Cleaned up some magic numbers

gamemanager.s

@@ -35,8 +35,6 @@ beginGameplay:
 	ldy #0
 	jsr renderPlayerHeader
 
-	jsr protectPlayers
-	jsr protectProjectiles
 	jsr prepareRowRendering
 
 	jsr compileTerrain
@@ -44,6 +42,7 @@ beginGameplay:
 	jsr renderTerrain
 
 	jsr renderInventory
+	jsr protectPlayers
 	jsr renderPlayers
 
 	; Fade in from menu
@@ -97,7 +96,6 @@ gameplayLoopScroll:
 
 	jsr scrollMap
 	jsr updateCrosshair
-	jsr protectCrosshair
 
 gameplayLoopAngleCheck:
 	lda projectileActive			; Skip interactivity during shots
@@ -153,6 +151,14 @@ gameplayLoopRender:
 	stz terrainDirty
 
 	; Render players
+	lda playersDirty		; Check if terrain moved since last protect
+	beq gameplayLoopRenderPlayersAnyway
+	jsr unrenderPlayers
+	jsr protectPlayers
+	jsr unrenderCrosshair
+	jsr protectCrosshair
+
+gameplayLoopRenderPlayersAnyway:
 	jsr renderPlayers
 
 gameplayLoopExplosions:
@@ -348,14 +354,11 @@ scrollMapApplyScrolling:
 	lda #$ffff
 	sta mapScrollRequested
 
-	jsr protectPlayers
-	jsr protectProjectiles
-	jsr renderPlayers
-	jsr renderProjectiles		; Prevents flicker, but ads jitter to shot tracking
-
 	lda #1
+	sta playersDirty
+	sta projectilesDirty
 	sta terrainDirty
-	stz projectilesDirty
+	sta crosshairDirty
 	rts
 
 
@@ -432,7 +435,7 @@ move:
 	beq moveParamsPlayer0
 	lda #-1
 	sta placeGameObjectRightOffset
-	lda #GAMEOBJECTWIDTH-7
+	lda #GAMEOBJECTWIDTH-(GAMEOBJECTWIDTH/2-1)
 	sta placeGameObjectLeftOffset
 
 movePerformMove:
@@ -440,7 +443,7 @@ movePerformMove:
 	bra moveCleanup
 
 moveParamsPlayer0:
-	lda #-6
+	lda #-(GAMEOBJECTWIDTH/2-2)
 	sta placeGameObjectRightOffset
 	lda #GAMEOBJECTWIDTH-2
 	sta placeGameObjectLeftOffset
@@ -482,6 +485,10 @@ playerMoveRequested:
 	.word $0000
 terrainDirty:
 	.word 1
+playersDirty:
+	.word 0
+crosshairDirty:
+	.word 0
 projectilesDirty:
 	.word 1
 inventoryDirty:

gameobject.s

@@ -8,8 +8,6 @@
 GAMEOBJECTWIDTH = 16
 GAMEOBJECTHEIGHT = 16
 MAXGAMEOBJECTS = 6		; Size of general purpose object pool
-MAXCLIMB = 16			; Highest pixel cliff we can climb
-
 
 ; Base class sample:
 ;gameobjectData:
@@ -132,49 +130,20 @@ moveGameObjectOnTerrain:
 	lda (PARAML0),y
 	clc
 	adc SCRATCHL2		; Apply X delta
-
-	clc					; Map into reversed terrain X space
-	adc #GAMEOBJECTWIDTH
-	sta SCRATCHL
-	lda #TERRAINWIDTH
-	sec
-	sbc SCRATCHL
-	sta SCRATCHL		; Desired X position
-
-	ldy #GO_POSY
-	lda (PARAML0),y
-	sec
-	sbc #GAMEOBJECTHEIGHT
-	sta SCRATCHL2		; Current Y position
-
-	lda SCRATCHL		; Check terrain height at new position
 	pha
-	jsr terrainHeightAtGameObjectPos
+
+	; Check for impassable gaps
 	sec
-	sbc SCRATCHL2
-	bmi moveGameObjectOnTerrainStepDown
+	sbc #GAMEOBJECTWIDTH/2
 
 moveGameObjectOnTerrainCheckHeight:
-	cmp #MAXCLIMB
-	bcs moveGameObjectOnTerrainTooFar
-	bra moveGameObjectOnTerrainStore
-
-moveGameObjectOnTerrainStepDown:
-	dec
-	eor #$ffff
-	bra moveGameObjectOnTerrainCheckHeight
+	jsr terrainHeightAtGameObjectPos
+	cmp #0
+	beq moveGameObjectOnTerrainTooFar
 
 moveGameObjectOnTerrainStore:
-	pla
-	sta SCRATCHL
-
-	; Reverse X position again
-	lda #TERRAINWIDTH
-	sec
-	sbc #GAMEOBJECTWIDTH
-	sbc SCRATCHL
-
 	ldy #GO_POSX
+	pla
 	sta (PARAML0),y
 	jsr placeGameObjectOnTerrain
 
@@ -186,7 +155,6 @@ moveGameObjectOnTerrainTooFar:
 	pla
 	bra moveGameObjectOnTerrainTooDone
 
-
 moveGameObjectLeftOffset:
 	.word 0
 moveGameObjectRightOffset: