TangentSpaceGenerator.h

// This file is a part of the OpenSurgSim project.
// Copyright 2013, SimQuest Solutions Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef SURGSIM_GRAPHICS_TANGENTSPACEGENERATOR_H
#define SURGSIM_GRAPHICS_TANGENTSPACEGENERATOR_H

#include <osg/NodeVisitor>
#include <osg/Geode>
#include <osg/Geometry>

namespace SurgSim
{
namespace Graphics
{

class GenerateTangentSpaceTriangleIndexFunctor
{
public:
    GenerateTangentSpaceTriangleIndexFunctor();

    void setBasisOrthonormality(bool orthonormal);

    bool getBasisOrthonormality();

    void set(const osg::Vec3Array* vertexArray,
             const osg::Vec3Array* normalArray,
             const osg::Vec2Array* textureCoordArray,
             osg::Vec4Array* tangentArray,
             osg::Vec4Array* bitangentArray);

    void orthogonalize();

    void reset();

    //  space basis vectors.
    void operator()(unsigned int vertexIndex1, unsigned int vertexIndex2, unsigned int vertexIndex3);

private:
    const osg::Vec3Array* m_vertexArray;

    const osg::Vec3Array* m_normalArray;

    const osg::Vec2Array* m_textureCoordArray;

    osg::Vec4Array* m_tangentArray;

    osg::Vec4Array* m_bitangentArray;

    bool m_createOrthonormalBasis;
};

class TangentSpaceGenerator : public osg::NodeVisitor
{
public:
    TangentSpaceGenerator(int textureCoordUnit, int tangentAttribIndex, int bitangentAttribIndex);

    virtual ~TangentSpaceGenerator();

    void setBasisOrthonormality(bool orthonormal);

    bool getBasisOrthonormality();

    void apply(osg::Geode& geode) override; // NOLINT

    static void generateTangentSpace(osg::Geometry* geometry,
                                     int textureCoordUnit,
                                     int tangentAttribIndex,
                                     int bitangentAttribIndex,
                                     bool orthonormal);

private:
    int m_textureCoordUnit;

    int m_tangentAttribIndex;

    int m_bitangentAttribIndex;

    bool m_createOrthonormalBasis;
};

}
}

#endif