# OgreHardwareBuffer.h

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    00001 /*
    00002 -----------------------------------------------------------------------------
    00003 This source file is part of OGRE
    00004     (Object-oriented Graphics Rendering Engine)
    00005 For the latest info, see http://www.ogre3d.org/
    00006
    00007 Copyright (c) 2000-2009 Torus Knot Software Ltd
    00008
    00009 Permission is hereby granted, free of charge, to any person obtaining a copy
    00010 of this software and associated documentation files (the "Software"), to deal
    00011 in the Software without restriction, including without limitation the rights
    00012 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    00013 copies of the Software, and to permit persons to whom the Software is
    00014 furnished to do so, subject to the following conditions:
    00015
    00016 The above copyright notice and this permission notice shall be included in
    00017 all copies or substantial portions of the Software.
    00018
    00019 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    00020 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    00021 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    00022 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    00023 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    00024 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    00025 THE SOFTWARE.
    00026 -----------------------------------------------------------------------------
    00027 */
    00028 #ifndef __HardwareBuffer__
    00029 #define __HardwareBuffer__
    00030
    00031 // Precompiler options
    00032 #include "OgrePrerequisites.h"
    00033
    00034 namespace Ogre {
    00035
    00073     class _OgreExport HardwareBuffer : public BufferAlloc
    00074     {
    00075
    00076         public:
    00078             enum Usage
    00079             {
    00083                 HBU_STATIC = 1,
    00089                 HBU_DYNAMIC = 2,
    00096                 HBU_WRITE_ONLY = 4,
    00105                 HBU_DISCARDABLE = 8,
    00107                 HBU_STATIC_WRITE_ONLY = 5,
    00113                 HBU_DYNAMIC_WRITE_ONLY = 6,
    00115                 HBU_DYNAMIC_WRITE_ONLY_DISCARDABLE = 14
    00116
    00117
    00118             };
    00120             enum LockOptions
    00121             {
    00123                 HBL_NORMAL,
    00128                 HBL_DISCARD,
    00132                 HBL_READ_ONLY,
    00136                 HBL_NO_OVERWRITE
    00137
    00138             };
    00139         protected:
    00140             size_t mSizeInBytes;
    00141             Usage mUsage;
    00142             bool mIsLocked;
    00143             size_t mLockStart;
    00144             size_t mLockSize;
    00145             bool mSystemMemory;
    00146             bool mUseShadowBuffer;
    00147             HardwareBuffer* mpShadowBuffer;
    00148             bool mShadowUpdated;
    00149             bool mSuppressHardwareUpdate;
    00150
    00152             virtual void* lockImpl(size_t offset, size_t length, LockOptions options) = 0;
    00154             virtual void unlockImpl(void) = 0;
    00155
    00156     public:
    00158             HardwareBuffer(Usage usage, bool systemMemory, bool useShadowBuffer)
    00159                 : mUsage(usage), mIsLocked(false), mSystemMemory(systemMemory),
    00160                 mUseShadowBuffer(useShadowBuffer), mpShadowBuffer(NULL), mShadowUpdated(false),
    00161                 mSuppressHardwareUpdate(false)
    00162             {
    00163                 // If use shadow buffer, upgrade to WRITE_ONLY on hardware side
    00164                 if (useShadowBuffer && usage == HBU_DYNAMIC)
    00165                 {
    00166                     mUsage = HBU_DYNAMIC_WRITE_ONLY;
    00167                 }
    00168                 else if (useShadowBuffer && usage == HBU_STATIC)
    00169                 {
    00170                     mUsage = HBU_STATIC_WRITE_ONLY;
    00171                 }
    00172             }
    00173             virtual ~HardwareBuffer() {}
    00180             virtual void* lock(size_t offset, size_t length, LockOptions options)
    00181             {
    00182                 assert(!isLocked() && "Cannot lock this buffer, it is already locked!");
    00183                 void* ret;
    00184                 if (mUseShadowBuffer)
    00185                 {
    00186                     if (options != HBL_READ_ONLY)
    00187                     {
    00188                         // we have to assume a read / write lock so we use the shadow buffer
    00189                         // and tag for sync on unlock()
    00190                         mShadowUpdated = true;
    00191                     }
    00192
    00193                     ret = mpShadowBuffer->lock(offset, length, options);
    00194                 }
    00195                 else
    00196                 {
    00197                     // Lock the real buffer if there is no shadow buffer
    00198                     ret = lockImpl(offset, length, options);
    00199                     mIsLocked = true;
    00200                 }
    00201                 mLockStart = offset;
    00202                 mLockSize = length;
    00203                 return ret;
    00204             }
    00205
    00210             void* lock(LockOptions options)
    00211             {
    00212                 return this->lock(0, mSizeInBytes, options);
    00213             }
    00226             virtual void unlock(void)
    00227             {
    00228                 assert(isLocked() && "Cannot unlock this buffer, it is not locked!");
    00229
    00230                 // If we used the shadow buffer this time...
    00231                 if (mUseShadowBuffer && mpShadowBuffer->isLocked())
    00232                 {
    00233                     mpShadowBuffer->unlock();
    00234                     // Potentially update the 'real' buffer from the shadow buffer
    00235                     _updateFromShadow();
    00236                 }
    00237                 else
    00238                 {
    00239                     // Otherwise, unlock the real one
    00240                     unlockImpl();
    00241                     mIsLocked = false;
    00242                 }
    00243
    00244             }
    00245
    00252             virtual void readData(size_t offset, size_t length, void* pDest) = 0;
    00261             virtual void writeData(size_t offset, size_t length, const void* pSource,
    00262                     bool discardWholeBuffer = false) = 0;
    00263
    00274             virtual void copyData(HardwareBuffer& srcBuffer, size_t srcOffset,
    00275                 size_t dstOffset, size_t length, bool discardWholeBuffer = false)
    00276             {
    00277                 const void *srcData = srcBuffer.lock(
    00278                     srcOffset, length, HBL_READ_ONLY);
    00279                 this->writeData(dstOffset, length, srcData, discardWholeBuffer);
    00280                 srcBuffer.unlock();
    00281             }
    00282
    00288             virtual void copyData(HardwareBuffer& srcBuffer)
    00289             {
    00290                 size_t sz = std::min(getSizeInBytes(), srcBuffer.getSizeInBytes());
    00291                 copyData(srcBuffer, 0, 0, sz, true);
    00292             }
    00293
    00295             virtual void _updateFromShadow(void)
    00296             {
    00297                 if (mUseShadowBuffer && mShadowUpdated && !mSuppressHardwareUpdate)
    00298                 {
    00299                     // Do this manually to avoid locking problems
    00300                     const void *srcData = mpShadowBuffer->lockImpl(
    00301                         mLockStart, mLockSize, HBL_READ_ONLY);
    00302                     // Lock with discard if the whole buffer was locked, otherwise normal
    00303                     LockOptions lockOpt;
    00304                     if (mLockStart == 0 && mLockSize == mSizeInBytes)
    00305                         lockOpt = HBL_DISCARD;
    00306                     else
    00307                         lockOpt = HBL_NORMAL;
    00308
    00309                     void *destData = this->lockImpl(
    00310                         mLockStart, mLockSize, lockOpt);
    00311                     // Copy shadow to real
    00312                     memcpy(destData, srcData, mLockSize);
    00313                     this->unlockImpl();
    00314                     mpShadowBuffer->unlockImpl();
    00315                     mShadowUpdated = false;
    00316                 }
    00317             }
    00318
    00320             size_t getSizeInBytes(void) const { return mSizeInBytes; }
    00322             Usage getUsage(void) const { return mUsage; }
    00324             bool isSystemMemory(void) const { return mSystemMemory; }
    00326             bool hasShadowBuffer(void) const { return mUseShadowBuffer; }
    00328             bool isLocked(void) const {
    00329                 return mIsLocked || (mUseShadowBuffer && mpShadowBuffer->isLocked());
    00330             }
    00332             void suppressHardwareUpdate(bool suppress) {
    00333                 mSuppressHardwareUpdate = suppress;
    00334                 if (!suppress)
    00335                     _updateFromShadow();
    00336             }
    00337
    00338
    00339
    00340
    00341
    00342     };
    00345 }
    00346 #endif
    00347
    00348

Copyright © 2008 Torus Knot Software Ltd
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
Last modified Wed Nov 3 2010 19:24:51