text: /*
  -----------------------------------------------------------------------------
  This source file is part of OGRE
      (Object-oriented Graphics Rendering Engine)
  For the latest info, see http://www.ogre3d.org/
  
  Copyright (c) 2000-2014 Torus Knot Software Ltd
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
  -----------------------------------------------------------------------------
  */
  #ifndef __InstanceBatchShader_H__
  #define __InstanceBatchShader_H__
  
  #include "OgreInstanceBatch.h"
  
  namespace Ogre
  {
  	/** \addtogroup Core
  	*  @{
  	*/
  	/** \addtogroup Scene
  	*  @{
  	*/
  
  	/** This is the same technique the old "InstancedGeometry" implementation used (with improvements).
  		Basically it creates a large vertex buffer with many repeating entities, and sends per instance
  		data through shader constants. Because SM 2.0 & 3.0 have up to 256 shader constant registers,
  		this means there can be approx up to 84 instances per batch, assuming they're not skinned
  		But using shader constants for other stuff (i.e. lighting) also affects negatively this number
  		A mesh with skeletally animated 2 bones reduces the number 84 to 42 instances per batch.
  		@par
  		The main advantage of this technique is that it's supported on a high variety of hardware
  		(SM 2.0 cards are required) and the same shader can be used for both skeletally animated
  		normal entities and instanced entities without a single change required.
  		@par
  		Unlike the old InstancedGeometry implementation, the developer doesn't need to worry about
  		reaching the 84 instances limit, the InstanceManager automatically takes care of splitting
  		and creating new batches. But beware internally, this means less performance improvement.
  		Another improvement is that vertex buffers are shared between batches, which significantly
  		reduces GPU VRAM usage.
  
          @remarks
  			Design discussion webpage: http://www.ogre3d.org/forums/viewtopic.php?f=4&t=59902
          @author
              Matias N. Goldberg ("dark_sylinc")
          @version
              1.0
       */
  	class _OgreExport InstanceBatchShader : public InstanceBatch
  	{
  		unsigned short	mNumWorldMatrices;
  
  		void setupVertices( const SubMesh* baseSubMesh );
  		void setupIndices( const SubMesh* baseSubMesh );
  
  		/** When the mesh is (hardware) skinned, a different code path is called so that
  			we reuse the index buffers and modify them in place. For example Instance #2
  			with reference to bone #5 would have BlendIndex = 2 + 5 = 7
  			Everything is copied identically except the VES_BLEND_INDICES semantic
  		*/
  		void setupHardwareSkinned( const SubMesh* baseSubMesh, VertexData *thisVertexData,
  									VertexData *baseVertexData );
  
  	public:
  		InstanceBatchShader( InstanceManager *creator, MeshPtr &meshReference, const MaterialPtr &material,
  							size_t instancesPerBatch, const Mesh::IndexMap *indexToBoneMap,
  							const String &batchName );
  		virtual ~InstanceBatchShader();
  
  		/** @see InstanceBatch::calculateMaxNumInstances */
  		size_t calculateMaxNumInstances( const SubMesh *baseSubMesh, uint16 flags ) const;
  
  		/** @see InstanceBatch::buildFrom */
  		void buildFrom( const SubMesh *baseSubMesh, const RenderOperation &renderOperation );
  
  		//Renderable overloads
  		void getWorldTransforms( Matrix4* xform ) const;
  		unsigned short getNumWorldTransforms(void) const;
  	};
  }
  
  #endif
  