+ void doGouraudTriangleShFill(GfxGouraudTriangleShading *shading);
+ void gouraudFillTriangle(double x0, double y0, GfxColor *color0,
+ double x1, double y1, GfxColor *color1,
+ double x2, double y2, GfxColor *color2,
+ int nComps, int depth);
+ void doPatchMeshShFill(GfxPatchMeshShading *shading);
+ void fillPatch(GfxPatch *patch, int nComps, int depth);