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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_ALPHAFUNC
#define OSG_ALPHAFUNC 1
#include <osg/StateAttribute>
#ifndef GL_ALPHA_TEST
#define GL_ALPHA_TEST 0x0BC0
#endif
namespace osg {
/** Encapsulates OpenGL glAlphaFunc.
*/
class OSG_EXPORT AlphaFunc : public StateAttribute
{
public :
enum ComparisonFunction {
NEVER = GL_NEVER,
LESS = GL_LESS,
EQUAL = GL_EQUAL,
LEQUAL = GL_LEQUAL,
GREATER = GL_GREATER,
NOTEQUAL = GL_NOTEQUAL,
GEQUAL = GL_GEQUAL,
ALWAYS = GL_ALWAYS
};
AlphaFunc();
AlphaFunc(ComparisonFunction func,float ref):
_comparisonFunc(func),
_referenceValue(ref) {}
/** Copy constructor using CopyOp to manage deep vs shallow copy. */
AlphaFunc(const AlphaFunc& af,const CopyOp& copyop=CopyOp::SHALLOW_COPY):
StateAttribute(af,copyop),
_comparisonFunc(af._comparisonFunc),
_referenceValue(af._referenceValue) {}
META_StateAttribute(osg, AlphaFunc,ALPHAFUNC);
/** 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_Parameter macros below.
COMPARE_StateAttribute_Types(AlphaFunc,sa)
// Compare each parameter in turn against the rhs.
COMPARE_StateAttribute_Parameter(_comparisonFunc)
COMPARE_StateAttribute_Parameter(_referenceValue)
return 0; // Passed all the above comparison macros, so must be equal.
}
virtual bool getModeUsage(StateAttribute::ModeUsage& usage) const
{
usage.usesMode(GL_ALPHA_TEST);
return true;
}
inline void setFunction(ComparisonFunction func,float ref)
{
_comparisonFunc = func;
_referenceValue = ref;
}
inline void setFunction(ComparisonFunction func) { _comparisonFunc=func; }
inline ComparisonFunction getFunction() const { return _comparisonFunc; }
inline void setReferenceValue(float value) { _referenceValue=value; }
inline float getReferenceValue() const { return _referenceValue; }
virtual void apply(State& state) const;
protected:
virtual ~AlphaFunc();
ComparisonFunction _comparisonFunc;
float _referenceValue;
};
}
#endif