feat: add boost, fix: make velocity work

main.asm

@@ -79,6 +79,11 @@ WaitVBlank:
 	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
 	ld hl, $9000
@@ -179,19 +184,42 @@ HandleInput::
 	ld [wMetaspritePosition.y+1], a
 .downend: 
 
+	; Skip jump code if not on ground
+	ld a, [wMetaspritePosition.z]
+	ld b, a
+	ld a, [wMetaspritePosition.z + 1]
+	or a, b
+	jr nz, .jumpend
+
+	; While on ground, set boost
+	ld a, $8
+	ld [wMetaspriteVelocity.boost], a
+
 	ld a, [wJoypadPressed]
 	bit PADB_A, a
-	jr z, .jumpend
+	jr z, .boostclear
 
 	ld a, [wMetaspriteVelocity.z]
-	sub a, $F0
+	sub a, $20
 	ld b, a
 	ld [wMetaspriteVelocity.z], a
 	ld a, [wMetaspriteVelocity.z+1]
 	sbc a, $00
 	ld c, a
 	ld [wMetaspriteVelocity.z+1], a 
+	jr .boostend
 .jumpend:
+	ld a, [wJoypadState]
+	bit PADB_A, a
+	jr z, .boostclear
+	ld a, $FF
+	ld [wMetaspriteVelocity.boosting], a
+	jr .boostend
+.boostclear:
+	ld a, $00
+	ld [wMetaspriteVelocity.boosting], a 
+.boostend:
+
 	ret
 
 HandleRender::
@@ -241,12 +269,24 @@ HandlePhysics::
 	ld b, a
 	ld a, [wMetaspritePosition.z + 1]
 	or a, b
-	cp 0
 	jr z, .endGravity
 
+	; Skip gravity if boosting
+	ld a, [wMetaspriteVelocity.boosting]
+	ld b, a
+	ld a, [wMetaspriteVelocity.boost]
+	and a, b
+	cp 0 
+	jr z, .startGravity
+	ld a, [wMetaspriteVelocity.boost]
+	dec a
+	ld [wMetaspriteVelocity.boost], a
+	jr .endGravity
+
+.startGravity
 	; Apply gravity
 	ld a, [wMetaspriteVelocity.z]
-	add a, $02
+	add a, $04
 	ld [wMetaspriteVelocity.z], a
 	ld a, [wMetaspriteVelocity.z+1]
 	adc a, $00
@@ -259,23 +299,24 @@ HandlePhysics::
 	ld c, a
 	ld a, [wMetaspritePosition.z]
 	add c
+	ld c, a
 	ld a, [wMetaspriteVelocity.z + 1]
 	ld b, a
 	ld a, [wMetaspritePosition.z + 1]
 	adc b
+	ld b, a
 
 	; If z is greater than or equal to 0, pos/vel to 0
-	jr nz, .endLanding1
-	jr nc, .endLanding1
+	jr nz, .endLanding
+	jr nc, .endLanding
 .startLanding
 	ld a, 0
+	ld [wMetaspritePosition.z], a
+	ld [wMetaspritePosition.z+1], a
 	ld [wMetaspriteVelocity.z], a
 	ld [wMetaspriteVelocity.z+1], a
-	ld c, 0
-	ld b, 0
-	jr .endLanding
-.endLanding1
-	nop
+	ld b, a
+	ld c, a
 .endLanding
 
 	; Update z position
@@ -507,6 +548,10 @@ wMetaspriteVelocity::
 	dw
 .z:
 	dw
+.boost:
+	db
+.boosting:
+	db
 
 SECTION "Joypad Vars", WRAM0
 wJoypadState: