mirror of
https://github.com/lscharen/iigs-game-engine.git
synced 2024-06-02 07:41:35 +00:00
62 lines
2.0 KiB
ArmAsm
62 lines
2.0 KiB
ArmAsm
; 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
|
|
ScreenTileHeight equ 12 ; Height of the playfield in 8x8 blocks
|
|
ScreenTileWidth equ 14 ; Width of the playfield in 8x8 blocks
|
|
|
|
StartX equ 16 ; Which code buffer byte is the left edge of the screen. Range = 0 to 167
|
|
StartY equ 18 ; Which code buffer line is the top of the screen. Range = 0 to 207
|
|
EngineMode equ 20 ; Defined the mode/capabilities that are enabled
|
|
; bit 0: 0 = Single Background, 1 = Parallax
|
|
DirtyBits equ 22 ; Identify values that have changed between frames
|
|
|
|
BG1DataBank equ 24 ; Data bank that holds BG1 layer data
|
|
BlitterDP equ 26 ; Direct page address the holder blitter data
|
|
|
|
OldStartX equ 28
|
|
OldStartY equ 30
|
|
|
|
LastPatchOffset equ 32 ; Offset into code field that was patched with BRA instructions
|
|
StartXMod164 equ 34
|
|
|
|
bstk equ 208 ; 16-byte stack to push bank addresses
|
|
|
|
tmp8 equ 224
|
|
tmp9 equ 226
|
|
tmp10 equ 228
|
|
|
|
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
|
|
|
|
DIRTY_BIT_BG0_X equ $0001
|
|
DIRTY_BIT_BG0_Y equ $0002
|
|
DIRTY_BIT_BG1_X equ $0004
|
|
DIRTY_BIT_BG1_Y equ $0008
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|