assimp/code/TextureTransform.h

/*
Open Asset Import Library (ASSIMP)
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*/

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

#include "BaseImporter.h"
#include "../include/aiTypes.h"
#include "../include/aiMaterial.h"
#include "../include/aiMesh.h"


struct aiNode;
#include "3DSHelper.h"

namespace Assimp
{

using namespace Assimp::Dot3DS;

// ---------------------------------------------------------------------------
/** Helper class representing texture coordinate transformations
*/
struct STransformVecInfo 
{
	//! Construction. The resulting matrix is the identity
	STransformVecInfo ()
		: 
		fScaleU(1.0f),fScaleV(1.0f),
		fOffsetU(0.0f),fOffsetV(0.0f),
		fRotation(0.0f),
		iUVIndex(0)
	{}

	//! Texture coordinate scaling in the x-direction 
	float fScaleU;
	//! Texture coordinate scaling in the y-direction 
	float fScaleV;
	//! Texture coordinate offset in the x-direction
	float fOffsetU;
	//! Texture coordinate offset in the y-direction
	float fOffsetV;
	//! Texture coordinate rotation, clockwise, in radians
	float fRotation;

	//! Source texture coordinate index
	unsigned int iUVIndex;


	//! List of all textures that use this texture
	//! coordinate transformations
	std::vector<Dot3DS::Texture*> pcTextures; 


	// -------------------------------------------------------------------
	/** Returns whether this is an untransformed texture coordinate set
	*/
	inline bool IsUntransformed() const
	{
		return 1.0f == fScaleU && 1.0f == fScaleV &&
			!fOffsetU && !fOffsetV && !fRotation;
	}

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

		if (1.0f != this->fScaleU || 1.0f != this->fScaleV)
		{
			aiMatrix3x3 mScale;
			mScale.a1 = this->fScaleU;
			mScale.b2 = this->fScaleV;
			mOut = mScale;
		}
		if (this->fRotation)
		{
			aiMatrix3x3 mRot; 
			mRot.a1 = mRot.b2 = cosf(this->fRotation);
			mRot.a2 = mRot.b1 = sinf(this->fRotation);
			mRot.a2 = -mRot.a2;
			mOut *= mRot;
		}
		if (this->fOffsetU || this->fOffsetV)
		{
			aiMatrix3x3 mTrans; 
			mTrans.a3 = this->fOffsetU;
			mTrans.b3 = this->fOffsetV;
			mOut *= mTrans;
		}
	}
};


// ---------------------------------------------------------------------------
/** Helper class used by the ASE/ASK and 3DS loaders to handle texture
 *  coordinate transformations correctly (such as offsets, scaling)
*/
class ASSIMP_API TextureTransform
{
	//! Constructor, it is not possible to create instances of this class
	TextureTransform() {}
public:


	// -------------------------------------------------------------------
	/** Returns true if a texture requires UV transformations
	 * \param rcIn Input texture
	*/
	inline static bool HasUVTransform(
		const Dot3DS::Texture& rcIn)
	{
		return (rcIn.mOffsetU || rcIn.mOffsetV ||
			1.0f != rcIn.mScaleU  ||  1.0f != rcIn.mScaleV || rcIn.mRotation);
	}

	// -------------------------------------------------------------------
	/** Must be called before HasUVTransform(rcIn) is called 
	 * \param rcIn Input texture
	*/
	static void PreProcessUVTransform(
		Dot3DS::Texture& rcIn);

	// -------------------------------------------------------------------
	/** Check whether the texture coordinate transformation of
	 *  a texture is already contained in a given list
	 * \param rasVec List of transformations
	 * \param pcTex Pointer to the texture
	*/
	static void AddToList(std::vector<STransformVecInfo>& rasVec,
		Dot3DS::Texture* pcTex);

	// -------------------------------------------------------------------
	/** Get a full list of all texture coordinate offsets required
	 *  for a material
	 * \param materials List of materials to be processed
	*/
	static void ApplyScaleNOffset(std::vector<Dot3DS::Material>& materials);

	// -------------------------------------------------------------------
	/** Get a full list of all texture coordinate offsets required
	 *  for a material
	 * \param material Material to be processed
	*/
	static void ApplyScaleNOffset(Dot3DS::Material& material);

	// -------------------------------------------------------------------
	/** Precompute as many texture coordinate transformations as possible
	 * \param pcMesh Mesh containing the texture coordinate data
	 * \param pcSrc Input material. Must have been passed to
	 * ApplyScaleNOffset
	*/
	static void BakeScaleNOffset(aiMesh* pcMesh, Dot3DS::Material* pcSrc);

	
	// -------------------------------------------------------------------
	/** Setup the correct UV source for a material
	 * \param pcMat Final material to be changed
	 * \param pcMatIn Input material, unconverted
	*/
	static void SetupMatUVSrc (aiMaterial* pcMat, 
		const Dot3DS::Material* pcMatIn);
};

}

#endif //! AI_TEXTURE_TRANSFORM_H_INCLUDED