Skip to navigation

Revs on the BBC Micro

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