5 PG
There is a special mode of operation, the pol?gon mode, in which many commands are not executed but store the path they would otherwise draw in the polygon buffer. The path is stored by storing the coordinates of all point traversed, together with the pen up/down condition. When a appropriate command is given, the paths are drawn as if they formed a single path (which is not necessarily connected).
The Star LaserPrinter 4111has a buffer capable of storing 1500 points, with pen up and down commands stored as points.
The following commands clear the polygon buffer and then use it to draw:
EA.ER,EW, RA, RR, WG.
The following commands use the polygon buffer when in the polygon mode:
AA, AR, AT, CI, PA, PD, PE, PR, PU, RT.
Other commands, if given in the polygon mode, are ignored.
If the polygon buffer overflows while executing a drawing (or edging) command, EPis executed. If the polygon buffer overflows while executing a filling command, FP is executed. Points that cannot fit in the buffer are ignored.
E r a c
EA x, ? [;]
This command draws a rectangle with the current cursor position as one corner and the diagonally opposite corner at x, }’.
This command clears the polygon buffer, then uses the buffer to draw.
E p c
EP [;]
This command draws the edge of the polygon stored in the polygon buffer (parts with the pen down). The contents of the buffer are not changed or deleted.
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