OpenSceneGraph/include/osg/TexEnvCombine

//C++ header - Open Scene Graph - Copyright (C) 1998-2002 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.

#ifndef OSG_TEXENVCOMBINE
#define OSG_TEXENVCOMBINE 1

#include <osg/GL>
#include <osg/StateAttribute>
#include <osg/Vec4>

// if not defined by gl.h use the definition found in:
// http://oss.sgi.com/projects/ogl-sample/registry/ARB/texture_env_combine.txt
#ifndef GL_ARB_texture_env_combine
#define GL_ARB_texture_env_combine 1
#define GL_COMBINE_ARB                                     0x8570
#define GL_COMBINE_RGB_ARB                                 0x8571
#define GL_COMBINE_ALPHA_ARB                               0x8572
#define GL_SOURCE0_RGB_ARB                                 0x8580
#define GL_SOURCE1_RGB_ARB                                 0x8581
#define GL_SOURCE2_RGB_ARB                                 0x8582
#define GL_SOURCE0_ALPHA_ARB                               0x8588
#define GL_SOURCE1_ALPHA_ARB                               0x8589
#define GL_SOURCE2_ALPHA_ARB                               0x858A
#define GL_OPERAND0_RGB_ARB                                0x8590
#define GL_OPERAND1_RGB_ARB                                0x8591
#define GL_OPERAND2_RGB_ARB                                0x8592
#define GL_OPERAND0_ALPHA_ARB                              0x8598
#define GL_OPERAND1_ALPHA_ARB                              0x8599
#define GL_OPERAND2_ALPHA_ARB                              0x859A
#define GL_RGB_SCALE_ARB                                   0x8573
#define GL_ADD_SIGNED_ARB                                  0x8574
#define GL_INTERPOLATE_ARB                                 0x8575
#define GL_SUBTRACT_ARB                                    0x84E7
#define GL_CONSTANT_ARB                                    0x8576
#define GL_PRIMARY_COLOR_ARB                               0x8577
#define GL_PREVIOUS_ARB                                    0x8578
#endif

namespace osg {

/** TexEnvCombine - encapsulates the OpenGL glTexEnvCombine (texture environment) state.*/
class SG_EXPORT TexEnvCombine : public StateAttribute
{
    public :

        TexEnvCombine();
        
        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
        TexEnvCombine(const TexEnvCombine& texenv,const CopyOp& copyop=CopyOp::SHALLOW_COPY):
            StateAttribute(texenv,copyop),
            _combine_RGB(texenv._combine_RGB),
            _combine_Alpha(texenv._combine_Alpha),
            _source0_RGB(texenv._source0_RGB),
            _source1_RGB(texenv._source1_RGB),
            _source2_RGB(texenv._source2_RGB),
            _source0_Alpha(texenv._source0_Alpha),
            _source1_Alpha(texenv._source1_Alpha),
            _source2_Alpha(texenv._source2_Alpha),
            _operand0_RGB(texenv._operand0_RGB),
            _operand1_RGB(texenv._operand1_RGB),
            _operand2_RGB(texenv._operand2_RGB),
            _operand0_Alpha(texenv._operand0_Alpha),
            _operand1_Alpha(texenv._operand1_Alpha),
            _operand2_Alpha(texenv._operand2_Alpha),
            _scale_RGB(texenv._scale_RGB),
            _scale_Alpha(texenv._scale_Alpha),
            _constantColor(texenv._constantColor) {}


        META_StateAttribute(osg, TexEnvCombine, TEXENV);


        virtual bool isTextureAttribute() const { return true; }

        /** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.*/
        virtual int compare(const StateAttribute& sa) const
        {
            // check the types are equal and then create the rhs variable
            // used by the COMPARE_StateAttribute_Paramter macro's below.
            COMPARE_StateAttribute_Types(TexEnvCombine,sa)

            // compare each paramter in turn against the rhs.
            COMPARE_StateAttribute_Parameter(_combine_RGB)
            COMPARE_StateAttribute_Parameter(_combine_Alpha)
            COMPARE_StateAttribute_Parameter(_source0_RGB)
            COMPARE_StateAttribute_Parameter(_source1_RGB)
            COMPARE_StateAttribute_Parameter(_source2_RGB)
            COMPARE_StateAttribute_Parameter(_source0_Alpha)
            COMPARE_StateAttribute_Parameter(_source1_Alpha)
            COMPARE_StateAttribute_Parameter(_source2_Alpha)
            COMPARE_StateAttribute_Parameter(_operand0_RGB)
            COMPARE_StateAttribute_Parameter(_operand1_RGB)
            COMPARE_StateAttribute_Parameter(_operand2_RGB)
            COMPARE_StateAttribute_Parameter(_operand0_Alpha)
            COMPARE_StateAttribute_Parameter(_operand1_Alpha)
            COMPARE_StateAttribute_Parameter(_operand2_Alpha)
            COMPARE_StateAttribute_Parameter(_scale_RGB)
            COMPARE_StateAttribute_Parameter(_scale_Alpha)
            COMPARE_StateAttribute_Parameter(_constantColor)

            return 0; // passed all the above comparison macro's, must be equal.
        }


        enum CombineParam
        {
            REPLACE         = GL_REPLACE,
            MODULATE        = GL_MODULATE,
            ADD             = GL_ADD,
            ADD_SIGNED      = GL_ADD_SIGNED_ARB,
            INTERPOLATE     = GL_INTERPOLATE_ARB,
            SUBTRACT        = GL_SUBTRACT_ARB
        };

        void setCombineRGB(GLint cm) { _combine_RGB = cm; }
        void setCombineAlpha(GLint cm) { _combine_Alpha = cm; }

        GLint getCombineRGB() const { return _combine_RGB; }
        GLint getCombineAlpha() const { return _combine_Alpha; }
        
        enum SourceParam
        {
            TEXTURE         = GL_TEXTURE,
            CONSTANT        = GL_CONSTANT_ARB,
            PRIMARY_COLOR   = GL_PRIMARY_COLOR_ARB,
            PREVIOUS        = GL_PREVIOUS_ARB
        };
        
        void setSource0_RGB(GLint sp) { _source0_RGB = sp; }
        void setSource1_RGB(GLint sp) { _source1_RGB = sp; }
        void setSource2_RGB(GLint sp) { _source2_RGB = sp; }
        
        void setSource0_Alpha(GLint sp) { _source0_Alpha = sp; }
        void setSource1_Alpha(GLint sp) { _source1_Alpha = sp; }
        void setSource2_Alpha(GLint sp) { _source2_Alpha = sp; }

        GLint getSource0_RGB() const { return _source0_RGB; }
        GLint getSource1_RGB() const { return _source1_RGB; }
        GLint getSource2_RGB() const { return _source2_RGB; }
        
        GLint getSource0_Alpha() const { return _source0_Alpha; }
        GLint getSource1_Alpha() const { return _source1_Alpha; }
        GLint getSource2_Alpha() const { return _source2_Alpha; }

        enum OperandParam
        {
            SRC_COLOR           = GL_SRC_COLOR,
            ONE_MINUS_SRC_COLOR = GL_ONE_MINUS_SRC_COLOR,
            SRC_ALPHA           = GL_SRC_ALPHA,
            ONE_MINUS_SRC_ALPHA = GL_ONE_MINUS_SRC_ALPHA
        };
        
        void setOperand0_RGB(GLint op) { _operand0_RGB = op; }
        void setOperand1_RGB(GLint op) { _operand1_RGB = op; }
        void setOperand2_RGB(GLint op) { _operand2_RGB = op; }
        
        void setOperand0_Alpha(GLint op) { _operand0_Alpha = op; }
        void setOperand1_Alpha(GLint op) { _operand1_Alpha = op; }
        void setOperand2_Alpha(GLint op) { _operand2_Alpha = op; }

        GLint getOperand0_RGB() const { return _operand0_RGB; }
        GLint getOperand1_RGB() const { return _operand1_RGB; }
        GLint getOperand2_RGB() const { return _operand2_RGB; }
        
        GLint getOperand0_Alpha() const { return _operand0_Alpha; }
        GLint getOperand1_Alpha() const { return _operand1_Alpha; }
        GLint getOperand2_Alpha() const { return _operand2_Alpha; }


        void setScale_RGB(float scale) { _scale_RGB = scale; }
        void setScale_Alpha(float scale) { _scale_Alpha = scale; }

        float getScale_RGB() const { return _scale_RGB; }
        float getScale_Alpha() const { return _scale_Alpha; }

        void setConstantColor( const Vec4& color ) { _constantColor = color; }
        const Vec4& getConstantColor() const { return _constantColor; }


        virtual void apply(State& state) const;

    protected :

        virtual ~TexEnvCombine();


        GLint           _combine_RGB;
        GLint           _combine_Alpha;


        GLint           _source0_RGB;
        GLint           _source1_RGB;
        GLint           _source2_RGB;
        
        GLint           _source0_Alpha;
        GLint           _source1_Alpha;
        GLint           _source2_Alpha;


        GLint           _operand0_RGB;
        GLint           _operand1_RGB;
        GLint           _operand2_RGB;
        
        GLint           _operand0_Alpha;
        GLint           _operand1_Alpha;
        GLint           _operand2_Alpha;


        float           _scale_RGB;
        float           _scale_Alpha;
        
        osg::Vec4       _constantColor;

};

}

#endif