MACRO CheckPlayerCameraPosition
CPX player1_object
BEQ notdoneWithCameraCheck
JMP doneWithCameraCheck
notdoneWithCameraCheck:
LDA gameHandler
AND #%10000000
BNE gameIsActive
JMP doneWithCameraCheck
gameIsActive:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;======== ALIGN SCREEN IF NOT LINED UP WITH NAMETABLE
;;; corrupts A
;;; if value is 1, it will skip gravity
;TXA
;STA tempx
;JSR AlignScreenToNametable
;BEQ dontAlignScreens
;JMP doneWithCameraCheck
;dontAlignScreens:
;LDX tempx
;;;; END HANDLE ALIGN SCREENS
;;;;;;;;======================================
;;;;; BOTTOM CHECK
LDA Object_y_lo,x
CLC
ADC Object_v_speed_lo,x
LDA Object_y_hi,x
ADC Object_v_speed_hi,x
CMP #BOUNDS_TOP
BCS notAtBoundsTop
; LDA xScroll
;BNE +
LDA #$00
STA xScroll
JSR doTopBounds_player
RTS
;+:
JMP notAtBoundsTop ;; comment out if you want to use align screen
;; do alignment of screen if it wasn't aligned.
;;; if player's scroll is the same as xScroll_hi, we need to reverse scroll.
;;; otherwise, it should be forward scroll
LDA Object_scroll,x
CMP xScroll_hi
BEQ + ;; need to reverse
;; forward auto scroll
LDA #%00000000
JMP ++
+ ;; need to reverse
LDA #%10000000
++
ORA #$02
STA align_screen_flag
LDA #ALIGN_TIMER
STA genericTimer
LDA #$01
STA prevent_scroll_flag
JMP doneWithCameraCheck
notAtBoundsTop:
LDA Object_y_lo,x
CLC
ADC Object_v_speed_lo,x
LDA Object_y_hi,x
ADC Object_v_speed_hi,x
ADC Object_bottom,x
CMP #BOUNDS_BOTTOM
BCS atBottomBounds
JMP notAtBottomBounds
atBottomBounds:
CPX player1_object
BEQ isPlayerAtBottomOfScrollingBounds
;; is not player at scrolling bounds
;;; check for gravity? if not player and is at bottom bounds, and is a platformer
DeactivateCurrentObject
JMP notAtBottomBounds
isPlayerAtBottomOfScrollingBounds:
;LDA xScroll
;BNE +
LDA #$00
STA xScroll
JSR doBottomBounds_player
RTS
;+: ;; do alignment of screen if it wasn't aligned.
JMP notAtBottomBounds ;; comment out if want to align screen
LDA Object_scroll,x
CMP xScroll_hi
BEQ + ;; need to reverse
;; forward auto scroll
LDA #%00000000
JMP ++
+ ;; need to reverse
LDA #%10000000
++
ORA #$01
STA align_screen_flag
LDA #ALIGN_TIMER
STA genericTimer
LDA #$01
STA prevent_scroll_flag
JMP doneWithCameraCheck
notAtBottomBounds:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; let's check to see if we're against the leftmost edge.
LDA xScroll_hi
BNE + ; not on screen 0
;; is on screen zero
LDA Object_h_speed_lo,x
CLC
ADC #$00
LDA Object_h_speed_hi,x
ADC #$00
BPL + ;; not moving left.
LDA Object_scroll,x
BNE +
LDA xScroll
CMP xHold_hi
BCS leftOfCameraForPlayer
JMP checkRightEdge
+
LDA nt_hold
CMP xScroll_hi
BCC leftOfCameraForPlayer
BNE checkRightEdge
LDA xHold_hi
CMP xScroll
BCC leftOfCameraForPlayer
BEQ leftOfCameraForPlayer
JMP checkRightEdge
leftOfCameraForPlayer:
;;; dont update position
JMP doScrollingLeftBounds
checkRightEdge:
LDA xScroll_hi
CLC
ADC #$01
STA temp
LDA xScroll
SEC
SBC Object_right,x
STA temp1
LDA temp
SBC #$00
STA temp
CMP nt_hold
BCC rightOfCameraEdgeForPlayer
BNE doneWithCameraCheck
LDA temp1
CMP xHold_hi
BCC rightOfCameraEdgeForPlayer
BEQ rightOfCameraEdgeForPlayer
JMP doneWithCameraCheck
rightOfCameraEdgeForPlayer:
JMP doScrollingRightBounds
doScrollingLeftBounds:
;;; enter what should happen at bounds for player.
;;; an RTS here will result in skipping position update.
JSR doLeftBounds_player
RTS
doScrollingRightBounds:
;;; enter what should happen at bounds for player.
;;; an RTS here will result in skipping position update.
JSR doRightBounds_player
RTS
doScrollingTopBounds:
JSR doTopBounds_player
RTS
doScrollingBottomBounds:
JSR doBottomBounds_player
RTS
doneWithCameraCheck:
ENDM
