void CHWTessellator::IsoLineProcessTessFactors()

in d3d/archive/images/d3d11/tessellator.cpp [1399:1485]
66 lines of code
11 McCabe index (conditional complexity)

void CHWTessellator::IsoLineProcessTessFactors( float TessFactor_V_LineDensity, float TessFactor_U_LineDetail, 
                                                PROCESSED_TESS_FACTORS_ISOLINE& processedTessFactors )
{
    // Is the patch culled?
    if( !(TessFactor_V_LineDensity > 0) || // NaN will pass
        !(TessFactor_U_LineDetail > 0) )
    {
        processedTessFactors.bPatchCulled = true;
        return;
    }
    else
    {
        processedTessFactors.bPatchCulled = false;
    }

    // Clamp edge TessFactors
    float lowerBound, upperBound;
    switch(m_originalPartitioning)
    {
        case D3D11_TESSELLATOR_PARTITIONING_INTEGER:
        case D3D11_TESSELLATOR_PARTITIONING_POW2: // don�t care about pow2 distinction for validation, just treat as integer
            lowerBound = D3D11_TESSELLATOR_MIN_ODD_TESSELLATION_FACTOR;
            upperBound = D3D11_TESSELLATOR_MAX_EVEN_TESSELLATION_FACTOR;
            break;
         
        case D3D11_TESSELLATOR_PARTITIONING_FRACTIONAL_EVEN:
            lowerBound = D3D11_TESSELLATOR_MIN_EVEN_TESSELLATION_FACTOR;
            upperBound = D3D11_TESSELLATOR_MAX_EVEN_TESSELLATION_FACTOR;
            break;

        case D3D11_TESSELLATOR_PARTITIONING_FRACTIONAL_ODD:
            lowerBound = D3D11_TESSELLATOR_MIN_ODD_TESSELLATION_FACTOR;
            upperBound = D3D11_TESSELLATOR_MAX_ODD_TESSELLATION_FACTOR;
            break;
    }

    TessFactor_V_LineDensity = fmin( D3D11_TESSELLATOR_MAX_ISOLINE_DENSITY_TESSELLATION_FACTOR, 
                                    fmax( D3D11_TESSELLATOR_MIN_ISOLINE_DENSITY_TESSELLATION_FACTOR, TessFactor_V_LineDensity ) );
    TessFactor_U_LineDetail = fmin( upperBound, fmax( lowerBound, TessFactor_U_LineDetail ) );

    // Reset our vertex and index buffers.  We have enough storage for the max tessFactor.
    m_NumPoints = 0;
    m_NumIndices = 0;

    // Process tessFactors
    if( HWIntegerPartitioning() )
    {
        TessFactor_U_LineDetail = ceil(TessFactor_U_LineDetail);
        processedTessFactors.lineDetailParity = isEven(TessFactor_U_LineDetail) ? TESSELLATOR_PARITY_EVEN : TESSELLATOR_PARITY_ODD;
    }
    else
    {
        processedTessFactors.lineDetailParity = m_originalParity;
    }

    FXP fxpTessFactor_U_LineDetail = floatToFixed(TessFactor_U_LineDetail);
    
    SetTessellationParity(processedTessFactors.lineDetailParity);

    ComputeTessFactorContext(fxpTessFactor_U_LineDetail, processedTessFactors.lineDetailTessFactorCtx);
    processedTessFactors.numPointsPerLine = NumPointsForTessFactor(fxpTessFactor_U_LineDetail);

    OverridePartitioning(D3D11_TESSELLATOR_PARTITIONING_INTEGER);

    TessFactor_V_LineDensity = ceil(TessFactor_V_LineDensity);
    processedTessFactors.lineDensityParity = isEven(TessFactor_V_LineDensity) ? TESSELLATOR_PARITY_EVEN : TESSELLATOR_PARITY_ODD;
    SetTessellationParity(processedTessFactors.lineDensityParity);
    FXP fxpTessFactor_V_LineDensity = floatToFixed(TessFactor_V_LineDensity);
    ComputeTessFactorContext(fxpTessFactor_V_LineDensity, processedTessFactors.lineDensityTessFactorCtx);

    processedTessFactors.numLines = NumPointsForTessFactor(fxpTessFactor_V_LineDensity) - 1; // don't draw last line at V == 1.

    RestorePartitioning();

    // Compute some initial data.

    // outside edge offsets
    m_NumPoints = processedTessFactors.numPointsPerLine * processedTessFactors.numLines;
    if( m_outputPrimitive == D3D11_TESSELLATOR_OUTPUT_POINT )
    {
        m_NumIndices = m_NumPoints;
    }
    else // line
    {
        m_NumIndices = processedTessFactors.numLines*(processedTessFactors.numPointsPerLine-1)*2;
    }
}