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Aviator on the BBC Micro

3D geometry: SetPointVisibility

Name: SetPointVisibility [Show more] Type: Subroutine Category: 3D geometry Summary: Set the status byte for multiple points to indicate that their coordinates and visibility have been calculated
Context: See this subroutine in context in the source code References: This subroutine is called as follows: * ProcessRunwayLine (Part 2 of 5) calls SetPointVisibility * ProcessRunwayLine (Part 4 of 5) calls SetPointVisibility

Arguments: X The ID of the point to update
.SetPointVisibility LDA #%10000000 \ Set bit 7 of point X's status byte, to indicate that ORA pointStatus,X \ the point's coordinates and visibility have been STA pointStatus,X \ calculated DEX \ Decrement X to point to the previous point BNE SetPointVisibility \ Loop back until we have set the status byte for points \ X down to 1, i.e. points 1 to X RTS \ Return from the subroutine