CrystalSpace

Public API Reference

cstool/rbuflock.h

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00001 /*
00002     Copyright (C) 2004 by Jorrit Tyberghein
00003               (C) 2004 by Frank Richter
00004 
00005     This library is free software; you can redistribute it and/or
00006     modify it under the terms of the GNU Library General Public
00007     License as published by the Free Software Foundation; either
00008     version 2 of the License, or (at your option) any later version.
00009 
00010     This library is distributed in the hope that it will be useful,
00011     but WITHOUT ANY WARRANTY; without even the implied warranty of
00012     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013     Library General Public License for more details.
00014 
00015     You should have received a copy of the GNU Library General Public
00016     License along with this library; if not, write to the Free
00017     Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00018 */
00019 
00020 #ifndef __CS_CSTOOL_RBUFLOCK_H__
00021 #define __CS_CSTOOL_RBUFLOCK_H__
00022 
00027 #include "csutil/ref.h"
00028 #include "ivideo/rndbuf.h"
00029 
00039 template <class T, class TbufferKeeper = csRef<iRenderBuffer> >
00040 class csRenderBufferLock
00041 {
00043   TbufferKeeper buffer;
00045   uint lockState;
00047   T* lockBuf;
00049   size_t bufStride;
00050 #ifdef CS_DEBUG
00051 
00052   size_t elements;
00053 #endif
00054 
00055   size_t currElement;
00056   
00057   enum { LockedFlag = 0x10000, LockTypeMask = 0xffff };
00058   inline bool IsLocked() { return (lockState & LockedFlag) != 0; }
00059   inline void SetLocked (bool b) 
00060   { lockState = b ? (lockState | LockedFlag) : (lockState & ~LockedFlag); }
00061   inline csRenderBufferLockType LockType() 
00062   { return (csRenderBufferLockType)(lockState & LockTypeMask); }
00063   
00064   csRenderBufferLock() {}
00065   // Copying the locking stuff is somewhat nasty so ... prevent it
00066   csRenderBufferLock (const csRenderBufferLock& other) {}
00067 public:
00071   csRenderBufferLock (iRenderBuffer* buf, 
00072     csRenderBufferLockType lock = CS_BUF_LOCK_NORMAL) : buffer(buf),
00073     lockState(lock), lockBuf(0), 
00074     bufStride(buf ? buf->GetElementDistance() : 0),
00075     currElement(0)
00076   {
00077 #ifdef CS_DEBUG
00078     elements = buf->GetElementCount();
00079 #endif
00080   }
00081   
00085   ~csRenderBufferLock()
00086   {
00087     Unlock();
00088   }
00089   
00094   T* Lock ()
00095   {
00096     CS_ASSERT (buffer != 0);
00097     if (!IsLocked())
00098     {
00099       lockBuf = 
00100         buffer ? ((T*)((uint8*)buffer->Lock (LockType()))) : (T*)-1;
00101       SetLocked (true);
00102     }
00103     return lockBuf;
00104   }
00105   
00107   void Unlock ()
00108   {
00109     if (IsLocked ())
00110     {
00111       if (buffer) buffer->Release();
00112       SetLocked (false);
00113     }
00114   }
00115   
00120   operator T* ()
00121   {
00122     return Lock();
00123   }
00124 
00126   T& operator*()
00127   {
00128     return Get (currElement);
00129   }
00130 
00132   void operator++ ()
00133   {
00134     currElement++;
00135     CS_ASSERT(currElement<elements);
00136   }
00137 
00139   T& operator [] (size_t n)
00140   {
00141     return Get (n);
00142   }
00143 
00145   T& Get (size_t n)
00146   {
00147     CS_ASSERT (n < elements);
00148     return *((T*)((uint8*)Lock() + n * bufStride));
00149   }
00150   
00152   size_t GetSize() const
00153   {
00154     return buffer ? buffer->GetElementCount() : 0;
00155   }
00156 
00158   bool IsValid() const { return buffer.IsValid(); }
00159 };
00160 
00161 #endif // __CS_CSTOOL_RBUFLOCK_H__

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