JPH0293774A - System for generating boldface projecting polygon - Google Patents

Abstract

PURPOSE:To efficiently execute dot transformation processing by obtaining a cross point between a scanning line and an internal and external shape line when the scanning line is positioned in a second data area and executing dot transformation to the cross point between the external and internal forms of the scanning line. CONSTITUTION:In a process to dislocate a scanning line XN by one dot, when the line XN is positioned in a first area E1, the line XN crosses only an external shape line Lo and the dot transformation is executed between cross points Po11 and Po12. Next, when the line XN is positioned in a second area E2, the line XN crosses both the external shape line Lo and an internal shape line Li and the dot transformation is executed between the two intervals of cross points Po21, Pi22 and Po22. Further, when the line XN is positioned in a third area E3, the line XN crosses only the external shape line Lo and samely as the case of the first area, the dot transformation is wholly executed to the inside of the external shape line Lo which is positioned in the third area. Thus, only by moving the scanning line once in a graphic area, the dot transformation of a boldface projecting polygon, which is purpose, is finished. Then, the dot transformation processing can be efficiently executed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for generating thick convex polygons that is applied to graphic processing in personal computers, etc.
The present invention relates to a thick line convex polygon generation method for generating a thick line convex polygon specified by outer shape information and inner shape information on a memory in which a dot image is developed.

F. Prior Art] In word processors, personal computers, etc. capable of graphic processing, when displaying a graphic on a CR'T display or printing out a graphic on a printer, the graphic to be displayed or printed out is displayed as a dot image. It is generated on the expanded memory (bitmap memory). In particular, two
For a thick line convex polygon having a line width greater than a dot, the corresponding thick line convex polygon is generated by dot expansion on the memory based on the outer shape information (LO) and inner shape information (Li) of the thick line. ing.

Conventionally, this thick line convex polygon is generated by making the polygon with a width of one dot specified by the internal shape information thicker one dot at a time, and repeating the process until the shape specified by the external shape information is reached. Furthermore, thick line segments are treated as rectangles, and thick convex polygons are processed as a set of rectangular line segments.

[Problems to be Solved by the Invention] The conventional convex polygon generation method described above has a limit in speeding up the processing.

In the method of thickening line segments one dot at a time,
The process of converting line segments into dots has to be repeated until the desired thickness is achieved, which makes the process enormous.Also, in the method of processing thick line segments as rectangles, each line segment must be processed individually. This is because the processing at the junction of line segments becomes complicated.

Therefore, an object of the present invention is to perform dot conversion processing as efficiently as possible when a thick line convex polygon is generated on a memory in which a dot image is developed.

[Means for Solving the Problems] The present invention is based on a thick line polygon generation method in which a thick line convex polygon specified by external shape information and internal shape information is generated on a memory in which a dot image is expanded. As shown in FIG. 7, the technical means for solving the above problem in this generation method is to
In addition to determining the highest point pou and the lowest point pod in the scanning line arrangement direction, the internal shape line L is determined based on the internal shape information.
The highest point Piu and the lowest point Pid in the scanning line array direction of i are determined, and the memory is stored in the scanning line array direction as a first area E1 between the outer shape upper point Pou and the inner shape upper point Piu, The area is divided into a second region E2 between the inner shape upper point Piu and the inner shape lower point Pid, and a third region E3 between the inner shape lower point Pid and the outer shape lower point pod, and the scanning line is In the process of shifting XN one dot at a time, the scanning line XN moves to the first area E1 or the third area E1.
3, the intersection point P011Po12 or P031.3 between the scanning line XN and the outline line LO. Find P o32 and calculate scanning line XN (7) corresponding intersection + ffi (PO
11, PO12) Mataha (P 031. P 032
) is converted into dots, and when the scanning line XN is located in the second area E2, the scanning line XN and the inner and outer contour lines 1-o, li
Intersection point P o21 P o22P i21. P+
22 between the outer and inner shape intersections of the scanning line XN (Po2
1. Pi21) (Pi22.Po22) is converted into dots.

The above dot conversion on memory usually involves logical information 111
This is done by writing I+.

Note that the direction of the scanning lines in the memory, that is, the direction in which they are arranged, can be set arbitrarily.

[Operation] In the process of shifting the scanning line XN one dot at a time, when the scanning line XN is located in the first area E1, the scanning line
1, Po12) is dot-converted. Therefore, when the movement of the scanning line XN within the first area is completed, the entire area inside the outline line LO located in the first area E1 is converted into dots. Next, the scanning line XN is the second f! When located in the R area ε2, the scanning line
, and the two intersections H (Po21.P
i21).

(P i22. P o22 ) are each dot-converted. Therefore, when the movement of the scanning line XN in the second area is completed, in the second area, everything inside the outer line 1o and outside the inner line li is converted into dots.

Furthermore, when the scanning line XN is located in the third area E3, the scanning line XN intersects only the outline line 1o, and the scanning line
As in the case of the area, all areas inside the outline line LO located in the third area are converted into dots.

The first area El, the second area E2. When the dot conversion process in the third area E3 is completed, the outer line LO and the inner line 1 are
-i is dot-converted, and a thick convex polygon formed by the outer line LO and inner line 1-i is developed on the memory.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a block diagram showing an example of the basic configuration of an image processing apparatus to which the convex polygon generation method according to the present invention is applied.

In the same figure, 10 is a CPL that performs overall control.
I, 12 is a graphics processor that performs image processing related to graphics; 14 is a ROM in which programs and the like are stored;
Reference numeral 16 denotes a RAM that includes a bitmap memory for expanding image information into dots, and also has an area for storing contour information (outer shape, inner shape) of figures.
1o, graphic processor 12, ROM14, RA
M16 are connected to each other by a bus. Reference numeral 18 denotes an interface circuit, through which the CRT display 13, printer 15, and input devices 17 such as a keyboard device and a scanner are connected.

Note that the graphic processor 12 has a graphic generation function according to the thick line convex polygon generation method according to the present invention.

Next, the graphic generation process will be explained according to the flowchart shown in FIG.

First, the bitmap memory has an area corresponding to the display screen of the CRT display 13 or one page of the printer 15, and the same coordinate system (X, Y) is set in each area. For example, if we look at the convex and concave polygons, the fourth
As shown in the figure, the vertices AO (XAo, Y
A.O.).

AI (XAI, YAI), A2 (XA2.YA
2), A3 (XA3. YA3), vertex BO (XBO.

YBo), Bl (XB1. YB1),
B2 (XB2. YB2)83 (XB3.
By specifying YB3) in the coordinate system (X, Y), the outline of the target rectangle, that is, the outline line LO(AO
→A1→A2→A3→Ao) and internal line Li (BO
→B1→B2→B3→Bo) is specified. The designation of each vertex is based on the shape (rectangle) read by the scanner.
In some cases, this is done by specifying the display position of the item, and in other cases, it is done directly by using the keyboard.

When targeting a rectangle specified by the outer line LO and inner line 1i as described above, the scanning line (parallel to the X axis) arrangement direction (Y axis direction) of the outer line 1o is ) are specified, and the highest point BO and lowest point B2 in the scanning line arrangement direction of the internal shape line 1-i are determined based on the coordinates of each vertex of the internal shape. be identified. Then, in the scanning line arrangement direction (Y), the first point between the outer shape upper point AO and the inner shape upper point BO is
The area El (YAo≦Y<YBO) and the second area E2 (YBo≦Y≦Y) between the inner shape upper point BO and the inner shape lower point B2
B2) and a third area E3 (YB2<y≦YA2) between the inner shape lower point B2 and the outer shape lower point A2 is set.

In this state, the scanning line XN parallel to the X-axis is positioned at the upper point AO of the outer shape, and from this position the scanning line XN is shifted one dot at a time in the Y direction. In the process, when the scanning line XN is located in the first area E1 (■), the intersection X1 of the outline line LO and the scanning line XN,
Find X2. Specifically, the vertex Ao (X^O,
YAO) and the vertex AI (XAI, XA1) The intersection point X1 of the straight line connecting the scanning line
(XAO.

YAo) and the vertex A3 (XA3.YA3) and the intersection of the scanning line XN x 2 is calculated. Then, on each scanning line XN of the bitmap memory, the bit between the intersections X1 and X2 is rewritten to 1''.

Through the processing in the first area E1, YAo≦Y<Y
All the bits inside the outline line LO that fall within the range of Bo become "1".

Next, when the scanning line XN is located in the second area E2 (■), the intersection X1 of the outline line LO and the scanning line XN
, X4 and the intersection point X2 of the internal line li and the scanning line XN
, find X3. Specifically, regarding the outline LO, the vertex Ao (XAo, YAo) and the vertex AI (XA
I, YA1) or the vertex AI (XA
I, YAI),! : Vertex A2 (XA2. YA
2) Calculate the intersection x 1 between the straight line connecting the lines and the scanning line
(XA3. YA3) or the vertex A3
(XA3. YA3) and vertex A2 (XA2. YA
2) Calculate the intersection point x4 between the straight line connecting the lines and the scanning line XN. Also, regarding the inner line 1-i, the vertex BO (X80
Calculate the intersection point X2 between the scanning line Vertex Bo (X
80. YBO) and vertex 83 (XB3. YB3)
Straight line or vertex 83 connecting (XB3. YB3)
,! : Calculate the intersection of the straight line connecting the vertex 82 (XB2. YB2) and the scanning line XN x 3. and,
Intersection X with the above outline line 1o on each scanning line XN
1 and the intersection x2 of the inner line 1-i is rewritten to 1'', and the bit between the other intersection x3 of the inner line Li etc. and the outer line 1
The bit between 1LO and other intersection points ×4 is rewritten to 1''. Through the processing in the second area E2, YBO≦Y≦Y
All bits located between the outer line LO and the inner line 1i in the range B2 become "1".

Furthermore, when the scanning line XN is in the third area E3, the same process as in the first area E1 is performed, and the outline line
The bit between the intersections of O and scanning line XN is rewritten to "1". Then, all bits inside the outline line LO in the range 'y'B2<Y≦YA2 become "1".

As described above, when the scan line XN is moved dot by dot from the first area E1 to the end (apex A2) of the third area E3, the process of generating the quadrilateral ends. At the end of this process, a thick line-shaped convex rectangle in which the area surrounded by the outer line LO and inner line 1-i is all 1'' is developed on the bitmap memory configured in the RAM 16 as shown in Fig. 4. be done.

The convex rectangle developed on this bitmap memory is CP
Based on the command from U10, the signal is supplied to the CRT display 13 or printer 15 via the interface circuit 18, and the thick convex rectangle is displayed or printed as dots.

As described above, according to this embodiment, one scanning line XN
Since the above dot conversion process is for the left and right sides of the convex quadrilateral, the scanning line
A thick convex rectangle is developed on the bitmap memory while moving only once from A2 to A2, resulting in more efficient processing.

Note that the direction of the scanning line can be arbitrarily set on the bitmap memory; for example, even if it is set in the Y direction (one direction) in FIG. 4, the processing can be performed in the same way.

Furthermore, if a part of the outline of the figure to be generated is parallel to the scanning line, as shown in FIG. Any point on the contour line to be located, for example, the endpoint of the line segment (
AO, A3, etc.).

Furthermore, a circle specified by a center coordinate point, an inner diameter, an outer diameter, etc. is similarly processed as a convex polygon.

[Effect of the Invention 1] As explained above, according to the present invention, in the process of dividing the area into a predetermined first area, second area, and third area and shifting the scanning line one bit at a time, the scanning line When the scanning line is located in the area or the third area, dot conversion is performed between the intersections of the scanning line and the outer contour line, and when the scanning line is located in the second area, the intersection between the scanning line and the inner and outer contour lines is subjected to dot conversion. Therefore, the dot conversion of the target thick line convex polygon is completed by moving the scanning line once in the graphic area, so that the dot conversion process is efficiently performed. Therefore, it is possible to further speed up the processing related to the generation of thick line convex polygons.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of the present invention, FIG. 2 is a block diagram showing an example of the basic configuration of an image processing device to which the convex polygon generation method according to the present invention is applied, and FIG. A flowchart showing an example of the generation process, FIGS. 4 and 5 are diagrams showing the outline of a thick-line convex quadrilateral to be generated, and FIG. 6 is an example of a thick-line convex polygon specified by an outer line and an inner line. FIG. El...First area E2...Second area E3...Third area Patent applicant LSI Systems Co., Ltd. Agent
Person Patent attorney Tomohiro Nakamura (3 others) [Explanation of symbols] 10... CPU 12... Graphic processor 13... CRT display 14... ROM 15... Printer 16... RAM 17. ...Input device 18...Interface circuit XN...Scanning line

Claims (1)

[Scope of Claims] A thick line convex polygon generation method that generates a thick line convex polygon specified by outer shape information and inner shape information on a memory in which a dot image is developed, the outer shape being determined based on the outer shape information. The highest point (Pou) and lowest point (Pod) of the line (Lo) in the scanning line arrangement direction (D)
), and also determine the inner line (Li) based on the inner shape information.
The highest point (Piu) and lowest point (Pid) in the scanning line arrangement direction (D) are determined, and the memory is stored in the outer shape upper point (Pou) and inner shape upper point (Puu) in the scanning line arrangement direction (D). ), and the inner shape upper point (Piu) and the inner shape lower point (Piu).
d) and the inner shape lower point (Pid
) and the third area (E3) between the outer lower point (Pod), and in the process of shifting the scanning line (XN) one dot at a time in memory, the first scanning line (XN) When located in the area (E1) or the third area (E3), the intersections (Po11) (Po12), (Po3) of the scanning line (XN) and the outline line (Lo)
1) Find (Po32) and calculate between the corresponding intersections of the scanning line (XN) (Po11, Po12), (Po31, Po32)
When the scanning line (XN) is located in the second area (E2), the intersection points (Po21) (Po22) (Pi21) ( Pi22
) between the outer and inner shape intersections of the scanning line (XN)
12, Pi12) (Pi22, Po22) is subjected to dot conversion.