JPH06274645A - Paint-out processing method for polygon - Google Patents

Abstract

PURPOSE:To considerably shorten time to the start of drawing by considerably shortening total time from the start of a hatching instruction to the end of paint-out processing. CONSTITUTION:A hatching line for painting out the inside of a polygon is generated based on a paint-out instruction contained in a plotter command and the apex coordinate of the polygon to be painted out. In that case, only the apex coordinate contained in the plotter command is transformed to the coordinate system of image processing inside a plotter and based on the apex coordinate after this coordinate transformation, the coordinate of an intersection with the hatching line is calculated. Thus, the intersection coordinate is excluded from the object of coordinate transformation, and coordinate transformation processing is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method for filling the inside of a polygon with a raster plotter based on a hatching command of a plotter command transferred from a CAD system, and more particularly to a coordinate system of vertex coordinates during transfer of the plotter command. The present invention relates to a polygon filling processing method that involves coordinate conversion processing from a raster to a coordinate system inside a raster plotter.

[0002]

2. Description of the Related Art When performing a hatching process for filling the inside of a polygon with a raster plotter based on a plotter command transferred from a CAD system, normally the vertex coordinates of the polygon are paired with the hatching command of the plotter command. Transferred from CAD system. On the raster plotter side, based on the transferred vertex coordinates, calculate the intersection coordinates of the hatching line at the specified interval and the polygon specified by the vertex coordinates, and execute the filling process inside the polygon. Go. By the way, generally, the coordinate system of the vertex coordinates transferred from the CAD system is called a user coordinate system, and the coordinate system of the plotter inside the raster plotter or the coordinate system of the image processor inside the raster plotter is one unit. The size and absolute position are different. Therefore, the hatching line generated by the hatching command of the plotter command also needs to be expanded in the final conversion coordinate system when finally expanding the bitmap in the image processing processor.

Therefore, conventionally, when a polygonal hatching command is included in a plotter command transferred from a CAD system by interruption at regular intervals, first, the vertex coordinates of the polygon represented in the user coordinate system are plotted. Convert it to the vertex coordinates of the coordinate system and register it in the polygon buffer,
After the hatching command is started after the plotter command has been transferred, the intersection of the line segment specified by the vertex coordinates and the hatching line specified by the hatching parameters is calculated, and then the vertex coordinates and the calculated intersection coordinates are plotted. The coordinate system is converted to the image processor coordinate system to perform bitmap expansion.

[0004]

However, in the above-mentioned conventional method, since it is necessary to perform the coordinate conversion processing of the vertex coordinates and the calculated intersection coordinates, it takes a lot of time until the coordinate conversion is completed, and the drawing is performed. There is a problem that the time to start is delayed.

The present invention has been made in order to solve such a problem. The total time from the start of the hatching command to the end of the filling process is greatly shortened, and the time until the start of drawing is greatly shortened. It is an object of the present invention to provide a polygonal filling processing method that can be performed.

[0006]

According to the present invention, a hatching line for filling the inside of a polygon is created based on a filling command included in a plotter command and the vertex coordinates of the polygon to be filled. In a polygon filling processing method for performing conversion processing from a coordinate system of vertex coordinates during transfer of the plotter command to a coordinate system of image processing inside the raster plotter, the vertex coordinates are coordinate systems of image processing inside the plotter. After the conversion, the intersection of the line segment specified by the converted vertex coordinates and the hatching line is calculated.

[0007]

According to the present invention, since the transferred vertex coordinates are transformed into the final coordinate system, the hatching intersection coordinates are calculated based on the transformed vertex coordinates. It is not necessary to perform coordinate conversion for the intersection coordinates. Therefore, it is possible to significantly reduce the number of objects to be subjected to coordinate conversion, and it is possible to significantly reduce the total time from the start of the hatching instruction to the end of the filling processing. Therefore, the time from the plotter command transfer to the start of plotting can be greatly shortened.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a functional block diagram of a raster plotter according to an embodiment of the present invention. CA not shown
The plotter command transferred online from the D system is stored in the input buffer 2 via the online interface (I / F) 1. Of the plotter commands stored in the input buffer 2, the vertex coordinates that specify the polygon associated with the fill command are registered in the polygon buffer 3.

The CPU 4 monitors and controls the peripheral circuit 5 such as the key panel, the sensor monitoring unit and the mechanical control unit, analyzes and executes the plotter command stored in the input buffer 2, and executes the hatching command when the hatching command is executed. The intersection of the polygon and the hatching line is calculated, and the image processor 6 is activated to generate the hatching line. The image processing processor 6 performs processing such as bitmap expansion of a figure in the frame buffer 7, movement, copying, etc. based on an image processing command given from the CPU 4.
Further, the image processor 6 transfers the image data stored in the frame buffer 7 to the output control unit 8 at a predetermined timing. The drawing control unit 8 drives a thermal head or the like according to the transferred image data to generate a drawing.

Next, the operation of the raster plotter configured as described above at the time of polygon filling processing will be described. The plotter command transferred from the CAD system when the polygon is filled has the form shown in FIG.
That is, the movement to the origin is instructed by "PA0,0;",
The registration of the vertex coordinates in the polygon buffer 3 is started by "PM0;". "PD100,0;", "PD100,
100; ","PD0,100;","PD0,0;"
Indicates the coordinates of the vertices A, B, C and D, respectively.
The registration in the polygon buffer 3 is completed by "PM2;". “FP;” is an execution command of the hatching instruction.

FIG. 3A is a diagram showing the transfer timing of such a plotter command and the timing of processing of the raster plotter. Plotter commands are transferred little by little by interrupt processing at regular intervals. CPU4
Interprets the plotter command stored in the input buffer 2, and when the vertex coordinate registration command "PM0;" appears,
The vertex coordinates after that are converted using the interrupt interval. Since the vertex coordinates at the time of transfer are expressed in the user coordinate system, here, as shown in FIG. 4, the image processing coordinates which can be converted by the image processing processor 6 from the user coordinate system to the plotter coordinate system. Convert to system. Of course, coordinate conversion from the user coordinate system to the image processing coordinate system may be performed at once. Note that the coordinate conversion processing here also includes polygon rotation processing when the hatching line is inclined with respect to the polygon, as shown in FIG. These coordinate conversion processes can be easily implemented by known matrix calculations. Further, as will be described later, at the time of this coordinate conversion, hatching parameters such as the hatching type, spacing, angle, etc. are also converted at the same time.

In FIG. 3A, when the transfer of the plotter command is completed, the hatching execution instruction "FP;" is executed. Here, first, the intersection of the line segment connecting the vertex coordinates registered in the polygon buffer 3 and the hatching line segment is obtained. The vertex coordinates have already been converted to the final image processing coordinate system at the end of the transfer, and parameters such as the hatching type, interval, and angle have also been converted to the image processing coordinate system at the end of the transfer. Therefore, the CPU 4 calculates the intersection in the image processing coordinate system based on these parameters. This has the advantage that it is not necessary to perform coordinate conversion processing on the calculated intersection.

When the intersection is calculated, the image processor 6 interpolates the obtained intersection by the EVEN / ODD algorithm to generate a hatching line segment.
As shown in FIG. 6, this algorithm is an algorithm that connects intersections with each other, and moves from an odd point to an even point by pen down (drawing) and from an even point to odd point by pen up (drawing). Not). When all hatching lines are generated by such processing, drawing is started.

As described above, according to this system, as shown in FIG.
As shown in (a), the vertex coordinate and hatching parameter coordinate change processing is completed during the online interrupt idle time during which the plotter command is transferred, so the coordinate conversion processing time after executing the hatching instruction is omitted. It is possible to significantly reduce the time required to start drawing. On the other hand, according to the conventional method shown in FIG. 3B, since the plotter commands are all transferred and the hatching command is executed, the intersection point calculation and the coordinate conversion process are performed, so that the drawing is started. There is a problem that it takes an extremely long time to get there.

Further, according to this system, the vertex coordinates are converted to the final coordinate system before the intersection is calculated. Therefore, the number of vertices is x, the number of intersections is y, the coordinate conversion processing time per point is α, 1
When the intersection calculation processing time per point is β, when coordinate conversion is performed after the intersection is calculated as in the conventional case, it takes xα + yβ + yα until the hatching line is generated after the hatching command is executed. , Yβ, and the time is reduced by (x + y) α. Assuming that the time for coordinate conversion and the time for calculating the intersection are almost the same, the conventional method = xα + 2yα and the present method = yα. Further, since the number of intersections y is generally larger than the number of vertices x, if xα≈0, the conventional method = 2yα, the present method = yα, and the present method requires almost half the processing time of the conventional method. .

In the above embodiment, the hatching parameters are converted at the same time as the polygon vertex coordinates are converted. However, when the inside of the polygon is solidly filled, no parameter conversion is necessary. The information that it is a solid color may be passed to the subsequent filling process.

[0017]

As described above, according to the present invention, after the transferred vertex coordinates are transformed to the final coordinate system, the hatching intersection coordinates are calculated based on the transformed vertex coordinates. As a result, the coordinate conversion process for the calculated intersection coordinates becomes unnecessary, and it is possible to significantly reduce the time from the plotter command transfer to the start of drawing.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a raster plotter according to an embodiment of the present invention.

FIG. 2 is a diagram showing a plotter command transferred to the plotter.

FIG. 3 is a timing chart showing a plotter command transfer timing and a paint processing timing of the plotter in comparison with a conventional example.

FIG. 4 is a diagram for explaining coordinate conversion processing in the plotter.

FIG. 5 is a diagram for explaining coordinate conversion processing in the plotter.

FIG. 6 is a diagram for explaining a hatching line generation algorithm in the plotter.

[Explanation of symbols]

1 ... Online interface, 2 ... Input buffer, 3
... Polygon buffer, 4 ... CPU, 5 ... Peripheral circuit, 6 ...
Image processor, 7 ... Frame buffer, 8 ... Output control unit.

Claims (1)

[Claims] 1. A hatching line for filling the inside of the polygon is generated based on a filling instruction included in the plotter command and the vertex coordinates of the polygon to be filled, and at the time of transfer of the plotter command. In a polygon filling processing method for performing conversion processing from a coordinate system of vertex coordinates to a coordinate system of image processing inside the raster plotter, after converting the vertex coordinates to a coordinate system of image processing inside the plotter, A polygon filling processing method characterized in that an intersection of a line segment specified by vertex coordinates and a hatching line is calculated.