85 lines
1.5 KiB
NASM
85 lines
1.5 KiB
NASM
IF !DEF(MAIN_ASM)
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DEF MAIN_ASM EQU 1
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INCLUDE "globals.asm"
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INCLUDE "res/tiles.inc"
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INCLUDE "res/gameplay_map.inc"
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INCLUDE "res/title_map.inc"
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SECTION "Globals", HRAM
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hGameState:: ds 1
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hSwapAB:: ds 1
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SECTION "Stack", WRAM0
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wStack::
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ds STACK_SIZE + 1
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wStackEnd::
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SECTION "Code Entry Point", ROM0
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Main::
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; Turn off LCD during initialization.
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wait_vram
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xor a, a
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ldh [rLCDC], a
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; Set up stack
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ld sp, wStackEnd-1
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; We use a single set of tiles for the entire game, so we copy it at the start.
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ld de, Tiles
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ld hl, _VRAM
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ld bc, TilesEnd - Tiles
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call UnsafeMemCopy
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; Clear OAM.
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call ClearOAM
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call SetNumberSpritePositions
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call CopyOAMHandler
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; Zero out the ram where needed.
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xor a, a
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ldh [hSwapAB], a
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call TimeInit
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call IntrInit
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call InputInit
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call SFXInit
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; Set up the interrupt handlers.
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call InitializeLCDCInterrupt
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; Switch to gameplay state.
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call SwitchToTitle
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EventLoop::
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; Play the sound effect, if any.
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call SFXPlay
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; Wrangle inputs and timers at the start of every frame.
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call GetInput
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call HandleTimers
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; Call the current state's event handler.
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ld b, 0
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ldh a, [hGameState]
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cp a, b
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jp nz, GamePlayEventLoopHandler
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jp TitleEventLoopHandler
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EventLoopPostHandler::
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; Wait for vblank.
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wait_vblank
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; Do OAM DMA.
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; This will chain jump into the vblank handler.
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jp hOAMDMA
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; The VBlank Handler is expected to end with jp EventLoop.
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ENDC
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