Drawing the screen: HideHiddenColour

       Name: HideHiddenColour                                        [Show more]
       Type: Subroutine
   Category: Drawing the screen
    Summary: Set the hidden colour to black, so that pixels in this colour in
             palette 0 are invisible
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * Main flight loop (Part 13 of 16) calls HideHiddenColour
             * RES2 calls HideHiddenColour
             * SPIN calls via oh


 Returns:

   A                    A is set to 15


 Other entry points:

   oh                   Contains an RTS


.HideHiddenColour

 LDA #$0F               ; Set hiddenColour to $0F, which is black, so this hides
 STA hiddenColour       ; any pixels that use the hidden colour in palette 0

.oh

 RTS                    ; Return from the subroutine