OpenSceneGraph/include/osg/GraphicsThread
2005-08-20 08:59:03 +00:00

153 lines
4.3 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2005 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_GRAPHICSTHREAD
#define OSG_GRAPHICSTHREAD 1
#include <osg/State>
#include <OpenThreads/Thread>
#include <OpenThreads/Barrier>
#include <OpenThreads/Condition>
#include <list>
namespace osg {
// forward declare GraphicsContext
class GraphicsContext;
class Block: public osg::Referenced {
public:
Block():_released(false) {}
inline void block()
{
OpenThreads::ScopedLock<OpenThreads::Mutex> mutlock(_mut);
if( !_released )
_cond.wait(&_mut);
}
inline void release()
{
OpenThreads::ScopedLock<OpenThreads::Mutex> mutlock(_mut);
if (!_released)
{
_released = true;
_cond.broadcast();
}
}
inline void reset()
{
OpenThreads::ScopedLock<OpenThreads::Mutex> mutlock(_mut);
_released = false;
}
inline void set(bool doRelease)
{
if (doRelease!=_released)
{
if (doRelease) release();
else reset();
}
}
protected:
~Block()
{
release();
}
private:
OpenThreads::Mutex _mut;
OpenThreads::Condition _cond;
bool _released;
};
/** GraphicsThread is a helper class for running OpenGL GraphicsOperation within a single thread assigned to a specific GraphicsContext.*/
class GraphicsThread : public Referenced, public OpenThreads::Thread
{
public:
GraphicsThread();
/** Base class for implementing GraphicsThread operations.*/
struct OSG_EXPORT Operation : public Referenced
{
virtual void operator () (GraphicsContext*) {}
};
/** Add operation to end of OperationQueue, this will be
* executed by the graphics thread once this operation gets to the head of the queue.*/
void add(Operation* operation, bool waitForCompletion=false);
/** Run does the graphics thread run loop.*/
virtual void run();
/** Cancel this graphics thread.*/
virtual int cancel();
protected:
virtual ~GraphicsThread();
friend class GraphicsContext;
GraphicsContext* _graphicsContext;
typedef std::list< ref_ptr<Operation> > OperationQueue;
bool _done;
OpenThreads::Mutex _operationsMutex;
osg::ref_ptr<osg::Block> _operationsBlock;
OperationQueue _operations;
};
/** SwapBufferOperation calls swap buffers on the GraphicsContext.*/
struct OSG_EXPORT SwapBuffersOperation : public GraphicsThread::Operation
{
virtual void operator () (GraphicsContext* context);
};
/** BarrierOperation allows one syncronize multiple GraphicsThreads with each other.*/
struct OSG_EXPORT BarrierOperation : public GraphicsThread::Operation, public OpenThreads::Barrier
{
enum PreBlockOp
{
NO_OPERATION,
GL_FLUSH,
GL_FINISH
};
BarrierOperation(int numThreads, PreBlockOp op=NO_OPERATION): OpenThreads::Barrier(numThreads), _preBlockOp(op) {}
virtual void operator () (GraphicsContext* context);
PreBlockOp _preBlockOp;
};
/** ReleaseContext_Block_MakeCurrentOperation releases the context for another thread to aquire,
* then blocks waiting for context to be released, once the block is release the context is re-aqquired.*/
struct OSG_EXPORT ReleaseContext_Block_MakeCurrentOperation : public GraphicsThread::Operation, public Block
{
ReleaseContext_Block_MakeCurrentOperation() {}
virtual void operator () (GraphicsContext* context);
};
}
#endif