Groundwork for moving characters

gamemanager.s

@@ -125,10 +125,15 @@ gameplayLoopPower:
 
 gameplayLoopFire:
 	lda fireRequested
-	beq gameplayLoopRender
+	beq gameplayLoopMove
 	jsr unrenderCrosshair
 	jsr fire
 	
+gameplayLoopMove:
+	lda playerMoveRequested
+	beq gameplayLoopRender
+	jsr move
+
 ;	BORDER_COLOR #$2
 
 gameplayLoopRender:
@@ -397,6 +402,24 @@ fire:
 	rts
 
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; move
+;
+; Handles moving a player
+;
+move:
+	jsr unrenderCrosshair
+	jsr unrenderPlayers
+	lda #playerData
+	sta PARAML0
+	ldx playerMoveRequested
+	jsr moveGameObjectOnTerrain
+	stz playerMoveRequested
+	jsr renderPlayers
+	jsr renderCrosshair
+	rts
+
+
 basePalette:
 	.word $06af,$0072,$0072,$0861,$0c93,$0eb4,$0d66,$0f9a,$0777,$0d00,$0bbb,$ddd,$007b,$0a5b,$0000,$0fff
 
@@ -413,6 +436,8 @@ fireRequested:
 	.word $0000
 turnRequested:
 	.word $0000
+playerMoveRequested:
+	.word $0000
 terrainDirty:
 	.word 1
 projectilesDirty:

gameobject.s

@@ -8,6 +8,7 @@
 GAMEOBJECTWIDTH = 16
 GAMEOBJECTHEIGHT = 16
 MAXGAMEOBJECTS = 6		; Size of general purpose object pool
+MAXCLIMB = 16			; Highest pixel cliff we can climb
 
 
 ; Base class sample:
@@ -25,16 +26,15 @@ GO_BACKGROUND = 4
 
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-; placeGameObjectOnTerrain
+; terrainHeightAtGameObjectPos
+;
+; A = GameObject position (left-edge relative)
+; A -> Terrain height at that position
 ;
-; PARAML0 = Pointer to gameobject data
 ; Trashes SCRATCHL
 ;
-placeGameObjectOnTerrain:
-	SAVE_AY
-
-	ldy #GO_POSX
-	lda (PARAML0),y
+terrainHeightAtGameObjectPos:
+	phy
 	clc					; Map into reversed terrain X space
 	adc #GAMEOBJECTWIDTH
 	sta SCRATCHL
@@ -45,7 +45,35 @@ placeGameObjectOnTerrain:
 	and #$fffe				; Force even
 	tay
 	lda terrainData,y
+	ply
+	rts
 
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; placeGameObjectOnTerrain
+;
+; PARAML0 = Pointer to gameobject data
+; Trashes SCRATCHL,SCRATCHL2
+;
+placeGameObjectOnTerrain:
+	SAVE_AY
+
+	; Check forwardmost position
+	ldy #GO_POSX
+	lda (PARAML0),y
+	jsr terrainHeightAtGameObjectPos
+	sta SCRATCHL2
+
+	; Check rearmost position
+	ldy #GO_POSX
+	lda (PARAML0),y
+	sec
+	sbc #GAMEOBJECTWIDTH
+	jsr terrainHeightAtGameObjectPos
+	cmp SCRATCHL2			; Take higher value
+	bcc placeGameObjectOnTerrainRear
+
+placeGameObjectOnTerrainDone:
 	clc
 	adc #GAMEOBJECTHEIGHT
 	ldy #GO_POSY
@@ -54,6 +82,84 @@ placeGameObjectOnTerrain:
 	RESTORE_AY
 	rts
 
+placeGameObjectOnTerrainRear:
+	lda SCRATCHL2
+	bra placeGameObjectOnTerrainDone
+	
+
+	
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; moveGameObjectOnTerrain
+;
+; PARAML0 = Pointer to gameobject data
+; X = Delta in pixels
+;
+; Trashes SCRATCHL,SCRATCHL2
+;
+moveGameObjectOnTerrain:
+	SAVE_AY
+
+	stx SCRATCHL2
+
+	ldy #GO_POSX
+	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
+	sec
+	sbc SCRATCHL2
+	bmi moveGameObjectOnTerrainStepDown
+
+moveGameObjectOnTerrainCheckHeight:
+	cmp #MAXCLIMB
+	bcs moveGameObjectOnTerrainTooFar
+	bra moveGameObjectOnTerrainStore
+
+moveGameObjectOnTerrainStepDown:
+	dec
+	eor #$ffff
+	bra moveGameObjectOnTerrainCheckHeight
+
+moveGameObjectOnTerrainStore:
+	pla
+	sta SCRATCHL
+
+	; Reverse X position again
+	lda #TERRAINWIDTH
+	sec
+	sbc #GAMEOBJECTWIDTH
+	sbc SCRATCHL
+
+	ldy #GO_POSX
+	sta (PARAML0),y
+	jsr placeGameObjectOnTerrain
+
+moveGameObjectOnTerrainTooDone:
+	RESTORE_AY
+	rts
+
+moveGameObjectOnTerrainTooFar:
+	pla
+	bra moveGameObjectOnTerrainTooDone
+
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ; vramPtr

input.s

@@ -28,7 +28,7 @@ kbdScanTitle:
 	beq kbdScanEnterTitle
 	cmp #(32 + $80)
 	beq kbdScanSpaceTitle
-	bra kbdScanDebugPiggyback
+	jmp kbdScanDebugPiggyback
 
 kbdScanTitleDone:
 	BITS16
@@ -64,6 +64,22 @@ kbdScanSpaceTitle:
 	rts
 
 
+;;;;;;;
+
+kbdScanApostrophe:
+	BITS16
+	lda #2
+	sta playerMoveRequested
+	rts
+
+kbdScanSemiColon:
+	BITS16
+	lda #-2
+	sta playerMoveRequested
+	rts
+
+
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ; kbdScanGameplay/Debug
 ; Processes keyboard input for gameplay
@@ -93,6 +109,10 @@ kbdScanGameplay:
 	beq kbdScanPeriod
 	cmp #(' ' + $80)
 	beq kbdScanSpace
+	cmp #(';' + $80)
+	beq kbdScanSemiColon
+	cmp #(39 + $80)
+	beq kbdScanApostrophe
 	cmp #(9 + $80)
 	bne kbdScanDebugPiggyback
 	jmp kbdScanTab
@@ -116,7 +136,6 @@ kbdScanDebugPiggyback:
 	beq kbdScanEquals
 	bra kbdScanDone
 
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ; Gameplay Key Handlers
 ;
@@ -145,13 +164,6 @@ kbdScanComma:
 	sta mapScrollRequested
 	rts
 
-kbdScanESC:
-	BITS16
-
-	lda #1
-	sta quitRequested
-	rts
-
 kbdScanLeftArrow:
 	BITS16
 	lda #2
@@ -176,6 +188,12 @@ kbdScanDownArrow:
 	sta powerDeltaRequested
 	rts
 
+kbdScanESC:
+	BITS16
+	lda #1
+	sta quitRequested
+	rts
+
 kbdScanSpace:
 	BITS16
 	lda #1