This module is part of the original MMBasic library. It is reproduced here with kind permission of Hugh Buckle and Geoff Graham. Be aware it may reference functionality which has changed or is deprecated in the latest versions of MMBasic.
'------------------------------------------------------------------------------
' SPRITE DEMONSTRATION
'
' by Nickolas Marentes
'
' June 2013
'------------------------------------------------------------------------------
Mode 3 ' Set video mode
LoadBMP"backdrop" ' Load backdrop image
Sprite Load "sprites" ' Load sprite definitions
Dim p(8,4) ' Define array size
For n=1 To 8 ' Set all 8 sprites data
p(n,1)=n*25+125 ' X co-ordinate
p(n,2)=216 ' Y co-ordinate
p(n,3)=Fix(Rnd*4)+1 ' Random 4 direction
Sprite on n,n*25+125,216 ' Turn on sprite
Next n
GAMELOOP:
For n=1 To 8 ' Start of main game loop
MOVEGHOST:
On p(n,3) GoTo LEFT,RIGHT,UP,DOWN ' Branch to direction
LEFT: ' Move sprite left
Sprite copy 11+b To n ' Copy sprite buffer graphics
p(n,1)=p(n,1)-1 ' Decrement X co-ordinate
GoTo REDRAW ' Branch to sprite redraw
RIGHT: ' Move sprite right
Sprite copy 9+b To n ' Copy sprite buffer graphics
p(n,1)=p(n,1)+1 ' Increment X co-ordinate
GoTo REDRAW ' Branch to sprite redraw
UP: ' Move sprite up
Sprite copy 13+b To n ' Copy sprite buffer graphics
p(n,2)=p(n,2)-1 ' Decrement Y co-ordinate
GoTo REDRAW ' Branch to sprite redraw
DOWN: ' Move sprite down
Sprite copy 15+b To n ' Copy sprite buffer graphics
p(n,2)=p(n,2)+1 ' Increment Y co-ordinate
REDRAW:
Sprite move n,p(n,1),p(n,2) ' Move current sprite
If Collision(n,edge)>0 Then GoTo BOUNCE ' Test for edge of screen
If Collision(n,sprite)>0 Then GoTo BOUNCE ' Test for another sprite
If Rnd>.99 Then p(n,3)=Fix(Rnd*4)+1 ' Randomly decide to turn
Next n ' Loop back for next sprite
c=c+1 ' Counter for sprite animate
If c>8 Then b=b Xor 1:c=0 ' Sets speed of animation
GoTo GAMELOOP ' Do it all again
BOUNCE: ' reverse sprite direction
p(n,3)=p(n,3)+1 ' Reverse direction
If p(n,3)=3 Then p(n,3)=1
If p(n,3)=5 Then p(n,3)=3
GoTo MOVEGHOST ' Go back to redraw sprite