assimp/code/BVHLoader.h

/** Defines the BHV motion capturing loader class */

/*
Open Asset Import Library (ASSIMP)
----------------------------------------------------------------------

Copyright (c) 2006-2008, ASSIMP Development Team
All rights reserved.

Redistribution and use of this software in source and binary forms, 
with or without modification, are permitted provided that the 
following conditions are met:

* Redistributions of source code must retain the above
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following disclaimer.

* Redistributions in binary form must reproduce the above
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* Neither the name of the ASSIMP team, nor the names of its
contributors may be used to endorse or promote products
derived from this software without specific prior
written permission of the ASSIMP Development Team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/

#ifndef AI_BVHLOADER_H_INC
#define AI_BVHLOADER_H_INC

#include "BaseImporter.h"

namespace Assimp
{

/** Loader class to read Motion Capturing data from a .bvh file. This format only contains a 
* hierarchy of joints and a series of keyframes for the hierarchy. It contains no actual mesh data,
* but we generate a dummy mesh inside the loader just to be able to see something.
*/
class BVHLoader : public BaseImporter
{
	friend class Importer;

	/** Possible animation channels for which the motion data holds the values */
	enum ChannelType
	{
		Channel_PositionX,
		Channel_PositionY,
		Channel_PositionZ,
		Channel_RotationX,
		Channel_RotationY,
		Channel_RotationZ
	};

	/** Collected list of node. Will be bones of the dummy mesh some day, addressed by their array index */
	struct Node
	{
		const aiNode* mNode;
		std::vector<ChannelType> mChannels;
		std::vector<float> mChannelValues; // motion data values for that node. Of size NumChannels * NumFrames

		Node() { }
		Node( const aiNode* pNode) : mNode( pNode) { }
	};

protected:
	/** Constructor to be privately used by Importer */
	BVHLoader();

	/** Destructor, private as well */
	~BVHLoader();

public:
	/** Returns whether the class can handle the format of the given file. 
	 * See BaseImporter::CanRead() for details.	*/
	bool CanRead( const std::string& pFile, IOSystem* pIOHandler) const;

protected:
	/** Called by Importer::GetExtensionList() for each loaded importer.
	 * See BaseImporter::GetExtensionList() for details
	 */
	void GetExtensionList( std::string& append)
	{
		append.append("*.bvh");
	}

	/** Imports the given file into the given scene structure. 
	 * See BaseImporter::InternReadFile() for details
	 */
	void InternReadFile( const std::string& pFile, aiScene* pScene, IOSystem* pIOHandler);

protected:
	/** Reads the file */
	void ReadStructure( aiScene* pScene);

	/** Reads the hierarchy */
	void ReadHierarchy( aiScene* pScene);

	/** Reads a node and recursively its childs and returns the created node. */
	aiNode* ReadNode();

	/** Reads an end node and returns the created node. */
	aiNode* ReadEndSite( const std::string& pParentName);

	/** Reads a node offset for the given node */
	void ReadNodeOffset( aiNode* pNode);

	/** Reads the animation channels into the given node */
	void ReadNodeChannels( BVHLoader::Node& pNode);

	/** Reads the motion data */
	void ReadMotion( aiScene* pScene);

	/** Retrieves the next token */
	std::string GetNextToken();

	/** Reads the next token as a float */
	float GetNextTokenAsFloat();

	/** Aborts the file reading with an exception */
	void ThrowException( const std::string& pError);

	/** Constructs an animation for the motion data and stores it in the given scene */
	void CreateAnimation( aiScene* pScene);

protected:
	/** Filename, for a verbose error message */
	std::string mFileName;

	/** Buffer to hold the loaded file */
	std::vector<char> mBuffer;

	/** Next char to read from the buffer */
	std::vector<char>::const_iterator mReader;

	/** Current line, for error messages */
	unsigned int mLine;

	/** Collected list of nodes. Will be bones of the dummy mesh some day, addressed by their array index.
	* Also contain the motion data for the node's channels
	*/
	std::vector<Node> mNodes;

	/** basic Animation parameters */
	float mAnimTickDuration;
	unsigned int mAnimNumFrames;
};

} // end of namespace Assimp

#endif // AI_BVHLOADER_H_INC