Add comments and update formatting

Sprites/Objects/minecart.asm

@@ -92,17 +92,15 @@ Sprite_Minecart_Prep:
       ; If link is in a cart, then draw the dummy cart
 
       LDA !LinkInCart : BNE .dummy_continue
-      .clear_cart
+        ; .clear_cart
         STZ.w $0DD0, X ; Otherwise, clear the sprite
         PLB
         RTL
 
   .continue
-    
     ; Unused dummy cart code
     ; LDA.w !LinkInCart : AND.b #$FF : BEQ .dummy_continue
     ; JMP .clear_cart
-
   .dummy_continue
     LDA SprY, X : SEC : SBC.b #$04 : STA SprY, X
     
@@ -141,7 +139,6 @@ Sprite_Minecart_Prep:
     %GotoAction(0) ; Minecart_WaitHoriz
 
   .done
-    
     PLB
     RTL
 }
@@ -238,7 +235,6 @@ Sprite_Minecart_Main:
           
     .lifting
       %HandleLiftAndToss()
-
       RTS
   }
   
@@ -255,8 +251,7 @@ Sprite_Minecart_Main:
           JSL Player_HaltDashAttack            ; Stop the player from dashing
           LDA #$02 : STA $02F5                 ; Somaria platform and moving 
           LDA $0FDA : SEC : SBC #$0B : STA $20 ; Adjust player pos 
-
+          LDA #$01 : STA !LinkInCart           ; Set Link in cart flag
-      LDA #$01 : STA !LinkInCart
           
           ; Check if the cart is facing north or south
           LDA SprSubtype, X : BEQ .opposite_direction
@@ -384,12 +379,19 @@ Sprite_Minecart_Main:
   }
 }
 
-; ===========================================================================
+; =========================================================
+; The purpose of this routine is to determine the direction
+; the sprite is facing and then adjust the X and Y positions
+; of the tile interaction lookup based on that direction.
+; If implemented correctly this would make sure the sprite
+; stays centered on the tracks when it makes corner turns.
+; Currently, depending on where the tile is placed the 
+; cart may make a turn too early and appear to be off center.
 
 SetTileLookupPosBasedOnDirection:
 {
-    ; Based on the direction of the Minecart, adjust the lookup position
+    ; Based on the direction of the Minecart, adjust the 
-    ; to be in front of the sprite
+    ; lookup position to be in front of the sprite
     LDA.w !MinecartDirection : CMP.b #$00 : BEQ .north
                                CMP.b #$01 : BEQ .east
                                CMP.b #$02 : BEQ .south
@@ -423,6 +425,8 @@ SetTileLookupPosBasedOnDirection:
     RTS
 }
 
+; =========================================================
+
 print "HandleTileDirections ", pc
 HandleTileDirections:
 {
@@ -587,8 +591,10 @@ HandleTileDirections:
     ; db $BE ; + any direction
 }
 
+; =========================================================
 ; Clamp the sprite position to a 16x16 grid
 ; Slows the game down if you run it too often :(
+
 ClampSpritePositionToGrid:
 {
     ; Check if SprX is already a multiple of 16
@@ -602,6 +608,10 @@ ClampSpritePositionToGrid:
     RTS
 }
 
+; =========================================================
+; Check for the switch_track sprite and move based on the 
+; state of that sprite.
+
 HandleDynamicSwitchTileDirections:
 {
     ; Find out if the sprite $B0 is in the room
@@ -620,9 +630,7 @@ HandleDynamicSwitchTileDirections:
           CMP.b #$02 : BEQ .north_or_south
 
       .east_or_west
-    
         LDA SwitchRam : BNE .go_west
-
         LDA #$01 : STA SprSubtype,       X
         LDA #$03 : STA !SpriteDirection, X
         %GotoAction(3) ; Minecart_MoveEast
@@ -651,7 +659,9 @@ HandleDynamicSwitchTileDirections:
     RTS
 }
 
+; =========================================================
 ; $00 = flag indicating presence of sprite ID $B0
+
 CheckSpritePresence:
 {
     PHX
@@ -752,6 +762,7 @@ DragPlayer:
   ; db -1,   0,   0,   0,  -1,   0,  -1,   0
 }
 
+; =========================================================
 
 CheckForPlayerInput:
 {
@@ -775,43 +786,29 @@ CheckForPlayerInput:
     LDA $0FA5 : CLC : CMP.b #$B6 : BNE .cant_input
 
       ; Check for input from the user (u,d,l,r)
-      
       LDY !SpriteDirection, X
-      
       LDA $F0 : AND .d_pad_press, Y : STA $00 : AND.b #$08 : BEQ .not_pressing_up
-      
         LDA.b #$00 : STA !SpriteDirection, X ; Moving Up 
         STA   SprSubtype,                  X
         %GotoAction(2) ; Minecart_MoveNorth
-      
         BRA .return
 
   .not_pressing_up:
-
       LDA $00 : AND.b #$04 : BEQ .not_pressing_down
-      
       LDA.b #$01 : STA !SpriteDirection, X
       LDA   #$02 : STA SprSubtype,       X
       %GotoAction(4) ; Minecart_MoveSouth
-
-      
       BRA .return
 
   .not_pressing_down
-
       LDA $00 : AND.b #$02 : BEQ .not_pressing_left
-      
       LDA.b #$02 : STA !SpriteDirection, X
       LDA   #$03 : STA SprSubtype,       X
       %GotoAction(5) ; Minecart_MoveWest
-
-      
       BRA .return
 
   .not_pressing_left
-
       LDA $00 : AND.b #$01 : BEQ .always
-      
       LDA.b #$03 : STA !SpriteDirection, X
       STA   SprSubtype,                  X
       %GotoAction(3) ; Minecart_MoveEast
@@ -819,12 +816,9 @@ CheckForPlayerInput:
   .always
 
   ;   LDA !SpriteDirection, X : CMP.b #$03 : BNE .not_going_right
-      
   ;   ; Default heading in reaction to this tile is going up.
   ;   ; LDA.b #$00 : STA !SpriteDirection, X
-
   ; .not_going_right
-
   ;   ;STZ $0D80, X
 
   .return
@@ -836,26 +830,31 @@ CheckForPlayerInput:
     db $0B, $07, $0E, $0D
 }
 
+; =========================================================
+; Sets carry if player is overlapping the sprite
+; Clear carry if player is outside the bounds
+
 CheckIfPlayerIsOn:
 {
     REP #$20
-    LDA $22 : CLC : ADC #$0009 : CMP $0FD8 : BCC .OutsideLeft
+    LDA $22 : CLC : ADC #$0009 : CMP $0FD8 : BCC .left
-    LDA $22 : SEC : SBC #$0009 : CMP $0FD8 : BCS .OutsideRight
+    LDA $22 : SEC : SBC #$0009 : CMP $0FD8 : BCS .right
 
-    LDA $20 : CLC : ADC #$0012 : CMP $0FDA : BCC .OutsideUp
+    LDA $20 : CLC : ADC #$0012 : CMP $0FDA : BCC .up
-    LDA $20 : SEC : SBC #$0012 : CMP $0FDA : BCS .OutsideDown
+    LDA $20 : SEC : SBC #$0012 : CMP $0FDA : BCS .down
     
     SEP #$21 : RTS ; Return with carry set
 
-  .OutsideLeft
+  .left
-  .OutsideRight
+  .right
-  .OutsideDown
+  .up
-  .OutsideUp
+  .down
     SEP #$20
     CLC : RTS ; Return with carry cleared
 }
 
 ; =========================================================
+; Draw the portion of the cart which is behind the player
 
 Sprite_Minecart_DrawTop:
 {
@@ -945,6 +944,8 @@ Sprite_Minecart_DrawTop:
     db $02, $02
 }
 
+; =========================================================
+; Draw the portion of the cart which is in front of the player
 
 Sprite_Minecart_DrawBottom:
 {