void CHWTessellator::QuadGeneratePoints()

in d3d/archive/images/d3d11/tessellator.cpp [686:787]
97 lines of code
21 McCabe index (conditional complexity)

void CHWTessellator::QuadGeneratePoints( const PROCESSED_TESS_FACTORS_QUAD& processedTessFactors )
{
    // Generate exterior ring edge points, clockwise from top-left
    int pointOffset = 0;
    int edge;
    for(edge = 0; edge < QUAD_EDGES; edge++ )
    {
        int parity = edge&0x1;
        int startPoint = 0;
        int endPoint = processedTessFactors.numPointsForOutsideEdge[edge] - 1;
        for(int p = startPoint; p < endPoint; p++,pointOffset++) // don't include end, since next edge starts with it.
        {
            FXP fxpParam;
            int q = ((edge==1)||(edge==2)) ? p : endPoint - p; // reverse order 
            SetTessellationParity(processedTessFactors.outsideTessFactorParity[edge]);
            PlacePointIn1D(processedTessFactors.outsideTessFactorCtx[edge],q,fxpParam);
            if( parity )
            {
                DefinePoint(/*U*/fxpParam,
                            /*V*/(edge == 3) ? FXP_ONE : 0,
                            /*pointStorageOffset*/pointOffset);
            }
            else
            {
                DefinePoint(/*U*/(edge == 2) ? FXP_ONE : 0,
                            /*V*/fxpParam,
                            /*pointStorageOffset*/pointOffset);
            }
        }
    }

    // Generate interior ring points, clockwise from (U==0,V==1) (bottom-left) spiralling toward center
    static const int startRing = 1;
    int minNumPointsForTessFactor = min(processedTessFactors.numPointsForInsideTessFactor[U],processedTessFactors.numPointsForInsideTessFactor[V]);
    int numRings = (minNumPointsForTessFactor >> 1);  // note for even tess we aren't counting center point here.
    for(int ring = startRing; ring < numRings; ring++)
    {
        int startPoint = ring;
        int endPoint[QUAD_AXES] = {processedTessFactors.numPointsForInsideTessFactor[U] - 1 - startPoint,
                                   processedTessFactors.numPointsForInsideTessFactor[V] - 1 - startPoint};

        for(edge = 0; edge < QUAD_EDGES; edge++ )
        {
            int parity[QUAD_AXES] = {edge&0x1,((edge+1)&0x1)};
            int perpendicularAxisPoint = (edge < 2) ? startPoint : endPoint[parity[0]];
            FXP fxpPerpParam;
            SetTessellationParity(processedTessFactors.insideTessFactorParity[parity[0]]);
            PlacePointIn1D(processedTessFactors.insideTessFactorCtx[parity[0]],perpendicularAxisPoint,fxpPerpParam);
            SetTessellationParity(processedTessFactors.insideTessFactorParity[parity[1]]);
            for(int p = startPoint; p < endPoint[parity[1]]; p++, pointOffset++) // don't include end: next edge starts with it. 
            {
                FXP fxpParam;
                int q = ((edge == 1)||(edge==2)) ? p : endPoint[parity[1]] - (p - startPoint);
                PlacePointIn1D(processedTessFactors.insideTessFactorCtx[parity[1]],q,fxpParam);
                if( parity[1] )
                {
                    DefinePoint(/*U*/fxpPerpParam,
                                /*V*/fxpParam,
                                /*pointStorageOffset*/pointOffset);
                }
                else
                {
                    DefinePoint(/*U*/fxpParam,
                                /*V*/fxpPerpParam,
                                /*pointStorageOffset*/pointOffset);
                }
            }
        }
    }
    // For even tessellation, the inner "ring" is degenerate - a row of points
    if( (processedTessFactors.numPointsForInsideTessFactor[U] > processedTessFactors.numPointsForInsideTessFactor[V]) && 
        (TESSELLATOR_PARITY_EVEN == processedTessFactors.insideTessFactorParity[V]) )
    {
        int startPoint = numRings;
        int endPoint = processedTessFactors.numPointsForInsideTessFactor[U] - 1 - startPoint;
        SetTessellationParity(processedTessFactors.insideTessFactorParity[U]);
        for( int p = startPoint; p <= endPoint; p++, pointOffset++ )
        {
            FXP fxpParam;
            PlacePointIn1D(processedTessFactors.insideTessFactorCtx[U],p,fxpParam);
            DefinePoint(/*U*/fxpParam,
                        /*V*/FXP_ONE_HALF, // middle
                        /*pointStorageOffset*/pointOffset);
        }
    }
    else if( (processedTessFactors.numPointsForInsideTessFactor[V] >= processedTessFactors.numPointsForInsideTessFactor[U]) && 
             (TESSELLATOR_PARITY_EVEN == processedTessFactors.insideTessFactorParity[U]) )
    {
        int startPoint = numRings;
        int endPoint;
        FXP fxpParam;
        endPoint = processedTessFactors.numPointsForInsideTessFactor[V] - 1 - startPoint;
        SetTessellationParity(processedTessFactors.insideTessFactorParity[V]);
        for( int p = endPoint; p >= startPoint; p--, pointOffset++ )
        {
            PlacePointIn1D(processedTessFactors.insideTessFactorCtx[V],p,fxpParam);
            DefinePoint(/*U*/FXP_ONE_HALF, // middle
                        /*V*/fxpParam,
                        /*pointStorageOffset*/pointOffset);
        }
    }
}