Method computeTriangles

Engine/RotoContext.cpp:3821–4035

}

void
RotoContextPrivate::computeTriangles(const Bezier * bezier, double time, unsigned int mipmapLevel, double featherDist,
                                     std::list<RotoFeatherVertex>* featherMesh,
                                     std::list<RotoTriangleFans>* internalFans,
                                     std::list<RotoTriangles>* internalTriangles,
                                     std::list<RotoTriangleStrips>* internalStrips)
{
    ///Note that we do not use the opacity when rendering the bezier, it is rendered with correct floating point opacity/color when converting
    ///to the Natron image.

    bool clockWise = bezier->isFeatherPolygonClockwiseOriented(false, time);

    const double absFeatherDist = std::abs(featherDist);

    std::list<std::list<ParametricPoint> > featherPolygon;
    std::list<std::list<ParametricPoint> > bezierPolygon;

    RectD featherPolyBBox;
    featherPolyBBox.setupInfinity();

#ifdef ROTO_BEZIER_EVAL_ITERATIVE
    int error = -1;
#else
    double error = 1;
#endif

    bezier->evaluateFeatherPointsAtTime_DeCasteljau(false, time, mipmapLevel,error, true, &featherPolygon, &featherPolyBBox);
    bezier->evaluateAtTime_DeCasteljau(false, time, mipmapLevel, error,&bezierPolygon, NULL);


    // First compute the mesh composed of triangles of the feather
    assert( !featherPolygon.empty() && !bezierPolygon.empty() && featherPolygon.size() == bezierPolygon.size());

    std::list<std::list<ParametricPoint> >::const_iterator fIt = featherPolygon.begin();
    for (std::list<std::list<ParametricPoint> > ::const_iterator it = bezierPolygon.begin(); it != bezierPolygon.end(); ++it, ++fIt) {

        // Iterate over each bezier segment.
        // There are the same number of bezier segments for the feather and the internal bezier. Each discretized segment is a contour (list of vertices)

        std::list<ParametricPoint>::const_iterator bSegmentIt = it->begin();
        std::list<ParametricPoint>::const_iterator fSegmentIt = fIt->begin();

        assert(!it->empty() && !fIt->empty());


        // prepare iterators to compute derivatives for feather distance
        std::list<ParametricPoint>::const_iterator fnext = fSegmentIt;
        ++fnext;  // can only be valid since we assert the list is not empty
        if ( fnext == fIt->end() ) {
            fnext = fIt->begin();
        }
        std::list<ParametricPoint>::const_iterator fprev = fIt->end();
        --fprev; // can only be valid since we assert the list is not empty


        // initialize the state with a segment between the first inner vertex and first outer vertex
        RotoFeatherVertex lastInnerVert,lastOutterVert;
        {