1/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 2 * 3 * This library is open source and may be redistributed and/or modified under 4 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 5 * (at your option) any later version. The full license is in LICENSE file 6 * included with this distribution, and on the openscenegraph.org website. 7 * 8 * This library is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * OpenSceneGraph Public License for more details. 12*/ 13 14#ifndef OSG_BLENDEQUATION 15#define OSG_BLENDEQUATION 1 16 17#include <osg/StateAttribute> 18 19#ifndef GL_VERSION_1_2 20/* Logic Ops */ 21#define GL_MIN 0x8007 22#define GL_MAX 0x8008 23#define GL_FUNC_ADD 0x8006 24#define GL_FUNC_SUBTRACT 0x800A 25#define GL_FUNC_REVERSE_SUBTRACT 0x800B 26#endif 27 28#ifndef GL_LOGIC_OP 29#define GL_LOGIC_OP 0x0BF1 30#endif 31 32#ifndef GL_ALPHA_MIN_SGIX 33#define GL_ALPHA_MIN_SGIX 0x8320 34#define GL_ALPHA_MAX_SGIX 0x8321 35#endif 36 37namespace osg { 38 39/** Encapsulates OpenGL BlendEquation state. */ 40class OSG_EXPORT BlendEquation : public StateAttribute 41{ 42 public : 43 44 enum Equation { 45 RGBA_MIN = GL_MIN, 46 RGBA_MAX = GL_MAX, 47 ALPHA_MIN = GL_ALPHA_MIN_SGIX, 48 ALPHA_MAX = GL_ALPHA_MAX_SGIX, 49 LOGIC_OP = GL_LOGIC_OP, 50 FUNC_ADD = GL_FUNC_ADD, 51 FUNC_SUBTRACT = GL_FUNC_SUBTRACT, 52 FUNC_REVERSE_SUBTRACT = GL_FUNC_REVERSE_SUBTRACT 53 }; 54 55 BlendEquation(); 56 57 BlendEquation(Equation equation); 58 59 BlendEquation(Equation equationRGB, Equation equationAlpha); 60 61 /** Copy constructor using CopyOp to manage deep vs shallow copy. */ 62 BlendEquation(const BlendEquation& trans,const CopyOp& copyop=CopyOp::SHALLOW_COPY): 63 StateAttribute(trans,copyop), 64 _equationRGB(trans._equationRGB), 65 _equationAlpha(trans._equationAlpha){} 66 67 META_StateAttribute(osg, BlendEquation,BLENDEQUATION); 68 69 /** Return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs. */ 70 virtual int compare(const StateAttribute& sa) const 71 { 72 // Check for equal types, then create the rhs variable 73 // used by the COMPARE_StateAttribute_Parameter macros below. 74 COMPARE_StateAttribute_Types(BlendEquation,sa) 75 76 // Compare each parameter in turn against the rhs. 77 COMPARE_StateAttribute_Parameter(_equationRGB) 78 COMPARE_StateAttribute_Parameter(_equationAlpha) 79 80 return 0; // Passed all the above comparison macros, so must be equal. 81 } 82 83 virtual bool getModeUsage(StateAttribute::ModeUsage& usage) const 84 { 85 usage.usesMode(GL_BLEND); 86 return true; 87 } 88 89 90 inline void setEquation(Equation equation) { _equationRGB = _equationAlpha = equation; } 91 inline Equation getEquation() const { return _equationRGB; } 92 93 inline void setEquationRGB(Equation equation) { _equationRGB = equation; } 94 inline Equation getEquationRGB() const { return _equationRGB; } 95 96 inline void setEquationAlpha(Equation equation) { _equationAlpha = equation; } 97 inline Equation getEquationAlpha() const { return _equationAlpha; } 98 99 virtual void apply(State& state) const; 100 101protected : 102 103 virtual ~BlendEquation(); 104 105 106 Equation _equationRGB, _equationAlpha; 107}; 108 109} 110 111#endif 112