JPH08147485A - Method and device for painting out closed pattern - Google Patents

Abstract

PURPOSE: To easily paint out a closed pattern without taking the intersection point of each line segment to constitute the closed pattern, a singular point, and projecting and recessing parts, etc., into consideration. CONSTITUTION: A plotting area in which plural unit areas to be displayed in a paint-out state or a null state in accordance with a bit value are arranged in the form of a matrix is generated, and a rectangular area 19 to surround the objective closed pattern 17 to be painted out plotted in the plotting area is set, and each passing unit area through which each line S1 to S7 to constitute the closed pattern 17 passes among the unit areas in the rectangular area 19 is determined, and in the rectangular area 19, the bit value of each unit area located in a prescribed direction such as, for instance, an x-axis direction, etc., is inverted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed figure painting method and a closed figure painting apparatus for painting a drawn closed figure.

[0002]

2. Description of the Related Art When a figure created by CAD or the like is printed out by a two-dimensional display device such as a CRT or a liquid crystal display or a printer, a part of the figure is painted in order to make it easy for an observer to see. Things are being done.

The figure to be filled is a polygon such as a triangle, a quadrangle, a pentagon, a hexagon, ... Or a curved shape such as a circle or an ellipse. There are also figures in which straight lines and curved lines are combined. However, both are closed figures. A general method for efficiently filling the closed figure is to draw a large number of straight lines in the closed figure without any gaps.

A general painting procedure will be described with reference to FIGS. 12 and 13. When painting the triangle 1 whose coordinates of the vertices are A, B, and C as shown in FIG. 12, first, the minimum rectangular area 2 surrounding the triangle 1 is set. Then, the minimum values Xmin, Ymin and the maximum values Xmax, Y on the x-axis and the y-axis that specify the position on the XY coordinate of the minimum rectangular area 2 are specified.
Find max.

Next, as shown in FIG. 13, a line segment parallel to the x-axis is assumed for an arbitrary y coordinate, and the intersection Q _AB between this line segment and each line segment AB, AC forming the triangle 1 is set. Find Q _AC . And the line segment 3 connecting the intersection points Q _AB and Q _{AC to} each other
To draw. Perform the drawing operation of this line segment 3 with the minimum value Y of the y coordinate.
By sequentially increasing the y value by 1 from min to the maximum value Ymax, the triangle 1 can be filled with a large number of line segments 3 and, as a result, the triangle 1 can be filled.

However, in the painting method described above,
As shown in FIG. 14A, when the closed figure to be filled has a line segment that is bent inward of the closed figure, the part that is bent inward is painted. Further, as shown in FIG. 14B, when a window part exists in the closed figure, this window part is also painted.

In order to eliminate such inconvenience, FIG.
As shown in FIG. 5, a line segment 4 parallel to the x-axis is assumed for an arbitrary y coordinate, and intersection points Q ₁ , Q ₂ , Q ₃ , of this line segment 4 and each line segment forming the closed figure 5 are Find Q ₄ in order,
In the process of drawing the line segment 4 from Xmin to Xmax, white (blank) and black (painted) are inverted every time the line segment 4 reaches each of the intersections Q _{1 to} Q ₄ . For example, in FIG. 15, starting from white, the sections Q _{1 to} Q ₂ and Q _{3 to} Q ₄ become black lines, and as a result, the closed figure 5 is correctly filled.

[0008]

However, even in the method of filling the closed figure 5 by the method shown in FIG. 15, there are still the following problems to be solved. That is, in the closed figure 5 composed of polygons, the vertices R ₁ , R ₂ . R ₃ , R ₄
When there is a singular point where the line segment of the closed figure 5 is in contact with the line segment 4 parallel to the x-axis at one point, it is necessary to prohibit black and white reversal. Therefore, when the painting process is executed by software using, for example, a computer, the program becomes complicated. In addition, there is a concern that the coating treatment efficiency may decrease.

Further, every time one line segment 4 is drawn, the intersection points Q ₁ , Q ₂ , between the line segment 4 and each line segment forming the closed figure 5 are drawn.
Since it is necessary to calculate Q ₃ and Q ₄ to calculate each coordinate, there is a concern that the program will be complicated and the painting efficiency will be reduced as in the above case.

The present invention has been made in view of such circumstances, and each line sentence forming a closed figure is drawn by drawing a line in a predetermined direction from each position of each line segment forming the closed figure according to a certain law. An object of the present invention is to provide a closed figure filling method and a closed figure filling apparatus that can efficiently fill a closed figure with a simple program without considering the intersections and the singular points.

[0011]

In order to solve the above problems, in the closed figure filling method of the present invention, a plurality of unit areas displayed in a filled state or a blank state according to a bit value are arranged in a matrix. Create an arrayed drawing area, set a rectangular area that encloses the closed figure to be filled drawn in this drawing area, and set each of the unit areas in this rectangular area to which each line that makes up the closed figure passes. The passing unit area is determined, and the bit value of each unit area existing in a predetermined direction from each passing unit area is inverted within the rectangular area.

Further, in the closed figure painting apparatus of the present invention, an image memory having a drawing area formed by arranging a plurality of unit areas displayed in a filled state or a blank state in a matrix according to a bit value is formed. A graphic information storage unit for storing graphic information for specifying a closed graphic to be painted; a graphic creating unit for reading the graphic information from the graphic information storage unit to create a closed graphic in a drawing area of an image memory; Rectangular area setting means for setting a rectangular area surrounding the closed figure created by the figure creating means, and each passing unit area through which each line forming the closed figure passes among the unit areas in the set rectangular area The passing unit area determining means, the bit value inverting means for inverting the bit value of each unit area existing in a predetermined direction from each passing unit area in the rectangular area, and the bit value inverting means. Tsu bets value and a display means for displaying in a fill state or blank state corresponding to each unit area of the drawing area of image memory containing a bit value is inverted to the bit value.

According to another aspect of the present invention, there is provided a closed figure painting apparatus, wherein the bit value inverting means in the closed figure painting apparatus of the above invention is a bit string of a prescribed number of unit areas forming one word existing in a predetermined direction. And an exclusive OR calculation means for calculating an exclusive OR value of a bit string consisting of a prescribed number of bits having a bit value in the filled state.

[0014]

The principle of filling a closed figure in the closed figure painting method and the painting apparatus thus constructed will be described. When a closed figure to be painted drawn in the drawing area is projected on one side (specific side) of a rectangular area surrounding the closed figure in a predetermined direction, the closed figure is drawn on the projected specific side. A line segment closer to the specific side in the line and a line segment farther to the specific side in the closed figure are projected in an overlapping manner.

In the present invention, when the rectangular area is composed of a plurality of unit areas arranged in a matrix which are displayed in a filled state or a blank state according to the bit value, a closed figure is formed. The bit value of each unit area existing in the above-mentioned predetermined direction is inverted from each passage unit area through which each line segment passes. It should be noted that each unit area is initially set to, for example, a blank state before the painting process is started.

Therefore, for example, first, when the bit value of each unit area existing in a predetermined direction of each passing unit area through which the line segment farther to the specific side passes is inverted, this far line segment and the above-mentioned specific All the unit areas existing up to the side are bit-inverted to be in a filled state.

Next, when the bit value of each unit area existing in the predetermined direction of each passing unit area through which the line segment closer to the specific side passes is inverted, the bit line exists near this line segment and the specific side. Since all the unit areas to be filled are already filled,
It is inverted again and returns to the blank state.

However, since each unit area existing between the line segment farther from the specific side and the line segment closer to the specific side is not inverted to the blank state again, the filled state is maintained. To do. Therefore, the closed figure constituted by each unit area between the line segment farther from the specific side and the line segment closer to the specific side is filled.

Next, consider the case where a window exists in a closed figure, as shown in FIG. 14 (b). Even in this case,
There are a line segment farther from the specific side and a line segment closer to the specific side forming the window. Therefore, when only this window exists in the rectangular area, the inside of this window is inverted from the blank state of the initial state to the filled state hot water according to the above-mentioned operation principle. However, since this window is formed in a closed figure,
If it is already in the filled state, this filled state can be regarded as the initial state, so that the initial state of this filled state is inverted and becomes a blank state. Therefore, the window remains blank.

Further, at a singular point as shown in FIG. 15, the bit value of each unit area from this singular point to a particular side is inverted and overlapped from the unit area corresponding to this singular point, resulting in Black and white reversal is prohibited.

According to another aspect of the present invention, when inverting bits of each unit area existing in a specific direction, each word is not sequentially inverted, but one word is defined. The exclusive OR value of the bit string of the number of unit areas and the bit string of the specified number of bits having the bit value in the filled state is calculated. Therefore, the reversal processing speed is improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a closed figure painting apparatus that adopts the closed figure painting method of the embodiment. This closed graphic painting device is composed of a kind of information processing device such as a computer, and has a graphic information file 11 formed in an auxiliary storage device such as an HDD and a work information formed on a storage element such as a RAM. A memory 12 and an image memory 15, an image processing unit 13 configured as a software on an application program, and an operation unit 14 such as a keyboard and a mouse.
And a CRT display unit 16.

A plurality of graphic information for creating a closed graphic is stored in a graphic information file 11 as a graphic information storage unit. For example, in the case where the closed figure is a closed figure 17 composed of a deformed polygon in which a triangular window 17b is formed in a deformed quadrangle 17a shown in FIG. 3, a total of seven line segments S1 constituting the closed figure 17, S2, S3, S4, S5, S
6 and S7 are stored. Further, specifically, each line segment S1 ～S7 the both ends of the coordinates (x _S, y _s),
(X _E, y _E) are stored in the form of.

When the closed figure is a circle or an ellipse, it is stored in the form of center coordinates, radius, elliptic coefficient and the like. further,
If the shape cannot be expressed by a function, it is stored as a dot image.

[1] or [0] is stored in the image memory 15.
A drawing area is formed in which a plurality of unit areas displayed in a filled state or a blank state according to the bit value of are arranged in a matrix. The size of each unit area forming this drawing area is a minute value such as the thickness of each line segment forming the closed figure to be filled. Then, the drawing areas arranged in a matrix are displayed and output on the CRT display unit 16. 9A and 9B, unit areas 18 arranged in a matrix in the drawing area in the image memory 15 are shown.
Indicates.

The operation unit 14 has an input function for the figure creator to input various information and operation instructions. The work memory 12 is a work area for temporarily storing the graphic information when the image processing unit 13 reads the graphic information from the graphic information file 11 or for creating a line segment or a graphic from the graphic information. Used as.

The image processing section 13 reads out each piece of figure information which constitutes one closed figure designated by the operation section 14, draws a closed figure, and fills the drawn closed figure with a closed figure painting process. To execute.

Next, the specific operation of the image processing unit 13 will be described. First, when a figure number or a figure name for identifying one closed figure is input from the operation unit 14, the figure information forming the corresponding closed figure is read from the figure information file 11 and once written in the work memory 12. . For example, when the closed figure is the deformed closed figure 17 having irregularities shown in FIG. 3, the closed figure 17 has start coordinates (x _S , y _s ) and end coordinates (in each of the seven line segments S1 to S7). x _E , y _E )
Indicated by. Then, as shown in FIG. 3, the seven line segments S1 to S7 are drawn on the working memory 12. Then, the closed figure 17 is produced.

Then, the rectangular area including the drawn closed figure 17 is determined. In fact, considering the processing efficiency,
The minimum rectangular area 19 parallel to the x and y axes of the XY coordinate system including the closed figure 17 is determined. Therefore, the minimum rectangular area 19 exists in the range of Xmin to Xmax in the x-axis direction and in the range of Ymin to Ymax in the y-axis direction.

When the above-mentioned preparation process is completed, as shown in the flowchart of FIG. 2, in ST (step) 1, the determined minimum rectangular area 19 (Xmin, Xmax, Ymin,
Ymax) is set in the drawing area of the image memory 15.

At ST2, the start coordinates (x) of one line segment forming the closed figure 17 drawn on the working memory 12 are drawn.
_S , y _s ) to each end coordinate (x _E , y _E ) of each passage unit area P ₁ .1 in the drawing area through which this line segment passes. P ₂ ,
P _3. …. P _N. ... Determine P _E. For example, line segment S1
In the case of, as shown in FIG.
The unit area 18 at the lower left corner of the is the leading passage unit area P ₁ .

At ST3, the Nth pass unit area P
_The coordinates (Xi, Yj) with the unit area of _N as one unit are read. Then, 8-bit data forming eight unit areas 18 [(Xi, Yj) to (Xi + 7, Yj)] existing in a direction parallel to the x-axis as a specific direction from the coordinates (Xi, Yj) Read D _M (ST4).

Then, the 8-bit data D _M [d1, d2, ... d8] and XOR data D _E with all of Line Data D ₁ of the 8 bits indicating 1] [11111111] indicating the black line of the fill [e1.
e2, ..., E8] is calculated (ST5). The calculated 8-bit exclusive OR data D _E [e1, e2,
…. e8] for each data value of the eight unit areas 18
Writing to each unit area 18 of [(Xi, Yj) to (Xi + 7, Yj)] (ST7).

FIG. 10 shows the relationship among the read data D _M , the line data D ₁ and the write data (exclusive OR data) D _E. As shown, the write data D _E is the read data D _M
Indicates that each bit value is inverted.

Eight unit areas 18 existing in the x-axis direction
When the bit value inversion processing for [(Xi, Yj) to (Xi + 7, Yj) is completed, in ST7, the coordinates are updated to the next eight unit regions [[Xi, Yj] =
(Xi + 8, Yj)].

After confirming that the updated x coordinate Xi does not exceed the maximum value Xmax of the minimum rectangular area 19, (ST
8) Then, the process returns to ST4 to start the inversion process of the next eight unit areas 18.

If the updated x coordinate Xi exceeds the maximum value Xmax of the minimum rectangular area 19 in ST8, ST
The process proceeds to 9 and moves to the next passing unit area P _N in the corresponding line segment (N = N + 1). When it is confirmed in ST10 that the updated passing unit area P _N does not exceed the final passing unit area P _E , the process proceeds to ST3, and the coordinates (Xi, Yj) of the updated passing unit area P _N are read. To do.

When the updated passing unit area P _N exceeds the final passing unit area P _E of the corresponding line segment in ST10, all unit areas existing on the side parallel to the x axis of the corresponding line segment. It is determined that the bit inversion process for 18 has been completed. Then, the process proceeds to ST11, where Xma of the corresponding line segment among the line segments forming the closed figure 17 designated by the operation unit 14
It is checked whether there is a line segment for which the inversion processing has not been completed for each unit area 18 existing on the x direction side.

If they exist, the process returns to ST2, and the passage unit areas P ₁ and P in the minimum rectangular area 19 through which the corresponding line segment passes.
₂ , P ₃ , ..., P _N , ..., P _E are determined. In ST11, when the reversing process for each unit area 18 corresponding to all the line segments forming the specified closed figure 17 is completed, the filling process for the specified closed figure 17 is completed.

Then, the closed figure 17 for which the above-mentioned painting processing has been completed is displayed and output to the CRT display section 16. Next, an actual processing procedure for filling the closed figure 17 shown in FIG. 3 performed by using the closed figure painting apparatus configured as described above will be described with reference to FIGS.
This will be described with reference to FIG.

(1) First, as shown in FIG. 3, the minimum rectangular area 19 is set. (2) Seven line segments S1 to S7 constituting this closed figure 17
Of each of the passage unit areas P ₁ in the _first line segment S ₁ ,
_{P 2, P 3, ...,} P N, ..., to determine the P _E, seeking head of passage unit region P ₁ of the coordinates (Xmin, Ymin), 4
As shown in the right side from the passage unit region P ₁ (Xmax
Side), the bit value of each unit area 18 existing in
Draw one black line 20.

(3) Next, the passing unit areas P _N are increased in order, and as shown in FIG. 5A, each passing unit area P _N
On the right side of, draw a black line 20 in sequence. Then, finally, as shown in FIG. 5B, the bit values of all the areas on the right side of the line segment S1 are inverted to be in a filled state.

(4) Next, as shown in FIG.
The bit values of each unit area 18 existing on the right side of the second line segment S2 are sequentially inverted. In this case, since all of the unit areas 18 on the right side are already filled with black due to the existence of the line segment S1, this black filled state is reversed and the original white blank state is restored. Therefore, when the processing for the line segment S2 is completed, the entire area on the right side of the line segment S2 becomes a white blank state as shown in FIG. 6B. However, the area between the line segment S1 and the line segment S2 maintains the black filled state.

(5) Next, as shown in FIG.
The bit value of each unit area 18 existing on the right side of the th line segment S3 is inverted. In this case, the triangular area 21 between the line segment S3 and the line segment S2 has already been filled with black due to the presence of the line segment S1, and therefore the original white blank state is restored. Further, since the triangular region 22 on the right side of the line segment S3 and on the right side of the line segment S2 has returned to the original blank state in the state of FIG. 6 (b), as shown in FIG. 7 (a). , It is inverted again to the black filled state.

(5) As shown in FIG. 7B, the bit value of each unit area 18 existing on the right side of the fourth line segment S4 is inverted. In this case, since the triangular area 23 between this line segment S4 and the previous line segment S3 has already been painted black in the state of FIG. 5B, it returns to the white blank state. Furthermore, FIG.
The state of each of the triangular regions 21 and 22 in (a) is inverted to invert to a black filled state and a white white blank state.

(6) As shown in FIG. 8A, the bit value of each unit area 18 existing on the right side of the fifth line segment S5 is inverted. In this case, the trapezoidal region 24 between this line segment S5 and the previous line segment S2 has already been painted black in the state of FIG. 5B, so it returns to the white blank state. Furthermore, the line segment S
Since the trapezoidal area 25 on the right side of 2 has already returned to the white blank state in the state of FIG. 6B, this trapezoidal area 2
In No. 5, the state shifts to the black filled state again.

(7) Further, as shown in FIG.
The bit value of each unit area 18 existing on the right side of the sixth line segment S6 is inverted. In this case, the trapezoidal region 24 between this line segment S6 and the previous line segment S2 has returned to the original white blank state in the state of FIG. 8A, so it is inverted again to the black filled state. To be done. Further, the black filled state of the trapezoidal area 25 on the right side of the line segment S2 in FIG. 8A returns to the original white blank state again. The window 17 between the line segment S5 and the line segment S6
The area forming b maintains a white blank state.

The seventh line segment S7 is the minimum rectangular area 1
Since it is parallel to the x-axis of No. 9, it does not directly affect the painting process this time. Therefore, as shown in FIG. 8B, the specified closed figure 17 is correctly painted, leaving the window 17b.

In the closed-figure painting device configured as described above, when the closed-figure 17 is filled, the closed-figure 17 is filled.
It is only necessary to sequentially invert the blank state or the filled state of each unit area 18 existing in the specific direction (right side) of each of the line segments S1 to S7 constituting the.

Therefore, in the reversal process for one line segment, it is not necessary to consider the existence of intersections with other line segments, singular points, etc., so that the program relating to the painting process can be greatly simplified.

As a result, even if the closed figure to be filled has a complicated shape with irregularities or is a figure with a window formed inside, the filling processing speed will not decrease. Absent.

Further, as shown in the flow chart of FIG. 2, when inverting the bits of each unit area 18 existing on the right side of each passing unit area P _{1 to} P _E of the line segment, each bit is turned in order. Rather than inverting it to calculate the exclusive OR value of the bit string of the specified number of unit areas forming one word and the bit string of the specified number of bits having the bit value in the filled state. There is. Therefore, the reversal processing speed is improved.

For example, as shown in FIG. 9B, 8-bit data D _M [d1,
d2, ... d8] straddles another line segment S2,
There is no need to consider the existence of this line segment S2 at all.

In the closed-figure painting device configured as described above, in addition to the polygon in which the closed figure to be filled is composed of straight lines, the closed figure composed of curved lines as shown in FIG. It goes without saying that it may be 26.
In this case, with respect to the first closed curve 26a forming the outer side and the second closed curve 26b forming the inner window, the closed curve 26a, 26b, so as to go around the closed curves 26a, 26b from a predetermined start point. If the blank state and the filled state of each unit area 18 located on the right side of 26b are reversed,
The closed figure 26 is correctly painted.

[0055]

As described above, in the closed figure filling method and the closed figure filling apparatus of the present invention, the blank state in each unit area existing in a predetermined direction from each position of each line segment forming the closed figure Alternatively, the closed figure is filled by sequentially reversing the filled state. Therefore, the closed figure can be efficiently filled with a simple program without making an intersection or a singular point with each line sentence forming the closed figure.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a closed graphic pattern painting apparatus adopting a closed graphic pattern painting method according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the apparatus of the embodiment.

FIG. 3 is a diagram showing a closed figure and a minimum rectangular area to be filled with the apparatus of the embodiment.

FIG. 4 is a diagram showing a procedure for filling the closed figure shown in FIG.

FIG. 5 is a diagram showing a painting processing procedure.

FIG. 6 is a diagram showing a procedure for painting processing in the same manner.

FIG. 7 is a diagram showing the procedure of the same painting process.

FIG. 8 is a diagram showing a procedure of the same painting process.

FIG. 9 is a diagram showing each unit area of a minimum rectangular area in which a drawing target graphic is drawn.

FIG. 10 is a diagram showing an exclusive OR operation performed by the apparatus of the embodiment.

FIG. 11 is a view showing a curved closed figure painted by the apparatus of the embodiment.

FIG. 12 is a diagram for explaining a conventional closed figure painting method.

FIG. 13 is a diagram for explaining a conventional closed figure filling method.

FIG. 14 is a diagram for explaining a problem of the conventional closed figure filling method.

FIG. 15 is a diagram for explaining the problems of the conventional closed figure filling method.

[Explanation of symbols]

11 ... Graphic information file, 12 ... Working memory, 13 ...
Image processing unit, 14 ... Operation unit, 15 ... Image memory, 16 ...
CRT table-shaped portion, 17 ... closed figure, 17b ... window, 18 ... unit area, 19 ... minimum rectangular area, S1 ～S7 ... segment, P ₁ ~
P _E ... transit unit area

Claims (3)

[Claims] 1. A drawing area in which a plurality of unit areas displayed in a filled state or a blank state according to a bit value is arranged in a matrix is created, and a closed figure to be filled drawn in the drawing area is created. A rectangular area that surrounds each of the unit areas in the rectangular area is determined, and each of the unit areas in the rectangular area through which each line of the closed figure passes is determined. A method for filling a closed figure, which comprises inverting the bit value of each unit area existing in. 2. An image memory having a drawing area formed by arranging a plurality of unit areas displayed in a filled state or a blank state according to a bit value in a matrix, and a figure for specifying a closed figure to be filled. A graphic information storage unit for storing information, a graphic creating unit for reading the graphic information from the graphic information storage unit to create a closed graphic in the drawing area of the image memory, and a closed graphic created by the graphic creating unit. A rectangular area setting means for setting a rectangular area surrounding the rectangular area, and a passing unit area determining means for determining each passing unit area through which each line forming the closed figure passes among the respective unit areas in the set rectangular area, In the rectangular area, bit value inverting means for inverting the bit value of each unit area existing in a predetermined direction from each of the passing unit areas, and bit value inverting by the bit value inverting means. And a display unit for displaying each unit area of the drawing area of the image memory including the bit value in a filled state or a blank state according to the bit value. 3. The bit value inverting means excludes a bit string of a specified number of unit areas forming one word existing in the predetermined direction and a bit string of a specified number of bits having a bit value in a filled state. 3. The closed figure filling device according to claim 2, which is an exclusive OR operation means for calculating a logical OR value.