icosahedron.hpp

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#pragma once
#ifndef OGLPLUS_SHAPES_ICOSAHEDRON_1206011111_HPP
#define OGLPLUS_SHAPES_ICOSAHEDRON_1206011111_HPP

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

#include <oglplus/shapes/vert_attr_info.hpp>
#include <oglplus/math/vector.hpp>
#include <oglplus/math/sphere.hpp>

namespace oglplus {
namespace shapes {

class IcosahedronBase
{
protected:
    static const GLushort* _indices(void);
    static const GLdouble* _positions(void);
};

class SimpleIcosahedron
 : public DrawingInstructionWriter
 , public DrawMode
 , public IcosahedronBase
{
public:
    FaceOrientation FaceWinding(void) const
    {
        return FaceOrientation::CCW;
    }

    typedef GLuint (SimpleIcosahedron::*VertexAttribFunc)(std::vector<GLfloat>&) const;

    template <typename T>
    GLuint Positions(std::vector<T>& dest) const
    {
        const GLdouble* p = _positions();
        dest.assign(p, p+12*3);
        return 3;
    }

#if OGLPLUS_DOCUMENTATION_ONLY

    typedef VertexAttribsInfo<Icosahedron> VertexAttribs;
#else
    typedef VertexAttribsInfo<
        SimpleIcosahedron,
        std::tuple<VertexPositionsTag>
    > VertexAttribs;
#endif

    template <typename T>
    void BoundingSphere(oglplus::Sphere<T>& bounding_sphere) const
    {
        bounding_sphere = oglplus::Sphere<T>(T(0), T(0), T(0), T(1));
    }

    typedef std::vector<GLushort> IndexArray;

    IndexArray Indices(Default = Default()) const
    {
        const GLushort* i = _indices();
        return IndexArray(i, i+20*3);
    }

    DrawingInstructions Instructions(PrimitiveType mode) const;

    DrawingInstructions Instructions(Default = Default()) const
    {
        return Instructions(PrimitiveType::Triangles);
    }
};

class Icosahedron
 : public DrawingInstructionWriter
 , public DrawMode
 , public IcosahedronBase
{
public:
    FaceOrientation FaceWinding(void) const
    {
        return FaceOrientation::CW;
    }

    typedef GLuint (Icosahedron::*VertexAttribFunc)(std::vector<GLfloat>&) const;

    template <typename T>
    GLuint Positions(std::vector<T>& dest) const
    {
        dest.resize(20*3*3);

        const GLdouble* p = _positions();
        const GLushort* i = _indices();

        for(GLuint f=0; f!=20; ++f)
        {
            for(GLuint v=0; v!=3; ++v)
            {
                for(GLuint c=0; c!=3; ++c)
                {
                    dest[f*9+v*3+c] = p[i[f*3+v]*3+c];
                }
            }
        }
        return 3;
    }

    template <typename T>
    GLuint Normals(std::vector<T>& dest) const
    {
        dest.resize(20*3*3);

        const GLdouble* p = _positions();
        const GLushort* i = _indices();

        for(GLuint f=0; f!=20; ++f)
        {
            Vector<T, 3> v0(
                p[i[f*3+0]*3+0],
                p[i[f*3+0]*3+1],
                p[i[f*3+0]*3+2]
            );
            Vector<T, 3> v1(
                p[i[f*3+1]*3+0],
                p[i[f*3+1]*3+1],
                p[i[f*3+1]*3+2]
            );
            Vector<T, 3> v2(
                p[i[f*3+2]*3+0],
                p[i[f*3+2]*3+1],
                p[i[f*3+2]*3+2]
            );
            Vector<T, 3> fn(Normalized(Cross(v1-v0, v2-v0)));

            for(GLuint v=0; v!=3; ++v)
            {
                for(GLuint c=0; c!=3; ++c)
                {
                    dest[f*9+v*3+c] = fn[c];
                }
            }
        }
        return 3;
    }

#if OGLPLUS_DOCUMENTATION_ONLY

    typedef VertexAttribsInfo<Icosahedron> VertexAttribs;
#else
    typedef VertexAttribsInfo<
        Icosahedron,
        std::tuple<
            VertexPositionsTag,
            VertexNormalsTag
        >
    > VertexAttribs;
#endif

    template <typename T>
    void BoundingSphere(Sphere<T>& center_and_radius) const
    {
        center_and_radius = Sphere<T>(T(0), T(0), T(0), T(1));
    }

    typedef std::vector<GLushort> IndexArray;

    IndexArray Indices(Default = Default()) const
    {
        return IndexArray();
    }

    DrawingInstructions Instructions(PrimitiveType mode) const;

    DrawingInstructions Instructions(Default = Default()) const
    {
        return Instructions(PrimitiveType::Triangles);
    }
};

} // shapes
} // oglplus

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

#endif // include guard