JPH04291684A - Thick line plotter - Google Patents

Abstract

PURPOSE:To speed up plotting by executing masking operation in a mask plane and writing data in an external memory in each word in the case of plotting a thick line. CONSTITUTION:An auxiliary control device 6 starts to form a signal for specifying a reference point for the plotting of a thick line based upon a control signal applied from a CPU 7. The formed signal is inputted to a mask operation control circuit 3. Receiving the signal, the circuit 3 controls masking operation on the mask plane 2. The mask plane 2 executes masking operation between the data of pen point pattern sent from a pen point plane 4 and data stored in itself and an output control part 5 executes masking operation between the masking operation result and the data of a specified address on a plotting plane 11 and outputs the result to a data bus 10 in each word.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thick line drawing device used for computer display display in DTP, CG, etc.

0002

[Prior Art] Conventionally, as a method for drawing thick lines on a display, a line segment that is the center line (hereinafter referred to as a guideline) when drawing a thick line with a size of one pixel per point, and a line segment parallel to the center line (hereinafter referred to as a guideline), For example, Japanese Patent Laid-Open No. 16928/1983 draws thick lines by using multiple line segments and drawing them on a drawing plane configured with an external memory such as a frame memory.
Using the method described in Publication No. 2, mask calculation is performed by making each point of the guideline correspond to the reference point in the brush tip plane that holds the brush tip pattern, and by repeating this process, thick lines can be drawn on the drawing plane. There was a way to do it by drawing.

FIG. 17 is a diagram schematically showing the case of drawing a thick line using the latter method, and is an example in which a mask operation is performed on a drawing plane 35 in correspondence with a reference point 36 in the shape of a brush tip pattern 34. ((a) in the same figure). The mask calculation is performed in the order of the shaded areas 38 to 42 ((b) in the same figure).

0004

[Problem to be solved by the invention] However, in the former case, since the line segment is used as a reference, the drawing process is fast, but smoothness cannot be obtained when the free curve is made into a thick line. There was a problem. Furthermore, although it is possible to shorten the line segments in order to obtain smoothness, in this case there is a limit to the smoothness and the high speed of drawing is impaired.

In the latter case, the mask calculation is repeated according to the guideline, so it is superior in terms of smoothness, but as shown in FIG. It has been subjected. In FIG. 17(a), a 2 pixel x 2 pixel pattern was used as the brush tip pattern 34, so the number of overlaps was small at 2. However, if a several pixel x several pixel pattern is used, the same point can be repeated pixel by pixel. Also, mask calculations are required, which increases the number of times external memory such as frame memory is accessed, making it difficult to perform high-speed drawing processing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thick line drawing device that eliminates the above-mentioned problems, maintains smoothness even when drawing a free curve as a thick line, and is capable of drawing at high speed.

[0007]

[Means for Solving the Problems] When drawing a thick line, the present invention allows each point of a guideline, which has a size of one pixel, to draw the thick line, to be placed within the brush tip plane holding the brush tip pattern. By performing mask calculation in correspondence with the reference point and repeating this process, when drawing a thick line, instead of directly masking the brush tip plane and drawing plane, M words x
A mask operation is performed between the mask plane having a size of (N words + 2 pixels) and the brush tip plane, the operation result is output in word units, and the mask operation with the data of the corresponding address in the drawing plane is performed in word units. The result is drawn on the drawing plane.

[0008]

[Operation] According to the present invention, the mask calculation of the brush tip plane and the mask plane is performed along the guideline as described above, so that the obtained thick line is smooth. In addition, the calculation results output from the mask plane are the results of multiple operations performed within the mask plane, which reduces the number of times the drawing plane is composed of external memory, and also allows word-by-word access to the drawing plane. Therefore, thick lines can be drawn at high speed, and mask calculation processing can be performed at high speed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block diagram of a thick line drawing apparatus according to an embodiment of the present invention. Next, a thick line drawing apparatus according to an embodiment of the present invention will be explained in detail using the drawings.

The thick line drawing device 1 includes a mask plane 2 composed of a logic circuit for carrying out mask operations, a register for holding the operation results, etc., and a mask operation control circuit for controlling the mask operation processing on the mask plane 2. 3, and a brush tip plane 4 composed of RAM or registers that hold the shape of the brush tip.
, an output control unit 5 that outputs the mask calculation result in units of one word, a memory that holds the coordinate values of each point of the guideline, a digital differential analysis circuit (DDA), etc., and the thick line in the mask calculation control circuit 3 It is composed of an auxiliary control device 6 that provides a reference point when drawing.

The CPU 7 performs a process of writing a brush tip pattern on the brush tip plane 4 through a control signal bus 8, an address bus 9, and a data bus 10, and instructs the auxiliary control device 6 about the start and end points when drawing a thick line. or instructs the start of thick line drawing processing. Further, data output from the thick line drawing device 1 is written on a drawing plane 11 constituted by an external memory (video RAM, field memory, etc.) and displayed on a display 12.

The operation of the apparatus of this embodiment will be explained below. First, the CPU 7 performs a process of writing a brush tip pattern on the brush tip plane 4 and a process of instructing the auxiliary control device 6 the starting point and ending point of a guideline, which is a set of reference points when performing thick line drawing processing. Next, a signal to start processing is given from the CPU 7 to the auxiliary control device 6, and the thick line drawing device 1
Processing starts at .

In the thick line drawing device 1, when a signal to start processing is given from the CPU 7 to the auxiliary control device 6, the data in the mask plane 2 is initialized, the brush tip pattern of the brush tip plane 4 is subjected to mask calculation, and the data is Results are retained.

Next, the auxiliary control device 6 supplies the mask calculation control circuit 3 with a displacement signal that provides the next reference point for mask calculation. This displacement signal can be a displacement signal between the starting point and the next point when a guideline is given, or a displacement signal given from a digital differentiation circuit when the starting point and end point of a thick line and the type of curve are given. A quantity signal is used. Data in the drawing plane 11 is read into the output control section 5 in accordance with an address signal outputted from the mask calculation control circuit 3 in response to this displacement amount signal. Also, according to the control signal given from the mask calculation control circuit 3, a mask calculation is performed on the mask plane 2 between the data held in the mask plane 2 and the brush tip pattern of the brush tip plane 4, and the result of the mask calculation and output control are performed. A mask operation is performed on the data of the drawing plane 11 read into the section 5, and the result is written in the position indicated by the address signal in the drawing plane 11.

After performing the above processing from the start point to the end point and performing a mask operation on the mask plane 2 using the end point as a reference point, all data in the mask plane 2 and their corresponding data in the drawing plane 11 are The output control unit 5 performs a mask calculation, and the calculation result is written on the drawing plane 11, thereby completing the thick line drawing process.

Next, the mask operation on the mask plane 2 will be explained in detail. FIG. 2 is a diagram showing the mask plane 2 of the thick line drawing device of the present invention, in which the vertical axis is the Y coordinate and the horizontal axis is the X coordinate.
Coordinates. The mask plane 2 includes a left mask plane 13 having a size of 1 word x 1 word, a center mask plane 14, a right mask plane 15, an upper scroll plane 16 and a lower scroll plane each having a size of 3 words x 1 pixel. 17 and an auxiliary plane 18 of 1 word x (1 word + 2 pixels). 19 is the central mask plane 1
4 reference point M ([n/2], [n/2]) ([ ] represents a Gauss symbol).

FIG. 3 is a diagram showing a 1 word x 1 word brush tip plane 4 that holds the brush tip pattern 20, and 21 is a reference point P ([n/2], [n/2]) of the brush tip plane. be.

Next, the operation of drawing a thick line will be explained using FIGS. 2 and 3 and FIGS. 4 to 16 showing the operation of the apparatus of this embodiment.

First, the CPU 7 gives the auxiliary control device 6 the starting point and ending point of the guideline. Next, CP
The entire mask plane 2 is reset to a blank state by a signal given from U7 instructing the start of thick line drawing processing.

Next, draw a drawing plane 1 with a size of W words×H rows.
1 into strip-shaped parts each having a size of 1 word x 1 line as shown in Figure 4, and these W x H x n strip-shaped parts are divided into T
(s, t) {0≦s≦(W-1), 0≦t≦(H-1)
}, the starting point S0(X0,Y0)22
Representative point 2 of the strip-shaped portion T (s0, t0) 23 that includes
4(n·s0+[n/2], t0), the reference point 19 in the mask plane 2 is made to correspond to the reference point 19 as shown in FIG. As a result, the starting point S022 on the drawing plane 11 is set to the mask plane 2.
It is associated with point S'0 (X'0, Y'0) 25 within. Next, the point S'025 in the mask plane 2 and the reference point P21 in the brush tip plane 4 that holds the brush tip pattern 20 are made to coincide with each other, and mask calculations are performed on the mask plane 2 and the brush tip plane 4. As a result, a figure as shown in FIG. 6 is drawn on the mask plane 2.

Next, displacement signals (dX0, dY0) indicating the reference point given from the auxiliary control device 6 (starting point S0
and the next reference point S1).
By the control signal given from the mask calculation control circuit 3,
The correspondence between the reference point S'025 in the mask plane 2 and the reference point P21 in the brush tip plane 4 is changed to perform mask calculations on the mask plane 2 and the brush tip plane 4.

The operation will be explained below for each case. Further, FIG. 7 shows an initial state (a state in which a mask operation has been performed on the starting point).

i) Displacement signal (dX0, dY0) = (±
1,0) A point obtained by adding ±1 to the X coordinate value of point S'025 (in this case, dX
=-1. ) S'1 (X'0-1, Y'0) 26 is associated with the reference point P21 in the brush tip plane 4, and a mask calculation is performed on the mask plane 2. The result is shown in FIG. In FIG. 8, the shaded area 27 is the newly drawn area. (Also in the figure below, the shaded area indicates the newly drawn part.) ii) Displacement amount signal (dX0, dY0) = (0, ±1)
In this case, the entire mask plane 1 is scrolled one pixel upward or downward in the Y-axis direction. In other words, if dY1 = 1, the data in the 1 word x 1 pixel range at the bottom of the left mask plane 13, center mask plane 14, and right mask plane 15 is sent to the lower scroll plane 17, and the data that was in the upper scroll plane 16 is sent to the lower scroll plane 17. The data is left mask plane 13, center mask plane 14,
It is sent to a 1 word x 1 pixel area at the top of the right mask plane 15. Also, the upper scroll plane 16 is provided with blank space.

After scrolling along the Y axis, dY1=-
If dY1 = 1, the 3-word data in the upper scroll plane 16 will be used, and if dY1 = 1, the 3-word data in the lower scroll plane 17 will be used in the mask calculation with the drawing plane 11 in the output control unit 5. . However, when the data of each word is all blank during the mask calculation with the drawing plane 11, the mask calculation for that word is skipped.

Also, during the mask calculation with the drawing plane 11, the Y coordinate value of point S'025 is changed by ±1 to point S'1(X'0,
Y'0±1) 26 is associated with the reference point P21 in the brush tip plane 4, and a mask calculation is performed on the mask plane 2. In this operation, points S'025 and S'126 appear to coincide due to the previously performed scrolling operation. dY1
The calculation results in the case of =1 are shown in FIG.

iii) Displacement signal (dX1, dY1)=
(±1, ±1) (sign is arbitrary) First, as in case i), set the X coordinate value of point S'025 to ±
The point S'1 (X'0±1, Y'0) 26 made by 1 is made to correspond to the reference point P21 in the brush tip plane 4. Next, as in case ii), the mask plane 2 is scrolled along the Y axis, and the output control unit 5 performs a mask operation between the data sent to either the upper or lower scroll plane and the drawing plane 11. At the same time, a mask calculation between the mask plane 2 and the brush tip plane 4 is executed on the mask plane 2. Figure 10 shows the calculation results in this case (when dX1=-1, dY1=1)
Shown below.

Hereinafter, the amount of displacement between the reference point Si given as a time-series signal and the next reference point Si+1 will be given (dXi
, dYi), the reference point S'i28 when performing the mask calculation between the brush tip plane 4 and the mask plane 2 becomes as shown in FIG.
A case may occur in which the mask plane moves from the central mask plane 14 to the left mask plane 13 or to the right mask plane 15.

This case will be explained by taking as an example a case where the reference point S'i 28 when performing mask calculation between the brush tip plane 4 and the mask plane 2 moves from the center mask plane 14 to the left mask plane 13.

First, all data on the right mask plane 15 is transferred to the auxiliary plane 18, all data on the center mask plane 14 is transferred to the right mask plane 15, and all data on the left mask plane 13 is transferred to the center mask plane 14 (FIG. 12). reference).

Next, all data on the left mask plane 13 is initialized. By performing this operation, mask plane 2
The data within will be shifted to the right by one word. Therefore, as shown in FIG. 12, the point S'i(0, [n/
2]) 28 is the point S"i+1 (n-1, [n/2]) 29
Move to.

Next, the process for the value of dYi described above is applied to the mask plane 2 and the auxiliary plane 18, and dYi=
If dYi = 1, the data of the top one word of the upper scroll plane 16 and the auxiliary plane 18 is masked, and if dYi = 1, the data of the bottom one word of the bottom scroll plane 17 and the auxiliary plane 18 is masked to the drawing plane 11. and the point S”i+1
The point S'i+130 moved from 29 (apparent position remains unchanged) is associated with the reference point P21 in the brush tip plane 4, and a mask calculation is performed (FIG. 13 shows the case when dYi=0).
. However, during this series of operations, no mask calculation is performed between the drawing plane 11 and the portion of the auxiliary plane 18 excluding the two upper and lower portions of 1 word x 1 pixel.
Data is held at 8. The processing of this data is then performed using a time series signal (dXi+1, dYi+1) given to this device.
).

[0032] Below, each time series signal (dXi+1
, dYi+1) will be explained.

i) Case of dXi+1=0 (dYi+1=±1) In this case, the processing based on the value of dYi+1 described above is performed. Further, a scroll operation is performed on the auxiliary plane 18, and if data exists in a 1 pixel x 1 word portion at the top or bottom of the auxiliary plane 18, a mask operation is performed on the drawing plane 11. However, even after this treatment,
As long as dXi+k of the time series signal after this is 0,
Processing continues while the data of the auxiliary plane 18 is saved. FIG. 14 shows a case where dXi+1=0 and dYi+1=1, and point S'i+130 moves to point S'i+232.

ii) When dXi+1=-1 (dYi+1=±1,0
) In this case, the above-described processing is performed using the values of dXi+1=-1 and dYi+1 (FIG. 15 shows the case where dYi+1=0, and point S'i+130 is moved to point S'i+232). During this time, the n-word data of the auxiliary plane 18 is subjected to a mask operation on the drawing plane 11, and the auxiliary plane 18 is initialized after performing the mask operation on all the data.

iii) When dXi+1=1 (dYi+1=±1,0
) In this case, first perform the reverse operation of the right shift. That is, all data on the central mask plane 14 is transferred to the left mask plane 13, all data on the right mask plane 15 is transferred to the central mask plane 14, and all data on the auxiliary plane 18 is transferred to the right mask plane 15.

Next, all data on the auxiliary plane 18 is initialized. After this operation, processing using the value of dYi+1 described above is performed. By performing the above operations, processing can be performed efficiently even when there is a 1-bit advance or retreat at a word boundary. Figure 16 shows the processing results in this case.
(When dYi+1=0).

The above description has been made using an example in which the reference point S'i 28 when performing mask calculation between the brush tip plane 4 and the mask plane 2 moves from the center mask plane 14 to the left mask plane 13. When the reference point S'i 28 is moved from the center mask plane 14 to the right mask plane 15 when performing a mask calculation between Since this is done by replacing , a detailed explanation will be omitted.

In this way, a thick line is drawn to the end point of the guideline, and when the end point is reached, all the data in the mask plane is scrolled down one pixel at a time, the data is sent to the lower scroll plane 17, and this A mask operation is performed on the data on the drawing plane 11. This process is carried out until all the data of length n pixels in the vertical direction are subjected to the mask calculation, and the drawing of the thick line is completed.

Note that it is also possible to draw a colored thick line by referring to a color register or the like with respect to the word unit data output from the thick line drawing device of the present invention.

Furthermore, by changing the brush tip pattern held within the brush tip plane, thick lines of various shapes can be easily drawn.

[0041]

[Effects of the Invention] As explained above, according to the present invention,
When drawing thick lines, mask calculations are performed between the brush tip plane and the mask plane according to the guidelines, making it possible to draw smooth thick lines. Also, the calculation results output from the mask plane do not overlap within the mask plane. This is the result of the calculation, and in addition to reducing the number of times it is drawn on the drawing plane made up of external memory, the calculation result is output in units of words, so by accessing the drawing plane in units of words, It becomes possible to perform mask calculation processing at high speed.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a thick line drawing device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a mask plane in the same embodiment.

FIG. 3 is a configuration diagram of a brush tip plane in the same embodiment.

FIG. 4 is a diagram showing the state of the drawing plane when thick line drawing is started.

FIG. 5 is a diagram showing how a drawing plane and a mask plane are associated when starting thick line drawing.

FIG. 6 is a diagram showing the correspondence between a mask plane and a brush tip plane.

FIG. 7 is a diagram showing the appearance of a mask plane immediately after mask calculation is performed on a starting point.

FIG. 8 is a diagram showing the state of the mask plane after processing in the case (dX0, dY0)=(-1, 0).

FIG. 9 is a diagram showing the state of the mask plane after processing in the case of (dX0, dY0)=(0, 1).

FIG. 10 is a diagram showing the state of the mask plane after processing in the case (dX0, dY0)=(-1, 1).

FIG. 11 is a diagram showing the state of the mask plane immediately before the reference point S'i moves from the central mask plane.

FIG. 12 is a diagram showing the state of the mask plane after the scrolling operation.

FIG. 13 is a diagram showing the state of the brush tip plane after the scroll operation and the mask plane after performing the mask calculation.

FIG. 14 is a diagram showing the state of the mask plane after processing when (dXi+1, dYi+1)=(0, 1).

[Figure 15] (dXi+1, dYi+1) = (-1, 0)
FIG. 3 is a diagram showing the state of the mask plane after processing in the case of .

FIG. 16 is a diagram showing the state of the mask plane after processing when (dXi+1, dYi+1)=(1, 0).

FIG. 17 is a diagram schematically showing a case where thick line drawing processing is performed using a conventional method.

[Explanation of symbols]

1 Thick line drawing device 2 Mask plane 3 Mask calculation control circuit 4 Brush tip plane 5 Output control section 6 Auxiliary control device 11 Drawing plane 13 Left mask plane 14 Central mask plane 15 Right mask plane 16 Upper scroll plane 17 Lower scroll plane 18 Auxiliary plane

Claims (5)

[Claims] [Claim 1] When drawing a thick line on a drawing plane of W words x H rows, where n pixels are one word and one pixel is one row,
When drawing a thick line, which is a set of points each having a size of one pixel, each point on the center line is associated with a reference point in the brush tip plane that holds the brush tip pattern, and a mask calculation is performed. When drawing thick lines by repeating, instead of directly masking the brush tip plane and drawing plane, M words x (
A mask operation is performed between a mask plane having a size of N words + 2 pixels) and a brush tip plane, the operation result is output in word units, and a mask operation is performed with the data of the corresponding address in the drawing plane in word units. , a thick line drawing device that draws the result on a drawing plane. 2. When drawing a thick line, the thick line is drawn using the start point and end point of the thick line and the displacement amount given by the digital differential analysis circuit instead of the center line used when drawing the thick line. drawing device. Claim 3: When a set of coordinate points constituting the center line for drawing a thick line is given, and mask operations are performed one after another using each point as a reference, the current reference point and the next reference point are Claim 1: A thick line is drawn by sending the displacement amount of coordinate values between the two.
The thick line drawing device described. 4. When performing mask operations on the drawing plane and the mask plane in units of words, if each word to be subjected to the mask operation is blank, the operation on that word is skipped and the next word is processed. Claim 1
The thick line drawing device described. 5. When there is repetition of horizontal movement of 1 bit at a horizontal word boundary, an auxiliary plane with a size of 1 word x (N words + 2 pixels) is used to temporarily hold data, 2. The thick line drawing device according to claim 1, wherein the number of mask calculations is reduced.