Chapter 2 Graphics Tutorial
2-18
Drawing Lines
The following example shows how to draw a line in the path mode.
!R! RES;
NEWP;
PMZP 1, 1;
PDZP 2, 3;
STRK;
PAGE;
EXIT;
Figure 2. 14. Drawing Lines in Path Mode
Line 1 of the program switches the printing system to the PRESCRIBE mode and resets
printing system parameters, including the unit (to inches), line width (to 3 dots), and var-
ious other aspects of the graphics state.
Path construction begins with the NEWP command on line 2. This command empties the
current path (if any), making it possible to start a new one. In doing so, it makes the posi-
tion of the cursor undefined.
The PMZP (Path, Move to Zero-relative Position) command on line 3 moves the cursor
to a position one inch from the top and left edge limits of the paper. The coordinates
specified may be positive or negative.
On line 4, the PDZP (Path, Draw to Zero-relative Position) draws a line from the current
cursor position to the position 2 inches from the left edge limit and 3 inches from the top
edge limit. The cursor remains at this position after the line is drawn.
On line 5, the STRK command strokes the path onto the page.
After stroking the current path, the STRK command clears the path in the same manner
as NEWP (start NEW Path).
Finally, PAGE prints out the page, allowing us to look at the result of our work and can-
celling all changes made during the course of the program, then EXIT ends the PRE-
SCRIBE mode.
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