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/*
* Copyright (C) 2010 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef LoopBlinnTextureCoords_h
#define LoopBlinnTextureCoords_h
#include "FloatPoint3D.h"
#include "LoopBlinnClassifier.h"
#include "LoopBlinnConstants.h"
#include <wtf/Noncopyable.h>
namespace WebCore {
// Computes three-dimensional texture coordinates for the control
// points of a cubic curve for rendering via the shader in "Rendering
// Vector Art on the GPU" by Loop and Blinn, GPU Gems 3, Chapter 25.
class LoopBlinnTextureCoords {
public:
// Container for the cubic texture coordinates and other associated
// information.
struct Result {
Result()
: isLineOrPoint(false)
, hasRenderingArtifact(false)
, subdivisionParameterValue(0.0f) { }
// The (k, l, m) texture coordinates that are to be associated
// with the four control points of the cubic curve.
FloatPoint3D klmCoordinates[4];
// Indicates whether the curve is a line or a point, in which case
// we do not need to add its triangles to the mesh.
bool isLineOrPoint;
// For the loop case, indicates whether a rendering artifact was
// detected, in which case the curve needs to be further
// subdivided.
bool hasRenderingArtifact;
// If a rendering artifact will occur for the given loop curve,
// this is the parameter value (0 <= value <= 1) at which the
// curve needs to be subdivided to fix the artifact.
float subdivisionParameterValue;
};
// Computes the texture coordinates for a cubic curve segment's
// control points, given the classification of the curve as well as
// an indication of which side is to be filled.
static Result compute(const LoopBlinnClassifier::Result& classification,
LoopBlinnConstants::FillSide sideToFill);
private:
// This class does not need to be instantiated.
LoopBlinnTextureCoords() { }
};
} // namespace WebCore
#endif // LoopBlinnTextureCoords_h
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