assimp/code/ColladaParser.h

/** Defines the parser helper class for the collada loader */

/*
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
copyright notice, this list of conditions and the
following disclaimer.

* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the
following disclaimer in the documentation and/or other
materials provided with the distribution.

* 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,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

----------------------------------------------------------------------
*/

#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( 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 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 effect library */
	void ReadEffectLibrary();

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

	/** Reads an effect entry containing a color or a texture defining that color */
	void ReadEffectColor( aiColor4D& pColor, std::string& 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 data array holding a number of floats, and stores it in the global library */
	void ReadFloatArray();

	/** 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();

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 { assert( mReader->getNodeType() == irr::io::EXN_ELEMENT); return strcmp( mReader->getNodeName(), pName) == 0; }

	/** 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();

	/** Calculates the resulting transformation fromm 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 */
	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;

	/** 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;
};

// ------------------------------------------------------------------------------------------------
// 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