Texas Instruments TI-89 - Page 37

EndIf
return {xd,yd,dr,dd}
EndFunc
©=================
© Begin mainline
©=================
StoGDB gdb © Save graph database settings
GetMode("ALL")→modedb © Save mode settings
setMode("3","1") © Set Angle mode to radians
ClrDraw © Clear all plots, functions and drawings
ClrGraph
PlotsOff
FnOff
SetGraph("3","1") © Turn grid off
SetGraph("4","1") © Turn axes off
DispG © Display graph screen
© Initialize calculator-specific parameters
if getconfg()[dim(getconfg())-14]=240 then © Determine calculator model by screen width
239→main\±x © For TI-92+: set maximum x-dimension
103→main\±y © set maximum y-dimension
111→ko © set [O] key code
109→km © set [M] key code
104→kh © set [H] key code
8273→khm © set [HOME] key code
.013772→main\±scl © set scale factor in inches/pixel
else
159→main\±x © For TI-89: set maximum x-dimension
77→main\±y © set maximum y-dimension
45→ko © set [O] key code
53→km © set [M] key code
56→kh © set [H] key code
277→khm © set [HOME] key code
.01381→main\±scl © set scale factor in inches/pixel
endif
© Initialize cursor positions
10→main\±ox © Set origin cursor 'x' 10 pixels from screen left
main\±y-10→main\±oy © Set origin cursor 'y' 10 pixels above screen bottom
intdiv(main\±x,2)→main\±tx © Set target cursor to center of screen
intdiv(main\±y,2)→main\±ty
1→mode © Set mode to move target cursor
draw_all() © Redraw cursors
help() © Display 'help'
© Main loop
Loop
GetKey()→key © Get pressed key code
If key=264 or key=khm or key=4360:Exit © Exit program
© Handle cursor movement keys
If key=340 Then © [RIGHT]
move_x(mode,1) © Move cursor 1 pixel right
draw_all() © Update screen
ElseIf key=337 Then © [LEFT]
move_x(mode,⁻1) © Move cursor 1 pixel left
draw_all() © Update screen
ElseIf key=338 Then © [UP]
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