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, 
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following disclaimer.

* Redistributions in binary form must reproduce the above
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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*/

/** @file BVHLoader.h
 *  @brief Biovision BVH import
 */

#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, bool cs) 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