JPH04115378A - Graphic display control system in graphic processing system - Google Patents

Abstract

PURPOSE:To rapidly plot a circle an ellipse, a circular arc, or an elliptic arc by setting up circular reference data in a graphic processing mechanism through a required plotting processing system and setting up plotting data in the graphic processing mechanism. CONSTITUTION:A plotting processing system program 103 in a main storage device 101 is provided with a circular reference data holding means 131 for holding circular reference data, a storing means 132 for calculating the 1st coordinate conversion value based upon a value indicating a circle or an ellipse specified from an application program 102 and storing the calculated value in a memory holding means 133, a coordinate conversion value setting means 134 for calculating the 2nd coordinate conversion value based upon a value indicating the display position of the circle or ellipse specified from the program 102 and the coordinate conversion value stored in the means 133 and setting up the 2nd coordinate conversion value in a coordinate conversion function 107 in a graphic processing mechanism 108, a radius calculating means 135 for calculating the radius of the circle or ellipse on the device coordinates based upon the 2nd coordinate conversion value, and a circular reference data setting means 136 for forming circular reference data obtained by properly thinning the number of vertexes based upon the data held in the means 131 and the radius calculated by the means 135 and setting up the circular reference data in the graphic processing mechanism 108. Consequently, a circular, an ellipse, or their arcs can rapidly be plotted by the small quantity of calculation without calculating the coordinate points of a segment string.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a graphic processing system, and particularly to a graphic processing system that controls the drawing of circles, ellipses, circular arcs, and elliptical arcs (including fan shapes, bow shapes, etc.) in the graphic processing system. This invention relates to a graphic display control method.

[Conventional technology]

Conventionally, in the graphic display control method of this type of graphic processing system, when drawing a circle or ellipse, the display position and radius (ellipse's The coordinate points expanded into a line segment sequence were calculated from information such as (indicates the conjugate radius in some cases), and these coordinate points were sent to a graphic processing mechanism to perform drawing.

Also, when drawing a circular arc or elliptical arc, the display position is determined every time the application program instructs the drawing of the circular arc or elliptical arc.

Coordinate points expanded into a line segment sequence are calculated from information such as the radius, start angle, and end angle, and these coordinate points are sent to a graphic processing mechanism, where drawing is performed based on these coordinate points.

[Problem to be solved by the invention]

In the graphic display control method in the conventional graphic processing system described above, each time an application program instructs the drawing of a circle, ellipse, circular arc, or elliptical arc, coordinate points expanded into a line segment sequence are calculated based on predetermined information. Since the data is sent to the figure processing mechanism and drawing is performed based on those coordinate points, the amount of data in the figure processing system and the amount of data when drawing becomes large, making it possible to draw figures such as circles at high speed. The drawback is that it cannot be done.

In view of the above-mentioned points, it is an object of the present invention to solve the above-mentioned drawbacks of the conventional technology, and to quickly (especially when continuously drawing circles and arcs of the same radius) use device coordinates. (
An object of the present invention is to provide a graphic display control system in a graphic processing system that can draw a circle, an elliptical arc, and an elliptical arc on a display device (coordinates on a display device).

[Means to solve the problem]

The graphic display control method in the graphic processing system of the present invention is a graphic processing system having a graphic processing mechanism with a coordinate conversion function, which includes a circle basic data holding means that holds circle basic data, and a circle or circle specified by an application program. Obtain the value that indicates the shape of the ellipse, and then calculate the first value based on that value.
storage means for calculating the coordinate transformation value of and storing the first coordinate transformation value in the memory retention means, and a value indicating the display position of the circle or ellipse designated by the application program and the first coordinate transformation value setting means for calculating a second coordinate transformation value based on the coordinate transformation value and setting the second coordinate transformation value in a coordinate transformation function within the graphic processing mechanism; Radius calculation means for calculating the radius of a circle or ellipse on device coordinates based on a second coordinate transformation value; and circle basic data held in the circle basic data storage means and device coordinates calculated by the radius calculation means. It has circle basic data setting means for generating circle basic data with the number of vertices appropriately thinned out based on the radius of the above circle or ellipse and setting the circle basic data in the graphic processing mechanism.

In addition, the graphic display control method in the graphic processing system of the present invention is such that, in a graphic processing system having a graphic processing mechanism with a coordinate conversion function, a circle basic data holding means for holding circle basic data and a circle basic data holding means that holds circle basic data, A storage means for acquiring a value indicating the shape of a circular arc or an elliptical arc, calculating a first coordinate transformation value based on the value, and storing the first coordinate transformation value in a memory storage means; A second coordinate transformation value is calculated based on the value indicating the display position of the elliptical arc and the first coordinate transformation value in the memory holding means, and the second coordinate transformation value is set in a coordinate transformation function in the graphic processing mechanism. a coordinate transformation value setting means; a radius calculation means for calculating the radius of a circular arc or an elliptical arc on the device coordinates based on the second coordinate transformation value calculated by the coordinate transformation value setting means; a start point and end point calculation means for calculating a start point and an end point of a circular arc or an elliptical arc on the circle basic data in the circle basic data holding means based on the start angle and end angle among the values indicating the shape of the ellipse; The circle basic data held in the circle basic data holding means, the radius of the circular arc or elliptical arc on the device coordinates calculated by the radius calculation means, and the start of the circular arc or elliptical arc calculated by the start point/end point calculation means The basic arc data setting means generates basic arc data with the number of vertices appropriately thinned out based on the points and end points, and sets the basic arc data in the graphic processing mechanism.

[Effect]

In the graphic display control method in the graphic processing system of the present invention, the circle basic data holding means holds the circle basic data, and the storing means acquires a value indicating the shape of a circle or an ellipse specified from an application program, and based on the value. The first coordinate transformation value is calculated and the first coordinate transformation value is stored in the memory storage means, and the coordinate transformation value setting means is configured to calculate a value indicating the display position of the circle or ellipse specified from the application program and store the first coordinate transformation value in the memory retention means. A second coordinate transformation value is calculated based on the first coordinate transformation value of The device calculates the radius of a circle or ellipse on the device coordinates based on the second coordinate transformation value, and the circle basic data setting means calculates the radius using the circle basic data held in the circle basic data holding means and the radius calculation means. Circle basic data is generated by appropriately thinning out the number of vertices based on the radius of the circle or ellipse on the coordinates, and the circle basic data is set in the graphic processing mechanism.

Further, in the graphic display control method in the graphic processing system of the present invention, the circle basic data holding means holds the circle basic data, and the storing means acquires a value indicating the shape of a circular arc or elliptical arc specified from an application program. The coordinate transformation value setting means calculates a first coordinate transformation value based on and stores the first coordinate transformation value in the memory storage means, and the coordinate transformation value setting means calculates a value indicating the display position of the circular arc or elliptical arc specified from the application program and stores it in the memory. A second coordinate transformation value is calculated based on the first coordinate transformation value within the means, and the second coordinate transformation value is set in the coordinate transformation function within the graphic processing mechanism, and the radius calculation means calculates the second coordinate transformation value based on the first coordinate transformation value within the means. The radius of the circular arc or elliptical arc on the device coordinates is calculated based on the calculated second coordinate transformation value, and the start point/end point calculation means calculates the starting angle in the value indicating the shape of the circle or ellipse specified from the application program. The starting point and the ending point of a circular arc or elliptical arc on the circle basic data in the circle basic data holding means are set based on the basic circle data holding means and the end angle, and the basic arc data setting means sets the basic circle data held in the basic circle data holding means. , arc basic data in which the number of vertices is appropriately thinned out based on the radius of the circular arc or elliptical arc on the device coordinates calculated by the radius calculation means, and the start point and terminal point of the circular arc or elliptical arc calculated by the start point and end point calculation means. Generate and set the arc basic data to the graphic processing mechanism.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a graphic display control method in a graphic processing system of the present invention. The graphic display control method in the graphic processing system of this embodiment consists of a main storage device 101, a loading means 104, and an auxiliary storage device 105 (in which the application program 102 and the drawing processing system program 103 loaded into the main storage device 101 are stored). display device 106 (CRT (Cathode Ray
(Tube) display device, etc.) and the coordinate conversion function 107 (
For example, it is configured to include a graphic processing mechanism 108 (consisting of one processor) (realized by an integer arithmetic processor) and a central processing unit 109. Note that the processing of the application program 102 and the drawing processing system program 103 is realized by the central processing unit 109, but in the following explanation, the central processing unit 1
No mention of 09.

The main storage device 101 contains an application program 1.
02 and the drawing processing nostem program 103 are loaded.

The drawing processing system program 103 includes a circle basic data holding means 131, a saving means 132, and a memory holding means 13.
3, coordinate conversion value setting means 134, and radius calculation means 13
5 and a circle basic data setting means 136.

In the coordinate transformation matrix (second coordinate transformation value) passed to the coordinate transformation function 107 in the graphic processing mechanism 108, the necessary head (component) is 6 (-2
X3) 6N area, 12 ( if it is a three-dimensional drawing mechanism)
= 3×4) tiI range (in this embodiment, the description will be made assuming that it is compatible with a two-dimensional drawing mechanism).

FIG. 2 shows the drawing processing system program 103 (circle basic data storage means 131. storage means 132 memory storage means 1).
33. Coordinate conversion value setting means 134° radius calculation means 135
and a flowchart showing the processing of the circle basic data setting means 136). This process includes a radius comparison step 1031;
Matrix MD calculation step 1032, matrix MD' calculation step 1033, radius and matrix MD' storage step 1034, matrix MD
Calculation step 1035, elliptic matrix MD calculation step 1036, and matrix MD setting step 10
37, a radius calculation step 1038 on device coordinates, and a circle or ellipse drawing step 1039.

FIG. 3 is a diagram showing in detail the concept of the generation process of the coordinate transformation matrix set in the coordinate transformation function 107 by the coordinate transformation value setting means 134 (the coordinate transformation value setting means 534 in FIG. The same applies to the coordinate transformation matrix set in the coordinate transformation function 507)
.

FIGS. 4(a) and 4(b) are diagrams showing examples of circles and ellipses that the application program 102 instructs the drawing processing system program 103 to draw.

Next, the operation of the graphic display control method in the graphic processing system of this embodiment configured as described above will be explained.

Loading means 104 loads application program 102 and drawing processing system program 103 from auxiliary storage device 105 to main storage device 101 .

The circle basic data holding means 131 in the drawing processing system program 103 stored in the main storage device 101 contains coordinates for dividing the circle into polygonal lines (segment sequences) and drawing them in a coordinate system with the lower left point as the origin. Circle basic data, which is a sequence of points (a set of coordinate values of vertices of a polygon made up of a sequence of line segments), is stored. For example, circle basic data consists of the following coordinate point sequence (each of the following coordinate values is converted into an integer and used so that it can be expressed by the graphic processing mechanism 108, which is an integer processor)
.

(rxs in (2πx (i/72)) +
r.

rxcos (2πX (i/72)l +r)
(i=0.1...., 72) Here, the radius r is a sufficiently large value within the coordinate range that can be expressed by the graphic processing mechanism 108 in order to obtain sufficient accuracy, and is a 2-hyde integer. If so, "4096" or r8192
The value is J.

Here, referring to FIG. 3, coordinate transformation value setting means 134
The concept of the generation process of the coordinate transformation matrix set in the coordinate transformation function 107 will be explained below.

First, the circle basic data held in the circle basic data holding means 132 has an origin at the center and (0,0
), a matrix MA (correction matrix) for correcting the origin from the lower left point to the center is obtained (step 31). Since the distance from the center to the lower left point is the radius r of the circle basic data, the matrix MA becomes as shown in equation (1) in FIG.

Next, a matrix MB (deformed matrix) is determined (step 32).

Here, the coordinate values (xi
, yi) and (x2.y2) are the following coordinate values.

When drawing a circle with radius R as shown in FIG. 4(a) is specified by the application program 102, (xi
, yl) = (R, O), and (x2.y2) = (
0,R).

The vectors (xi, yl) and (
x2. y2) (vector from point 0 to point A and vector from point 0 to point B), if the application program 102 specifies drawing of an ellipse with a conjugate radius, the X component of those vectors. and the y component become the coordinate values of (Xl, yl) and (x2.y2) as they are.

Note that the manner in which the above-mentioned vectors are specified by the application program 102 includes the size and inclination (angles α and β) for specifying these two vectors.
is specified, or the coordinate values of the center (point ○) and the end points of the two conjugate radii (points A and B) are specified.

The matrix MB is larger than or equal to (xl, yl) and (x
2. y2) and the radius r of the circle basic data, the third
The result is as shown in equation (2) in the figure.

Next, the scaled circle or ellipse is converted into device coordinates (coordinates on the display device 106 or display device 506).
Display position of the upper circle or ellipse, that is, the center specified by the application program 102 (Xc, Yc)
Matrix MC (
movement matrix) is determined (step 33). This matrix MC becomes as shown in equation (3) in FIG.

Finally, the above matrices MA, MB, and MC are multiplied and combined to correct the origin of the basic circle data, scale the circle or ellipse, and move it to any display position on the device coordinates. A matrix MD is obtained (step 34). This matrix MD is a coordinate transformation matrix for converting the circle basic data into a circle or ellipse designated by the application program 102, and this matrix MD is calculated as (4) in FIG. ) as shown in the formula.

In addition, as shown in equation (5) in FIG.
AJ is defined as matrix MD'. This matrix MD' is referred to as a first coordinate transformation value with respect to matrix MD which is a second coordinate transformation value.

The memory holding means 133 stores this matrix MD' and the radius of the circle in the previous drawing of the circle.

Now, from the application program 102 in FIG.
When the drawing processing system program 103 is requested to draw a circle as shown in a), the drawing processing system program 103 performs the following processing.

First, the storage means 132 stores a radius R of a circle (a value indicating the shape of the circle) specified by the application program 102.
is obtained, and it is compared whether the radius set in the memory holding means 133 at that time (the radius of the circle when the circle was drawn last time) is equal to the specified radius R (step 1031 >.

If the two are equal in this comparison, the coordinate conversion value setting means 134 acquires the coordinate value of the center of the circle specified from the application program 102 (value indicating the display position of the circle), and converts it to its X coordinate (Xc). and the X coordinate (Yc) respectively to the (1, 3) and (2, 3) components of the matrix MD' set in the memory holding means 133 to generate the matrix MD (see FIG. 3) (Step 1032 ), the matrix MD is processed by the graphic processing mechanism 10
8 and set in the coordinate transformation function 107 (as described above, such setting is realized by the central processing unit 109) (step 1037).

Next, the radius calculation means 135 calculates the coordinate transformation value setting means 13.
4, the radius of the circle on the device coordinates (radius of the circle drawn on the display device 106) is calculated.

This radius is used as a guide for thinning out some vertices from the basic circle data, as described later.
A rough estimate is sufficient for the calculation. Here, matrix MD
2'' times the largest value among the values of component (1,1), component (1°2), component (2,1), and component (2,2) is calculated as the radius (step 1038) .

Finally, the circle basic data setting means 136 performs step 10.
Based on the radius calculated in step 38, some vertices are thinned out from the circle basic data in the circle basic data holding means 131 (coordinate values regarding those vertices are removed from the circle basic data), and the number of vertices is appropriately thinned out. Basic circle data (can be sufficiently recognized as a circle considering the radius mentioned above, and the amount of data (
The circle basic data is generated by subtracting the number of vertices), and the circle basic data is transferred to the graphic processing mechanism 108 and set.

As a result, the circle specified by the application program 102 is transformed into the display device 106 by the mapping of the coordinate transformation function 107 in which the matrix MD is set.
(Step 10)
39).

For example, if the circle actually drawn has a radius of about 10 dots, an octagon can be recognized as a 16-sided circle. When drawing is performed, a circle can be drawn with appropriate precision and at high speed (the same applies to one ellipse arc and an elliptical arc, which will be described later).

Furthermore, as can be seen from the process in step 1032, the display process when circles with the same radius are drawn consecutively is performed at high speed.

If the two are not equal in the comparison at step 1031,
The storage means 132 stores the application program 102.
Obtain the radius R of the specified circle and the coordinate values of the center of the circle, and create a new matrix MD' based on these values.
Step 1033), calculate the new radius (radius R)
and the generated matrix MD' is stored in the memory holding means 1
33 (step 1034).

The coordinate transformation value setting means 134 calculates the matrix MD from the matrix MD' and the coordinate values of the center of the circle (step 1035), transfers the matrix MD to the graphic processing mechanism 108, and sets it in the coordinate transformation function 107 (step 1037). ).

Next, the radius calculation means 135 calculates the coordinate transformation value setting means 13.
4, the radius of the circle on the device coordinates is calculated (step 1038).

Finally, the circle basic data setting means 136 sets the circle basic data in the circle basic data holding means 131 and step 103.
Based on the radius of the circle on the device coordinates calculated in step 8, circle basic data is generated by appropriately thinning out the number of vertices, and the circle basic data is transferred to the graphic processing mechanism 108 and set. As a result, the circle specified by the application run program 102 is drawn on the display device 106 with appropriate precision and at high speed (step 1039).

In addition, the application program 102 can also be used as shown in FIG.
When the drawing processing system program 103 is requested to draw an ellipse as shown in b), the drawing processing system program 103 performs the following processing.

First, the coordinate transformation value setting means 134 obtains a vector representing two conjugate radii (a value indicating the shape of the ellipse) and a coordinate value of the center of the ellipse (a value indicating the display position of the ellipse) specified by the application program 102. Then, a new matrix MD is calculated based on these values (step 1036), and the matrix MD is sent to the graphic processing mechanism 10.
8 and set it in the coordinate transformation function 107 (Step 1
037).

Next, the radius calculation means 135 calculates the coordinate transformation value setting means 13.
4, the radius of the ellipse in device coordinates (the radius of the ellipse drawn on the display device 106) is calculated. This calculation is sufficient around summer, and the components (1, 1) and (1, 2) of the matrix MD
, component (2°1) and component (2,2), 2'' times the largest value is calculated as its radius (step 1038).

Finally, the circle basic data setting means 136 sets the circle basic data in the circle basic data holding means 131 and step 103.
Based on the radius of the ellipse on the device coordinates calculated in step 8, circle basic data is generated with the number of vertices appropriately thinned out, and the circle basic data is transferred to the graphic processing mechanism 108 and set. As a result, the ellipse specified by the application program 102 is drawn on the display device 106 with appropriate precision and at high speed (step 1039).

FIG. 5 is a block diagram showing the configuration of another embodiment of the graphic display control method in the graphic processing system of the present invention.

The graphic display control method in the graphic processing system of this embodiment includes a main storage device 501, a loading means 504, and an auxiliary storage device 505 (in which an application program 502 and a drawing processing system program 503 to be loaded into the main storage device 501 are stored). ), a display device 506 (such as a CRT display device), and a coordinate conversion function 507
It is configured to include a graphic processing mechanism 508 (realized by an integer processor) having a processor (for example, consisting of one processor) and a central processing unit 509.

Note that although the processing of the application program 502 and the drawing processing system program 503 is realized by the central processing unit 509, the central processing unit 509 will not be referred to in the following description.

The main storage device 501 contains an application program 5.
02 and the drawing processing system program 503 are loaded.

The drawing processing system program 503 includes a circle basic data holding means 531, a saving means 532, and a memory holding means 53.
3, coordinate conversion value setting means 534, and radius calculation means 53
5, a start point/end point calculation means 536, and an arc basic data setting means 537.

The required area (component) in the coordinate transformation matrix (second coordinate transformation value) passed to the coordinate transformation function 507 in the graphic processing mechanism 508 is 6 (=2
X3) 81 area, and 12 (=
3x4) fil area (this embodiment will be explained as being compatible with a two-dimensional drawing mechanism).

FIG. 6 shows the drawing processing system program 503 (circle basic data holding means 531. saving means 532° memory holding means 533. coordinate conversion value setting means 534° radius calculating means 53).
5. 5 is a flowchart showing the processing of the start point/end point summer output means 536 and arc basic data setting means 537). This process includes a radius comparison step 5031, a matrix MD measurement step 5032, a matrix MD' measurement step 5033, a radius and matrix MD' storage step 5034, and a matrix MD measurement step 503.
5, an elliptical arc matrix MD calculation step 5036, a matrix MD setting step 5037, a radius calculation step 5038 on device coordinates, a start point and end point calculation step 5o39, and a circular arc or elliptic arc drawing step 5040.

FIGS. 7(a) and 7(b) are diagrams showing examples of circular arcs and elliptical arcs that are instructed to be drawn by the drawing processing system program 503 from the application program 502.

Next, the operation of the graphic display control method in the graphic processing system of this embodiment configured as described above will be explained.

Loading means 504 loads application program 502 and drawing processing system program 503 from auxiliary storage device 505 to main storage device 501 .

The circle basic data holding means 531 in the drawing processing system program 503 stored in the main storage device 501 contains coordinates for dividing the circle into polygonal lines (segment sequences) and drawing them in a coordinate system with the lower left point as the origin. Circle basic data, which is a sequence of points (a set of coordinate values of vertices of a polygon made up of a sequence of line segments), is stored. This is similar to the circle basic data in the circle basic data holding means 131 in FIG.

Further, the coordinate transformation function 5 is set by the coordinate transformation value setting means 534.
The concept of the generation process of the coordinate transformation matrix (second coordinate transformation value) set to 07 is the same as the concept shown in FIG. 3 regarding the coordinate transformation value setting means 134 in FIG. 1.

Therefore, the memory holding means 533 stores the matrix MD' (first coordinate transformation value) in FIG. 3 and the radius of the arc in the previous drawing of the arc.

Now, from the application program 502 in FIG.
When the drawing processing system program 503 is requested to draw an arc as shown in a), the drawing processing system program 503 performs the following processing.

First, the storage means 532 acquires the radius R (part of the value indicating the shape of the arc) of the specified arc from the applicator program 502, and acquires the radius R (part of the value indicating the shape of the arc) set in the memory storage means 533 at that time (previously set). The radius of the circular arc when the circular arc is drawn is compared with the designated radius R (step 5031).

If the two are equal in this comparison, the coordinate conversion value setting means 534 sets the coordinate value of the center of the arc (a value indicating the display position of the arc) specified by the application program 502.
is acquired, and its X coordinate (XC) and Y coordinate (Yc) are set in the memory holding means 533.
(see FIG. 3) (step 5032), and add the matrix MD to the (1, 3) and (2, 3) components of ', respectively.
08 and set in the coordinate transformation function 507 (as described above, such setting is realized by the central processing unit 509) (step 5037).

Next, the radius calculation means 535 calculates the coordinate transformation value setting means 53.
4, the radius of the arc on the device coordinates (the radius of the arc drawn on the display device 506) is calculated. Since this radius is used as a guideline for thinning out some vertices from the arc basic data as will be described later, it is sufficient that the calculation is approximately true.

Here, the component (1,1) of the matrix MD is the component (1,1)
, 2), calculate the radius by multiplying 217 of the largest value among the values of component (2, 1) and component (2゜2) (
Step 5038).

Furthermore, the start point and end point calculation means 536 acquires the start angle and end angle (part of the value indicating the shape of the arc) of the arc specified from the application program 502, and uses these values and the circle basic data holding means 531. The start point and end point of the arc on the circle basic data are calculated based on the circle basic data in (step 5039).

Finally, the arc basic data setting means 537 generates data existing between the above-mentioned starting point and end point among the circle basic data in the circle basic data holding means 531 as arc basic data, and further, in step 5038 Based on the radius calculated, some vertices are thinned out from the arc basic data (by removing the coordinate values related to those vertices from the arc basic data), and the number of vertices is appropriately thinned out (from the radius above). Generate arc basic data that can be sufficiently recognized as an arc in view of the above, and reduce the amount of data (number of vertices),
The arc basic data is transferred to the graphic processing mechanism 508 and set. As a result, the arc specified by the application program 502 is drawn on the display device 506 with appropriate precision and at high speed by mapping by the coordinate conversion function 507 in which the matrix MD is set (step 5040).

Further, as can be seen from the processing in step 5032, the display processing when circular arcs with the same radius are drawn consecutively is performed at high speed.

If the two are not equal in the comparison at step 5031,
The storage means 532 stores the application program 502
Obtain the radius R of the specified arc and the coordinate values of the center of the arc, and create a new matrix M based on those values.
D' is calculated (step 5033), and the new radius (radius R) and the generated matrix MD' are stored in the storage means 533 (step 5034).

The coordinate transformation value setting means 534 calculates the matrix MD from the matrix MD' and the coordinate value of the center of the circle (step 5035), transfers the matrix MD to the graphic processing mechanism 508, and sets it in the coordinate transformation function 507 (step 5037). ).

Next, the radius calculation means 535 calculates the coordinate transformation value setting means 53.
4, the radius of the circular arc on the device coordinates is calculated (step 5038).

Further, the start point and end point calculation means 536 obtains the start angle and end angle of the arc specified from the application program 502, and based on these values and the circle basic data in the circle basic data holding means 531, the circle basic data is calculated. Calculate the starting and ending points of the arc above (step 503
9).

Finally, the arc basic data setting means 537 sets the circle basic data in the circle basic data holding means 131 in step 5038.
Generate arc basic data with the number of vertices appropriately thinned out based on the radius of the arc on the device coordinates calculated in , and the above-mentioned start and end points, and transfer the arc basic data to the graphic processing mechanism lO8 and set it. do. As a result, the arc specified by the application program 502 is drawn on the display device 506 with appropriate precision and at high speed (step 5040).

Also, from the application program 502 as shown in FIG.
) When the drawing processing system program 503 is requested to draw an elliptical arc as shown in (l), the drawing processing system program 503 performs the following processing.

First, the coordinate transformation value setting means 534 sets a vector representing two conjugate radii specified by the application program 502 (a part of the value indicating the shape of the elliptical arc) and a coordinate value of the center of the elliptical arc (a value indicating the display position of the elliptical arc). ), a new matrix MD is calculated based on these values (step 5036), and the matrix MD is transferred to the graphic processing mechanism 508 and set in the coordinate transformation function 507 (step 5037).

Next, the radius calculation means 535 calculates the coordinate transformation value setting means 53.
4, the radius of the elliptical arc on the device coordinates (the radius of the elliptical arc drawn on the display device 506) is calculated. This calculation is sufficient in about summer, and the component (1, 1) of the matrix MD, the component (1,
2), 21'' times the largest value among the values of component (2, ■) and component (2, 2) is calculated as its radius (step 5038).

Furthermore, the start point and end point calculation means 535 obtains the start angle and end angle (part of the value indicating the shape of the elliptical arc) of the elliptical arc specified from the application program 502,
Based on these values and the circle basic data in the circle basic data holding means 531, the starting point and end point of the elliptical arc on the circle basic data are calculated (step 5039).

Finally, the arc basic data setting means 535 generates data existing between the above-mentioned start point and end point in the circle basic data as arc basic data, and uses the arc basic data and the data calculated in step 5038. Generate basic arc data with the number of vertices appropriately thinned out based on the radius of the elliptical arc on the device coordinates, and send the basic arc data to the graphic processing mechanism 508.
Transfer to and configure. As a result, the elliptical arc specified by the application program 502 is drawn on the display device 506 with appropriate precision and at high speed (step 5040).

〔Effect of the invention〕

As explained above, the present invention makes it possible to draw a circle, three elliptical arcs, or an elliptical arc by determining one coordinate transformation matrix when drawing a circle, two elliptical arcs, or an elliptical arc. By appropriately reducing the amount of data (data amount), it becomes possible to perform high-speed graphic processing with appropriate accuracy when drawing large amounts of circles, elliptical arcs, or elliptical arcs, resulting in a better response for users. This has the advantage of being able to provide a graphics processing system.

In particular, when a large number of circles or arcs with the same radius are continuously drawn, the above-mentioned effect becomes noticeable.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of an embodiment of the present invention, Fig. 2 is a flow chart showing the processing of the drawing processing system program in Fig. 1, and Fig. 3 explains the concept of the coordinate transformation matrix generation process. FIGS. 4(a) and 4(b) are diagrams showing examples of circles and ellipses whose drawing is specified from the application program in FIG. 1 to the drawing processing system program, and FIG. A block diagram showing the configuration of another embodiment; FIG. 6 is a flowchart showing the processing of the drawing processing system program in FIG. 5; FIGS. 7(a) and (b) are drawings from the application program in FIG. 5. FIG. 3 is a diagram illustrating an example of a circular arc and an elliptical arc whose drawing is specified by a processing system program. In the figure, 101.501...Main storage device, 102.502...Application program, 103.503...Drawing processing system program, 104.504...Loading means, 105.505...Auxiliary memory Device, 106, 506 ・ 107, 507 ・ 108 508 ・ 109 509 ・ 131, 531 ・ 132, 532 ・ 133, 533 ・ 134, 534 ・ 135, 535 ・ 136 ・ ・ ・ ・ 536 ・ ・ ・・ 537 ・ ・・ ・ It is. Display device, coordinate conversion function, graphic processing mechanism, central processing unit, circle basic data holding means, storage means, memory holding means, coordinate conversion value setting means, radius calculation means, circle basic data setting means, starting point ending point summer means , Arc basic data setting means Fig. 1

Claims (2)

[Claims] (1) In a graphics processing system that has a graphics processing mechanism with a coordinate transformation function, there is a circle basic data holding means that holds circle basic data, and a value that indicates the shape of a circle or ellipse specified from an application program is acquired and stored. a storage means that calculates a first coordinate transformation value based on the value and stores the first coordinate transformation value in a memory storage means; a value indicating a display position of a circle or an ellipse designated by an application program; and the storage storage means coordinate transformation value setting means for calculating a second coordinate transformation value based on the first coordinate transformation value in the graphics processing mechanism and setting the second coordinate transformation value in a coordinate transformation function within the graphic processing mechanism; a radius calculation means for calculating the radius of a circle or an ellipse on the device coordinates based on the second coordinate transformation value calculated by the means; and circle basic data held in the circle basic data holding means and the radius calculation means. The apparatus is characterized by comprising circle basic data setting means for generating circle basic data with the number of vertices appropriately thinned out based on the radius of the circle or ellipse on the calculated device coordinates and setting the circle basic data in the graphic processing mechanism. A graphic display control method for graphic processing systems. (2) In a graphics processing system that has a graphics processing mechanism with a coordinate conversion function, there is a circle basic data holding means that holds circle basic data, and a value that indicates the shape of a circular arc or elliptical arc specified from an application program. a storage means for calculating a first coordinate transformation value based on the value and storing the first coordinate transformation value in a memory storage means; a value indicating a display position of a circular arc or an elliptical arc specified by an application program; and the storage storage means. the first of
coordinate transformation value setting means for calculating a second coordinate transformation value based on the coordinate transformation value and setting the second coordinate transformation value in a coordinate transformation function within the graphic processing mechanism; a radius calculation means for calculating the radius of a circular arc or elliptical arc on the device coordinates based on the second coordinate transformation value; a start point and end point calculation means for calculating the start point and end point of a circular arc or an elliptical arc on the circle basic data in the circle basic data holding means; the circle basic data held in the circle basic data holding means; Arc basic data in which the number of vertices is appropriately thinned out based on the radius of the circular arc or elliptical arc on the device coordinates calculated by the radius calculation means and the start point and end point of the circular arc or elliptical arc calculated by the start point and end point calculation means. 1. A graphic display control method in a graphic processing system, comprising arc basic data setting means for generating and setting the arc basic data in a graphic processing mechanism.