assimp/tools/assimp_view/Normals.cpp

/*
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Open Asset Import Library (ASSIMP)
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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.

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  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/


#include "stdafx.h"
#include "assimp_view.h"

#include "GenFaceNormalsProcess.h"
#include "GenVertexNormalsProcess.h"
#include "JoinVerticesProcess.h"
#include "CalcTangentsProcess.h"

namespace AssimpView {


bool g_bWasFlipped = false;

//-------------------------------------------------------------------------------
// Flip all normal vectors
//-------------------------------------------------------------------------------
void AssetHelper::FlipNormals()
{
	// invert all normal vectors
	for (unsigned int i = 0; i < this->pcScene->mNumMeshes;++i)
	{
		aiMesh* pcMesh = this->pcScene->mMeshes[i];
		for (unsigned int a = 0; a < pcMesh->mNumVertices;++a)
		{
			pcMesh->mNormals[a] *= -1.0f;
		}
	}
	// recreate native data
	DeleteAssetData(true);
	CreateAssetData();
	g_bWasFlipped = ! g_bWasFlipped;
}

//-------------------------------------------------------------------------------
// Set the normal set of the scene
//-------------------------------------------------------------------------------
void AssetHelper::SetNormalSet(unsigned int iSet)
{
	if (this->iNormalSet == iSet)return;

	// we need to build an unique set of vertices for this ...
	for (unsigned int i = 0; i < this->pcScene->mNumMeshes;++i)
	{
		aiMesh* pcMesh = this->pcScene->mMeshes[i];
		const unsigned int iNumVerts = pcMesh->mNumFaces*3;

		aiVector3D* pvPositions = new aiVector3D[iNumVerts];
		aiVector3D* pvNormals = new aiVector3D[iNumVerts];
		aiVector3D* pvTangents(NULL), *pvBitangents(NULL);

		ai_assert(AI_MAX_NUMBER_OF_TEXTURECOORDS == 4);
		ai_assert(AI_MAX_NUMBER_OF_COLOR_SETS == 4);
		aiVector3D* apvTextureCoords[AI_MAX_NUMBER_OF_TEXTURECOORDS] = {NULL,NULL,NULL,NULL};
		aiColor4D* apvColorSets[AI_MAX_NUMBER_OF_COLOR_SETS] = {NULL,NULL,NULL,NULL};


		unsigned int p = 0;
		while (pcMesh->HasTextureCoords(p))
			apvTextureCoords[p++] = new aiVector3D[iNumVerts];

		p = 0;
		while (pcMesh->HasVertexColors(p))
			apvColorSets[p++] = new aiColor4D[iNumVerts];

		// iterate through all faces and build a clean list
		unsigned int iIndex = 0;
		for (unsigned int a = 0; a< pcMesh->mNumFaces;++a)
		{
			aiFace* pcFace = &pcMesh->mFaces[a];
			for (unsigned int q = 0; q < 3;++q,++iIndex)
			{
				pvPositions[iIndex] = pcMesh->mVertices[pcFace->mIndices[q]];
				pvNormals[iIndex] = pcMesh->mNormals[pcFace->mIndices[q]];

				unsigned int p = 0;
				while (pcMesh->HasTextureCoords(p))
				{
					apvTextureCoords[p][iIndex] = pcMesh->mTextureCoords[p][pcFace->mIndices[q]];
					++p;
				}
				p = 0;
				while (pcMesh->HasVertexColors(p))
				{
					apvColorSets[p][iIndex] = pcMesh->mColors[p][pcFace->mIndices[q]];
					++p;
				}
				pcFace->mIndices[q] = iIndex;
			}
		}

		// delete the old members
		delete[] pcMesh->mVertices;
		pcMesh->mVertices = pvPositions;

		p = 0;
		while (pcMesh->HasTextureCoords(p))
		{
			delete pcMesh->mTextureCoords[p];
			pcMesh->mTextureCoords[p] = apvTextureCoords[p];
			++p;
		}
		p = 0;
		while (pcMesh->HasVertexColors(p))
		{
			delete pcMesh->mColors[p];
			pcMesh->mColors[p] = apvColorSets[p];
			++p;
		}
		pcMesh->mNumVertices = iNumVerts;

		// keep the pointer to the normals 
		delete[] pcMesh->mNormals;
		pcMesh->mNormals = NULL;

		if (!this->apcMeshes[i]->pvOriginalNormals)
			this->apcMeshes[i]->pvOriginalNormals = pvNormals;
	}

	// now we can start to calculate a new set of normals
	if (HARD == iSet)
	{
		Assimp::GenFaceNormalsProcess* pcProcess = new Assimp::GenFaceNormalsProcess();
		pcProcess->Execute(this->pcScene);
		delete pcProcess;
	}
	else if (SMOOTH == iSet)
	{
		Assimp::GenVertexNormalsProcess* pcProcess = new Assimp::GenVertexNormalsProcess();
		pcProcess->Execute(this->pcScene);
		delete pcProcess;
	}
	else if (ORIGINAL == iSet)
	{
		for (unsigned int i = 0; i < this->pcScene->mNumMeshes;++i)
		{
			this->pcScene->mMeshes[i]->mNormals = this->apcMeshes[i]->pvOriginalNormals;
		}
	}

	// recalculate tangents and bitangents
	Assimp::BaseProcess* pcProcess = new Assimp::CalcTangentsProcess();
	pcProcess->Execute(this->pcScene);
	delete pcProcess;

	// join the mesh vertices again
	pcProcess = new Assimp::JoinVerticesProcess();
	pcProcess->Execute(this->pcScene);
	delete pcProcess;

	this->iNormalSet = iSet;

	if (g_bWasFlipped && ORIGINAL != iSet)
	{
		// invert all normal vectors
		for (unsigned int i = 0; i < this->pcScene->mNumMeshes;++i)
		{
			aiMesh* pcMesh = this->pcScene->mMeshes[i];
			for (unsigned int a = 0; a < pcMesh->mNumVertices;++a)
			{
				pcMesh->mNormals[a] *= -1.0f;
			}
		}
	}

	// recreate native data
	DeleteAssetData(true);
	CreateAssetData();
	return;
}

};