assimp/code/ColladaParser.h

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

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

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* Redistributions in binary form must reproduce the above
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*/

/** @file ColladaParser.h
 *  @brief Defines the parser helper class for the collada loader 
 */

#ifndef AI_COLLADAPARSER_H_INC
#define AI_COLLADAPARSER_H_INC

#include "irrXMLWrapper.h"
#include "ColladaHelper.h"

namespace Assimp
{

// ------------------------------------------------------------------------------------------
/** Parser helper class for the Collada loader. 
 *
 *  Does all the XML reading and builds internal data structures from it, 
 *  but leaves the resolving of all the references to the loader.
*/
class ColladaParser
{
	friend class ColladaLoader;

protected:
	/** Constructor from XML file */
	ColladaParser( IOSystem* pIOHandler, const std::string& pFile);

	/** Destructor */
	~ColladaParser();

	/** Reads the contents of the file */
	void ReadContents();

	/** Reads the structure of the file */
	void ReadStructure();

	/** Reads asset informations such as coordinate system informations and legal blah */
	void ReadAssetInfo();

	/** Reads the skeleton controller library */
	void ReadControllerLibrary();

	/** Reads a controller into the given mesh structure */
	void ReadController( Collada::Controller& pController);

	/** Reads the joint definitions for the given controller */
	void ReadControllerJoints( Collada::Controller& pController);

	/** Reads the joint weights for the given controller */
	void ReadControllerWeights( Collada::Controller& pController);

	/** Reads the image library contents */
	void ReadImageLibrary();

	/** Reads an image entry into the given image */
	void ReadImage( Collada::Image& pImage);

	/** Reads the material library */
	void ReadMaterialLibrary();

	/** Reads a material entry into the given material */
	void ReadMaterial( Collada::Material& pMaterial);

	/** Reads the camera library */
	void ReadCameraLibrary();

	/** Reads a camera entry into the given camera */
	void ReadCamera( Collada::Camera& pCamera);

	/** Reads the light library */
	void ReadLightLibrary();

	/** Reads a light entry into the given light */
	void ReadLight( Collada::Light& pLight);

	/** Reads the effect library */
	void ReadEffectLibrary();

	/** Reads an effect entry into the given effect*/
	void ReadEffect( Collada::Effect& pEffect);

	/** Read sampler properties */
	void ReadSamplerProperties( Collada::Sampler& pSampler);

	/** Reads an effect entry containing a color or a texture defining that color */
	void ReadEffectColor( aiColor4D& pColor, Collada::Sampler& pSampler);

	/** Reads an effect entry containing a float */
	void ReadEffectFloat( float& pFloat);

	/** Reads an effect parameter specification of any kind */
	void ReadEffectParam( Collada::EffectParam& pParam);

	/** Reads the geometry library contents */
	void ReadGeometryLibrary();

	/** Reads a geometry from the geometry library. */
	void ReadGeometry( Collada::Mesh* pMesh);

	/** Reads a mesh from the geometry library */
	void ReadMesh( Collada::Mesh* pMesh);

	/** Reads a source element - a combination of raw data and an accessor defining 
	 * things that should not be redefinable. Yes, that's another rant.
	 */
	void ReadSource();

	/** Reads a data array holding a number of elements, and stores it in the global library.
	 * Currently supported are array of floats and arrays of strings.
	 */
	void ReadDataArray();

	/** Reads an accessor and stores it in the global library under the given ID - 
	 * accessors use the ID of the parent <source> element
	 */
	void ReadAccessor( const std::string& pID);

	/** Reads input declarations of per-vertex mesh data into the given mesh */
	void ReadVertexData( Collada::Mesh* pMesh);

	/** Reads input declarations of per-index mesh data into the given mesh */
	void ReadIndexData( Collada::Mesh* pMesh);

	/** Reads a single input channel element and stores it in the given array, if valid */
	void ReadInputChannel( std::vector<Collada::InputChannel>& poChannels);

	/** Reads a <p> primitive index list and assembles the mesh data into the given mesh */
	void ReadPrimitives( Collada::Mesh* pMesh, std::vector<Collada::InputChannel>& pPerIndexChannels, 
		size_t pNumPrimitives, const std::vector<size_t>& pVCount, Collada::PrimitiveType pPrimType);

	/** Extracts a single object from an input channel and stores it in the appropriate mesh data array */
	void ExtractDataObjectFromChannel( const Collada::InputChannel& pInput, size_t pLocalIndex, Collada::Mesh* pMesh);

	/** Reads the library of node hierarchies and scene parts */
	void ReadSceneLibrary();

	/** Reads a scene node's contents including children and stores it in the given node */
	void ReadSceneNode( Collada::Node* pNode);

	/** Reads a node transformation entry of the given type and adds it to the given node's transformation list. */
	void ReadNodeTransformation( Collada::Node* pNode, Collada::TransformType pType);

	/** Reads a mesh reference in a node and adds it to the node's mesh list */
	void ReadNodeGeometry( Collada::Node* pNode);

	/** Reads the collada scene */
	void ReadScene();

	// Processes bind_vertex_input and bind elements
	void ReadMaterialVertexInputBinding( Collada::SemanticMappingTable& tbl);

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

	/** Skips all data until the end node of the current element */
	void SkipElement();

	/** Skips all data until the end node of the given element */
	void SkipElement( const char* pElement);

	/** Compares the current xml element name to the given string and returns true if equal */
	bool IsElement( const char* pName) const;

	/** Tests for the opening tag of the given element, throws an exception if not found */
	void TestOpening( const char* pName);

	/** Tests for the closing tag of the given element, throws an exception if not found */
	void TestClosing( const char* pName);

	/** Checks the present element for the presence of the attribute, returns its index 
	    or throws an exception if not found */
	int GetAttribute( const char* pAttr) const;

	/** Returns the index of the named attribute or -1 if not found. Does not throw,
	    therefore useful for optional attributes */
	int TestAttribute( const char* pAttr) const;

	/** Reads the text contents of an element, throws an exception if not given. 
	    Skips leading whitespace. */
	const char* GetTextContent();

	/** Reads the text contents of an element, returns NULL if not given.
	    Skips leading whitespace. */
	const char* TestTextContent();

	/** Reads a single bool from current text content */
	bool ReadBoolFromTextContent();

	/** Reads a single float from current text content */
	float ReadFloatFromTextContent();

	/** Calculates the resulting transformation from all the given transform steps */
	aiMatrix4x4 CalculateResultTransform( const std::vector<Collada::Transform>& pTransforms) const;

	/** Determines the input data type for the given semantic string */
	Collada::InputType GetTypeForSemantic( const std::string& pSemantic);

	/** Finds the item in the given library by its reference, throws if not found */
	template <typename Type> const Type& ResolveLibraryReference(
		const std::map<std::string, Type>& pLibrary, const std::string& pURL) const;

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

	/** XML reader, member for everyday use */
	irr::io::IrrXMLReader* mReader;

	/** All data arrays found in the file by ID. Might be referred to by actually 
	    everyone. Collada, you are a steaming pile of indirection. */
	typedef std::map<std::string, Collada::Data> DataLibrary;
	DataLibrary mDataLibrary;

	/** Same for accessors which define how the data in a data array is accessed. */
	typedef std::map<std::string, Collada::Accessor> AccessorLibrary;
	AccessorLibrary mAccessorLibrary;

	/** Mesh library: mesh by ID */
	typedef std::map<std::string, Collada::Mesh*> MeshLibrary;
	MeshLibrary mMeshLibrary;

	/** node library: root node of the hierarchy part by ID */
	typedef std::map<std::string, Collada::Node*> NodeLibrary;
	NodeLibrary mNodeLibrary;

	/** Image library: stores texture properties by ID */
	typedef std::map<std::string, Collada::Image> ImageLibrary;
	ImageLibrary mImageLibrary;

	/** Effect library: surface attributes by ID */
	typedef std::map<std::string, Collada::Effect> EffectLibrary;
	EffectLibrary mEffectLibrary;

	/** Material library: surface material by ID */
	typedef std::map<std::string, Collada::Material> MaterialLibrary;
	MaterialLibrary mMaterialLibrary;

	/** Light library: surface light by ID */
	typedef std::map<std::string, Collada::Light> LightLibrary;
	LightLibrary mLightLibrary;

	/** Camera library: surface material by ID */
	typedef std::map<std::string, Collada::Camera> CameraLibrary;
	CameraLibrary mCameraLibrary;

	/** Controller library: joint controllers by ID */
	typedef std::map<std::string, Collada::Controller> ControllerLibrary;
	ControllerLibrary mControllerLibrary;

	/** Pointer to the root node. Don't delete, it just points to one of 
	    the nodes in the node library. */
	Collada::Node* mRootNode;

	/** Size unit: how large compared to a meter */
	float mUnitSize;

	/** Which is the up vector */
	enum { UP_X, UP_Y, UP_Z } mUpDirection;

	/** Collada file format version */
	Collada::FormatVersion mFormat;
};

// ------------------------------------------------------------------------------------------------
// Check for element match
inline bool ColladaParser::IsElement( const char* pName) const
{
	ai_assert( mReader->getNodeType() == irr::io::EXN_ELEMENT); 
	return ::strcmp( mReader->getNodeName(), pName) == 0; 
}

// ------------------------------------------------------------------------------------------------
// Finds the item in the given library by its reference, throws if not found
template <typename Type> 
const Type& ColladaParser::ResolveLibraryReference( const std::map<std::string, Type>& pLibrary, const std::string& pURL) const
{
	typename std::map<std::string, Type>::const_iterator it = pLibrary.find( pURL);
	if( it == pLibrary.end())
		ThrowException( boost::str( boost::format( "Unable to resolve library reference \"%s\".") % pURL));
	return it->second;
}

} // end of namespace Assimp

#endif // AI_COLLADAPARSER_H_INC