MainLoop

进入主循环

void Root::startRendering(void){ assert(mActiveRenderer != 0); mActiveRenderer->_initRenderTargets(); // Clear event timesclearEventTimes(); // Infinite loop, until broken out of by frame listeners // or break out by calling queueEndRendering() mQueuedEnd = false; while( !mQueuedEnd ) {//Pump messages in all registered RenderWindow windowsWindowEventUtilities::messagePump();if (!renderOneFrame()) break; }} 

 

渲染一帧

bool Root::renderOneFrame(void){ if(!_fireFrameStarted()) return false;if (!_updateAllRenderTargets())return false; return _fireFrameEnded();}

一帧开始事件

bool Root::_fireFrameStarted(){ FrameEvent evt;populateFrameEvent(FETT_STARTED, evt); return _fireFrameStarted(evt);}bool Root::_fireFrameStarted(FrameEvent& evt){OgreProfileBeginGroup("Frame", OGREPROF_GENERAL); // Remove all marked listeners set<FrameListener*>::type::iterator i; for (i = mRemovedFrameListeners.begin(); i != mRemovedFrameListeners.end(); i++) { mFrameListeners.erase(*i); } mRemovedFrameListeners.clear(); // Tell all listeners for (i= mFrameListeners.begin(); i != mFrameListeners.end(); ++i) { if (!(*i)->frameStarted(evt)) return false; } return true;}

帧队列事件

bool Root::_updateAllRenderTargets(void){ // update all targets but don't swap buffers mActiveRenderer->_updateAllRenderTargets(false);// give client app opportunity to use queued GPU timebool ret = _fireFrameRenderingQueued();// block for final swapmActiveRenderer->_swapAllRenderTargetBuffers(mActiveRenderer->getWaitForVerticalBlank()); // This belongs here, as all render targets must be updated before events are // triggered, otherwise targets could be mismatched. This could produce artifacts, // for instance, with shadows. for (SceneManagerEnumerator::SceneManagerIterator it = getSceneManagerIterator(); it.hasMoreElements(); it.moveNext()) it.peekNextValue()->_handleLodEvents();return ret;}bool Root::_fireFrameRenderingQueued(){FrameEvent evt;populateFrameEvent(FETT_QUEUED, evt); return _fireFrameRenderingQueued(evt);}bool Root::_fireFrameRenderingQueued(FrameEvent& evt){// Increment next frame number++mNextFrame; // Remove all marked listeners set<FrameListener*>::type::iterator i; for (i = mRemovedFrameListeners.begin(); i != mRemovedFrameListeners.end(); i++) { mFrameListeners.erase(*i); } mRemovedFrameListeners.clear(); // Tell all listeners for (i= mFrameListeners.begin(); i != mFrameListeners.end(); ++i) { if (!(*i)->frameRenderingQueued(evt)) return false; } return true;} 

一帧结束事件

bool Root::_fireFrameEnded(){ FrameEvent evt;populateFrameEvent(FETT_ENDED, evt); return _fireFrameEnded(evt);}bool Root::_fireFrameEnded(FrameEvent& evt){ // Remove all marked listeners set<FrameListener*>::type::iterator i; for (i = mRemovedFrameListeners.begin(); i != mRemovedFrameListeners.end(); i++) { mFrameListeners.erase(*i); } mRemovedFrameListeners.clear(); // Tell all listenersbool ret = true; for (i= mFrameListeners.begin(); i != mFrameListeners.end(); ++i) { if (!(*i)->frameEnded(evt)){ ret = false;break;} } // Tell buffer manager to free temp buffers used this frame if (HardwareBufferManager::getSingletonPtr()) HardwareBufferManager::getSingleton()._releaseBufferCopies();// Tell the queue to process responsesmWorkQueue->processResponses();OgreProfileEndGroup("Frame", OGREPROF_GENERAL); return ret;}