nuclear@0: /*
nuclear@0: ---------------------------------------------------------------------------
nuclear@0: Open Asset Import Library (assimp)
nuclear@0: ---------------------------------------------------------------------------
nuclear@0: 
nuclear@0: Copyright (c) 2006-2012, assimp team
nuclear@0: 
nuclear@0: All rights reserved.
nuclear@0: 
nuclear@0: Redistribution and use of this software in source and binary forms, 
nuclear@0: with or without modification, are permitted provided that the following 
nuclear@0: conditions are met:
nuclear@0: 
nuclear@0: * Redistributions of source code must retain the above
nuclear@0:   copyright notice, this list of conditions and the
nuclear@0:   following disclaimer.
nuclear@0: 
nuclear@0: * Redistributions in binary form must reproduce the above
nuclear@0:   copyright notice, this list of conditions and the
nuclear@0:   following disclaimer in the documentation and/or other
nuclear@0:   materials provided with the distribution.
nuclear@0: 
nuclear@0: * Neither the name of the assimp team, nor the names of its
nuclear@0:   contributors may be used to endorse or promote products
nuclear@0:   derived from this software without specific prior
nuclear@0:   written permission of the assimp team.
nuclear@0: 
nuclear@0: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
nuclear@0: "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
nuclear@0: LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
nuclear@0: A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
nuclear@0: OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
nuclear@0: SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
nuclear@0: LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
nuclear@0: DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
nuclear@0: THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
nuclear@0: (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
nuclear@0: OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
nuclear@0: ---------------------------------------------------------------------------
nuclear@0: */
nuclear@0: 
nuclear@0: /** @file Implementation of the post processing step to invert
nuclear@0:  * all normals in meshes with infacing normals.
nuclear@0:  */
nuclear@0: 
nuclear@0: #include "AssimpPCH.h"
nuclear@0: 
nuclear@0: // internal headers
nuclear@0: #include "FixNormalsStep.h"
nuclear@0: 
nuclear@0: using namespace Assimp;
nuclear@0: 
nuclear@0: 
nuclear@0: // ------------------------------------------------------------------------------------------------
nuclear@0: // Constructor to be privately used by Importer
nuclear@0: FixInfacingNormalsProcess::FixInfacingNormalsProcess()
nuclear@0: {
nuclear@0: 	// nothing to do here
nuclear@0: }
nuclear@0: 
nuclear@0: // ------------------------------------------------------------------------------------------------
nuclear@0: // Destructor, private as well
nuclear@0: FixInfacingNormalsProcess::~FixInfacingNormalsProcess()
nuclear@0: {
nuclear@0: 	// nothing to do here
nuclear@0: }
nuclear@0: 
nuclear@0: // ------------------------------------------------------------------------------------------------
nuclear@0: // Returns whether the processing step is present in the given flag field.
nuclear@0: bool FixInfacingNormalsProcess::IsActive( unsigned int pFlags) const
nuclear@0: {
nuclear@0: 	return (pFlags & aiProcess_FixInfacingNormals) != 0;
nuclear@0: }
nuclear@0: 
nuclear@0: // ------------------------------------------------------------------------------------------------
nuclear@0: // Executes the post processing step on the given imported data.
nuclear@0: void FixInfacingNormalsProcess::Execute( aiScene* pScene)
nuclear@0: {
nuclear@0: 	DefaultLogger::get()->debug("FixInfacingNormalsProcess begin");
nuclear@0: 
nuclear@0: 	bool bHas = false;
nuclear@0: 	for( unsigned int a = 0; a < pScene->mNumMeshes; a++)
nuclear@0: 		if(ProcessMesh( pScene->mMeshes[a],a))bHas = true;
nuclear@0: 
nuclear@0: 	if (bHas)
nuclear@0: 		 DefaultLogger::get()->debug("FixInfacingNormalsProcess finished. Found issues.");
nuclear@0: 	else DefaultLogger::get()->debug("FixInfacingNormalsProcess finished. No changes to the scene.");
nuclear@0: }
nuclear@0: 
nuclear@0: // ------------------------------------------------------------------------------------------------
nuclear@0: // Apply the step to the mesh
nuclear@0: bool FixInfacingNormalsProcess::ProcessMesh( aiMesh* pcMesh, unsigned int index)
nuclear@0: {
nuclear@0: 	ai_assert(NULL != pcMesh);
nuclear@0: 
nuclear@0: 	// Nothing to do if there are no model normals
nuclear@0: 	if (!pcMesh->HasNormals())return false;
nuclear@0: 
nuclear@0: 	// Compute the bounding box of both the model vertices + normals and
nuclear@0: 	// the umodified model vertices. Then check whether the first BB
nuclear@0: 	// is smaller than the second. In this case we can assume that the
nuclear@0: 	// normals need to be flipped, although there are a few special cases ..
nuclear@0: 	// convex, concave, planar models ...
nuclear@0: 
nuclear@0: 	aiVector3D vMin0 (1e10f,1e10f,1e10f);
nuclear@0: 	aiVector3D vMin1 (1e10f,1e10f,1e10f);
nuclear@0: 	aiVector3D vMax0 (-1e10f,-1e10f,-1e10f);
nuclear@0: 	aiVector3D vMax1 (-1e10f,-1e10f,-1e10f);
nuclear@0: 
nuclear@0: 	for (unsigned int i = 0; i < pcMesh->mNumVertices;++i)
nuclear@0: 	{
nuclear@0: 		vMin1.x = std::min(vMin1.x,pcMesh->mVertices[i].x);
nuclear@0: 		vMin1.y = std::min(vMin1.y,pcMesh->mVertices[i].y);
nuclear@0: 		vMin1.z = std::min(vMin1.z,pcMesh->mVertices[i].z);
nuclear@0: 
nuclear@0: 		vMax1.x = std::max(vMax1.x,pcMesh->mVertices[i].x);
nuclear@0: 		vMax1.y = std::max(vMax1.y,pcMesh->mVertices[i].y);
nuclear@0: 		vMax1.z = std::max(vMax1.z,pcMesh->mVertices[i].z);
nuclear@0: 
nuclear@0: 		const aiVector3D vWithNormal = pcMesh->mVertices[i] + pcMesh->mNormals[i];
nuclear@0: 
nuclear@0: 		vMin0.x = std::min(vMin0.x,vWithNormal.x);
nuclear@0: 		vMin0.y = std::min(vMin0.y,vWithNormal.y);
nuclear@0: 		vMin0.z = std::min(vMin0.z,vWithNormal.z);
nuclear@0: 
nuclear@0: 		vMax0.x = std::max(vMax0.x,vWithNormal.x);
nuclear@0: 		vMax0.y = std::max(vMax0.y,vWithNormal.y);
nuclear@0: 		vMax0.z = std::max(vMax0.z,vWithNormal.z);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	const float fDelta0_x = (vMax0.x - vMin0.x);
nuclear@0: 	const float fDelta0_y = (vMax0.y - vMin0.y);
nuclear@0: 	const float fDelta0_z = (vMax0.z - vMin0.z);
nuclear@0: 
nuclear@0: 	const float fDelta1_x = (vMax1.x - vMin1.x);
nuclear@0: 	const float fDelta1_y = (vMax1.y - vMin1.y);
nuclear@0: 	const float fDelta1_z = (vMax1.z - vMin1.z);
nuclear@0: 
nuclear@0: 	// Check whether the boxes are overlapping
nuclear@0: 	if ((fDelta0_x > 0.0f) != (fDelta1_x > 0.0f))return false;
nuclear@0: 	if ((fDelta0_y > 0.0f) != (fDelta1_y > 0.0f))return false;
nuclear@0: 	if ((fDelta0_z > 0.0f) != (fDelta1_z > 0.0f))return false;
nuclear@0: 
nuclear@0: 	// Check whether this is a planar surface
nuclear@0: 	const float fDelta1_yz = fDelta1_y * fDelta1_z;
nuclear@0: 
nuclear@0: 	if (fDelta1_x < 0.05f * sqrtf( fDelta1_yz ))return false;
nuclear@0: 	if (fDelta1_y < 0.05f * sqrtf( fDelta1_z * fDelta1_x ))return false;
nuclear@0: 	if (fDelta1_z < 0.05f * sqrtf( fDelta1_y * fDelta1_x ))return false;
nuclear@0: 
nuclear@0: 	// now compare the volumes of the bounding boxes
nuclear@0: 	if (::fabsf(fDelta0_x * fDelta1_yz) <
nuclear@0: 		::fabsf(fDelta1_x * fDelta1_y * fDelta1_z))
nuclear@0: 	{
nuclear@0: 		if (!DefaultLogger::isNullLogger())
nuclear@0: 		{
nuclear@0: 			char buffer[128]; // should be sufficiently large
nuclear@0: 			::sprintf(buffer,"Mesh %i: Normals are facing inwards (or the mesh is planar)",index);
nuclear@0: 			DefaultLogger::get()->info(buffer);
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		// Invert normals
nuclear@0: 		for (unsigned int i = 0; i < pcMesh->mNumVertices;++i)
nuclear@0: 			pcMesh->mNormals[i] *= -1.0f;
nuclear@0: 
nuclear@0: 		// ... and flip faces
nuclear@0: 		for (unsigned int i = 0; i < pcMesh->mNumFaces;++i)
nuclear@0: 		{
nuclear@0: 			aiFace& face = pcMesh->mFaces[i];
nuclear@0: 			for( unsigned int b = 0; b < face.mNumIndices / 2; b++)
nuclear@0: 				std::swap( face.mIndices[b], face.mIndices[ face.mNumIndices - 1 - b]);
nuclear@0: 		}
nuclear@0: 		return true;
nuclear@0: 	}
nuclear@0: 	return false;
nuclear@0: }