/* -*-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
/** Encapsulate OpenGL glStencilFunc/Op/Mask functions.
*
* All functionality except INCR_WRAP and DECR_WRAP is supported by OpenGL 1.1.
* INCR_WRAP an DECR_WRAP are available since OpenGL 1.4 or when
* GL_EXT_stencil_wrap extension is present.
*
* If INCR_WRAP or DECR_WRAP values are used while they are detected to be not supported,
* the INCR or DECR values are sent to OpenGL instead. Note: do not use Stencil::getFunction()
* to detect whether WRAP operations is used as the object's value is kept intact.
* Use osg::Stencil::getExtensions() method instead.
*
* OpenGL 2.0 introduced two side stenciling that is available through
* osg::StencilTwoSided class.
*/
class OSG_EXPORT Stencil : public StateAttribute
{
public :
Stencil();
/** Copy constructor using CopyOp to manage deep vs shallow copy.*/
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);
/** 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_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
};
/** set the operations to apply when the various stencil and depth
* tests fail or pass. First parameter is to control the operation
* when the stencil test fails. The second parameter is to control the
* operation when the stencil test passes, but depth test fails. The
* third parameter controls the operation when both the stencil test
* and depth pass. Ordering of parameter is the same as if using
* glStencilOp(,,).*/
inline void setOperation(Operation sfail, Operation zfail, Operation zpass)
{
_sfail = sfail;
_zfail = zfail;
_zpass = zpass;
}
/** set the operation when the stencil test fails.*/
inline void setStencilFailOperation(Operation sfail) { _sfail = sfail; }
/** get the operation when the stencil test fails.*/
inline Operation getStencilFailOperation() const { return _sfail; }
/** set the operation when the stencil test passes but the depth test fails.*/
inline void setStencilPassAndDepthFailOperation(Operation zfail) { _zfail=zfail; }
/** get the operation when the stencil test passes but the depth test fails.*/
inline Operation getStencilPassAndDepthFailOperation() const { return _zfail; }
/** set the operation when both the stencil test and the depth test pass.*/
inline void setStencilPassAndDepthPassOperation(Operation zpass) { _zpass=zpass; }
/** get the operation when both the stencil test and the depth test pass.*/
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;
/** Extensions class which encapsulates the querying of extensions and
* associated function pointers, and provide convenience wrappers to
* check for the extensions or use the associated 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);
void setStencilWrapSupported(bool flag) { _isStencilWrapSupported = flag; }
bool isStencilWrapSupported() const { return _isStencilWrapSupported; }
protected:
~Extensions() {}
bool _isStencilWrapSupported;
};
/** Function to call to get the extension of a specified context.
* If the Extension object for that context has not yet been created
* and the 'createIfNotInitalized' flag been set to false then returns NULL.
* If 'createIfNotInitalized' is true then the Extensions object is
* automatically created. However, in this case the extension object
* will only be created with the graphics context associated with ContextID.
*/
static Extensions* getExtensions(unsigned int contextID, bool createIfNotInitalized);
/** The setExtensions method 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 ~Stencil();
Function _func;
int _funcRef;
unsigned int _funcMask;
Operation _sfail;
Operation _zfail;
Operation _zpass;
unsigned int _writeMask;
};
}
#endif