JPH07105390A - Perimeter line drawing data control method - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a peripheral line drawing data control method for dividing a polygon into a plurality of triangles for drawing, and for dividing triangle data at the time of drawing an outer peripheral line of a polygonal figure at high speed. Processing and reducing the amount of data and simplifying the processing of the outer peripheral line data of the divided triangles when the triangle is clipped, and reducing unnecessary data when transmitting the outer peripheral line data for drawing processing. The purpose is to shorten the sending time. [Structure] A polygon division processing unit which inputs polygon data and divides the triangle data into a plurality of triangles includes a vertex flag for each of the divided triangle data and an identification flag indicating whether it is a boundary line or a dividing line. Add. When the drawing processing unit receives each of the triangular data created and divided by the polygon division processing unit, the drawing processing unit processes the outer peripheral line of each triangle based on the identification flag to draw the polygon.

Description

Detailed Description of the Invention

[0001]

The present invention divides a polygon into triangles.
The present invention relates to a control method for drawing outer peripheral lines when drawing.

In order to draw a polygon, a method is used in which the polygon is divided into a plurality of triangles and each triangle is drawn. In this case, when processing and drawing a triangle at high speed, each side of each triangle is a side forming the original polygon (called a boundary line) or a side formed by division (called a dividing line). Since it is necessary to determine whether or not to draw the outer peripheral line, the outer peripheral line is created and drawn independently.

Further, a triangle generated by dividing a polygon is clipped (processing of cutting a figure with a rectangular frame of a specified size and position) to generate a triangle, and the outer peripheral line data of the triangle is drawn. However, efficient transfer processing of outer peripheral line data is desired.

[0004]

2. Description of the Related Art FIG. 12 is a block diagram of a conventional outer peripheral line drawing, and FIG. 13 is an operation example of a conventional outer peripheral line drawing.

In FIG. 12, a polygon data storage unit 10
Data of the polygon to be drawn is stored in 0. In this example, in FIG. The pentagonal data shown in is stored, and the first vertex (see FIG.
A.3. No. 1) to the fifth vertex (5 in A. of FIG. 13).
The coordinates (X, Y, Z) of each vertex are stored. The polygon division processing unit 102 first divides the pentagon into three triangles by the triangle division processing unit 103 on the polygon data 101. As a result, the A. Is a triangle composed of vertices 1, 2, and 3, vertices 1, 3,
It is divided into three, that is, a triangle formed by 4 and a triangle formed by vertices 1, 4, and 5, and the data of each triangle is stored as triangle data 106 in the triangle / peripheral line data storage unit 105.

On the other hand, a pentagonal outer peripheral line (a line representing a contour)
Is created by the peripheral line data creation processing unit 104, and the created data is the triangle / peripheral line data storage unit 105.
Is stored as the outer peripheral line data 107. The outer peripheral line data 107 is composed of the coordinates of the first to fifth vertices.

The triangle data 106 in the triangle / perimeter line data storage unit 105 is transferred to the drawing processing unit 108 in units of each triangle, and the perimeter line data 107 is transferred in the same manner. Next, drawing of a figure is performed in each part of the drawing processing unit 108. First, in the triangle data processing unit 109, the vertex data of the first triangle of the triangle data is analyzed and the processing for creating the triangle drawing data is performed. Then, the triangle drawing unit 111 draws the first triangle in the frame memory 114. . B. of FIG. Shows the state where the first triangle is drawn in the frame memory. Similarly, the triangle data processing unit 10
9 and the triangle drawing unit 111 execute data processing and drawing of each triangle of the second triangle and the third triangle. And D are shown in which each triangle is sequentially added and drawn.

On the other hand, the outer peripheral line data processing unit 110 of the drawing processing unit 108 determines whether to perform processing depending on which of the drawing conditions “outer peripheral line visible / invisible” stored in the attribute data storage unit 113 is set. Is decided. Various kinds of conditions are prepared in this drawing condition, which can be selected and set by the user before drawing, and when the visible outer line is set, it is a contour when drawing a pentagon. It is drawn so that the outer peripheral line is clearly displayed, and if the invisible is set, the outer peripheral line is not drawn, and the inside of the pentagon can be drawn by shading or colors.

When the outer peripheral line visible is set, the outer peripheral line data processing unit 110 analyzes each data of the first vertex and the second vertex of the outer peripheral line data 107 to create the outer peripheral line data, The data is drawn on the frame memory 114 by the peripheral line drawing unit 112. E. of FIG. The state in which this outer peripheral line is drawn is shown in FIG. Next, drawing is performed for the second vertex and the third vertex by the same process.
Vertex and fourth vertex, fourth vertex and fifth vertex, fifth vertex and first
Drawing is sequentially performed for each outer peripheral line of the apex. F. of FIG. ~ I. Shows how each outer peripheral line is drawn at that time.

Next, a method of drawing the outer peripheral line data of the triangle divided by the clipping process from the triangle data obtained by dividing the figure data into polygons will be described. FIG. 14 is an explanatory diagram of a control method of triangle outer peripheral line data divided by the conventional clip processing. The graphic data 120 in FIG. 14 is data representing a polygon, and when this data is input to the polygon division processing unit 121 (similar to 102 in FIG. 12), processing for dividing the polygon into a plurality of triangles is performed. Be seen. By this division processing, the polygon is divided into a plurality of triangles, the triangle data 122 including the vertex data of each triangle is created, and the outer peripheral line data 123 is created. These data are
In the clip processing unit 124, the intersection point with the clip frame is calculated as the vertex data transmitted in order, the newly obtained vertex data is stored in the graphic data storage area 128, and then stored in the drawing processing unit 125.

The function of the clip processing unit 124 in this case will be described. As shown in the lower left part of FIG.
A triangle with three vertices is clipped (cut out) with a clip frame having corners a to d, and when the coordinates e and f which are the intersections of the clip frame and the triangle are obtained, the triangle formed by this clip New vertex data of (A, e,
f) is the triangle data 129 of the graphic data storage area 128
Was stored in.

Further, when the outer peripheral line data of the triangle divided by the clip is sent to the drawing processing section 125, the outer peripheral line data 123 is set as the outer peripheral line segment L1 (between the vertex A and the intersection e as shown in FIG. 14). 2 segment data of a vertex S1 (representing the start position of the line segment L1 and the coordinates of the vertex A) and a vertex E1 (representing the end point of the line segment L1 and the coordinate of the intersection point e) are transmitted as data of the line segment of As the data of the line segment L2, the vertex S2 (coordinates of the intersection f which is the start position) and the vertex E
The two vertex data of 2 (coordinates of the vertex A which is the end point) are sequentially sent to the rendering processing unit 125, whereby the outer peripheral line rendering is guaranteed.

[0013]

According to the conventional peripheral line drawing method shown in FIGS. 12 and 13, the drawing processing section is
The triangle data processing unit processes each triangle divided into an arbitrary number according to each vertex data in units of one triangle, and the triangle data is a part of the polygon or independent. It is processed without being aware of whether it is a triangular shape.

Further, regarding the outer peripheral line, the drawing attribute (visible / invisible) is set in the outer peripheral line data processing section of the graphic drawing section.
Although it is drawn when it is "visible" depending on the condition, when drawing the outer line of a polygonal figure, conventionally it is the side that forms the original polygon (hereinafter referred to as the boundary line) or divided into triangles. Since it is not discriminated whether it is a side formed at that time (hereinafter referred to as a dividing line), it is necessary to perform data creation and drawing processing on the outer peripheral line independently of the triangle, which increases the memory capacity for storing the data. There was a problem that processing took time.

In the conventional clipped outer peripheral line data of the triangle shown in FIG. 14, the outer peripheral line segment L1 is first transmitted as the apex data of the outer peripheral line segment L1 to the rendering processing unit, and then the outer peripheral line segment is transmitted. The data of the vertex S2 as the data of the segment L2 and the data of the vertex E2 which is originally the same as the vertex S1 are newly sent to the drawing processing unit as the data of another outer peripheral line segment, so that there is a problem in that data is wasted. .

A first object of the present invention is to provide a peripheral line drawing data control method capable of processing divided triangle data at high speed and reducing the amount of data when drawing the peripheral line of a polygonal figure. The purpose of this is to control the outer peripheral line data when clipping the triangle in the clip processing part and to control the outer peripheral line data when sending the outer peripheral line data to the drawing processing part, by reducing unnecessary data and shortening the data sending time. The second purpose is to provide a method.

[0017]

FIG. 1 is a first principle configuration diagram of the present invention, and FIG. 2 is a second principle configuration diagram of the present invention.

In FIG. 1, 1 is a polygon data storage unit containing polygon vertex data, 2 is a polygon division processing unit that divides a polygon into a plurality of triangles, 3 is a triangle / peripheral line data storage unit, 4 Is triangle data such as the first triangle data, the second triangle data, etc. stored in the triangle / peripheral line data storage unit 3, and 4a to 4c are first to third vertex coordinates and vertexes of each triangle. Each vertex data constituted by an identification flag indicating whether the side corresponding to is a boundary line (outer peripheral line of polygon) or a dividing line (line generated when the polygon is divided), 5 is a drawing processing unit, and 5a is A data processing unit for processing triangle data, 5b is a triangle drawing unit, 5c is a peripheral line drawing unit, 6 is an attribute data storage unit including drawing conditions, and 7 is a frame memory.

In FIG. 2, 10 is a polygon data storage unit, 11 is a polygon division processing unit, 12 is a clip processing unit, 13 is a peripheral line linear control unit provided in the clip processing unit 12, and 14 is the same clip. An outer peripheral line connection processing unit provided in the processing unit 12, 15 is a graphic data storage unit, 16 is a drawing processing unit, and 17 is a frame memory. 1 of this FIG.
The parts 0, 11, 16 and 17 correspond to the parts 1, 2, 5 and 7 in FIG. 1, respectively.

According to the first configuration of the present invention, when a polygon is divided, a flag indicating whether the side connecting to the next vertex is a boundary line or a dividing line is added to each vertex data of the triangle, and the drawing is performed. The processing unit is capable of drawing the outer peripheral line at high speed. Further, in the second configuration, the divided triangles are divided into triangles in the clip processing by the clip frame, and a flag indicating whether or not to draw the outer peripheral line corresponding to each vertex is added to the triangle data. The flag is used to identify the type of outer peripheral line drawing, and only the necessary outer peripheral line data is sent to the drawing processing unit.

[0021]

In the configuration of FIG. 1, the polygon division processing unit 2 inputs the polygon data in the polygon data storage unit 1 and divides the polygon into a plurality of triangles. An identification flag indicating a boundary line / division line is added to the vertices of each triangle created by this division and stored as triangle data 4 in the triangle data storage unit 3. Triangle data 4 is three vertex data 4a-4
c, which is composed of vertex coordinates and an identification flag.

The triangle data 4 is transferred to the drawing processing unit 5, and the data processing unit 5a therein analyzes each vertex data, the triangle drawing unit 5b draws a triangle in the frame memory 7, and the outer peripheral line drawing unit 5c. Referring to the drawing condition (outer peripheral line visible / invisible) in the attribute data storage unit 6, if visible, only the vertices to which the flag representing the boundary line is attached are stored in the frame memory 7
Draw a peripheral line on. The drawing processing unit 5 similarly draws for all triangles.

In the configuration of FIG. 2, the polygon division processing unit 1
In the same manner as in FIG. 1, 1 inputs polygon data in the polygon data storage unit 10 and divides it into a plurality of triangles. The clip processing unit 12 performs clip processing on each of the divided triangle data with a clip frame, divides the figure in the frame into triangles, and the vertex coordinates of the divided triangles and the outer peripheral line corresponding to each vertex are visible. Triangle data with an outer peripheral line flag indicating whether it is invisible or not is created. An outer peripheral line flag corresponding to each vertex is input to the outer peripheral line linear control unit 13, and a line flag indicating a drawing type of a triangle (a pattern of which side among the three sides is drawn) is used by using the outer peripheral line flag. To create. Next, the outer peripheral line connection processing unit 14 connects the vertex data only for the outer peripheral line segment to be drawn based on the line flag, and stores it in the graphic data storage unit 15.
The contents of the graphic data storage unit 15 are sent to the drawing processing unit 16. The drawing processing unit 16 performs a triangle drawing process and a peripheral line drawing process, and stores it in the frame memory 17.

[0024]

FIG. 3 is a block diagram of the first embodiment, FIG. 4 is a configuration example of triangular data, and FIG. 5 is an example of drawing a pentagon according to the first embodiment.

The first embodiment has a structure corresponding to the first principle structure of the present invention shown in FIG. In FIG. 3, 2
4, 5, and 7 are devices having the same names as those in FIG. 1, and in particular, the details of the inside of the drawing processing unit 5 are shown.

The operation of the first embodiment will be described below. The polygon division processing unit 2 uses the polygon data (not shown in FIG. 12; the same as 100 in FIG. 12) to draw polygon data (101 in FIG. 12). ) Is received, a process of dividing this into a plurality of triangles is performed, and the data of each divided triangle is stored in the triangle / peripheral line data storage unit 3. At this time, the first triangle data, the second triangle data ...
It is created sequentially. For example, when pentagonal data is input as polygonal data, first, second, and third triangular data are created.

The polygon division processing unit 2 of the present invention generates first vertex coordinates to third vertex coordinates as each triangle data, and for each vertex coordinate, the outer peripheral line corresponding to the vertex is a boundary line or a division. An identification flag indicating whether the line is a line is set. This identification flag is set to "1" as the boundary line flag when the outer peripheral line corresponding to each vertex represents the boundary of the original polygon, and is set to "0" as the dividing line flag if the outer peripheral line is generated by division. Is set.

In the configuration example of the triangle data shown in FIG. 4, as one vertex coordinate, X, Y, and Z coordinate data (32 bits each) is set in 40 to 42, and flag data 43 is set in this. It The flag data 43 is composed of a total of 32 bits from 0 bit to 31 bit, and 1 of them is included.
"1" (boundary line flag) or "0" (dividing line flag) is set in 6 bits.

In this way, the triangle data 4a to 4c created by the polygon division processing unit 2 are stored in the triangle / peripheral line data storage unit 3 together with each vertex coordinate and the identification flag as shown in the figure. .

The triangle / peripheral line data storage unit 3 transfers the triangle data to the drawing processing unit 5 in units of one triangle. In the drawing processing unit 5, the triangle / outer peripheral line data input unit 50 inputs the triangle data, and the data processing unit 51 (corresponding to 5a in FIG. 1) performs processing. As shown in the data processing unit 51 of FIG. 3, the processing flow of the data processing unit 51 is as follows.
First, in the nth triangle data analysis (n is an arbitrary number up to the number of triangles created by division), each vertex data of the nth triangle is analyzed (S1 in 51 of FIG. 3), Triangle / perimeter line drawing data is created based on the analysis result (at step S2). In this case, the identification flag of the outer peripheral line corresponding to the vertex coordinates of the triangle is created integrally. While the created data is sent to the drawing unit 52, it is determined whether or not there is other triangle data (at step S3), and if there is, the same processing is performed on the next triangle / peripheral line data.

The drawing unit 52 draws the n-th triangle of the sent triangle / peripheral line drawing data in the triangle drawing unit 53 (corresponding to 5b in FIG. 1). First, the first triangle is drawn in the frame memory 7, and then the outer peripheral line drawing unit 54
Then, the outer peripheral line of the first triangle is drawn. At this time, referring to the drawing conditions (outer peripheral line visible / invisible) stored in the attribute data storage unit 6, only the outer peripheral line visible to the outer peripheral line and corresponding to the vertex to which the boundary line flag is added is drawn in the frame memory 7. To do.

When the next triangle / peripheral line drawing data of the second triangle is sent from the data processing unit 51, the triangle and the peripheral line drawing data are similarly drawn, and the frame memory 7 for all the triangle / peripheral line drawing data. Drawn on top.

Explaining with the example of FIG. When the pentagon shown in is divided into three triangles and drawn, the first triangle has the vertex coordinates of vertices 1, 2 and 3 and the outer peripheral line (the line connecting vertex 1 and vertex 2) corresponding to vertex 1. A boundary flag is added, and a peripheral line corresponding to vertex 2 (a line connecting vertex 2 and vertex 3) is also added with a boundary flag, and a peripheral line corresponding to vertex 3 (a line connecting vertex 3 and vertex 1) is A dividing line flag is added.

The data of the first triangle is processed by the data processing unit 51 and drawn by the drawing unit 52. As shown in (1), the first triangle (shaded area) composed of the vertices 1, 2, and 3 and the two outer peripheral lines (between the vertices 1 and 2 and the vertices 2 and 3) indicated by thick lines are drawn together. After this, a perimeter line (vertex 3
5), the drawing of the second triangle with the data of the vertex 3 representing C. 5D, and finally the third triangle is D.I. The drawing of the entire pentagon is completed.

Next, FIGS. 6 to 10 are diagrams showing the configuration of the second embodiment corresponding to the second principle configuration of the present invention shown in FIG. In the configuration shown in FIG. 2, with respect to one triangle divided by the polygon division processing unit 11, the clipping processing unit 12 performs clipping processing by obtaining an intersection between the clipping frame and the triangle in the same manner as in the conventional case. This specific example will be described with reference to FIG.

FIG. 6 shows an example of triangles clipped by the clipping process, and the divided triangles are vertices A, B and C.
The triangle and the clip frame D intersect at a point B ′ and a point C ′. Therefore, by the clipping process, the triangle newly formed by the vertices A, B ′, and C ′ becomes the original vertex A,
The triangle formed by B and C is divided.

The clip processing unit 12 draws (visible) or does not draw (invisible) each peripheral line of a triangle (triangles of vertices A, B ', and C'in FIG. 6) divided by the clip.
An outer peripheral line flag indicating whether or not is created. That is, the line segment L1 (the outer peripheral line between the vertices A and B ′) and the line segment L2 (the outer peripheral line between the vertices A and C ′) in FIG. 6 are both line segments on the outer peripheral line of the original triangle. From the above, the outer peripheral line flag is set to the state of being visible (drawn), but since the line segment between the vertices B ′ and C ′ is the outer peripheral line generated by the division by the clip processing, the outer peripheral line flag is set to the state of not being drawn. Is set.

FIG. 7 is an explanatory diagram of the outer circumference line flag.
A. Is a block diagram of the peripheral line flag, B. Indicates the relationship between the vertex and the peripheral line flag. A. As shown in
It is set to the 0 bit position in the 32 bit data, and when this 0 bit is "1", the outer peripheral line is visible (with drawing),
When "0", it indicates that the outer peripheral line is invisible (no drawing). This peripheral line flag is As shown in, the outer peripheral line flags of the outer peripheral lines (en: meaning edge n) of the apex n and the apex n + 1 are added to the coordinate data of the apex n. A flag is added, and a peripheral line flag of en + 2 (edge n + 2) is added to the vertex n + 2.

8 and 9 are processing flow charts (No. 1) and (No. 2) of the second embodiment. This processing flow is performed by the outer peripheral line linear control unit (13 in FIG. 2) and the outer peripheral line connection processing unit (FIG.
14) of the above.

In this processing flow, the clip processing unit creates a triangle having the vertices P1, P2 and P3 shown on the right side of FIG. It is assumed that it is added to the coordinate data of each vertex in the same relationship as, and the outer peripheral line flag of each edge is arbitrarily set to either "0" or "1".

When the process of FIG. 8 is started, the process of the outer peripheral line linear control unit is executed, and a variable (memory called a line flag (displayed as LINEFLG)) provided in a specific area of an internal memory (not shown) Specific area) is initialized to 0 (S1 in FIG. 8). Next, in step S2, the following processing is executed. That is, first, the contents of the outer peripheral line flag of edge 1 (edge1) are set to the line flag (LINEFLG). At this time, the A. As shown in, the content (1 or 0) representing the flag set at the 0 bit position in 32 bits is set to the 0 bit of the line flag (LINEFLG).

Next, the outer peripheral line flag of edge 2 is shifted to the left by 1 bit, and the bit of the outer peripheral line flag is shifted to the left (1 bit to the left.
Bit position) is set to the corresponding 1 bit position of the line flag (LINEFLG). In addition, edge 3 (edge
The outer peripheral line flag of 3) is shifted to the left by 2 bits, and the bit of the line flag (at the 2 bit position within 32 bits)
To the line flag (LINEFLG).

The processing contents of step S2 will be described with reference to the line flag diagram shown in FIG. A. of FIG. In the figure, ~ indicates the state after the left shift corresponding to the outer peripheral line flags of edge 1 to edge 3, and indicates the line flag. The contents of each 0 bit position (flag bit) of are set to three bit positions of the line flag as shown in.

Returning to FIG. 8, it is judged whether or not the content of the line flag (LINEFLG) obtained next is 0 (FIG. 8).
S3). If all the contents of the line flag (LINEFLG) are 0 (all bits are "0") in this determination, there is no outer peripheral line to be drawn, and the process ends without performing the outer peripheral line connecting process.
If the content is not 0, the jump destination is set by the line flag (LINEFLG) (S4 in FIG. 8), and the jump destination is set (any of M1 to M7: M1 to M7 will be described later) (same). S5). This jump destination is
It is a peripheral line connection processing unit shown in FIG. 9.

The operation of the line flag (LINEFLG) will now be described with reference to FIG. Thus, for the 3 bits of the line flag (LINEFLG), the outermost line flag of edge 1 is set at the lowest 0 bit position, the outermost line flag of edge 2 is set at the 1st bit position, and the outermost line flag of edge 3 is set at the 2th bit position. Has been done. The range represented by 3 bits of this line flag (LINEFLG) is 000 to 111, and has eight values of decimal numbers 0 to 7.

B. of FIG. Table shows this line flag (LI
Each of the eight NEFLG) values represents a drawing pattern of a peripheral line drawing line segment, and an example of a pattern of a peripheral line drawing line segment corresponding to this is shown in FIG.

That is, as shown in FIG. Where the number
(1) is the case where the line flag is 0, there is no drawing, the jump destination is M0 (when it is determined to be 0 in step S3 of FIG. 8), and the outer peripheral line drawing line segment is ( 1)
Not transferred as shown in. Further, the number (2) indicates that the line flag is 1, the peripheral line drawing line segment indicates to draw between the vertices P1 and P2 of the triangle shown on the right side of FIG. 8, and the peripheral line edge to be used is The edge is 1, and the jump destination is M1. In this case, the jump destination is (2) in FIG.
The drawing shown in is performed.

Similarly, the numbers (3) to (8) correspond to the values of "2" to "7" of the line flag (LINEFLG) and correspond to the values of FIG.
B. Each vertex section indicated by each outer line drawing line segment instructed to draw using the corresponding outer line edge, and each jump destination is M2 to M7 corresponding to the value of the line flag (LINEFLG). .

FIG. 9 shows a processing flow of the outer peripheral line connection processing unit which is jumped from the outer peripheral line linear control unit of FIG. 8, and the outer periphery corresponding to any one of M1 to M7 set as the jump destination. The line connection process is executed, and after execution, the process returns to FIG. 8 and ends. In addition, M1 to M7 are B. It corresponds to each number (2) to (7) of.

For example, when the jump destination is M1, the data of the first vertex (P1 of the triangle of FIG. 8) is stored in the graphic data storage unit (15 of FIG. 2), and then the second vertex (triangle of FIG. 8). The data of P2) is stored. As a result,
A peripheral line as shown in (2) is drawn.

The case of drawing the two outer peripheral lines of the triangle created by the clip shown in FIG. 6 corresponds to the case of drawing between the vertices P2-P3-P1 of the triangle of FIG. At this time, the 3 bits of the line flag (LINEFLG) is set to “110”, which is a decimal number “6”, so M
Jump to 6. In this case, according to the flow of FIG. 9, the storage of the data of the second vertex (P2) (in the graphic data storage unit), the storage of the data of the third vertex, and the storage of the data of the first vertex are sequentially performed, and three vertexes are stored. When the data is stored, these data are drawn in the frame memory by the drawing processing unit (16 in FIG. 2).

In this case, the vertex data transferred to the drawing processing unit is three by connecting two outer peripheral line segments, and two vertex data of start point-end point are transferred for each line segment as in the conventional example. There is no need to do so, the memory capacity can be reduced, and the transfer time can be shortened.

[0053]

According to the first principle of the present invention, when a polygon is divided into a plurality of triangles, an identification flag representing a boundary line / dividing line is added to the vertex data and processed. Since it can be drawn, the peripheral line processing can be speeded up and the memory can be reduced. That is, it is possible to simplify the outer peripheral line data creation process, reduce the data transfer amount between the polygon division processing unit and the drawing processing unit, and reduce the outer peripheral line data processing in the drawing process.

According to the second principle of the present invention, when the outer peripheral line of a triangle is drawn, the outer peripheral line flag is set when the outer peripheral line vertex data of a complicated triangle is managed after the divided triangles are clipped. Can be used to simplify the data. In addition, the peripheral line apex data required for drawing can be reduced, and the data transmission time can be shortened.

[Brief description of drawings]

FIG. 1 is a first principle configuration diagram of the present invention.

FIG. 2 is a second principle configuration diagram of the present invention.

FIG. 3 is a configuration diagram of a first embodiment.

FIG. 4 is a diagram showing a configuration example of triangle data.

FIG. 5 is a diagram showing an example of drawing a pentagon according to the first embodiment.

FIG. 6 is a diagram showing an example of a triangle clipped by a clipping process.

FIG. 7 is an explanatory diagram of a peripheral line flag.

FIG. 8 is a processing flow diagram (part 1) of the second embodiment.

FIG. 9 is a process flow diagram (2) of the second embodiment.

FIG. 10 is an explanatory diagram of line flags.

FIG. 11 is a diagram showing a pattern example of an outer peripheral line drawing line segment.

FIG. 12 is a configuration diagram of conventional peripheral line drawing.

FIG. 13 is a diagram showing an operation example of drawing an outer peripheral line according to a conventional example.

FIG. 14 is an explanatory diagram of a control method of triangular outer peripheral line data divided by conventional clip processing.

[Explanation of symbols]

 1 Polygon data storage unit 2 Polygon division processing unit 3 Triangle / perimeter line data storage unit 4 Triangle data 4a to 4c Vertex data 5 Drawing processing unit 5a Data processing unit 5b Triangle drawing unit 5c Perimeter line drawing unit 6 Attribute data storage Part 7 Frame memory

Claims (6)

[Claims] 1. In a peripheral line drawing data control method for drawing a polygon by dividing it into a plurality of triangles, a polygon division processing unit for inputting polygon data and dividing the polygon into a plurality of triangles, Triangle data composed of each vertex coordinate of the above and an identification flag indicating whether the outer peripheral line corresponding to each vertex coordinate is a boundary line or a dividing line, and the drawing processing unit A peripheral line drawing data control method, wherein a polygon is drawn by receiving each of the divided triangular data created and processing an outer peripheral line of each triangle based on the identification flag. 2. The drawing processing unit according to claim 1,
An outer peripheral line drawing data control method characterized in that only the outer peripheral lines corresponding to the vertices to which the boundary line flag is added are drawn and the respective triangle data are drawn. 3. The drawing method according to claim 1, wherein when drawing the outer peripheral line, only the outer peripheral line for which the outer peripheral line visible is set is drawn with reference to a drawing condition set in advance in the attribute data storage unit. Perimeter line drawing data control method. 4. A polygon dividing process for inputting polygon data and dividing the polygon into a plurality of triangles in a peripheral line drawing data control method in which a polygon is divided into a plurality of triangles and cut out by clipping processing and then drawn. The section creates each divided triangle data, and performs clip processing. The clip processing section performs triangle division on the triangle data created by the polygon division processing section with a clip frame, and divides each triangle into triangles generated by clipping. When generating triangle data having an outer peripheral line flag indicating whether or not to draw an outer peripheral line and sending the triangular data generated by clipping using the respective outer peripheral line flags to the drawing processing unit, the respective outer peripheral line flags A peripheral line drawing data control method characterized by connecting vertex data of each triangle by using. 5. The clip processing unit according to claim 4, wherein the clip processing unit sets the peripheral line flag depending on whether or not the peripheral line of the original triangle before being clipped, and the correspondence of the triangles divided by the clip. A peripheral line linear control for generating a line flag composed of a plurality of bits by adding a peripheral line flag to each vertex data and processing the peripheral line flag for each vertex of the triangle A peripheral line drawing data control method characterized by comprising a section. 6. The outer peripheral line according to claim 5, wherein the clip processing unit connects the vertex data of the outer peripheral line segment for drawing processing based on the pattern of the line flag and stores it in the graphic data storage unit. A peripheral line drawing data control method comprising a connecting portion.