the thick line, and then calculates the distance between the horizontal end points within the calculated polygonal outline (see ★ in Figure 7 (C)). ) by sequentially filling in the lines with a line width of 1 dot (see the dot sequence . in FIG. 7(C)).

), to draw the thick line you want. This third method uses a polygon surface painting mechanism (polygon processor).

[Problem to be solved by the invention]

The first and second methods described above have the advantage of being relatively simple and inexpensive and can use simple hardware; however, the first method draws the same dot many times (overwriting the frame memory). ), this processing requires wasted time and is a factor that hinders speeding up. The second method described above can reduce the number of times the same dot is overwritten, but since writing to the frame memory is done in units of one dot, this increases the processing time, making it difficult to speed up the processing. is preventing The third method can completely eliminate overwriting of the same dot, but at the cost of complicating the algorithm and therefore increasing the processing load on the processor that executes the algorithm. This increases the time required for drawing, which also becomes an obstacle to speeding up the processing. As a way to avoid this, it is possible to speed up drawing using a dedicated processor called a polygon processor.
This requires the use of expensive polygon processors.

The present invention was created in view of the above problems, and an object of the present invention is to provide a thick line drawing method and apparatus capable of drawing thick lines at high speed using inexpensive hardware and simple software.

[Means to solve the problem]

A first aspect of the present invention is to fill in the starting point of a line segment to be drawn with an end point shape pattern, and when filling in the line segment area from the starting point of the line segment to the end point of the line segment, the end point shape pattern and A rectangular filling pattern determined by the end point shape pattern and the line segment area is determined for each filling advance amount determined by the line segment area, and the line segment area is filled with the determined rectangular filling pattern, and the filling process is performed on the line segment. When the end point is reached, the end point is painted with an end point shape pattern.

The second invention, as shown in the principle block diagram of FIG.
It comprises a frame memory 2, a pattern memory 4 for storing an end point shape pattern, a bit mover 6, and a thick line drawing control means 8 for drawing line segments in the frame memory 2 using the DDA method. The drawing control means 8
An end point drawing means 10 that activates the bit mover 6 to draw the end point shape pattern at the starting point and end point of the line segment, an initial setting means 11 that initializes filling with a rectangular pattern, and a determining means 12 for determining whether a line segment area between end points is being drawn; a drawing determining means 14 for determining whether or not a rectangular fill pattern can be drawn at the drawing start point of a rectangular fill pattern; a rectangular pattern drawing means 16 that starts the bit mover 6 and draws the line segment area in a rectangular filling pattern determined by the end point shape pattern and the line segment area;
When drawing is not possible, both the starting point moving means 18 which advances the drawing starting point from the drawing starting point by a value determined by the end point shape pattern and the line segment area and the drawing determining means 4 use the DDA method. and a correction means 20 for correcting the error term.

[Operation] In the present invention, when the thick line drawing process is started, the end point drawing means 10 draws the end point shape pattern read from the pattern memory 4 at the starting point of the thick line. At the end of the process, initial setting means 11 performs initial setting for filling with a rectangular pattern.

When the determining means 12 determines that the drawing of the line segment area between the starting point and the ending point of the thick line has started, the modifying means 20 uses the DDA method when the drawing determining means 14 determines whether drawing is possible. After correcting the error term in step 1, the rectangular pattern drawing means 16 continues sequentially drawing the line segment area in a rectangular filled pattern. To perform this drawing, it is not necessary to transfer the end point shape pattern as in the conventional method, and the hardware required to generate the rectangular filling pattern is simple. When the drawing determining means 14 determines whether or not drawing is possible for each sequential drawing, if it is determined that drawing is not possible, the starting point moving means 18 moves the current drawing starting point from the drawing starting point to the end point shape pattern and Advances the drawing start point by the value determined by the line segment area.

Also at this time, the correction means 20 corrects the error term using the DDA method. As a result of this correction, when the drawing determination means 14 again determines that drawing is possible, the rectangular pattern drawing means 16 draws the line segment area in a rectangular filled pattern in the same manner as described above.

When the filling of the line segment area with the rectangular filling pattern is completed, an end point shape pattern is drawn for the end point of the line segment in the same manner as for the starting point.

In this way, the line segment area between the start point and the end point of the thick line to be drawn is determined as described above without the need to transfer the end point shape pattern, and the rectangular filling pattern that enables high-speed drawing is used. Since the lines are filled in sequentially, thick lines can be drawn at high speed. No complex hardware is required to perform this process.

〔Example〕

FIG. 2 shows an embodiment of the invention. This figure shows a large line drawing device implementing the present invention. 30 is a CPU, 32 is a bus, 34 is a memory, 36 is a bit mover, 38 is a pattern memory, 40 is a frame memory (screen memory), 42
is a CRT controller, and 44 is a CRT display device. The memory 34 stores a program that executes the processing flow shown in FIG. bit mover 36
has a mode register 50, a fill start position register 52, an end point shape pattern transfer source register 54, and a size register 56. The pattern memo U 38 stores end point shape patterns. In the present invention, the storage format of the end point shape pattern does not need to be a specific format, and may be stored in advance or stored as necessary. In addition, as will be clear from what will be described later, the dimensions A, B, C, and D shown in FIG. 4 for the end point shape pattern to be stored.

W is stored in the memory 34 in a table format that can be indexed by each endpoint shape pattern as shown in FIG. Mode register 50 is used to switch between pattern transfer mode and rectangle filling mode. The filling start position register 52 specifies the transfer start position on the frame memory 40 or the rectangle filling start position. The endpoint shape pattern transfer source register 54 specifies the transfer start position of the endpoint shape pattern stored in the pattern memory 38 in the pattern transfer mode. Two-dimensional coordinate positions are set in the filling start position register 52 and end point shape pattern transfer source register 54. The size register 56 specifies the size of the end point shape pattern or the filled rectangular area. The width and height are set in the size register 56.

In FIGS. 2 and 3, frame memory 40 corresponds to frame memory 2 in FIG.
corresponds to the pattern memory 4 in FIG. Bit mover 6 corresponds to bit mover 36 in FIG. CPU
30, the bus 32, the bit mover 36, and the program for executing steps Sl, 32, and 316 in FIG. 3 stored in the memory 34 correspond to the end point drawing means 10 in FIG.
Step 33 of FIG. 3 is stored in the PU 30, bus 32, and memory 34. The program that executes S4 corresponds to the initial setting means 11 in FIG. CPU30, bus 32,
Step S5. of FIG. 3 stored in memory 34. The program that executes S6 corresponds to the determination means 12 in FIG. The program for executing step S7 in FIG. 3 stored in the CPU 30, bus 32, and memory 34 corresponds to the drawing determination means 14 in FIG. The program that executes steps 39 and 514 in FIG. 3 corresponds to the rectangular pattern drawing means 16 in FIG. Step SI0 in FIG. 3 stored in the CPU 30, bus 32, and memory 34
, 311, 313 corresponds to the starting point moving means 18 in FIG. The program that executes S12 corresponds to the modification means 20 in FIG.

The operation of the apparatus of the present invention having the above configuration will be explained below.

After the apparatus of the present invention enters the operating state, when drawing a thick line, when the end point shape pattern used for drawing the thick line and the drawing start point and drawing end point of the thick line are specified, each coordinate component xs of the drawing start point is specified.

ys to the dimension value A of the specified end point shape pattern,
The values obtained by subtracting B from the corresponding coordinate components are stored in the memory 34 as the drawing start points x and y of the thick line (S in Fig. 3).
(see 1). This is because the drawing start point used in the bit mover is generally at the upper left of the pattern. Also, assume that this drawing example is the one in FIG. 6, and therefore x, -X, ≧
'! a Y, ≧0. This relationship changes depending on the thick line drawn.

Then start Bitmover. This activation sets the pattern transfer mode in the mode register 50, and sets the drawing start point x, y of the thick line in the filling start position register 52.
This is done by setting the upper left coordinates of the end point shape pattern stored in the pattern memory 38 in the end point shape pattern transfer source register 54, and setting the width, height, and line width of the size in the size register 56. As a result, an end point shape pattern (see (1) in FIG. 6) is drawn with the thick line drawing start points x and y as the center of the end point shape pattern.

The thick line areas are sequentially drawn in a rectangular pattern determined by the determination method described below between the drawn end point shape pattern and the drawing end point of the thick line.

First, each parameter used in the conventional DDA algorithm is determined. These parameters are each coordinate component dx=xe-xs from the drawing start point to the drawing end point of the thick line,
dy=ye-ys, DDA decision variable or error term d
=2Xdy-dx, loop counter 1=dx (see S3 in FIG. 3). Then, first find the upper left coordinates of the rectangular pattern to be drawn. This coordinate is
It can be obtained by adding a value C determined by the end point shape pattern to and setting it as a new X, setting this X as xp, and setting the above y as yp. Prior to starting the drawing of this first drawn rectangular pattern, it is determined whether or not it is necessary to continue drawing the rectangular pattern (see 85 and S6 in FIG. 3). In this judgment, if the loop counter l is smaller than 0 and the error term d is also not smaller than O (see 36.S7 N in Figure 3), then the first rectangular pattern is drawn as follows. Process. d+2X (dy
-dx) as a new error term d (see 38 in FIG. 3), by starting the bit mover 36,
The first rectangular pattern (see (2) in FIG. 6) is drawn in the same manner as described in step S2 above. That is, set the rectangular pattern filling mode in the mode register 50, set the upper left coordinates (xp, yp) of the rectangular pattern in the filling start position register 52, and set the coordinates (χ-xp+D, W) in the size register 56. This is done by setting the . However, D and W are multi-values (see FIG. 4) in the end point shape pattern described above.

After the drawing process of this first rectangular pattern is completed, the x,
Add 1 to each of y (see x, y at 54 in Fig. 3) (see S10 in Fig. 3), and convert the new x, y to the upper left coordinates (χp ,y
p) (see Sll in FIG. 3), and before starting the drawing of the rectangular pattern to be drawn next, the same judgment process as that performed before starting the drawing process of the first rectangular pattern is performed. (See 36.S7 in Figure 3).

In this determination, if the same processing conditions as the first rectangular pattern drawing processing occur (36, 37 in FIG.
(see N in FIG. 6), the drawing process for the first rectangular pattern and the drawing process for a similar rectangular pattern (for example, see (3) in FIG. 6).

If the same processing conditions as the first rectangular pattern drawing process do not occur (see N in S6 and Y in S7 in FIG. 3), a new error term d=d+2XdV and a coordinate component x=
x+1 is found (see 812.313 in FIG. 3) and the judgment using this new error term d is performed. The process of calculating the coordinate component x=x+1 here is a process that is repeated while the dots are continuous in the horizontal direction. The thick line is the 6th
If it differs from the diagram, other calculation processing will be required.

When such processing is repeated, if the same processing conditions as the first rectangular pattern drawing process exist again (see 56.S7 N in FIG. 3), the first rectangular pattern drawing process A similar rectangular pattern drawing process is performed.

As is clear from the foregoing, the width of the rectangular pattern drawn according to the present invention is determined by the length of the section of consecutive dot rows in the horizontal direction determined by the DDA algorithm.

In the above judgment, when the loop counter 2 becomes smaller than 0 (see 56 Y in FIG. 3), drawing processing is started using the final rectangular pattern to fill the line segment area (
314 in FIG. 3, see (4) in FIG. 6, for example). The drawing process is the same as the filling process of the line segment area.

After the drawing process using the last rectangular pattern is completed, the upper left coordinates of the end point shape pattern are determined as follows. Find and store the coordinate component x=x−C (3 in Figure 3).
15). In this way, at the start of drawing the thick line, the bit mover 36 is activated in step S2 to draw an end point shape pattern with the end point shape pattern centered at the drawing start point Xs+y of the thick line. An end point shape pattern centered at the center is drawn (see 516 in FIG. 3 and (4) in FIG. 6).

[Effects of the Invention] As is clear from the above, according to the present invention,
The line segment area between the start point and end point of a thick line is filled with a rectangular filling pattern generated by the end point shape pattern and the drawn line segment area, instead of drawing with the transferred end point shape pattern as in the past. Therefore, thick lines can be drawn at high speed without requiring complicated hardware. In addition, the complexity of the required software can be avoided, reducing the burden on the processor.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a diagram showing an embodiment of the invention, Fig. 3 is a diagram showing the processing flow of the invention, and Fig. 4 is a diagram showing an example of an end point shape pattern. , FIG. 5 is a diagram showing an end point shape pattern registration table, FIG. 6 is an explanatory diagram of an example of thick line drawing according to the present invention, and FIG. 7 is a diagram showing three examples of conventional thick line drawing methods. 1 to 3, 2 is a frame memory (frame memory 40), 4 is a pattern memory (pattern memory 38), 6 is a bit mover (bit mover 36), 8 is a thick line drawing control means, and 10 is an end point drawing. Step S in FIG. 3 stored in means (CPU 30, bus 32, bit mover 36, memory 34)
l, S2. 11 is an initial setting means (CPU 30, bus 32, memory 3
Step 33 of FIG. 12 is a determination means (a program for executing steps S5 and S6 in FIG. 3 stored in the CPU 30, bus 32, and memory 34); 14 is a drawing determination means (CPU 30, bus 32, and memory 3);
4), 16 is a rectangular pattern drawing means ((CPU 30, bus 32
, bit mover 36, and step S9. of FIG. 3 stored in memory 34. 18 is a starting point moving means (steps 310 to 311.3 of FIG. 3 stored in the CPU 30, bus 32, and memory 34);
13), 20 is a correction means (CPU
30, bus 32, and a program for executing step S8 of FIG. 3 stored in memory 34). Urushi, Qe Tsuki no Rin 1 B'O-vri diagram Figure 1/1-departing F3 SE~lj Figure 2

Claims (2)

[Claims] (1) Filling the starting point of the line segment to be drawn with an end point shape pattern, and when filling in the line segment area from the starting point of the line segment to the end point of the line segment, filling determined by the end point shape pattern and the line segment area. A rectangular filling pattern determined by the end point shape pattern and the line segment area is determined for each advance amount, the line segment area is filled with the determined rectangular filling pattern, and when the filling process reaches the end point of the line segment, A thick line drawing method characterized by filling the end points with an end point shape pattern. (2) A frame memory (2), a pattern memory (4) for storing an end point shape pattern, a bit mover (6), and a thick line drawing control means for drawing line segments in the frame memory (2) using the DDA method. (8), the thick line drawing control means (8) includes end point drawing means (
10), initial setting means (11) for performing initial settings for filling with a rectangular pattern, and determining means (12) for determining that a line segment area between the start point and end point of the line segment is being drawn; a drawing determination means (14) for determining whether drawing of a rectangular filling pattern is possible at a drawing start point of the rectangular filling pattern; and, when drawing is possible, activating the bit mover (6) to determine the shape determined by the end point shape pattern and the line segment area. Rectangular pattern drawing means (16) for drawing the line segment area in a rectangular filled pattern; and when drawing is not possible, starting point movement that advances the drawing starting point from the drawing starting point by a value determined by the end point shape pattern and the line segment area. means (18); and the drawing determination means (1
4) A thick line drawing device comprising a correction means (20) for correcting an error term using a DDA method in any of the determinations according to the above.