JPH01128093A - Lithography apparatus - Google Patents

Abstract

PURPOSE: To effect a fast painting-out process by providing two digital differential analyzers(DDA) which find the panting-out border of a polygon is addition to a DDA which finds pixels to be painted out. CONSTITUTION: This plotting device has the 1st and 2nd DDAs 2 and 3 equipped with DDA arithmetic parts, X-axial counters, Y-axial counters, and clock control parts 5 and 8 controlling a clock for operating them and the 3rd DDA 16 which finds pixels to actually be drawn from the arithmetic results of the 1st and 2nd DDAs 2 and 3, and is equipped with a DDA control part 15 for controlling the 1st, 2nd, and 3rd DDAs 2, 3, and 16; and the 1st and 2nd DDAs 2 and 3 operate the border of a figure to be painted out to paint out the polygon. Consequently, the need to divide the polygon is eliminated, the start and end pints of a straight line to be plotted are calculated fast, and the frequency of transfer of data to the DDAs is decreased, so that the polygon is painted out fast.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a drawing device that can fill in polygons at high speed.

BACKGROUND ART In a drawing device that has a frame memory corresponding to the screen to be displayed, writes an arbitrary figure to this frame memory, and displays the figure by reading from the frame memory in response to double-sided scanning, To draw a straight line from an arbitrary starting point to an ending point, you need a function to calculate the coordinates of pixels located on the straight line, and a function to write point data to the pixel at the calculated coordinates in frame memory. The point data string becomes a straight line.

Generally, a drawing device is a digital differential analyzer (DigitalDi) that generates point coordinates on a line segment from a starting point to an ending point.
(hereinafter abbreviated as DDA) and a frame memory ◇ Fig. 3 shows the configuration of a conventional drawing device using DDA. When the coordinates of the starting point and the ending point are given from the c p U 21, the DDA 22 calculates the coordinates of the pixel where the point data is to be drawn, and writes the color data into the frame memory 23 using this data as a mask.

FIG. 4 shows an example of filling in the convex polygon ABCDE. First, when the CPU 21 receives a command to fill in the polygon ABCDE, it rearranges the coordinates of the vertices and moves the polygon horizontally at each vertex in order starting from the Y coordinate. Divide into triangles or trapezoids and fill in the triangles or squares. That is, in this example, polygon ABCDE is divided into triangle EAa, trapezoid AdDa, trapezoid dBbD, and triangle BCb.
U21 calculates the X coordinate on the straight line EA when Y=Yθ, then calculates the X coordinate on the straight line Ea when Y=Ye, and sends these coordinates to the DDA21.
The 0th order CPU 21 draws a straight line with Y=Ye.
Calculate the X coordinate on the straight line EA when Ye-1, then Y
Calculate the X coordinate on the straight line Ea when =Ye-1, send these coordinates to the DDA 21, and the DDA 21 calculates Y = Ye-1.
1 (D Draw a straight line. After filling in the triangle E A a, the next step is to fill in the trapezoid A d D a.

Problems to be Solved by the Invention In such a conventional configuration, when filling a polygon, it is difficult to rearrange the coordinates of the vertices, divide the polygon, and calculate the starting and ending points of the straight line to be actually drawn. Also, it took a long time to transfer Dagu to DDA, so it was not possible to fill in the color at high speed.

The present invention has been made in view of these points, and it is possible to eliminate the need for dividing polygons, to quickly calculate the starting point and end point of a straight line to be drawn using DDA, and to transfer data to DDA. The object of the present invention is to provide a drawing device that can perform high-speed filling by reducing the number of times.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides first and It has a second DDA and a third DDA that calculates pixels to be actually drawn from the calculation results of the first and second DDA, and a DDA for controlling the first, second and third DDA. The drawing apparatus is characterized in that it fills a polygon by calculating the boundary of the figure to be filled in using the first and second DDA.

Operation The present invention uses p and DDA to calculate the boundary of a filled figure with the above-described configuration, thereby eliminating the need for dividing polygons and speeding up calculation of the start and end points of straight lines to be drawn. Embodiment Figure 1 is a block diagram showing an embodiment of the drawing device of the present invention. It is a diagram. The case of filling a polygon starting from the larger Y coordinate will be explained. In FIG. 1, when the CPU 1 receives a command to fill a polygon, it rearranges the coordinates of the vertices.

That is, the points are arranged in order from the point with the largest Y coordinate to the point with the smallest Y coordinate. Next, the CPU 1 sends a flag indicating filling to the register 12, and the selector 13 outputs the data from DDA2.
Send to DAl 8. This data becomes the coordinates of the starting point of DDAl 6 @ Also, the selector 14 outputs the data from DDA 3 and sends it to DDAl 6. This data is DDAl
The coordinates of the end point of 6 are 0.Then, CPU1 sends the points on the right hand side to DDA2 in descending order, and sends the points on the left hand side to DDA3 in descending order. 2 is a diagram illustrating an example of filling in a pentagon ABCDE in order to calculate the boundary of the pentagon ABCDE and perform the left-handed boundary of the filled figure using DDA3.

First, the CPU 1 is the apex A (Xa, Ya) of the pentagon.

Vertex B (Xb, Yb), Vertex C (Xc, Yc), Vertex D
(Xd, Yd) and vertex E (Xe, Ye), the coordinates are rearranged, and the coordinates of point E are sent to DDA2 as starting point data, and the coordinates of point A are sent as ending point data. Next, CPU1 sends the coordinates of point E as starting point data to DDA3, and sends the coordinates of the point as ending point data◎ Then, DDA2 and DDA3 receive and take the coordinates of the starting point and ending point, and the polygon is Start calculation of filled boundary 0
That is, when Y=Yn, the clock control section 5 in the DDA 2 outputs a clock to the DDA calculation section 4 and the X-axis counter 6. Then, when the X coordinate at Y=Yn is determined, the DDA
A signal is sent from the calculation unit 4 to the clock control unit 5, and the clock control unit 5 stops outputting the clock, and also
A signal is also sent to the control unit 16, and the DDA control unit 15 is informed that the X coordinate at Y=Yn has been found.
A similar calculation is performed on A3, and the DDA calculation unit 9 calculates Y=Y.
When the X coordinate at n is determined, the operation of the clock control unit 8 is stopped, and the DDA control unit 15 is notified that the X coordinate at Y=Yn has been determined. Also, DDAl6 indicates whether the calculation is being executed. The 0DDA control unit 16 that sends the signal to the DDA control unit 16 has DDA2 and DDA3 set to Y.
=Yn completes the operation, and if DDAle is not performing the operation, sends a data write signal to DDAl6p, operates DDAl6, and DDA2
and restart the operation of DDA3 o DDA 1
If a is performing an operation, DDAl sends a write signal to DDAl6 after completing the operation.

That is, in the DDA2, the clock control section 6 first decreases the value of the Y-axis counter 7 by one, and then sends a clock to the DDA calculation section 4 and the X-axis counter 6, and continues until the X coordinate at Y=Yn-1 is determined.

The same applies to DDA3.

Further, DDAle used the data received from DDA2 and DDA3 to calculate the coordinates of the pixel where point data should be drawn, and wrote the color data into the frame memory 18 using this data as a mask.

Let us now discuss the pentagon shown in Figure 2.

As described above, the DDA2 performs address calculations for the straight line EA, and the DDA3 performs address calculations for the straight line ED. That is, when the DDA 2 receives the coordinates of points E and A from the CPU 1, the clock control section 6 sends a clock to the DDA calculation section 4 and the X-axis counter 6 to perform calculations. When point 1 is found, D
The DA calculation section 4 outputs a signal, stops the operation of the clock control section 5, and notifies the DDA control section 15 that point 1 has been found. That is, the coordinates of point 1 are output from the selector 13. Also, in DDA3, the coordinates of point E and point A are CP
When receiving is received from U1, the clock control unit 8 is connected to the DDA calculation unit 9.
A clock is sent to the X-axis counter 1o, and calculations are performed. When point 2 is found, the DDA performance section 9 outputs a signal, stops the operation of the clock control section 8, and notifies the DDA control section 16 that point 2 has been found. That is, the coordinates of point 2 are output from the selector 14.

Furthermore, DDAl,e sends a signal to the DDA control unit 15 indicating whether or not DDAl 6 is executing an operation. This signal is now in a state indicating that DDAl6 is not performing calculations, so the DDA control unit 15
While sending a write signal to Al 6, DDA2 and DD
Resume the calculation of A3.

Then, DDAl6 starts drawing a straight line from point 1 to point 2.

Next, when the calculation of point 3 is completed in DDA2, the clock control unit 6 stops the operation, and the DDA2 indicates that the calculation of point 3 has been completed.
The control unit 15 is notified. Further, in the DDA 3, when the calculation at point 4 is completed, the clock control unit 8 stops the operation and notifies the DDA control unit 15 that the calculation at point 4 has been completed.

At this time, if the DDAla is drawing a straight line from point 1 to point 2, a signal indicating that the calculation is being executed is sent to the DDA control unit 16 from the DDA1 6.

The DDA control unit 15 controls the signal when the signal is in a state indicating that no calculation is being performed, that is, when DDAl 6 is set to point 1.
When the drawing of the straight line from to point 2 is completed, a write signal is sent to DDAl6 and the calculations of DDA2 and DDA3 are restarted. Then, DDAl 6 draws a straight line from point 3 to point 4.

When DDA2 finishes calculating the straight line EA, CPU1
The coordinates of point B are sent to DDA2, and DDA2 performs address calculation for straight line AB. Moreover, when DDA3 finishes the address calculation of straight line ED, CPU2 sends the coordinates of point C to DDA3,
DDA3 performs linear DC address calculation.

Then, when drawing is completed up to point C, filling is completed.

If the figure to be filled in is a concave polygon, it goes without saying that the CPU 1 divides it into convex polygons and then fills it.

In addition, when drawing a straight line, the CPU 1 first sends a flag indicating drawing of a straight line to the register 12, and selector 13
and the selector 14 outputs the data from the CPU 1. Then, the coordinates of the starting point and ending point of the straight line are sent to DDAl 8, and the straight line is drawn.

As a result of the invention, it is possible to quickly calculate the starting point of a straight line to be drawn, eliminate the need for dividing polygons, and reduce the number of times data is transferred to the DDA. Therefore, the drawing device of the present invention is extremely useful for filling polygons.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is an explanatory drawing showing an example of filling a polygon, Fig. 3 is a block diagram of a conventional drawing device, and Fig. 4 is a block diagram of a conventional drawing device. FIG. 2 is an explanatory diagram showing an example of filling in a polygon by a drawing device. 1...CPU, 2,3,16...DDA
, 4゜9...DDA operation section, 6, 8...
・Clock control unit, 6.10...X-axis counter, 7, 11...Y-axis counter, 12...
・Register, 13, 14...Selector, 15・
...DDA control unit, 18...Frame memory. Name of agent: Patent attorney Toshio Nakao and 1 other person
3 Figure 4

Claims (1)

[Claims] first and second digital differential analyzers each including a DDA calculation section, an X-axis counter, a Y-axis counter, and a clock control section that controls a clock for operating them;
and a third digital differential analyzer that calculates pixels to be actually drawn from the calculation results of the second digital differential analyzer, and a DDA for controlling the first, second, and third digital differential analyzers. A drawing device, comprising: a controller, and fills a polygon by calculating boundaries of the figure to be filled using the first and second digital differential analyzers.