Implement RNG

src/header.asm

@@ -1,8 +1,4 @@
-; *****************************************************************************
+SECTION "Cartridge Header", ROM0[$100]
-; *                                                                           *
+    nop
-; *  Cartridge Header.                                                        *
+    jp Main
-; *                                                                           *
+    ds $150 - @, 0
-; *****************************************************************************
-SECTION "Header", ROM0[$100]
-    jp MainEntryPoint
-    ds $150 - @, 0 ; RGBFIX will fill in the header.

src/include/rng.asm

@@ -1,34 +1,138 @@
+IF !DEF(RNG_ASM)
+DEF RNG_ASM EQU 1
+
+
+INCLUDE "globals.asm"
+
+
+SECTION "RNG Variables", WRAM0
+wRNGSeed:      ds 4
+wPieceHistory: ds 4
+wNextPiece::   ds 1
+
+
 section "RNG Functions", ROM0
-NextByte::
+StartNewGame::
+    ; Do some bit fuckery on the seed using the gameboy's free-running timers.
+    ld hl, wRNGSeed
+    ldh a, [rDIV]
+    xor a, [hl]
+    ld [hl+], a
+
+    ldh a, [rTIMA]
+    xor a, [hl]
+    ld [hl+], a
+
+    ldh a, [rDIV]
+    xor a, [hl]
+    ld [hl+], a
+
+    ldh a, [rTIMA]
+    xor a, [hl]
+    ld [hl], a
+
+    ; Initialize the next history.
+    ld hl, wPieceHistory
+    ld a, PIECE_Z
+    ld [hl+], a
+    ld [hl+], a
+    ld a, PIECE_S
+    ld [hl+], a
+    ld [hl], a
+
+    ; Get the first piece and make sure it's not Z, S or O.
+:   call NextPiece
+    cp a, PIECE_Z
+    jr z, :-
+    cp a, PIECE_S
+    jr z, :-
+    cp a, PIECE_O
+    jr z, :-
+
+    ; Store it.
+    ld hl, wPieceHistory
+    ld [hl], a
+    ld hl, wNextPiece
+    ld [hl], a
+    ret
+
+
+GetNextPiece::
+    ld e, 7
+:   dec e
+    jr z, :+
+
+    call NextPiece
+    ld hl, wPieceHistory
+    cp a, [hl]
+    jr z, :-
+    inc hl
+    cp a, [hl]
+    jr z, :-
+    inc hl
+    cp a, [hl]
+    jr z, :-
+    inc hl
+    cp a, [hl]
+    jr z, :-
+
+:   ld hl, wNextPiece
+    ld [hl], a
+    ld b, a
+    ld hl, wPieceHistory+2
+    ld a, [hl+]
+    ld [hl], a
+    ld hl, wPieceHistory+1
+    ld a, [hl+]
+    ld [hl], a
+    ld hl, wPieceHistory
+    ld a, [hl+]
+    ld [hl-], a
+    ld a, b
+    ld [hl], a
+    ret
+
+
+NextPiece:
+    call NextByte
+    and a, $07
+    cp a, 7
+    ret nz
+    dec a
+    ret
+
+NextByte:
     ; Load seed
     ld hl,wRNGSeed+3
-    ld a,[hl-]
+    ld a, [hl-]
-    ld b,a
+    ld b, a
-    ld a,[hl-]
+    ld a, [hl-]
-    ld c,a
+    ld c, a
-    ld a,[hl-]
+    ld a, [hl-]
 
     ; Multiply by 0x01010101
     add [hl]
-    ld d,a
+    ld d, a
     adc c
-    ld c,a
+    ld c, a
     adc b
-    ld b,a
+    ld b, a
 
     ; Add 0x31415927 and write back
-    ld a,[hl]
+    ld a, [hl]
     add $27
-    ld [hl+],a
+    ld [hl+], a
-    ld a,d
+    ld a, d
     adc $59
-    ld [hl+],a
+    ld [hl+], a
-    ld a,c
+    ld a, c
     adc $41
-    ld [hl+],a
+    ld [hl+], a
-    ld c,a
+    ld c, a
-    ld a,b
+    ld a, b
     adc $31
-    ld [hl],a
+    ld [hl], a
-    ld b,a
     ret
+
+
+ENDC

src/main.asm

@@ -1,18 +1,21 @@
 INCLUDE "globals.asm"
-INCLUDE "memcpy.asm"
+INCLUDE "memory.asm"
-INCLUDE "hardwarectl.asm"
 INCLUDE "interrupts.asm"
 INCLUDE "sprites.asm"
+INCLUDE "rng.asm"
 INCLUDE "res/tiles.inc"
 INCLUDE "res/gameplay_map.inc"
 
 SECTION "Code Entry Point", ROM0
-MainEntryPoint::
+Main::
     ; Turn off LCD during initialization.
-    call DisableLCD
+    wait_vram
+    xor a, a
+    ldh [rLCDC], a
 
     ; Save some power and turn off the audio.
-    call DisableAudio
+    xor a, a
+    ldh [rNR52], a
 
     ; We use a single set of tiles for the entire game, so we copy it at the start.
     ld de, Tiles
@@ -27,7 +30,9 @@ MainEntryPoint::
     call UnsafeMemCopy
 
     ; Make sure both sprites and bg use the same tile data.
-    call SetTileDataBanks
+    ldh a, [rLCDC]
+    or LCDCF_BLK01
+    ldh [rLCDC], a
 
     ; The tilemap is just for testing for now.
     ld de, GameplayTilemap
@@ -44,6 +49,11 @@ MainEntryPoint::
     ld a, PALETTE_REGULAR
     set_all_palettes
 
+    ; Get the timer going. It's used for RNG.
+    xor a, a
+    ldh [rTMA], a
+    ld a, TACF_262KHZ | TACF_START
+
     ; Zero out the ram where needed.
     call InitializeVariables
 
@@ -51,12 +61,17 @@ MainEntryPoint::
     call InitializeLCDCInterrupt
 
     ; And turn the LCD back on before we start.
-    call EnableLCD
+    ldh a, [rLCDC]
+    or LCDCF_ON | LCDCF_BGON | LCDCF_OBJON
+    ldh [rLCDC], a
 
     ; Make sure the first game loop starts just like all the future ones.
     wait_vblank
     wait_vblank_end
 
+    ; TEMP: Set up the game.
+    call StartNewGame
+
 
 GameLoop::
     call GetInput
@@ -65,10 +80,18 @@ GameLoop::
     ; Handle gameplay here
     ; TODO
 
-    ld a, 0
+    ldh a, [hCtr]
+    inc a
+    and a, $1F
+    ldh [hCtr], a
+
+    jr nz, :+
+    call GetNextPiece
+
+:   ld a, [wNextPiece]
     call ApplyNext
 
-    ld a, 4
+    ld a, [wNextPiece]
     call ApplyHold
 
     ld hl, wSPRScore1

tools/Emulicious.ini

@@ -1,5 +1,5 @@
 #Emulicious settings file
-#Wed Oct 11 08:17:53 CEST 2023
+#Fri Oct 13 08:36:54 CEST 2023
 SouthPanelHeight=635
 GameBoyErrorBreakpointMessage6=
 GameBoyErrorBreakpointMessage5=
@@ -46,7 +46,7 @@ GameBoyErrorBreakpointEnabled3=false
 Gamepad0Key5=-1
 GameBoyErrorBreakpointEnabled2=false
 Gamepad0Key4=-1
-WindowVideoViewerOpen=true
+WindowVideoViewerOpen=false
 GameBoyErrorBreakpointEnabled1=false
 Gamepad0Key3=-1
 GameBoyErrorBreakpointEnabled0=false
@@ -63,7 +63,7 @@ WindowEventViewerWindowY=489
 WindowEventViewerWindowX=1472
 WindowSpriteViewerHeight=527
 WindowSpriteViewerWidth=370
-DebuggerWestPanelSelectedTab=1
+DebuggerWestPanelSelectedTab=0
 WindowMemoryTracerWindowHeight=289
 Gamepad0Key37=-1
 Gamepad0Key36=-1
@@ -76,7 +76,7 @@ Gamepad0Key32=-1
 Gamepad0Key31=-1
 Gamepad0Key30=-1
 DebuggerSouthPanelSelectedTab=0
-StackWidth=940
+StackWidth=1311
 SMSGamepadAKeyboard=false
 GameBoyErrorBreakpointCondition19=
 GameBoyErrorBreakpointCondition18=
@@ -148,33 +148,33 @@ Gamepad1Key21=-1
 Gamepad1Key20=-1
 StackSplitLocation=320
 FontSize=13
-CombineVideoViewers=true
-WindowEmuliciousHeight=781
 CodeFontSize=13
+WindowEmuliciousHeight=781
+CombineVideoViewers=true
 WindowTilemapViewerY=544
-MemoryTracer=true
-GBGamepadKeyboard=false
-UninitializedMemoryBreakpointSuspend=true
 WindowTilemapViewerX=1013
+UninitializedMemoryBreakpointSuspend=true
+GBGamepadKeyboard=false
+MemoryTracer=true
 SMSGamepadBKeyboard=false
 DebuggerConsoleLogBreakpoints=true
 SMSGamepadBThreshold=50
 Gamepad1Key19=-1
-Gamepad1Key18=-1
 BankSwapAtPCBreakpointEnabled=false
+Gamepad1Key18=-1
 Gamepad1Key17=-1
-WindowPaletteViewerWidth=485
 Gamepad1Key16=-1
-Gamepad1Key15=-1
+WindowPaletteViewerWidth=485
-Recent0=C\:\\workspace\\dmgtris\\bin\\out.gb
 GameBoyErrorBreakpointSuspend32=true
+Recent0=C\:\\workspace\\dmgtris\\bin\\out.gb
+Gamepad1Key15=-1
 Gamepad1Key14=-1
 Gamepad1Key13=-1
 Gamepad1Key12=-1
-Gamepad1Key11=-1
 GameBoyErrorBreakpointSuspend9=true
-Gamepad1Key10=-1
+Gamepad1Key11=-1
 GameBoyErrorBreakpointSuspend8=true
+Gamepad1Key10=-1
 GameBoyErrorBreakpointSuspend7=true
 GameBoyErrorBreakpointSuspend6=true
 GameBoyErrorBreakpointSuspend5=true
@@ -184,73 +184,73 @@ GameBoyErrorBreakpointSuspend2=true
 GameBoyErrorBreakpointSuspend1=true
 GameBoyErrorBreakpointSuspend0=true
 Scale=5.0
-DebuggerMemorySelectedAddress=0
+DebuggerMemorySelectedAddress=390
 WindowEmuliciousWidth=816
 GameBoyErrorBreakpointSuspend20=true
 DataExecutionBreakpointCondition=
-GameBoyErrorBreakpointMessage32=
-BankSwapAtPCBreakpointCondition=
 WindowTilemapViewerWidth=404
+BankSwapAtPCBreakpointCondition=
+GameBoyErrorBreakpointMessage32=
 SMSbuttonsThreshold=50
 WindowTileViewerY=549
-Gamepad1Key9=-1
 WindowTileViewerX=271
-Gamepad1Key8=-1
+Gamepad1Key9=-1
 UninitializedMemoryBreakpointCondition=
-Gamepad1Key7=-1
+Gamepad1Key8=-1
 GameBoyErrorBreakpointSuspend19=true
-Gamepad1Key6=-1
+Gamepad1Key7=-1
 GameBoyErrorBreakpointSuspend18=true
-Gamepad1Key5=-1
+Gamepad1Key6=-1
 GameBoyErrorBreakpointSuspend17=true
-Gamepad1Key4=-1
+Gamepad1Key5=-1
 GameBoyErrorBreakpointSuspend16=true
-WindowVideoViewerY=275
+Gamepad1Key4=-1
 Gamepad1Key3=-1
-WindowVideoViewerX=946
+WindowVideoViewerY=275
 Gamepad1Key2=-1
+WindowVideoViewerX=946
 Gamepad1Key1=-1
 Gamepad1Key0=-1
 GameBoyErrorBreakpointSuspend10=true
-WindowTilemapViewerHeight=744
 WindowEventViewerWindowDivider=309
+WindowTilemapViewerHeight=744
 GameBoyErrorBreakpointMessage20=
-MemoryTracerDisplayFileOffsetsForROM=true
 WindowTileViewerWidth=467
-WindowDebuggerY=158
+MemoryTracerDisplayFileOffsetsForROM=true
-WindowDebuggerX=939
+WindowDebuggerY=189
+WindowDebuggerX=1113
 Key37=-1
 Key36=-1
-Key35=-1
-GameBoyErrorBreakpointCondition9=
-GameBoyErrorBreakpointEnabled32=false
 WindowTileViewerOpen=false
-Key34=-1
+GameBoyErrorBreakpointEnabled32=false
+GameBoyErrorBreakpointCondition9=
+Key35=-1
 GameBoyErrorBreakpointCondition8=
-Key33=-1
+Key34=-1
-GameBoyErrorBreakpointMessage19=
 GameBoyErrorBreakpointCondition7=
-Key32=-1
+GameBoyErrorBreakpointMessage19=
-GameBoyErrorBreakpointCondition6=
+Key33=-1
-GameBoyErrorBreakpointMessage18=
 DebuggerMemoryTabVisibleRect=0,0,0,0
-Key31=-1
+GameBoyErrorBreakpointMessage18=
-GameBoyErrorBreakpointCondition5=
+GameBoyErrorBreakpointCondition6=
-GameBoyErrorBreakpointMessage17=
+Key32=-1
-OutlineWidth=425
 WindowEventViewerWindowWidth=930
-Key30=-1
+OutlineWidth=425
-GameBoyErrorBreakpointCondition4=
+GameBoyErrorBreakpointMessage17=
+GameBoyErrorBreakpointCondition5=
+Key31=-1
 GameBoyErrorBreakpointMessage16=
+GameBoyErrorBreakpointCondition4=
+Key30=-1
 GameBoyErrorBreakpointCondition3=
 GameBoyErrorBreakpointCondition2=
-GameBoyErrorBreakpointCondition1=
 Key9=40
-GameBoyErrorBreakpointCondition0=
+GameBoyErrorBreakpointCondition1=
 Key8=38
+GameBoyErrorBreakpointCondition0=
 Key7=83
-Key6=87
 GameBoyErrorBreakpointMessage10=
+Key6=87
 Key5=65
 Key4=68
 Key3=10
@@ -262,21 +262,21 @@ Update=2
 Key29=-1
 Key28=10
 Key27=-1
-WindowSpriteViewerOpen=false
 Key26=-1
+WindowSpriteViewerOpen=false
 Key25=-1
-Key24=-1
 WindowTileViewerHeight=453
-Key23=10
+Key24=-1
 GameBoyErrorBreakpointEnabled20=false
+Key23=10
 Key22=-1
 Key21=-1
-Key20=-1
 BankSwapAtPCBreakpointSuspend=true
-WindowEmuliciousY=376
+Key20=-1
-WindowEmuliciousX=146
+WindowEmuliciousY=489
-DebuggerMemorySelectedTab=HRAM
+WindowEmuliciousX=666
-WindowDebuggerWidth=1110
+DebuggerMemorySelectedTab=RAM
+WindowDebuggerWidth=1481
 GameBoyErrorBreakpointMessage9=
 GameBoyErrorBreakpointMessage8=
 GameBoyErrorBreakpointMessage7=