HP 39g+, User Manual

Page: 230 / 294

16-20 Programming
ERASE
Clears the display
ERASE:
FREEZE
Halts the program, freezing the current display.
Execution resumes when any key is pressed.
LINE
Draws a line from
(x1, y1)
to
( x2, y2 )
.
LINE
x1;y1;x2;y2:
PIXOFF
Turns off the pixel at the specified coordinates
(x,y)
.
PIXOFF
x;y:
PIXON
Turns on the pixel at the specified coordinates
(x,y)
.
PIXON
x;y:
TLINE
Toggles the pixels along the line from
(x1, y1)
to
( x2, y2 )
on and off. Any pixel that was turned off, is turned on;
any pixel that was turned on, is turned off. TLINE can be
used to erase a line.
TLINE
x1;y1;x2;y2:
Example
TLINE 0;0;3;3:
Erases previously drawn 45 degree line from (0,0) to
(3,3), or draws that line if it doesn’t already exist.
Graphic commands
The graphic commands use the graphics variables G0
through G9—or the Page variable from Sketch—as
graphicname arguments. The position argument takes the
form (
x,y
). Position coordinates depend on the current
aplet’s scale, which is specified by Xmin, Xmax, Ymin,
and Ymax. The upper left corner of the target graphic
(
graphic2 ) is at (Xmin,Ymax).
You can capture the current display and store it in G0 by
simultaneously pressing
+ .
DISPLAY
→
Stores the current display in graphicname .
DISPLAY
→
graphicname :