TexGen

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/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * OpenSceneGraph Public License for more details.
*/
 
#ifndef OSG_TEXGEN
#define OSG_TEXGEN 1
 
#include <osg/Plane>
#include <osg/StateAttribute>
 
#if defined(OSG_GLES1_AVAILABLE) || defined(OSG_GLES2_AVAILABLE) || defined(OSG_GLES3_AVAILABLE) || defined(OSG_GL3_AVAILABLE)
    #define GL_OBJECT_LINEAR    0x2401
    #define GL_EYE_LINEAR       0x2400
    #define GL_SPHERE_MAP       0x2402
    #define GL_TEXTURE_GEN_S    0x0C60
    #define GL_TEXTURE_GEN_T    0x0C61
    #define GL_TEXTURE_GEN_R    0x0C62
    #define GL_TEXTURE_GEN_Q    0x0C63
#endif
 
#ifndef GL_NORMAL_MAP_ARB
    #define GL_NORMAL_MAP_ARB                   0x8511
#endif
 
#ifndef GL_REFLECTION_MAP_ARB
    #define GL_REFLECTION_MAP_ARB               0x8512
#endif
 
namespace osg {

class OSG_EXPORT TexGen : public StateAttribute
{
    public :
 
        TexGen();

        TexGen(const TexGen& texgen,const CopyOp& copyop=CopyOp::SHALLOW_COPY):
            StateAttribute(texgen,copyop),
            _mode(texgen._mode),
            _plane_s(texgen._plane_s),
            _plane_t(texgen._plane_t),
            _plane_r(texgen._plane_r),
            _plane_q(texgen._plane_q) {}
 
        META_StateAttribute(osg, TexGen, TEXGEN);
 
        virtual bool isTextureAttribute() const { return true; }

        virtual int compare(const StateAttribute& sa) const
        {
            // Check for equal types, then create the rhs variable
            // used by the COMPARE_StateAttribute_Parameter macros below.
            COMPARE_StateAttribute_Types(TexGen,sa)
 
            // Compare each parameter in turn against the rhs.
            COMPARE_StateAttribute_Parameter(_mode)
            COMPARE_StateAttribute_Parameter(_plane_s)
            COMPARE_StateAttribute_Parameter(_plane_t)
            COMPARE_StateAttribute_Parameter(_plane_r)
            COMPARE_StateAttribute_Parameter(_plane_q)
 
            return 0; // Passed all the above comparison macros, so must be equal.
        }
 
        virtual bool getModeUsage(StateAttribute::ModeUsage& usage) const
        {
            usage.usesTextureMode(GL_TEXTURE_GEN_S);
            usage.usesTextureMode(GL_TEXTURE_GEN_T);
 
            // Not happy with turning all tex gen parameters on
            // as the OSG currently only supports 2D textures and therefore
            // only S and T will be required, R&Q would be redundant...
            // So commenting out the following until OSG supports 3D textures.
            // I plan to revamp the OpenGL state management later so will
            // tidy up then.  Robert Osfield. Jan 2001.
 
            // The tidy up is now happening, but will have a think before
            // resolving the below parameters.
 
            usage.usesTextureMode(GL_TEXTURE_GEN_R);
            usage.usesTextureMode(GL_TEXTURE_GEN_Q);
            return true;
        }
 
        virtual void apply(State& state) const;
 
        enum Mode {
            OBJECT_LINEAR  = GL_OBJECT_LINEAR,
            EYE_LINEAR     = GL_EYE_LINEAR,
            SPHERE_MAP     = GL_SPHERE_MAP,
            NORMAL_MAP     = GL_NORMAL_MAP_ARB,
            REFLECTION_MAP = GL_REFLECTION_MAP_ARB
        };
 
        inline void setMode( Mode mode ) { _mode = mode; }
 
        Mode getMode() const { return _mode; }
 
        enum Coord {
          S, T, R, Q
        };
 
        void setPlane(Coord which, const Plane& plane);
 
        Plane& getPlane(Coord which);
 
        const Plane& getPlane(Coord which) const;

        void setPlanesFromMatrix(const Matrixd& matrix);
 
    protected :
 
        virtual ~TexGen( void );
 
        Mode _mode;

        Plane _plane_s, _plane_t, _plane_r, _plane_q;
 
};
 
}
 
#endif