Dashboard: CopyTyreDashEdges

       Name: CopyTyreDashEdges                                       [Show more]
       Type: Subroutine
   Category: Dashboard
    Summary: Fetch the pixel bytes from the right edge of the left tyre and the
             right edge of the dashboard, and fill to the right of the edge
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * MainDrivingLoop (Part 2 of 5) calls CopyTyreDashEdges


 This routine populates the tyreRightEdge and dashRightEdge tables with the
 pixel bytes along the right edge of the left tyre and the right edge of the
 dashboard respectively. It also fills the block to the right of the edge with
 the appropriate content, so the feathered edges don't fill to the right.


.CopyTyreDashEdges

 LDA #HI(tyreRightEdge) \ Set (S R) = tyreRightEdge
 STA S                  \
 LDA #LO(tyreRightEdge) \ so the call to GetTyreDashEdges copies the pixel data
 STA R                  \ from the tyre edge into the tyreRightEdge table

 LDY #27                \ Start at byte 27 in the dash data, so we work down the
                        \ screen from track line 27

 LDX #3                 \ Loop through dash data blocks 3 to 5
 LDA #6

 JSR GetTyreDashEdges   \ Fetch the pixel bytes from along the right edge of the
                        \ left tyre and fill the block to the right of the edge
                        \ with the appropriate content

 LDA #HI(dashRightEdge) \ Set (S R) = dashRightEdge
 STA S                  \
 LDA #LO(dashRightEdge) \ so the call to GetTyreDashEdges copies the pixel data
 STA R                  \ from the dashboard edge into the dashRightEdge table

 LDY #43                \ Start at byte 43 in the dash data, so we work down the
                        \ screen from track line 43

 LDX #26                \ Loop through dash data blocks 26 to 33
 LDA #34

 JSR GetTyreDashEdges   \ Fetch the pixel bytes from along the right edge of the
                        \ dashboard and fill the block to the right of the edge
                        \ with the appropriate content

 RTS                    \ Return from the subroutine