Stencil

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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_STENCIL
#define OSG_STENCIL 1
 
#include <osg/StateAttribute>
 
namespace osg {
 
#ifndef GL_INCR_WRAP
#define GL_INCR_WRAP 0x8507
#define GL_DECR_WRAP 0x8508
#endif
 

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

        Stencil(const Stencil& stencil,const CopyOp& copyop=CopyOp::SHALLOW_COPY):
            StateAttribute(stencil,copyop),
            _func(stencil._func),
            _funcRef(stencil._funcRef),
            _funcMask(stencil._funcMask),
            _sfail(stencil._sfail),
            _zfail(stencil._zfail),
            _zpass(stencil._zpass),
            _writeMask(stencil._writeMask) {}
 
 
        META_StateAttribute(osg, Stencil, STENCIL);

        virtual int compare(const StateAttribute& sa) const
        {
            // check the types are equal and then create the rhs variable
            // used by the COMPARE_StateAttribute_Parameter macros below.
            COMPARE_StateAttribute_Types(Stencil,sa)
 
            // compare each parameter in turn against the rhs.
            COMPARE_StateAttribute_Parameter(_func)
            COMPARE_StateAttribute_Parameter(_funcRef)
            COMPARE_StateAttribute_Parameter(_funcMask)
            COMPARE_StateAttribute_Parameter(_sfail)
            COMPARE_StateAttribute_Parameter(_zfail)
            COMPARE_StateAttribute_Parameter(_zpass)
            COMPARE_StateAttribute_Parameter(_writeMask)
 
            return 0; // passed all the above comparison macros, must be equal.
        }
 
        virtual bool getModeUsage(StateAttribute::ModeUsage& usage) const
        {
            usage.usesMode(GL_STENCIL_TEST);
            return true;
        }
 
        enum Function
        {
            NEVER = GL_NEVER,
            LESS = GL_LESS,
            EQUAL = GL_EQUAL,
            LEQUAL = GL_LEQUAL,
            GREATER = GL_GREATER,
            NOTEQUAL = GL_NOTEQUAL,
            GEQUAL = GL_GEQUAL,
            ALWAYS = GL_ALWAYS
        };
 
        inline void setFunction(Function func,int ref,unsigned int mask)
        {
            _func = func;
            _funcRef = ref;
            _funcMask = mask;
        }
 
        inline void setFunction(Function func) { _func = func; }
        inline Function getFunction() const { return _func; }
 
        inline void setFunctionRef(int ref) { _funcRef=ref; }
        inline int getFunctionRef() const { return _funcRef; }
 
        inline void setFunctionMask(unsigned int mask) { _funcMask=mask; }
        inline unsigned int getFunctionMask() const { return _funcMask; }
 
 
        enum Operation
        {
            KEEP = GL_KEEP,
            ZERO = GL_ZERO,
            REPLACE = GL_REPLACE,
            INCR = GL_INCR,
            DECR = GL_DECR,
            INVERT = GL_INVERT,
            INCR_WRAP = GL_INCR_WRAP,
            DECR_WRAP = GL_DECR_WRAP
        };

        inline void setOperation(Operation sfail, Operation zfail, Operation zpass)
        {
            _sfail = sfail;
            _zfail = zfail;
            _zpass = zpass;
        }

        inline void setStencilFailOperation(Operation sfail) { _sfail = sfail; }

        inline Operation getStencilFailOperation() const { return _sfail; }

        inline void setStencilPassAndDepthFailOperation(Operation zfail) { _zfail=zfail; }

        inline Operation getStencilPassAndDepthFailOperation() const { return _zfail; }

        inline void setStencilPassAndDepthPassOperation(Operation zpass) { _zpass=zpass; }

        inline Operation getStencilPassAndDepthPassOperation() const { return _zpass; }
 
 
        inline void setWriteMask(unsigned int mask) { _writeMask = mask; }
 
        inline unsigned int getWriteMask() const { return _writeMask; }
 
 
        virtual void apply(State& state) const;
 
 
    protected:
 
        virtual ~Stencil();
 
        Function            _func;
        int                 _funcRef;
        unsigned int        _funcMask;
 
        Operation           _sfail;
        Operation           _zfail;
        Operation           _zpass;
 
        unsigned int        _writeMask;
 
};
 
}
 
#endif