JPH01220081A - Line segment drawing device - Google Patents

Abstract

PURPOSE:To improve a graphics display quality by changing the shape of a line to correspond to the case when the line width of various kinds of line segments is changed. CONSTITUTION:A down counter 7 which ordinarily executes an 'H' output, down-counts a clock pulse CLK by setting a line width value with a line width holding register 5 and executes an 'L' output when a count value is '0' and a register control part 8 which controls the MSB output of a line kind holding register 3 by inputting the clock pulse CLK, drawing picture mode specification signals m0 and m1, an MSB from a line kind holding register 3 and a down counter 7 output are provided. Several kinds of drawing picture modes are specified, the line width value is adopted in accordance with these modes, the clock pulse CLK giving to the line kind holding register 3 is controlled, the shape of the line is changed, since the line segment of the desired shape is drawing-pictured, the shape of the line can be changed corresponding to the case of when the line width of the several kinds of the line segments are changed. Thus, the graphics display quality is improved.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to the field of graphics processing.
The present invention relates to a line segment drawing device that is improved so that when drawing various line segments such as dotted and dashed lines, the shape and line width of the line can be arbitrarily changed.

<Prior art> Normally, in the field of graphics processing, when drawing various line segments such as dotted lines and dashed lines, the line type pattern is stored in the line type holding register as bit information (for example, rHHLL for a dotted line).
HHLL, , - If it is a dashed line, r HHL HL H
HL J, etc.) and store it as a DDA device (Digita
l Differential Analyzer
) is used to draw a drawing pattern such as a circle or a rectangle, and the bit information of the line type pattern described above is multiplied by this pattern to draw various line segments.

Problems to be solved by the present invention> The results drawn as described above are shown in FIG.

FIG. 9(a) is a dotted line with a line width of one dot.

FIG. 9(b) is a diagram in which the line width of the dotted line shown in FIG. 9(a>) has been expanded.

In this way, with conventional devices, when increasing the width of a line segment to be drawn, although it is possible to increase the width in the direction of arrow a, does not change, because the line width value to be expanded is matched to the vertical and horizontal directions of the pattern to be drawn, but horizontal expansion is not possible unless the bit information of the line type pattern changes, and only the vertical direction is expanded. It is.

However, in the field of graphics processing, there are many demands for changing not only the line width but also the line shape, that is, the interval between dotted lines, the length of each line segment that makes up the dotted line, etc., and there has been no suitable measure to deal with this.

The present invention has been devised to solve the above problem, and improves the quality of graphics display by changing the shape of the line when changing the line width of various line segments. The purpose is to

Means for Solving the Problems> In order to solve the above problems, the present invention specifies the drawing mode and controls the clock pulse given to the register storing the line type according to the line width to be changed. The specific configuration is as follows.

That is, the configuration of the present invention includes a coordinate value generation section that outputs coordinate values for drawing, a pattern generation section that generates a drawing pattern based on these coordinate values, and a clock that is given bit information constituting the line type to be drawn. - Equipped with a line type holding register that outputs according to pulses, a drawing section that performs drawing based on the bit information and the drawing pattern, and a line width holding register that provides line width information to the pattern generation section, and displays line segments on a CRT display device. A line segment drawing device for drawing a line segment, characterized in that a control section is provided for controlling a clock pulse given to the line type holding register in accordance with a value of the line width information using a drawing mode designation signal. It is a device.

Function> The line segment drawing device of the present invention specifies several types of drawing modes, takes in line width values according to these modes, controls clock pulses given to registers holding line types, and draws dotted lines. A line segment having a desired shape is drawn by changing the shape of the line, such as the distance between the dotted line and the length of each line segment making up the dotted line.

<Embodiment> FIG. 1 shows an example of the configuration of a line segment drawing device embodying the present invention.

In this figure, 1 is a DDA generating section that generates a drawing coordinate value every time a clock pulse CLK is applied, 2 is a pattern generating section that generates a drawing pattern such as a circle or a rectangle, and 3
The line type holding register 4 is a rotating register that holds line type patterns such as dotted lines and dashed-dotted lines as several words of bit information (line @1) and outputs the MSB (most significant bit) according to the tarok pulse CLK. 5 is a drawing unit that draws a line segment by multiplying the drawing pattern corresponding to the drawing coordinate value and the bit information (MSB) output from the line type holding register 3, and 5 is used to change the line width of the line segment to be drawn. A line width holding register 6 has a line width value set therein and supplies the value to the pattern generating section 2C, and 6 is a CRT display device, and the configuration up to this point is the same as that of a conventional line segment drawing device.

Furthermore, in addition to the above-described configuration, the present invention usually has "H"
A down counter 7 outputs a line width value from the line width holding register 5, counts down the clock pulse CLK, and outputs an "L" level when the count value is "0".
, clock pulse CLK, drawing mode designation signal mO
, ml, the MSB from the line type holding register 3, and the output of the down counter 7, and a register control unit 8 for controlling the MSB output of the line type holding register 3.

FIG. 2 shows a logical configuration diagram of the input and output 2 of the register control section 8.

Here, the drawing mode designation signals mo, ml are H'',
By combining "L", (1) line segment drawing as usual (mO="L"), (2) enlargement of only each line segment that makes up the dotted line (n0shi "H", m1="shi"), <3) Expansion of each line segment composing the dotted line and expansion of the dotted line interval (mo=″H
”, ml="H").

(1) When mo="L" The output Z of the register control unit 8 is
is always the clock pulse CLK.

The operation at this time is the same as the conventional line segment drawing operation described in the <Prior Art> section, and the operation is shown in the flowchart of FIG.

That is, when mo=“L”, the MSB is output from the line type holding register 3 in synchronization with the clock pulse CLK every time the DDA generating reactor generates one stroke coordinate value.

When MSB="L", no drawing operation is performed and the line type holding register 3 is rotated.

When MSB = “H”, the line width value is given to the pattern generation unit 2 from the line width holding register 5, and (drawing pattern)
After the line width) is calculated and a drawing operation is performed, the line type holding register 3 is rotated.

The drawing results are shown in FIGS. 6(a), (b), and (c).

Shown in (d).

The drawing results are similar to those of the conventional device shown in FIG. This is the case where the line width is 4.

In this way, when the line width value is set to a large value, each line segment forming the dotted line is enlarged in the vertical direction while the interval between dotted lines remains the same.

(2) When mo="" + m 1 = "1da" When the MSB of the line type holding register 3 is "L", the output Z is the clock pulse CLK, and the MSB is "H".
When the down counter 7 output is “L” (down
When the count ends), the clock pulse CLK is output, and when the down counter 7 output is “H” (during down count), the clock pulse CLK is “
L” (output inactive).

The operation at this time is shown in the flowchart of FIG.

First, the line@value of the line@holding register 5 is set as the initial value of the down carantuff.

According to clock pulse CLK, DDA generation generator 1
The image coordinate value is output, and the line type holding register 3 outputs the MSB.

When MSB="L", the drawing operation and down counter 7 are not decremented, and the line type holding register 3 is rotated (a new MSB is output from the line type holding register 3). Therefore, the drawing operation is not performed. Parts that are not done (81
minute intervals) always correspond to one clock pulse.

When MSB="L", the line width value is given to the pattern generator 2 from the line width holding register 5, and (drawing pattern)
The line @) is calculated and a drawing operation is performed. At the same time, the down counter 7 counts down the tarok pulse CLK from the line width value. This operation is performed by down counter 7.
This is repeated until the count value of 0 becomes 0, and when the value of the down counter 5 becomes 0, the line type register 3 is rotated.

That is, when MSB="L", no drawing operation is performed and the line type holding register 3 is rotated, and when MSB="L", drawing is performed for the number of tarok pulses CLK corresponding to the line width value. Therefore, the length of each line segment forming the dotted line in the horizontal direction increases with the length in the vertical direction.

The drawing results are shown in FIG.

FIG. 7(a) is a dotted line with the same line width l as in FIG. 6(a>). FIG.

As shown in this figure, the drawing mode designation signal mO="L"
If 9m1="S", the distance between the centers of each line segment forming the dotted line remains unchanged, and each line segment is expanded equally in length and width.

<3) When mo="H" and ml="H', the output 2 of the register control unit 8 is the clock pulse CLK when the down counter 7 output is "L" (down counting is completed).
When the output of the down counter 7 is high (during down counting), it is low (output inactive).

The operation at this time is shown in the flowchart of FIG.

First, the line width value of the line width holding register 5 is set as the initial value of the down callantuff.

According to clock pulse CLK, DDA generation generator 1
The image M standard value is output, and the line type holding register 3 outputs the MSB.

When MSB="L", no drawing operation is performed and the down counter 7 counts down. Then, the drawing operation is not performed until the count value of the down counter 7 reaches O, and when the count value of the down counter 7 reaches O, the line type holding register 3 is rotated.

When MSB="H", the line width value is given from the line width holding register 5 to the pattern generating section 2, (drawing pattern) X (line width) is calculated, and a drawing operation is performed. Then, the down counter 7 counts down the clock pulse CLK based on the line width value.

This operation is continued until the count value of the down counter 7 reaches O, and when the count value of the down counter 7 reaches O, the line type holding register 3 is rotated.

That is, when MSB="L", drawing is not performed for the number of clock pulses CLK corresponding to the line width value, and when MSB="H"
'', drawing is performed for the number of clock pulses CLK corresponding to the line width value, so the interval between drawn dotted lines becomes longer, and the horizontal length of each line segment that makes up the dotted line becomes longer than the vertical length. It becomes longer with time.

The drawing results are shown in FIG.

FIG. 8(a) is a dotted line with a line width of 1, which is the same as FIG. 6(a) and FIG. 7(a). (b) is line @2, (Cf) is 1m@
3, (d) has a line width of 4.

As shown in this figure, the drawing mode designation signal m.

= “H”1m1 When = “H”, the line segments that make up the dotted line are expanded equally in the vertical and horizontal directions, and the center distance of each line segment that makes up the dotted line is also expanded in accordance with the set line width value. .

As described above, the present invention provides the drawing mode designation signal mo
By combining . 3) Expansion of each line segment making up the dotted line and expansion of the dotted line interval (mO=“H”1
Drawing can be performed by specifying m1="H"), and the shape of the line, such as the interval between dotted lines and the length of each line segment making up the dotted line, can be changed.

The logical configuration of the register control unit 8 that performs the operations described above is most effectively realized by the firmware (microprogram) of a microprocessor, and can also be realized by a combination of AND circuits such as gate arrays and OR circuits. It is also easy to do.

<Effects of the Invention> The line segment drawing device of the present invention specifies several types of drawing modes, takes in line width values according to these modes, and controls clock pulses given to registers holding line types. , the shape of the line, such as the interval between dotted lines, the length of each line segment that makes up the dotted line, etc., is changed to draw line segments of the desired shape, so when changing the line width of various line segments, it is possible to The shape of the line can also be changed to improve graphics display quality.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a line segment drawing device embodying the present invention, FIG. 2 is a logical configuration diagram of the register control unit 8 of the device of the present invention, and FIGS. 3 to 5 are diagrams showing cases when the drawing designation signal is changed. A flowchart showing the operation of the device of the present invention, FIG. 6(a),
(b), (c). (d) to Figure 8 (a), (b), (c), and (d) are the third
The drawing results of the operations shown in FIGS. 9 to 5, and FIGS. 9(a) and 9(b) are diagrams showing the drawing results of the conventional apparatus. DESCRIPTION OF SYMBOLS 1... DDA generation section, 2... Pattern generation section, 3... Line type holding register, 4... Drawing section, 5.
...Line width holding register, 6...CRT display device, 7
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Claims (1)

[Claims] (1) A coordinate value generation unit that outputs coordinate values for drawing, a pattern generation unit that generates a drawing pattern at these coordinate values,
A line type holding register that outputs bit information constituting the line type to be drawn in accordance with a given clock pulse, a drawing section that performs drawing based on the bit information and the drawing pattern, and a line width In a line segment drawing device that draws line segments on a CRT display device, the line segment drawing device includes a line width holding register that provides information, and a line segment drawing device that draws line segments on a CRT display device. A line segment drawing device comprising a control section for controlling pulses.