feat: add Memset, clear memory at init

main.asm

@@ -27,13 +27,13 @@ WaitVBlank:
 	call InitSprObjLib
 
 	; Reset hardware OAM
-	xor a, a
+	ld a, 0
 	ld b, 160
 	ld hl, _OAMRAM
 .resetOAM
 	ld [hli], a
 	dec b
-	jr nz, .resetOAM
+	jp nz, .resetOAM
 
 	; Copy cat sprite
 	ld de, GfxCat
@@ -42,47 +42,15 @@ WaitVBlank:
 	call Memcopy
 
 	; Reset positions
-	ld hl, wMetaspritePosition.x
-	ld a, $10
+	ld d, 0
+	ld hl, wMetaspriteBegin
+	ld bc, wMetaspriteEnd - wMetaspriteBegin
+	call Memset
+
+	; Clear player data
+	ld a, $F0
 	ld [wMetaspritePosition.x], a 
-	ld a, $0
-	ld [wMetaspritePosition.x + 1], a
-
-	ld hl, wMetaspritePosition.y
-	ld a, $10
 	ld [wMetaspritePosition.y], a
-	ld a, $01
-	ld [wMetaspritePosition.y + 1], a
-
-	ld hl, wMetaspritePosition.z
-	ld a, $00
-	ld [wMetaspritePosition.z], a 
-	ld a, $0
-	ld [wMetaspritePosition.z + 1], a 
-
-	; Reset velocity
-	ld hl, wMetaspriteVelocity.x
-	ld a, $0
-	ld [wMetaspriteVelocity.x], a
-	ld a, $0
-	ld [wMetaspriteVelocity.x + 1], a
-
-	ld hl, wMetaspriteVelocity.y
-	ld a, $0
-	ld [wMetaspriteVelocity.y], a
-	ld a, $0
-	ld [wMetaspriteVelocity.y + 1], a
-
-	ld hl, wMetaspriteVelocity.z
-	ld a, $0
-	ld [wMetaspriteVelocity.z], a 
-	ld a, $0
-	ld [wMetaspriteVelocity.z + 1], a 
-
-	ld hl, wMetaspriteVelocity.boost
-	ld a, $0
-	ld [wMetaspriteVelocity.boost], a 
-	ld [wMetaspriteVelocity.boosting], a 
 
 	; Copy the tile data
 	ld de, Tiles
@@ -90,12 +58,17 @@ WaitVBlank:
 	ld bc, TilesEnd - Tiles
 	call Memcopy
 
-	; Copy the tilemap
-	ld de, Tilemap
+	; Clear the tilemap
 	ld hl, $9800
-	ld bc, TilemapEnd - Tilemap
-	call Memcopy
+	ld bc, (32 * 20)
+	ld d, 0
+	call Memset
 
+	; Clear shadown OAM
+	ld hl, wShadowOAM
+	ld bc, 160
+	ld d, 0
+	call Memset
 	
 	; Turn the LCD on
 	ld a, LCDCF_ON | LCDCF_BGON | LCDCF_OBJON | LCDCF_OBJ8
@@ -363,7 +336,7 @@ UpdateJoypadState::
 	ld [wJoypadState], a
 	ret
 
-SECTION "MemCopy Routine", ROM0
+SECTION "Memcopy Routine", ROM0
 Memcopy::
 	dec bc
 	inc b
@@ -378,6 +351,23 @@ Memcopy::
 	jr nz, .loop
 	ret  
 
+; @param hl - Location
+; @param bc - Length
+; @param d - Value
+SECTION "Memset Routine", ROM0
+Memset::
+	dec bc
+	inc b
+	inc c
+.loop:
+	ld a, d
+	ld [hli], a
+	dec c
+	jr nz, .loop
+	dec b
+	jr nz, .loop
+	ret  
+
 SECTION "VBlank Interrupt", ROM0[$0040]
 VBlankInterrupt:
 	; Store registers to prevent clobbering
@@ -391,17 +381,6 @@ SECTION "VBlank Handler", ROM0
 VBlankHandler:
 	ldh a, [hFrameCounter]
 
-	/*
-	bit 5, a
-
-	ld a, %11100100
-
-	jr z, .skipCpl
-	cpl ; Invert a
-.skipCpl:
-	ldh [rBGP], a
-	*/
-
 	ld a, HIGH(wShadowOAM)
 	call hOAMDMA
 
@@ -416,7 +395,6 @@ SECTION "Frame Counter", HRAM
 hFrameCounter: 
 	db
 
-
 SECTION "Tile data", ROM0
 
 Tiles:
@@ -429,6 +407,52 @@ Tilemap:
 	INCBIN "tileset.tilemap"
 TilemapEnd:
 
+SECTION "Level data", ROM0
+	db $03 ; width
+	db $03 ; height
+
+	; Each byte stores whether it is solid or not
+
+	; Z = 1
+	db $01
+	db $01
+	db $01
+
+	db $01
+	db $01
+	db $01
+
+	db $01
+	db $01
+	db $00
+
+	; Z = 2
+	db $01
+	db $01
+	db $01
+
+	db $01
+	db $01
+	db $01
+
+	db $00
+	db $00
+	db $00
+
+	; Z = 3
+	db $01
+	db $00
+	db $00
+
+	db $00
+	db $00
+	db $00
+
+	db $00
+	db $00
+	db $00
+
+
 SECTION "Graphics", ROM0
 GfxCat:
 	INCBIN "sprites.2bpp"
@@ -444,6 +468,7 @@ ShadowMetasprite:
 	db 128
 
 SECTION "Position Vars", WRAM0 
+ wMetaspriteBegin:
 ; Q12.4 fixed-point X posiition
 wMetaspritePosition::
 .x:
@@ -465,6 +490,7 @@ wMetaspriteVelocity::
 	db
 .boosting:
 	db
+ wMetaspriteEnd:
 
 SECTION "Joypad Vars", WRAM0
 wJoypadState: