Home » Archimedes archive » Archimedes World » AW-1991-05.adf » May91 » !AWMay91/Goodies/FiveAlive/BACKSCROLL

!AWMay91/Goodies/FiveAlive/BACKSCROLL

This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.

Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.

Tape/disk: Home » Archimedes archive » Archimedes World » AW-1991-05.adf » May91
Filename: !AWMay91/Goodies/FiveAlive/BACKSCROLL
Read OK:
File size: 0665 bytes
Load address: 0000
Exec address: 0000
File contents
   10REM > BACKSCROLL
   20
   21LIBRARY "SPRITELIB"
   30PROCinit
   60PROCanimate3
   70PROCanimate4
   71MODE 12
   80END
   90
  100DEFPROCinit
  110off=104
  120PROCinit_screen
  130REM Load screen into two screen banks
  140*SCREENLOAD SCREEN
  150PROCswitch_update_bank
  160*SCREENLOAD SCREEN
  170PROCswitch_update_bank
  180PROCinit_sprites("demo",100)
  190ENDPROC
  200
  930DEFPROCanimate3
  940PROCanimate_back("L")
  950ENDPROC
  960
  970DEFPROCanimate4
  980PROCanimate_back("R")
  990ENDPROC
 1000
 1010DEFPROCanimate_back(dir$)
 1020REM Sprite animation with use of screen banking
 1030REM Horizontal animation by moving background rather than
 1040REM sprite
 1050LOCAL X,Y,x,y,xfac,started1,started2,shiftstarted,xstep,back1(),back2(),xshift,shift
 1060started1=FALSE:started2=FALSE:shiftstarted=FALSE:xstep=2:X=0
 1070DIM back1(4),back2(4)
 1080xfac=1240/360:xshift=xfac*xstep
 1090REPEAT
 1100X+=xstep:IF X>360 THEN X=0
 1110Y=SINRAD(X)
 1120x=640-50
 1130y=512+400*Y-50
 1140IF NOT shiftstarted THEN
 1150shift=2*xshift
 1160shiftstarted=TRUE
 1170ELSE
 1180shift=4*xshift
 1190ENDIF
 1200PROCswitch_update_bank
 1210CASE update_bank OF
 1220WHEN 1
 1230IF started1 THEN PROCrestorebox(back1(),"back1")
 1240started1=TRUE
 1250PROCshiftscreen(shift,dir$)
 1260back1(1)=x:back1(2)=y:back1(3)=x+off:back1(4)=y+off
 1270PROCgrabbox(back1(),"back1")
 1280WHEN 2
 1290IF started2 THEN PROCrestorebox(back2(),"back2")
 1300started2=TRUE
 1310PROCshiftscreen(shift,dir$)
 1320back2(1)=x:back2(2)=y:back2(3)=x+off:back2(4)=y+off
 1330PROCgrabbox(back2(),"back2")
 1340ENDCASE
 1350PROCplot_sprite("ball",x,y,8)
 1360PROCswitch_display_bank
 1370UNTIL NOT INKEY(0)
 1380REM Remove sprites from both screens
 1390CASE update_bank OF
 1400WHEN 1
 1410PROCrestorebox(back1(),"back1")
 1420PROCswitch_update_bank
 1430PROCrestorebox(back2(),"back2")
 1440WHEN 2
 1450PROCrestorebox(back2(),"back2")
 1460PROCswitch_update_bank
 1470PROCrestorebox(back1(),"back1")
 1480ENDCASE
 1490PROCswitch_update_bank
 1500ENDPROC
 1510

� > BACKSCROLL

ț "SPRITELIB"
	�init
<
�animate3
F
�animate4
G� 12
P�
Z
d
��init
noff=104
x�init_screen
�'� Load screen into two screen banks
�*SCREENLOAD SCREEN
��switch_update_bank
�*SCREENLOAD SCREEN
��switch_update_bank
��init_sprites("demo",100)
��
�
���animate3
��animate_back("L")
��
�
���animate4
��animate_back("R")
��
�
���animate_back(dir$)
�1� Sprite animation with use of screen banking
;� Horizontal animation by moving background rather than
� sprite
T� X,Y,x,y,xfac,started1,started2,shiftstarted,xstep,back1(),back2(),xshift,shift
$4started1=�:started2=�:shiftstarted=�:xstep=2:X=0
.� back1(4),back2(4)
8#xfac=1240/360:xshift=xfac*xstep
B�
LX+=xstep:� X>360 � X=0
VY=��(X)
`x=640-50
jy=512+400*Y-50
t� � shiftstarted �
~shift=2*xshift
�shiftstarted=�
��
�shift=4*xshift
��
��switch_update_bank
�Ȏ update_bank �
�� 1
�-� started1 � �restorebox(back1(),"back1")
�started1=�
��shiftscreen(shift,dir$)
�7back1(1)=x:back1(2)=y:back1(3)=x+off:back1(4)=y+off
��grabbox(back1(),"back1")
� 2

-� started2 � �restorebox(back2(),"back2")
started2=�
�shiftscreen(shift,dir$)
(7back2(1)=x:back2(2)=y:back2(3)=x+off:back2(4)=y+off
2�grabbox(back2(),"back2")
<�
F�plot_sprite("ball",x,y,8)
P�switch_display_bank
Z� � �(0)
d&� Remove sprites from both screens
nȎ update_bank �
x� 1
� �restorebox(back1(),"back1")
��switch_update_bank
� �restorebox(back2(),"back2")
�� 2
� �restorebox(back2(),"back2")
��switch_update_bank
� �restorebox(back1(),"back1")
��
��switch_update_bank
��
�
�
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00000010  4c 4c 0d 00 14 04 0d 00  15 12 c8 9b 20 22 53 50  |LL.......... "SP|
00000020  52 49 54 45 4c 49 42 22  0d 00 1e 09 f2 69 6e 69  |RITELIB".....ini|
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00000040  46 0d f2 61 6e 69 6d 61  74 65 34 0d 00 47 08 eb  |F..animate4..G..|
00000050  20 31 32 0d 00 50 05 e0  0d 00 5a 04 0d 00 64 0a  | 12..P....Z...d.|
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00000080  6e 0d 00 82 27 f4 20 4c  6f 61 64 20 73 63 72 65  |n...'. Load scre|
00000090  65 6e 20 69 6e 74 6f 20  74 77 6f 20 73 63 72 65  |en into two scre|
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00000100  6e 6b 0d 00 b4 1d f2 69  6e 69 74 5f 73 70 72 69  |nk.....init_spri|
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00000660  05 e6 04 0d ff                                    |.....|
00000665