tetrahedrons.hpp

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#pragma once
#ifndef OGLPLUS_SHAPES_TETRAHEDRONS_1201311347_HPP
#define OGLPLUS_SHAPES_TETRAHEDRONS_1201311347_HPP

#include <oglplus/shapes/draw.hpp>
#include <oglplus/face_mode.hpp>

#include <oglplus/shapes/vert_attr_info.hpp>

#include <oglplus/math/sphere.hpp>
#include <cmath>
#include <cassert>

namespace oglplus {
namespace shapes {

class Tetrahedrons
 : public DrawingInstructionWriter
 , public DrawMode
{
private:
    GLdouble _side;
    unsigned _divisions;
public:
    Tetrahedrons(void)
     : _side(1.0)
     , _divisions(10)
    { }

    Tetrahedrons(GLdouble side, unsigned divisions)
     : _side(side)
     , _divisions(divisions)
    {
        assert(_side > 0.0);
        assert(divisions > 0);
    }

    FaceOrientation FaceWinding(void) const
    {
        return FaceOrientation::CW;
    }

    template <typename T>
    GLuint Positions(std::vector<T>& dest) const
    {
        const unsigned n = _divisions + 1;
        unsigned k = 0;
        dest.resize(n*n*n*3+3);

        dest[k++] = T(0);
        dest[k++] = T(0);
        dest[k++] = T(0);

        GLdouble step = _side / _divisions;
        //
        for(unsigned z=0; z!=n; ++z)
        for(unsigned y=0; y!=n; ++y)
        for(unsigned x=0; x!=n; ++x)
        {
            dest[k++] = T(x*step);
            dest[k++] = T(y*step);
            dest[k++] = T(z*step);
        }
        assert(k == dest.size());
        return 3;
    }

    template <typename T>
    GLuint TexCoordinates(std::vector<T>& dest) const
    {
        const unsigned n = _divisions + 1;
        unsigned k = 0;
        dest.resize(n*n*n*3+3);

        dest[k++] = T(0);
        dest[k++] = T(0);
        dest[k++] = T(0);

        GLdouble step = 1.0 / _divisions;
        //
        for(unsigned z=0; z!=n; ++z)
        for(unsigned y=0; y!=n; ++y)
        for(unsigned x=0; x!=n; ++x)
        {
            dest[k++] = T(x*step);
            dest[k++] = T(y*step);
            dest[k++] = T(z*step);
        }
        assert(k == dest.size());
        return 3;
    }

#if OGLPLUS_DOCUMENTATION_ONLY

    typedef VertexAttribsInfo<Tetrahedrons> VertexAttribs;
#else
    typedef VertexAttribsInfo<
        Tetrahedrons,
        std::tuple<
            VertexPositionsTag,
            VertexTexCoordinatesTag
        >
    > VertexAttribs;
#endif

    // This is here just for consistency with Shape wrapper
    template <typename T>
    void BoundingSphere(oglplus::Sphere<T>&) const
    {
    }

    typedef std::vector<GLuint> IndexArray;

    IndexArray Indices(WithAdjacency = WithAdjacency()) const;

    DrawingInstructions Instructions(WithAdjacency = WithAdjacency()) const;
};

} // shapes
} // oglplus

#if !OGLPLUS_LINK_LIBRARY || defined(OGLPLUS_IMPLEMENTING_LIBRARY)
#include <oglplus/shapes/tetrahedrons.ipp>
#endif //OGLPLUS_LINK_LIBRARY

#endif // include guard