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26 #ifndef LoopBlinnTextureCoords_h
27 #define LoopBlinnTextureCoords_h
29 #include "FloatPoint3D.h"
30 #include "LoopBlinnClassifier.h"
31 #include "LoopBlinnConstants.h"
33 #include <wtf/Noncopyable.h>
37 // Computes three-dimensional texture coordinates for the control
38 // points of a cubic curve for rendering via the shader in "Rendering
39 // Vector Art on the GPU" by Loop and Blinn, GPU Gems 3, Chapter 25.
40 class LoopBlinnTextureCoords {
42 // Container for the cubic texture coordinates and other associated
46 : isLineOrPoint(false)
47 , hasRenderingArtifact(false)
48 , subdivisionParameterValue(0.0f) { }
50 // The (k, l, m) texture coordinates that are to be associated
51 // with the four control points of the cubic curve.
52 FloatPoint3D klmCoordinates[4];
54 // Indicates whether the curve is a line or a point, in which case
55 // we do not need to add its triangles to the mesh.
58 // For the loop case, indicates whether a rendering artifact was
59 // detected, in which case the curve needs to be further
61 bool hasRenderingArtifact;
63 // If a rendering artifact will occur for the given loop curve,
64 // this is the parameter value (0 <= value <= 1) at which the
65 // curve needs to be subdivided to fix the artifact.
66 float subdivisionParameterValue;
69 // Computes the texture coordinates for a cubic curve segment's
70 // control points, given the classification of the curve as well as
71 // an indication of which side is to be filled.
72 static Result compute(const LoopBlinnClassifier::Result& classification,
73 LoopBlinnConstants::FillSide sideToFill);
76 // This class does not need to be instantiated.
77 LoopBlinnTextureCoords() { }
80 } // namespace WebCore
82 #endif // LoopBlinnTextureCoords_h