JPH0683971A - Graphic display device - Google Patents

Abstract

PURPOSE:To eliminate the area required for registration, to perform the copy processing at the time of plotting, and to enable high-speed plotting by registering one part of plotting data of paint-out circle to be used frequently. CONSTITUTION:When a user specifies a radius and performs the registration specification, four segment areas except for rectangular area inscribed to the circle of the radius are calculated in a circumference area registration means 2. The rectangular area including the segment shape is registered in a circumference area storage means 5 as circumference area data. Then, when a circle plotting specification is performed, a circumference area plotting means 3 reads out the circumference are data of the paint-out circle of the radius specified from the means 5 are read out and its effective pixel is written in the specified plotting position of a frame buffer 6, resulting in plotting the four segment areas. In an inscribed square plotting means 4, the area of the inscribed square is calculated based on the center position and the radius of the paint-out circle, performing the internal paint-out plotting of the square on the frame buffer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic display device capable of drawing a filled circle.

[0002]

2. Description of the Related Art In a conventional graphic display device of this type,
When drawing a filled circle, the circle is approximated to a polygon and the polygon filling process is performed. Alternatively, for speeding up, a frequently used radius is filled, a circle is registered with drawing data, and copying is performed to perform drawing.

[0003]

The conventional filled circle drawing method described above has a drawback in that the drawing performance is slow in the case of approximating a polygon due to the line segment decomposition of the circumference and the polygon filling process. Further, when the drawing data of the filled circle is registered in advance and the copy drawing is performed, the drawing performance is high, but there is a drawback that a huge area for storing the drawing data is required.

[0004]

A graphic display device according to a first aspect of the present invention includes a frame buffer, a circumferential area storage means for storing drawing data of a part of a plurality of filled circles having different radii, and a circle registration instruction. When activated, the specified filled circle is divided into four arc-shaped regions, excluding the square region inscribed in the circle from the inside region of the circle, and registered in the circumferential region storage means as circumferential region data. Circumferential area registration means,
A circumferential area drawing means that is activated by a circle drawing instruction, reads the circumferential area data having a specified radius from the circumferential area storage means, and writes the circumferential area data to the frame buffer at the position, and is started from the circumferential area drawing means, A graphic display device having an inscribed square drawing means for performing a filled drawing of a square inscribed in a circle having a radius designated at the position of the frame buffer.

The graphic display device according to the second aspect of the present invention is activated and designated by a frame buffer, a partial circumferential area storage means for storing drawing data of a part of a plurality of filled circles having different radii, and a circle registration instruction. For filled circles,
4 excluding the square area inscribed in the circle from the area inside the circle
Partial circumferential area registration means for registering an area obtained by dividing one of the two arcuate areas perpendicularly to the chord into two pieces as partial circumferential area data in the partial circumferential area storage means, and activated by a circle drawing instruction. The partial circumferential area data of the specified radius is read from the partial circumferential area storage means, and the partial circumferential area registration means creates the partial circumferential area data from the partial circumferential area data by utilizing the symmetry of the circle. A circumferential area drawing means for reproducing the four bow-shaped areas and writing the four bow-shaped areas at the positions of the frame buffer, and starting from the circumferential area drawing means,
A graphic display device having an inscribed square drawing means for performing a filled drawing of a square inscribed in a circle having a radius designated at the position of the frame buffer.

[0006]

Embodiments of the present invention will now be described with reference to the drawings.

Referring to FIG. 1 showing a first embodiment of the present invention, the present embodiment has an input means 1, a circumferential area registration means 2, a circumferential area drawing means 3, an inscribed square drawing means 4, a circumferential area. It is composed of a storage means 5, a frame buffer 6 and a display means 7.

FIG. 2 shows the details of the circumferential area registration means 2,
It is composed of an arcuate region calculation unit 21 and a circumferential region registration unit 22.

FIG. 3 shows the details of the circumferential area drawing means 3,
It is composed of a circumferential area reading section 31, an arcuate area drawing section 32, and an interior square drawing means starting section 33.

FIG. 4 shows the details of the inscribed square drawing means.
It is composed of an inscribed square area calculation unit 41 and a rectangular area filling drawing unit 42.

FIG. 5 is a diagram showing an example of the circumferential area data registered in the circumferential area storage means 5 and a filled circle drawn by using the circumferential area data.

Next, the operation of the embodiment will be described.

First, when the user specifies a radius from the input means 1 and gives an instruction to register a circle, the circumferential area registration means 2 is activated. In the circumferential area registration unit 2, the arcuate area calculation unit 21 calculates four arcuate areas excluding the inscribed square area from the circle with the specified radius, and the circumferential area registration unit 2 calculates the short area including the arcuate shape. Is registered in the circumferential area storage means 5 as circumferential area data. FIG. 5 shows an example of a filled circle having a radius of 8, and as shown in FIG.
Circumferential region data including the arcuate regions of (2) and (4) is calculated.

Next, when the user gives a circle drawing instruction from the input means 1, the circumferential area drawing means 3 is activated. In the circumferential area drawing means 3, first, the circumferential area continuous portion 31 reads the circumferential area data of the filled circle having the specified radius from the circumferential area storage means 5. Then, the effective pixel (that is, the filled portion) of the circumferential area data read by the arcuate area drawing unit 32 is written in the designated drawing position of the frame buffer 6, and as a result, four arcuate areas are drawn. Next, the inscribed square drawing means activation unit 33 activates the inscribed square drawing means 4.

In the inscribed square drawing means 4, the inscribed square area calculation unit 41 calculates the area of the inscribed square from the center position and radius of the filled circle. And shape area filling 4
In step 2, the square internal filling drawing is performed at the position on the frame buffer 6. In FIG. 5 (b), the area marked with ● represents the pixels of the arcuate area drawn by the circumferential area drawing means 3, and the area marked with ■ represents the pixels inside the square interior filled area drawn by the inscribed square drawing means 4. It represents.

Referring to FIG. 6 showing a second embodiment of the present invention, in this embodiment, an input means 1, a partial circumferential area registration means 8, a circumferential area drawing means 9, an inscribed square means drawing means 4,
It is composed of a partial circumferential area storage means 10, a frame buffer 6, and a display means 7.

FIG. 7 shows the details of the partial circumferential area registration means 8, which is an arcuate area calculation section 81 and a partial circumferential area registration section 82.
It consists of

FIG. 8 shows the details of the circumferential area drawing means 9, which is composed of a partial circumferential area reading section 91, an arcuate area drawing section 92 and an inscribed square drawing means starting section 93.

FIG. 9 is a diagram showing an example of partial circle area data registered in the partial circle area storage means 10 and a filled circle drawn using the partial circle data.

Next, the operation of the embodiment will be described.

First, when the user specifies a radius from the input means 1 and gives an instruction to register a circle, the partial circumferential area means 8 is activated. In the partial circumference area registration means 8, the arcuate area calculation unit 81
Thus, four arcuate regions are calculated by removing the inscribed square region from the designated radius. Then, one arcuate area is selected by the partial circumferential area registration unit 82 and further divided into two perpendicular to the chord, and the rectangular area including this graphic area is stored as partial circumferential area data as the partial circumferential area storage means 10. Be registered with. FIG. 9 shows an example of a filled circle having a radius of 8, but partial circumferential area data including an area obtained by dividing the arcuate area of (1) shown in FIG. 10A into two is calculated and registered.

Next, when the user gives a circle drawing instruction from the input means 1, the circumferential area drawing means 9 is activated. In the circumferential area drawing unit 9, first, the partial circumferential area reading unit 91 reads the partial circumferential area data of the filled circle having the specified radius from the partial circumferential area storage unit 10. Then, by utilizing the symmetry of the circle by the arcuate area drawing unit 92, four arcuate areas are reproduced from the read partial circumferential area data, and the effective pixels (that is, the filled areas) are written at the designated drawing positions in the frame buffer 6. As a result, four arcuate regions are drawn. Next, the inscribed square drawing means activation unit 93 activates the inscribed square drawing means 4.

In the inscribed square drawing means 4, the inscribed square area calculation unit 41 calculates the area of the inscribed square from the center position and radius of the filled circle. Then, the rectangular area filling drawing unit 42 draws a square inside drawing at the position on the frame buffer 6. In FIG. 10 (b), the area marked with ● represents the pixels in the arcuate area drawn by the circumferential area drawing means 9, and the area marked with ■ represents the pixels in the square interior filled area drawn by the inscribed square drawing means 4. It represents.

The data written in the frame buffer 6 is reflected on the display means 7 at regular time intervals.

[0025]

As described above, by registering a part of drawing data of a filled circle that is frequently used,
Since the area required for registration can be deleted and the copy processing can be performed at the time of drawing, there is an effect that high speed drawing is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a filled circle drawing method of the present invention.

FIG. 2 is a diagram showing a flow of processing in a circumferential area registration means 2 in FIG.

FIG. 3 is a diagram showing the flow of processing in the circumferential area drawing means in FIG.

FIG. 4 is a diagram showing a flow of processing in an inscribed square drawing means 4 in FIG.

FIG. 5 is a diagram showing an example of the circumferential area data stored in the circumferential area storage unit 5 in FIG. 1 and the painted filling.

FIG. 6 is a diagram showing a second embodiment of the filled circle drawing method of the present invention.

FIG. 7 is a diagram showing a flow in the partial circumferential area registration means 8 in FIG.

FIG. 8 is a diagram showing a flow in processing of a circumferential area drawing means 9 in FIG.

FIG. 9 is a diagram showing an example of partial circle area data stored in the partial circle area storage unit 10 in FIG. 6 and a filled circle drawn.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input means 2 Circumference area registration means 3 Circumference area drawing means 4 Inscribed square drawing means 5 Circumference area storage means 6 Frame buffer 7 Display means 8 Partial circumference area registration means 9 Circumference area drawing means 10 Partial circumference Area storage means

Claims (2)

[Claims] 1. A frame buffer, a circumferential area storage means for storing drawing data of a part of a plurality of filled circles having different radii, and a circle registration instruction, which is activated for a designated filled circle, inside the circle. Circle area registration means for dividing four areas excluding a square area inscribed in the circle into arcuate areas, and registering the circle area data in the circumference area storage means; A circumferential area drawing means for reading the circumferential area data having a specified radius from the circumferential area storage means and writing the circumferential area data in the frame buffer at the position, and the circumferential area drawing means activated by the circumferential area drawing means and designated at the position in the frame buffer. A graphic display device having an inscribed square drawing means for performing a filled drawing of a square inscribed in a circle having a different radius. 2. A frame huffer, a partial circumferential area storage means for storing drawing data of a part of a plurality of filled circles having different radii, and a circle registration instruction activated for a designated filled circle for the designated filled circle. A region in which one of four arcuate regions excluding a square region inscribed in the circle from the inside region of the circle is divided into two perpendicular to the chord is registered as partial circumferential region data in the partial circumferential region storage means. Circumferential region registration means, activated by a circle drawing instruction, reads out partial circumferential region data of a specified radius from the partial circumferential region storage means,
A circumferential area drawing means for reproducing the four arcuate areas created by the partial circumferential area registration means at the time of registering the partial circumferential area data from the partial circumferential area data by utilizing the symmetry of the circle and writing the four arcuate areas at the positions of the frame buffer. And a inscribed square drawing unit that is activated by the circumferential area drawing unit and draws a square inscribed in a circle having a radius designated at the position of the frame buffer.