assimp/code/TextureTransform.h

/*
Open Asset Import Library (assimp)
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  following disclaimer.

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*/

/** @file Definition of a helper step that processes texture transformations */
#ifndef AI_TEXTURE_TRANSFORM_H_INCLUDED
#define AI_TEXTURE_TRANSFORM_H_INCLUDED

#include "BaseImporter.h"
#include "BaseProcess.h"

#include "../include/assimp/material.h"
#include <list>

struct aiNode;
struct aiMaterial;

namespace Assimp	{

#define AI_TT_UV_IDX_LOCK_TBD	0xffffffff
#define AI_TT_UV_IDX_LOCK_NONE	0xeeeeeeee


#define AI_TT_ROTATION_EPSILON	((float)AI_DEG_TO_RAD(0.5))

// ---------------------------------------------------------------------------
/** Small helper structure representing a shortcut into the material list
 *  to be able to update some values quickly.
*/
struct TTUpdateInfo
{
	TTUpdateInfo() :
			directShortcut	(NULL)
		,	mat				(NULL)
		,	semantic		(0)
		,	index			(0)
	{}

	//! Direct shortcut, if available
	unsigned int* directShortcut;

	//! Material 
	aiMaterial *mat;

	//! Texture type and index
	unsigned int semantic, index;
};


// ---------------------------------------------------------------------------
/** Helper class representing texture coordinate transformations
*/
struct STransformVecInfo : public aiUVTransform
{

	STransformVecInfo()
		:	uvIndex		(0)
		,	mapU		(aiTextureMapMode_Wrap)
		,	mapV		(aiTextureMapMode_Wrap)
		,	lockedPos	(AI_TT_UV_IDX_LOCK_NONE)
	{}

	//! Source texture coordinate index
	unsigned int uvIndex;

	//! Texture mapping mode in the u, v direction
	aiTextureMapMode mapU,mapV;

	//! Locked destination UV index
	//! AI_TT_UV_IDX_LOCK_TBD - to be determined
	//! AI_TT_UV_IDX_LOCK_NONE - none (default)
	unsigned int lockedPos;

	//! Update info - shortcuts into all materials
	//! that are referencing this transform setup
	std::list<TTUpdateInfo> updateList;


	// -------------------------------------------------------------------
	/** Compare two transform setups
	*/
	inline bool operator== (const STransformVecInfo& other) const
	{
		// We use a small epsilon here
		const static float epsilon = 0.05f;

		if (std::fabs( mTranslation.x - other.mTranslation.x ) > epsilon ||
			std::fabs( mTranslation.y - other.mTranslation.y ) > epsilon)
		{
			return false;
		}

		if (std::fabs( mScaling.x - other.mScaling.x ) > epsilon ||
			std::fabs( mScaling.y - other.mScaling.y ) > epsilon)
		{
			return false;
		}

		if (std::fabs( mRotation - other.mRotation) > epsilon)
		{
			return false;
		}
		return true;
	}

	inline bool operator!= (const STransformVecInfo& other) const
	{
			return !(*this == other);
	}


	// -------------------------------------------------------------------
	/** Returns whether this is an untransformed texture coordinate set
	*/
	inline bool IsUntransformed() const
	{
		return (1.0f == mScaling.x && 1.f == mScaling.y &&
			!mTranslation.x && !mTranslation.y && 
			mRotation < AI_TT_ROTATION_EPSILON);
	}

	// -------------------------------------------------------------------
	/** Build a 3x3 matrix from the transformations
	*/
	inline void GetMatrix(aiMatrix3x3& mOut)
	{
		mOut = aiMatrix3x3();

		if (1.0f != mScaling.x || 1.0f != mScaling.y)
		{
			aiMatrix3x3 mScale;
			mScale.a1 = mScaling.x;
			mScale.b2 = mScaling.y;
			mOut = mScale;
		}
		if (mRotation)
		{
			aiMatrix3x3 mRot; 
			mRot.a1 = mRot.b2 = std::cos(mRotation);
			mRot.a2 = mRot.b1 = std::sin(mRotation);
			mRot.a2 = -mRot.a2;
			mOut *= mRot;
		}
		if (mTranslation.x || mTranslation.y)
		{
			aiMatrix3x3 mTrans; 
			mTrans.a3 = mTranslation.x;
			mTrans.b3 = mTranslation.y;
			mOut *= mTrans;
		}
	}
};


// ---------------------------------------------------------------------------
/** Helper step to compute final UV coordinate sets if there are scalings
 *  or rotations in the original data read from the file.
*/
class TextureTransformStep : public BaseProcess
{
public:

	TextureTransformStep();
	~TextureTransformStep();

public:

	// -------------------------------------------------------------------
	bool IsActive( unsigned int pFlags) const;

	// -------------------------------------------------------------------
	void Execute( aiScene* pScene);

	// -------------------------------------------------------------------
	void SetupProperties(const Importer* pImp);


protected:


	// -------------------------------------------------------------------
	/** Preprocess a specific UV transformation setup
	 *
	 *  @param info Transformation setup to be preprocessed.
	*/
	void PreProcessUVTransform(STransformVecInfo& info);

private:

	unsigned int configFlags;
};

}

#endif //! AI_TEXTURE_TRANSFORM_H_INCLUDED