Re-add libassimp 3.1.1 to 3rd party

Previously the assimp library was a dependency that was
always built, but it is possible to use an external
system version if one is available.  It is however non-
trivial to provide the dependency on platforms other
than Linux, so now we provide a copy of libassimp for
use when it is not already available.

This commit is a combination of reverting commit
672b3e47299f6ba0034f73b252d0436b55fb3085 which removed
assimp and introduced the scene parser, and adding the
logic to use the system version when available.

Change-Id: Ia05f9a92b8d82f19a0db3588b2bbeafe71404386
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

1 files changed, 138 insertions, 0 deletions

diff --git a/src/3rdparty/assimp/code/GenFaceNormalsProcess.cpp b/src/3rdparty/assimp/code/GenFaceNormalsProcess.cpp
new file mode 100644
index 000000000..573d93299
--- /dev/null
+++ b/src/3rdparty/assimp/code/GenFaceNormalsProcess.cpp
@@ -0,0 +1,138 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2012, assimp 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 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.
+---------------------------------------------------------------------------
+*/
+
+/** @file Implementation of the post processing step to generate face
+* normals for all imported faces.
+*/
+
+#include "AssimpPCH.h"
+#include "GenFaceNormalsProcess.h"
+
+
+using namespace Assimp;
+
+// ------------------------------------------------------------------------------------------------
+// Constructor to be privately used by Importer
+GenFaceNormalsProcess::GenFaceNormalsProcess()
+{
+	// nothing to do here
+}
+
+// ------------------------------------------------------------------------------------------------
+// Destructor, private as well
+GenFaceNormalsProcess::~GenFaceNormalsProcess()
+{
+	// nothing to do here
+}
+
+// ------------------------------------------------------------------------------------------------
+// Returns whether the processing step is present in the given flag field.
+bool GenFaceNormalsProcess::IsActive( unsigned int pFlags) const
+{
+	return	(pFlags & aiProcess_GenNormals) != 0;
+}
+
+// ------------------------------------------------------------------------------------------------
+// Executes the post processing step on the given imported data.
+void GenFaceNormalsProcess::Execute( aiScene* pScene)
+{
+	DefaultLogger::get()->debug("GenFaceNormalsProcess begin");
+
+	if (pScene->mFlags & AI_SCENE_FLAGS_NON_VERBOSE_FORMAT) {
+		throw DeadlyImportError("Post-processing order mismatch: expecting pseudo-indexed (\"verbose\") vertices here");
+	}
+
+	bool bHas = false;
+	for( unsigned int a = 0; a < pScene->mNumMeshes; a++)	{
+		if(this->GenMeshFaceNormals( pScene->mMeshes[a])) {
+			bHas = true;
+		}
+	}
+	if (bHas)	{
+		DefaultLogger::get()->info("GenFaceNormalsProcess finished. "
+			"Face normals have been calculated");
+	}
+	else DefaultLogger::get()->debug("GenFaceNormalsProcess finished. "
+		"Normals are already there");
+}
+
+// ------------------------------------------------------------------------------------------------
+// Executes the post processing step on the given imported data.
+bool GenFaceNormalsProcess::GenMeshFaceNormals (aiMesh* pMesh)
+{
+	if (NULL != pMesh->mNormals) {
+		return false;
+	}
+
+	// If the mesh consists of lines and/or points but not of
+	// triangles or higher-order polygons the normal vectors
+	// are undefined.
+	if (!(pMesh->mPrimitiveTypes & (aiPrimitiveType_TRIANGLE | aiPrimitiveType_POLYGON)))	{
+		DefaultLogger::get()->info("Normal vectors are undefined for line and point meshes");
+		return false;
+	}
+
+	// allocate an array to hold the output normals
+	pMesh->mNormals = new aiVector3D[pMesh->mNumVertices];
+	const float qnan = get_qnan();
+
+	// iterate through all faces and compute per-face normals but store them per-vertex. 
+	for( unsigned int a = 0; a < pMesh->mNumFaces; a++)	{
+		const aiFace& face = pMesh->mFaces[a];
+		if (face.mNumIndices < 3)	{
+			// either a point or a line -> no well-defined normal vector
+			for (unsigned int i = 0;i < face.mNumIndices;++i) {
+				pMesh->mNormals[face.mIndices[i]] = aiVector3D(qnan);
+			}
+			continue;
+		}
+
+		const aiVector3D* pV1 = &pMesh->mVertices[face.mIndices[0]];
+		const aiVector3D* pV2 = &pMesh->mVertices[face.mIndices[1]];
+		const aiVector3D* pV3 = &pMesh->mVertices[face.mIndices[face.mNumIndices-1]];
+		const aiVector3D vNor = ((*pV2 - *pV1) ^ (*pV3 - *pV1)).Normalize();
+
+		for (unsigned int i = 0;i < face.mNumIndices;++i) {
+			pMesh->mNormals[face.mIndices[i]] = vNor;
+		}
+	}
+	return true;
+}