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SUBROUTINE INQPVI (VINDEX,MAXVTX,NVERTX)
C$ (Inquire Polygon Vertex Indices)
C$ Return the current polygon vertex indices. These are color
C$ lookup table indices for each polygon vertex which are to
C$ be used for filling polygons of interior style "shaded".
C$ The shading is done in a two step process. First the edge
C$ values are determined by linear interpolation along the
C$ edges using the vertex values. Then the interior values
C$ are determined by linear interpolation from edge to edge
C$ along the scan lines that cover the interior of the polygon
C$ image. The arguments are:
C$
C$ VINDEX(*).........Array of current polygon vertex color
C$ lookup table indices.
C$ MAXVTX............Actual declared dimension of VINDEX(*).
C$ NVERTX............Number of vertex entries currently
C$ present in the internal vertex index
C$ list. On return, if it is larger than
C$ MAXVTX, only the first MAXVTX elements
C$ have been returned in VINDEX(*), and an
C$ error message has been issued.
C$
C$ Note that the facility offered by this routine is only
C$ available on rather sophisticated (and expensive) raster
C$ display devices, and cannot be conveniently simulated on
C$ non-raster display devices. No warning is given if the
C$ selected display device cannot support it, and the
C$ operation requested will simply be ignored.
C$ (27-JAN-82)