Dashboard: GetTyreDashEdge

       Name: GetTyreDashEdge                                         [Show more]
       Type: Subroutine
   Category: Dashboard
    Summary: Copy the pixel bytes along the tyre and dashboard edges so they
             can be feathered
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * GetTyreDashEdges calls GetTyreDashEdge


 Modify the FillAfterObject routine before calling it.


 Arguments:

   X                    Sets the destination address for the copy

   Y                    Alters the routine flow to either fill or copy

   A                    The value to use when copying black pixel bytes


IF _ACORNSOFT OR _4TRACKS

.GetTyreDashEdge

 STX edge7+1            \ Modify the following instruction at edge7:
                        \
                        \   STA (P),Y -> STA (R),Y          when X = LO(R)
                        \
                        \   STA (P),Y -> STA (P),Y          when X = LO(P)

 STY edge11+1           \ Modify the following instruction at edge11:
                        \
                        \   BNE edge3 -> BNE edge1          when Y = &DF
                        \
                        \   BNE edge3 -> BNE edge3          when Y = &E7

 STA edge6+1            \ Modify the following instruction at edge6:
                        \
                        \   LDA #&55 -> LDA #0              when A = 0
                        \
                        \   LDA #&55 -> LDA #&55            when A = &55

                        \ Fall through into FillAfterObject to copy the edge
                        \ data to the location specified in (S R)

ENDIF