Apple-2gs-SW/iigs-game-engine
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Store scrren width and height in tiles

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Lucas Scharenbroich 2021-03-24 06:36:47 -05:00
parent 04f202c9f8
commit 89c9a5c791
1 changed files with 20 additions and 16 deletions
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36
src/blitter/DirectPage.s
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@ -1,23 +1,27 @@
; Direct page locations used by the engine
ScreenHeight equ 0 ; Height of the playfield in scan lines
ScreenWidth equ 2 ; Width of the playfield in bytes
ScreenY0 equ 4 ; First vertical line on the physical screen of the playfield
ScreenY1 equ 6 ; End of playfield on the physical screen. If the height is 20 and Y0 is
ScreenX0 equ 8 ; 100, then ScreenY1 = 120.
ScreenX1 equ 10
ScreenHeight equ 0 ; Height of the playfield in scan lines
ScreenWidth equ 2 ; Width of the playfield in bytes
ScreenY0 equ 4 ; First vertical line on the physical screen of the playfield
ScreenY1 equ 6 ; End of playfield on the physical screen. If the height is 20 and Y0 is
ScreenX0 equ 8 ; 100, then ScreenY1 = 120.
ScreenX1 equ 10
ScreenTileHeight equ 12 ; Height of the playfield in 8x8 blocks
ScreenTileWidth equ 14 ; Width of the playfield in 8x8 blocks
StartY equ 12 ; Which code buffer line displays first on screen. Range = 0 to 207
StartY equ 16 ; Which code buffer line displays first on screen. Range = 0 to 207
bstk equ 224 ; 16-byte stack to push bank addresses
tmp0 equ 240 ; 16 bytes of temporary space to be used as scratch
tmp1 equ 242
tmp2 equ 244
tmp3 equ 246
tmp4 equ 248
tmp5 equ 250
tmp6 equ 252
tmp7 equ 254
bstk equ 224 ; 16-byte stack to push bank addresses
tmp0 equ 240 ; 16 bytes of temporary space to be used as scratch
tmp1 equ 242
tmp2 equ 244
tmp3 equ 246
tmp4 equ 248
tmp5 equ 250
tmp6 equ 252
tmp7 equ 254