OpenSceneGraph/include/osg/BlendEquation

162 lines
6.3 KiB
C++

/* -*-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_BLENDEQUATION
#define OSG_BLENDEQUATION 1
#include <osg/StateAttribute>
#ifndef GL_VERSION_1_2
/* Logic Ops */
#define GL_MIN 0x8007
#define GL_MAX 0x8008
#define GL_FUNC_ADD 0x8006
#define GL_FUNC_SUBTRACT 0x800A
#define GL_FUNC_REVERSE_SUBTRACT 0x800B
#endif
#ifndef GL_LOGIC_OP
#define GL_LOGIC_OP 0x0BF1
#endif
#ifndef GL_ALPHA_MIN_SGIX
#define GL_ALPHA_MIN_SGIX 0x8320
#define GL_ALPHA_MAX_SGIX 0x8321
#endif
namespace osg {
/** Encapsulates OpenGL BlendEquation state. */
class OSG_EXPORT BlendEquation : public StateAttribute
{
public :
enum Equation {
RGBA_MIN = GL_MIN,
RGBA_MAX = GL_MAX,
ALPHA_MIN = GL_ALPHA_MIN_SGIX,
ALPHA_MAX = GL_ALPHA_MAX_SGIX,
LOGIC_OP = GL_LOGIC_OP,
FUNC_ADD = GL_FUNC_ADD,
FUNC_SUBTRACT = GL_FUNC_SUBTRACT,
FUNC_REVERSE_SUBTRACT = GL_FUNC_REVERSE_SUBTRACT
};
BlendEquation();
BlendEquation(Equation equation);
BlendEquation(Equation equationRGB, Equation equationAlpha);
/** Copy constructor using CopyOp to manage deep vs shallow copy. */
BlendEquation(const BlendEquation& trans,const CopyOp& copyop=CopyOp::SHALLOW_COPY):
StateAttribute(trans,copyop),
_equationRGB(trans._equationRGB),
_equationAlpha(trans._equationAlpha){}
META_StateAttribute(osg, BlendEquation,BLENDEQUATION);
/** Return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs. */
virtual int compare(const StateAttribute& sa) const
{
// Check for equal types, then create the rhs variable
// used by the COMPARE_StateAttribute_Paramter macros below.
COMPARE_StateAttribute_Types(BlendEquation,sa)
// Compare each parameter in turn against the rhs.
COMPARE_StateAttribute_Parameter(_equationRGB)
COMPARE_StateAttribute_Parameter(_equationAlpha)
return 0; // Passed all the above comparison macros, so must be equal.
}
virtual bool getModeUsage(StateAttribute::ModeUsage& usage) const
{
usage.usesMode(GL_BLEND);
return true;
}
inline void setEquation(Equation equation) { _equationRGB = _equationAlpha = equation; }
inline Equation getEquation() const { return _equationRGB; }
inline void setEquationRGB(Equation equation) { _equationRGB = equation; }
inline Equation getEquationRGB() const { return _equationRGB; }
inline void setEquationAlpha(Equation equation) { _equationAlpha = equation; }
inline Equation getEquationAlpha() const { return _equationAlpha; }
virtual void apply(State& state) const;
/** Encapsulates queries of extension availability, obtains extension
* function pointers, and provides convenience wrappers for
* calling extension functions. */
class OSG_EXPORT Extensions : public osg::Referenced
{
public:
Extensions(unsigned int contextID);
Extensions(const Extensions& rhs);
void lowestCommonDenominator(const Extensions& rhs);
void setupGLExtensions(unsigned int contextID);
bool isBlendEquationSupported() const { return _isBlendEquationSupported; }
bool isBlendEquationSeparateSupported() const { return _isBlendEquationSeparateSupported; }
bool isSGIXMinMaxSupported() const { return _isSGIXMinMaxSupported; }
bool isLogicOpSupported() const { return _isLogicOpSupported; }
void glBlendEquation(GLenum mode) const;
void glBlendEquationSeparate(GLenum modeRGB, GLenum modeAlpha) const;
protected:
~Extensions() {}
typedef void (APIENTRY * GLBlendEquationProc)(GLenum mode);
typedef void (APIENTRY * GLBlendEquationSeparateProc)(GLenum modeRGB, GLenum modeAlpha);
bool _isBlendEquationSupported;
bool _isBlendEquationSeparateSupported;
bool _isSGIXMinMaxSupported;
bool _isLogicOpSupported;
GLBlendEquationProc _glBlendEquation;
GLBlendEquationSeparateProc _glBlendEquationSeparate;
};
/** Returns the Extensions object for the given context.
* If createIfNotInitalized is true and the Extensions object doesn't
* exist, getExtensions() creates it on the given context.
* Returns NULL if createIfNotInitalized is false and the Extensions
* object doesn't exist. */
static Extensions* getExtensions(unsigned int contextID,bool createIfNotInitalized);
/** setExtensions() allows users to override the extensions across graphics contexts.
* Typically used when you have different extensions supported across graphics pipes,
* but need to ensure that they all use the same low common denominator extensions. */
static void setExtensions(unsigned int contextID,Extensions* extensions);
protected :
virtual ~BlendEquation();
Equation _equationRGB, _equationAlpha;
};
}
#endif