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⌂ ∞ ▽ The Sentinel on the BBC Micro

Drawing polygons: trianglePointAdd

       Name: trianglePointAdd                                        [Show more]
       Type: Variable
   Category: Drawing polygons
    Summary: The value to add to the second point number to get the third point
             number when drawing a tile face as two triangles

    Context: See this variable in context in the source code
 References: This variable is used as follows:
             * GetPolygonLines (Part 1 of 6) uses trianglePointAdd




.trianglePointAdd

 EQUB 1                 \ Add when triangleStartPoint = 0 and we are drawing the
                        \ first of the two triangles

 EQUB 32 + 1            \ Add when triangleStartPoint = 1 and we are drawing the
                        \ first of the two triangles

 EQUB -1                \ Add when triangleStartPoint = 0 and we are drawing the
                        \ second of the two triangles

 EQUB 32 - 1            \ Add when triangleStartPoint = 1 and we are drawing the
                        \ second of the two triangles