Cleanup and correct some collision handling logic

10 files changed, 57 insertions, 52 deletions

diff --git a/engine/pinball_game.asm b/engine/pinball_game.asm
index f094e82..86fd199 100644
--- a/engine/pinball_game.asm
+++ b/engine/pinball_game.asm
@@ -70,23 +70,23 @@ GameScreenFunction_HandleBallPhysics: ; 0xd909
 ; main loop for stage logic

 	xor a

 	ld [wFlipperCollision], a

-	ld [wd7eb], a

+	ld [wSpinForceAmplification], a

 	call ApplyGravityToBall

 	call LimitBallVelocity

 	xor a

-	ld [wd7e9], a

+	ld [wIsBallColliding], a

 	call HandleTilts

 	ld a, [wCurrentStage]

 	bit 0, a

-	callba nz, HandleFlippers  ; only perform flipper routines on the lower-half of stages

+	callba nz, HandleFlippers  ; only perform flipper logic on the lower half of stages

 	ld a, [wFlipperCollision]

 	and a

-	ld a, [wCollisionForceAngle]

+	ld a, [wCollisionNormalAngle]

 	push af

-	call CheckObjectCollision  ; collision stuff

+	call CheckStageCollision

 	pop af

 	jr z, .noFlipperCollision

-	ld [wCollisionForceAngle], a

+	ld [wCollisionNormalAngle], a

 .noFlipperCollision

 	call CheckGameObjectCollisions

 	call ResolveGameObjectCollisions

@@ -98,17 +98,20 @@ GameScreenFunction_HandleBallPhysics: ; 0xd909
 	callba HandleInGameMenu

 	jp z, SaveGame

 .didntPressMenuKey

-	ld a, [wd7e9]  ; check for collision flag

+	ld a, [wIsBallColliding]  ; check for collision flag

 	and a

-	jr z, .skip_collision

+	jr z, .moveBallPosition

 	call ApplyTiltForces

 	call LoadBallVelocity ; bc = x velocity, de = y velocity

-	ld a, [wCollisionForceAngle]

-	call ApplyCollisionForce

-	call ApplyTorque

+	; First, rotate the velocity vector into a standardized coordinate

+	; system where the normal angle points upwards.

+	ld a, [wCollisionNormalAngle]

+	call RotateVector

+	; Apply the collision forces to the ball in the rotated coordinate system.

+	call ApplyCollisionForces

 	ld a, [wFlipperCollision]

 	and a

-	jr z, .not_flippers_2

+	jr z, .noFlipperCollision2

 	; de -= *wFlipperYForce

 	ld hl, wFlipperYForce

 	ld a, [hli]

@@ -131,17 +134,19 @@ GameScreenFunction_HandleBallPhysics: ; 0xd909
 	ld a, b

 	adc h

 	ld b, a

-	jr .next

+	jr .updateBallVelocity

 

-.not_flippers_2

-	ld a, [wd7f8]

+.noFlipperCollision2

+	ld a, [wNoCollisionApplied]

 	and a

-	jr nz, .skip_collision

-.next

-	ld a, [wCollisionForceAngle]

-	call NegateAngleAndApplyCollisionForce

+	jr nz, .moveBallPosition

+.updateBallVelocity

+	; Rotate the velocity vector back to the regular coordinate system, and

+	; set the ball's velocity to the resulting vector.

+	ld a, [wCollisionNormalAngle]

+	call NegateAngleAndRotateVector

 	call SetBallVelocity

-.skip_collision

+.moveBallPosition

 	call MoveBallPosition

 	callba CheckStageTransition

 	callba DrawSpritesForStage

@@ -176,9 +181,9 @@ GameScreenFunction_HandleBallLoss: ; 0xda36
 	ld [hNewlyPressedButtons], a

 	ld [hPressedButtons], a

 	ld [wFlipperCollision], a

-	ld [wd7eb], a

+	ld [wSpinForceAmplification], a

 	xor a

-	ld [wd7e9], a

+	ld [wIsBallColliding], a

 	ld [wPinballIsVisible], a

 	ld [wEnableBallGravityAndTilt], a

 	call HandleTilts

diff --git a/engine/pinball_game/flippers.asm b/engine/pinball_game/flippers.asm
index d71419a..4ecc0b1 100644
--- a/engine/pinball_game/flippers.asm
+++ b/engine/pinball_game/flippers.asm
@@ -601,7 +601,7 @@ HandleFlipperCollision: ; 0xe442
 ; This is called when the ball is colliding with either the

 ; right or left flipper.

 	ld a, $1

-	ld [wd7e9], a

+	ld [wIsBallColliding], a

 	xor a

 	ld [wBallPositionPointerOffsetFromStageTopLeft], a

 	ld [wBallPositionPointerOffsetFromStageTopLeft + 1], a

@@ -638,9 +638,9 @@ HandleFlipperCollision: ; 0xe442
 	cpl  ; invert the x collision attribute

 	inc a

 .asm_e48b

-	ld [wCollisionForceAngle], a

-	ld a, $1

-	ld [wd7eb], a

+	ld [wCollisionNormalAngle], a

+	ld a, 1

+	ld [wSpinForceAmplification], a

 	ld a, [wFlipperYForce + 1]

 	bit 7, a

 	ret z

diff --git a/engine/pinball_game/object_collision/blue_stage_resolve_collision.asm b/engine/pinball_game/object_collision/blue_stage_resolve_collision.asm
index 6b07d73..3bcc995 100644
--- a/engine/pinball_game/object_collision/blue_stage_resolve_collision.asm
+++ b/engine/pinball_game/object_collision/blue_stage_resolve_collision.asm
@@ -598,9 +598,9 @@ ApplyBumperCollision_BlueField: ; 0x1ce94
 	ld b, $0

 	ld hl, BumperCollisionAngleDeltas_BlueField

 	add hl, bc

-	ld a, [wCollisionForceAngle]

+	ld a, [wCollisionNormalAngle]

 	add [hl]

-	ld [wCollisionForceAngle], a

+	ld [wCollisionNormalAngle], a

 	lb de, $00, $0b

 	call PlaySoundEffect

 	ret

@@ -1808,10 +1808,10 @@ AddScorePsyduckOrPoliwag: ; 0x1de22
 	ret z

 	ld a, $55

 	ld [wRumblePattern], a

-	ld a, $4

+	ld a, 4

 	ld [wRumbleDuration], a

-	ld a, $2

-	ld [wd7eb], a

+	ld a, 2

+	ld [wSpinForceAmplification], a

 	ld bc, FiveHundredPoints

 	callba AddBigBCD6FromQueueWithBallMultiplier

 	lb de, $00, $0f

diff --git a/engine/pinball_game/object_collision/diglett_bonus_object_collision.asm b/engine/pinball_game/object_collision/diglett_bonus_object_collision.asm
index 91e0f82..e9ad851 100644
--- a/engine/pinball_game/object_collision/diglett_bonus_object_collision.asm
+++ b/engine/pinball_game/object_collision/diglett_bonus_object_collision.asm
@@ -10,7 +10,7 @@ CheckDiglettBonusStageDiglettHeadsCollision: ; 0x19aba
 	ld a, [wd73b]

 	bit 7, a

 	jr nz, .asm_19b16

-	ld a, [wd7e9]

+	ld a, [wIsBallColliding]

 	and a

 	ret z ; is a collision happening?

 	ld a, [wCurCollisionAttribute]

@@ -86,7 +86,7 @@ CheckDiglettBonusStageDugtrioCollision: ; 0x19b4b
 	ld a, [wd75f]

 	bit 7, a

 	jr nz, .asm_19b86

-	ld a, [wd7e9]

+	ld a, [wIsBallColliding]

 	and a

 	ret z

 	ld a, [wCurCollisionAttribute]

diff --git a/engine/pinball_game/object_collision/gengar_bonus_object_collision.asm b/engine/pinball_game/object_collision/gengar_bonus_object_collision.asm
index adf048b..f436b4d 100644
--- a/engine/pinball_game/object_collision/gengar_bonus_object_collision.asm
+++ b/engine/pinball_game/object_collision/gengar_bonus_object_collision.asm
@@ -79,9 +79,9 @@ CheckSingleGastlyCollision: ; 0x1820d
 	bit 7, a

 	jr nz, .noCollision

 	sla a

-	ld [wCollisionForceAngle], a

+	ld [wCollisionNormalAngle], a

 	ld a, $1

-	ld [wd7e9], a

+	ld [wIsBallColliding], a

 	scf

 	ret

 

@@ -156,9 +156,9 @@ CheckSingleHaunterCollision: ; 0x18298
 	bit 7, a

 	jr nz, .noCollision

 	sla a

-	ld [wCollisionForceAngle], a

+	ld [wCollisionNormalAngle], a

 	ld a, $1

-	ld [wd7e9], a

+	ld [wIsBallColliding], a

 	scf

 	ret

 

@@ -219,9 +219,9 @@ CheckGiantGengarCollision: ; 0x18308
 	bit 7, a

 	jr nz, .noCollision

 	sla a

-	ld [wCollisionForceAngle], a

+	ld [wCollisionNormalAngle], a

 	ld a, $1

-	ld [wd7e9], a

+	ld [wIsBallColliding], a

 	scf

 	ret

 

diff --git a/engine/pinball_game/object_collision/meowth_bonus_object_collision.asm b/engine/pinball_game/object_collision/meowth_bonus_object_collision.asm
index 4fc6179..71e326f 100644
--- a/engine/pinball_game/object_collision/meowth_bonus_object_collision.asm
+++ b/engine/pinball_game/object_collision/meowth_bonus_object_collision.asm
@@ -57,9 +57,9 @@ CheckMeowthCollision: ; 0x24170
 	bit 7, a

 	jr nz, .noCollision

 	sla a

-	ld [wCollisionForceAngle], a

+	ld [wCollisionNormalAngle], a

 	ld a, $1

-	ld [wd7e9], a

+	ld [wIsBallColliding], a

 	ld a, [wd6ec]

 	cp $2

 	ret z

@@ -205,9 +205,9 @@ CheckJewelCollision: ; 0x24272
 	bit 7, a

 	jr nz, .noCollision

 	sla a

-	ld [wCollisionForceAngle], a

+	ld [wCollisionNormalAngle], a

 	ld a, $1

-	ld [wd7e9], a

+	ld [wIsBallColliding], a

 	scf

 	ret

 

diff --git a/engine/pinball_game/object_collision/mewtwo_bonus_object_collision.asm b/engine/pinball_game/object_collision/mewtwo_bonus_object_collision.asm
index 7b15498..d1bdd07 100644
--- a/engine/pinball_game/object_collision/mewtwo_bonus_object_collision.asm
+++ b/engine/pinball_game/object_collision/mewtwo_bonus_object_collision.asm
@@ -159,7 +159,7 @@ Func_19414: ; 0x19414
 	ld a, [wd6aa]

 	bit 7, a

 	jr nz, .asm_1944f

-	ld a, [wd7e9]

+	ld a, [wIsBallColliding]

 	and a

 	ret z

 	ld a, [wCurCollisionAttribute]

diff --git a/engine/pinball_game/object_collision/object_collision.asm b/engine/pinball_game/object_collision/object_collision.asm
index 7e4c2ea..b80cddb 100644
--- a/engine/pinball_game/object_collision/object_collision.asm
+++ b/engine/pinball_game/object_collision/object_collision.asm
@@ -125,7 +125,7 @@ IsCollisionInList: ; 0x27da
 	ld c, [hl]

 	add hl, bc

 .checkList

-	ld a, [wd7e9]

+	ld a, [wIsBallColliding]

 	and a

 	ret z

 	ld a, [wCurCollisionAttribute]

diff --git a/engine/pinball_game/object_collision/red_stage_resolve_collision.asm b/engine/pinball_game/object_collision/red_stage_resolve_collision.asm
index 84867d6..d79411c 100644
--- a/engine/pinball_game/object_collision/red_stage_resolve_collision.asm
+++ b/engine/pinball_game/object_collision/red_stage_resolve_collision.asm
@@ -460,10 +460,10 @@ HitLeftDiglett3Times: ; 0x14947
 AddScoreForHittingDiglett: ; 0x1496d

 	ld a, $55

 	ld [wRumblePattern], a

-	ld a, $4

+	ld a, 4

 	ld [wRumbleDuration], a

-	ld a, $2

-	ld [wd7eb], a

+	ld a, 2

+	ld [wSpinForceAmplification], a

 	ld bc, FiveHundredPoints

 	callba AddBigBCD6FromQueueWithBallMultiplier

 	lb de, $00, $0f

@@ -1699,9 +1699,9 @@ ApplyBumperCollision_RedField: ; 0x15fda
 	ld b, $0

 	ld hl, BumperCollisionAngleDeltas_RedField

 	add hl, bc

-	ld a, [wCollisionForceAngle]

+	ld a, [wCollisionNormalAngle]

 	add [hl]

-	ld [wCollisionForceAngle], a

+	ld [wCollisionNormalAngle], a

 	lb de, $00, $0b

 	call PlaySoundEffect

 	ret

diff --git a/engine/pinball_game/object_collision/seel_bonus_object_collision.asm b/engine/pinball_game/object_collision/seel_bonus_object_collision.asm
index e702dd2..1bf1791 100644
--- a/engine/pinball_game/object_collision/seel_bonus_object_collision.asm
+++ b/engine/pinball_game/object_collision/seel_bonus_object_collision.asm
@@ -80,9 +80,9 @@ CheckSeelHeadCollision: ; 0x25c12
 	bit 7, a

 	jr nz, .noCollision

 	sla a

-	ld [wCollisionForceAngle], a

+	ld [wCollisionNormalAngle], a

 	ld a, $1

-	ld [wd7e9], a

+	ld [wIsBallColliding], a

 	scf

 	ret