Chapter 2 Graphics Tutorial
2-30
Figure 2. 31. A Closed Path
Filled Areas
!R! RES; UNIT C;
NEWP;
GPAT .5;
PMZP 4, 2;
PARC 3, 3, 1, 90, 270;
PARC 5, 3, 1, 270, 90;
FILL 1;
PAGE;
EXIT;
This program is similar to the previous one. In this case, we choose to fill the path
instead of stroking it. We select a shade of gray for filling the path (.5, a value directly
between black and white) with the GPAT (set Gray PATtern) command on line 3.
First, we construct the path by drawing arcs around the center points. However, we will
not close it explicitly.
Then we execute the FILL command. This implicitly closes the path, drawing a line
between the ending point of the second arc and the starting point of the first one, then
fills the closed path with the selected gray scale pattern.
Note that we could have filled the path with a standard mode fill pattern instead of a
gray-scale pattern. The only change necessary would be to replace the GPAT command
on line 3 with a PAT or FPAT command specifying the pattern to be used.
The format of the FILL command is
FILL rule;
The rule parameter specifies the convention according to which the path is filled.
To Next Page
Loading...
Need help?
General