HP 39gs - 14 Variables and memory management; Introduction; Graphic commands

Programming 18-21
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:
→
DISPLAY Displays graphic from graphicname in the display.
→DISPLAY graphicname:
→GROB Creates a graphic from expression, using font_size, and
stores the resulting graphic in graphicname. Font sizes
are 1, 2, or 3. If the fontsize argument is 0, the HP 39gs
creates a graphic display like that created by the SHOW
operation.
→GROB graphicname;expression; fontsize:
GROBNOT Replaces graphic in graphicname with bitwise-inverted
graphic.
GROBNOT graphicname:
GROBOR Using the logical OR, superimposes graphicname2 onto
graphicname1. The upper left corner of graphicname2 is
placed at position.
GROBOR graphicname1;(position);graphicname2:
Example
GROBOR G0; (1,1); G1:
HP 39gs English.book Page 21 Wednesday, December 7, 2005 11:24 PM