text: /*
  ---------------------------------------------------------------------------
  Open Asset Import Library (assimp)
  ---------------------------------------------------------------------------
  
  Copyright (c) 2006-2021, 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 IrrMesh importer class */
  
  #ifndef ASSIMP_BUILD_NO_IRRMESH_IMPORTER
  
  #include "IRRMeshLoader.h"
  #include <assimp/ParsingUtils.h>
  #include <assimp/fast_atof.h>
  #include <assimp/importerdesc.h>
  #include <assimp/material.h>
  #include <assimp/mesh.h>
  #include <assimp/scene.h>
  #include <assimp/DefaultLogger.hpp>
  #include <assimp/IOSystem.hpp>
  #include <memory>
  
  using namespace Assimp;
  
  static const aiImporterDesc desc = {
  	"Irrlicht Mesh Reader",
  	"",
  	"",
  	"http://irrlicht.sourceforge.net/",
  	aiImporterFlags_SupportTextFlavour,
  	0,
  	0,
  	0,
  	0,
  	"xml irrmesh"
  };
  
  // ------------------------------------------------------------------------------------------------
  // Constructor to be privately used by Importer
  IRRMeshImporter::IRRMeshImporter() :
          BaseImporter(),
          IrrlichtBase() {
      // empty
  }
  
  // ------------------------------------------------------------------------------------------------
  // Destructor, private as well
  IRRMeshImporter::~IRRMeshImporter() {}
  
  // ------------------------------------------------------------------------------------------------
  // Returns whether the class can handle the format of the given file.
  bool IRRMeshImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool checkSig) const {
  	/* NOTE: A simple check for the file extension is not enough
       * here. Irrmesh and irr are easy, but xml is too generic
       * and could be collada, too. So we need to open the file and
       * search for typical tokens.
       */
  	const std::string extension = GetExtension(pFile);
  
  	if (extension == "irrmesh")
  		return true;
  	else if (extension == "xml" || checkSig) {
  		/*  If CanRead() is called to check whether the loader
           *  supports a specific file extension in general we
           *  must return true here.
           */
  		if (!pIOHandler) return true;
  		const char *tokens[] = { "irrmesh" };
  		return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  	}
  	return false;
  }
  
  // ------------------------------------------------------------------------------------------------
  // Get a list of all file extensions which are handled by this class
  const aiImporterDesc *IRRMeshImporter::GetInfo() const {
  	return &desc;
  }
  
  static void releaseMaterial(aiMaterial **mat) {
  	if (*mat != nullptr) {
  		delete *mat;
  		*mat = nullptr;
  	}
  }
  
  static void releaseMesh(aiMesh **mesh) {
  	if (*mesh != nullptr) {
  		delete *mesh;
  		*mesh = nullptr;
  	}
  }
  
  // ------------------------------------------------------------------------------------------------
  // Imports the given file into the given scene structure.
  void IRRMeshImporter::InternReadFile(const std::string &pFile,
  		aiScene *pScene, IOSystem *pIOHandler) {
  	std::unique_ptr<IOStream> file(pIOHandler->Open(pFile));
  
  	// Check whether we can read from the file
  	if (file.get() == NULL)
          throw DeadlyImportError("Failed to open IRRMESH file ", pFile);
  
  	// Construct the irrXML parser
  	XmlParser parser;
      if (!parser.parse( file.get() )) {
          throw DeadlyImportError("XML parse error while loading IRRMESH file ", pFile);
      }
      XmlNode root = parser.getRootNode();
  
  	// final data
  	std::vector<aiMaterial *> materials;
  	std::vector<aiMesh *> meshes;
  	materials.reserve(5);
  	meshes.reserve(5);
  
  	// temporary data - current mesh buffer
  	aiMaterial *curMat = nullptr;
  	aiMesh *curMesh = nullptr;
  	unsigned int curMatFlags = 0;
  
  	std::vector<aiVector3D> curVertices, curNormals, curTangents, curBitangents;
  	std::vector<aiColor4D> curColors;
  	std::vector<aiVector3D> curUVs, curUV2s;
  
  	// some temporary variables
  	int textMeaning = 0;
  	int vertexFormat = 0; // 0 = normal; 1 = 2 tcoords, 2 = tangents
  	bool useColors = false;
  
  	// Parse the XML file
  	for (pugi::xml_node child : root.children()) {
  		if (child.type() == pugi::node_element) {
  			if (!ASSIMP_stricmp(child.name(), "buffer") && (curMat || curMesh)) {
  				// end of previous buffer. A material and a mesh should be there
  				if (!curMat || !curMesh) {
  					ASSIMP_LOG_ERROR("IRRMESH: A buffer must contain a mesh and a material");
  					releaseMaterial(&curMat);
  					releaseMesh(&curMesh);
  				} else {
  					materials.push_back(curMat);
  					meshes.push_back(curMesh);
  				}
  				curMat = nullptr;
  				curMesh = nullptr;
  
  				curVertices.clear();
  				curColors.clear();
  				curNormals.clear();
  				curUV2s.clear();
  				curUVs.clear();
  				curTangents.clear();
  				curBitangents.clear();
  			}
  
  			if (!ASSIMP_stricmp(child.name(), "material")) {
  				if (curMat) {
  					ASSIMP_LOG_WARN("IRRMESH: Only one material description per buffer, please");
  					releaseMaterial(&curMat);
  				}
  				curMat = ParseMaterial(curMatFlags);
  			}
  			/* no else here! */ if (!ASSIMP_stricmp(child.name(), "vertices")) {
  				pugi::xml_attribute attr = child.attribute("vertexCount");
  				int num = attr.as_int();
                  //int num = reader->getAttributeValueAsInt("vertexCount");
  
  				if (!num) {
  					// This is possible ... remove the mesh from the list and skip further reading
  					ASSIMP_LOG_WARN("IRRMESH: Found mesh with zero vertices");
  
  					releaseMaterial(&curMat);
  					releaseMesh(&curMesh);
  					textMeaning = 0;
  					continue;
  				}
  
  				curVertices.reserve(num);
  				curNormals.reserve(num);
  				curColors.reserve(num);
  				curUVs.reserve(num);
  
  				// Determine the file format
  				//const char *t = reader->getAttributeValueSafe("type");
                  pugi::xml_attribute t = child.attribute("type");
  				if (!ASSIMP_stricmp("2tcoords", t.name())) {
  					curUV2s.reserve(num);
  					vertexFormat = 1;
  
  					if (curMatFlags & AI_IRRMESH_EXTRA_2ND_TEXTURE) {
  						// *********************************************************
  						// We have a second texture! So use this UV channel
  						// for it. The 2nd texture can be either a normal
  						// texture (solid_2layer or lightmap_xxx) or a normal
  						// map (normal_..., parallax_...)
  						// *********************************************************
  						int idx = 1;
  						aiMaterial *mat = (aiMaterial *)curMat;
  
  						if (curMatFlags & AI_IRRMESH_MAT_lightmap) {
  							mat->AddProperty(&idx, 1, AI_MATKEY_UVWSRC_LIGHTMAP(0));
  						} else if (curMatFlags & AI_IRRMESH_MAT_normalmap_solid) {
  							mat->AddProperty(&idx, 1, AI_MATKEY_UVWSRC_NORMALS(0));
  						} else if (curMatFlags & AI_IRRMESH_MAT_solid_2layer) {
  							mat->AddProperty(&idx, 1, AI_MATKEY_UVWSRC_DIFFUSE(1));
  						}
  					}
  				} else if (!ASSIMP_stricmp("tangents", t.name())) {
  					curTangents.reserve(num);
  					curBitangents.reserve(num);
  					vertexFormat = 2;
  				} else if (ASSIMP_stricmp("standard", t.name())) {
  					releaseMaterial(&curMat);
  					ASSIMP_LOG_WARN("IRRMESH: Unknown vertex format");
  				} else
  					vertexFormat = 0;
  				textMeaning = 1;
  			} else if (!ASSIMP_stricmp(child.name(), "indices")) {
  				if (curVertices.empty() && curMat) {
  					releaseMaterial(&curMat);
  					throw DeadlyImportError("IRRMESH: indices must come after vertices");
  				}
  
  				textMeaning = 2;
  
  				// start a new mesh
  				curMesh = new aiMesh();
  
  				// allocate storage for all faces
  				pugi::xml_attribute attr = child.attribute("indexCount");
  				curMesh->mNumVertices = attr.as_int();
  				if (!curMesh->mNumVertices) {
  					// This is possible ... remove the mesh from the list and skip further reading
  					ASSIMP_LOG_WARN("IRRMESH: Found mesh with zero indices");
  
  					// mesh - away
  					releaseMesh(&curMesh);
  
  					// material - away
  					releaseMaterial(&curMat);
  
  					textMeaning = 0;
  					continue;
  				}
  
  				if (curMesh->mNumVertices % 3) {
  					ASSIMP_LOG_WARN("IRRMESH: Number if indices isn't divisible by 3");
  				}
  
  				curMesh->mNumFaces = curMesh->mNumVertices / 3;
  				curMesh->mFaces = new aiFace[curMesh->mNumFaces];
  
  				// setup some members
  				curMesh->mMaterialIndex = (unsigned int)materials.size();
  				curMesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;
  
  				// allocate storage for all vertices
  				curMesh->mVertices = new aiVector3D[curMesh->mNumVertices];
  
  				if (curNormals.size() == curVertices.size()) {
  					curMesh->mNormals = new aiVector3D[curMesh->mNumVertices];
  				}
  				if (curTangents.size() == curVertices.size()) {
  					curMesh->mTangents = new aiVector3D[curMesh->mNumVertices];
  				}
  				if (curBitangents.size() == curVertices.size()) {
  					curMesh->mBitangents = new aiVector3D[curMesh->mNumVertices];
  				}
  				if (curColors.size() == curVertices.size() && useColors) {
  					curMesh->mColors[0] = new aiColor4D[curMesh->mNumVertices];
  				}
  				if (curUVs.size() == curVertices.size()) {
  					curMesh->mTextureCoords[0] = new aiVector3D[curMesh->mNumVertices];
  				}
  				if (curUV2s.size() == curVertices.size()) {
  					curMesh->mTextureCoords[1] = new aiVector3D[curMesh->mNumVertices];
  				}
  			}
  			//break;
  
  			//case EXN_TEXT: {
  			const char *sz = child.child_value();
  			if (textMeaning == 1) {
  				textMeaning = 0;
  
  				// read vertices
  				do {
  					SkipSpacesAndLineEnd(&sz);
  					aiVector3D temp;
  					aiColor4D c;
  
  					// Read the vertex position
  					sz = fast_atoreal_move<float>(sz, (float &)temp.x);
  					SkipSpaces(&sz);
  
  					sz = fast_atoreal_move<float>(sz, (float &)temp.y);
  					SkipSpaces(&sz);
  
  					sz = fast_atoreal_move<float>(sz, (float &)temp.z);
  					SkipSpaces(&sz);
  					curVertices.push_back(temp);
  
  					// Read the vertex normals
  					sz = fast_atoreal_move<float>(sz, (float &)temp.x);
  					SkipSpaces(&sz);
  
  					sz = fast_atoreal_move<float>(sz, (float &)temp.y);
  					SkipSpaces(&sz);
  
  					sz = fast_atoreal_move<float>(sz, (float &)temp.z);
  					SkipSpaces(&sz);
  					curNormals.push_back(temp);
  
  					// read the vertex colors
  					uint32_t clr = strtoul16(sz, &sz);
  					ColorFromARGBPacked(clr, c);
  
  					if (!curColors.empty() && c != *(curColors.end() - 1))
  						useColors = true;
  
  					curColors.push_back(c);
  					SkipSpaces(&sz);
  
  					// read the first UV coordinate set
  					sz = fast_atoreal_move<float>(sz, (float &)temp.x);
  					SkipSpaces(&sz);
  
  					sz = fast_atoreal_move<float>(sz, (float &)temp.y);
  					SkipSpaces(&sz);
  					temp.z = 0.f;
  					temp.y = 1.f - temp.y; // DX to OGL
  					curUVs.push_back(temp);
  
  					// read the (optional) second UV coordinate set
  					if (vertexFormat == 1) {
  						sz = fast_atoreal_move<float>(sz, (float &)temp.x);
  						SkipSpaces(&sz);
  
  						sz = fast_atoreal_move<float>(sz, (float &)temp.y);
  						temp.y = 1.f - temp.y; // DX to OGL
  						curUV2s.push_back(temp);
  					}
  					// read optional tangent and bitangent vectors
  					else if (vertexFormat == 2) {
  						// tangents
  						sz = fast_atoreal_move<float>(sz, (float &)temp.x);
  						SkipSpaces(&sz);
  
  						sz = fast_atoreal_move<float>(sz, (float &)temp.z);
  						SkipSpaces(&sz);
  
  						sz = fast_atoreal_move<float>(sz, (float &)temp.y);
  						SkipSpaces(&sz);
  						temp.y *= -1.0f;
  						curTangents.push_back(temp);
  
  						// bitangents
  						sz = fast_atoreal_move<float>(sz, (float &)temp.x);
  						SkipSpaces(&sz);
  
  						sz = fast_atoreal_move<float>(sz, (float &)temp.z);
  						SkipSpaces(&sz);
  
  						sz = fast_atoreal_move<float>(sz, (float &)temp.y);
  						SkipSpaces(&sz);
  						temp.y *= -1.0f;
  						curBitangents.push_back(temp);
  					}
  				}
  
  				/* IMPORTANT: We assume that each vertex is specified in one
                  line. So we can skip the rest of the line - unknown vertex
                  elements are ignored.
                  */
  
  				while (SkipLine(&sz));
  			} else if (textMeaning == 2) {
  				textMeaning = 0;
  
  				// read indices
  				aiFace *curFace = curMesh->mFaces;
  				aiFace *const faceEnd = curMesh->mFaces + curMesh->mNumFaces;
  
  				aiVector3D *pcV = curMesh->mVertices;
  				aiVector3D *pcN = curMesh->mNormals;
  				aiVector3D *pcT = curMesh->mTangents;
  				aiVector3D *pcB = curMesh->mBitangents;
  				aiColor4D *pcC0 = curMesh->mColors[0];
  				aiVector3D *pcT0 = curMesh->mTextureCoords[0];
  				aiVector3D *pcT1 = curMesh->mTextureCoords[1];
  
  				unsigned int curIdx = 0;
  				unsigned int total = 0;
  				while (SkipSpacesAndLineEnd(&sz)) {
  					if (curFace >= faceEnd) {
  						ASSIMP_LOG_ERROR("IRRMESH: Too many indices");
  						break;
  					}
  					if (!curIdx) {
  						curFace->mNumIndices = 3;
  						curFace->mIndices = new unsigned int[3];
  					}
  
  					unsigned int idx = strtoul10(sz, &sz);
  					if (idx >= curVertices.size()) {
  						ASSIMP_LOG_ERROR("IRRMESH: Index out of range");
  						idx = 0;
  					}
  
  					curFace->mIndices[curIdx] = total++;
  
  					*pcV++ = curVertices[idx];
  					if (pcN) *pcN++ = curNormals[idx];
  					if (pcT) *pcT++ = curTangents[idx];
  					if (pcB) *pcB++ = curBitangents[idx];
  					if (pcC0) *pcC0++ = curColors[idx];
  					if (pcT0) *pcT0++ = curUVs[idx];
  					if (pcT1) *pcT1++ = curUV2s[idx];
  
  					if (++curIdx == 3) {
  						++curFace;
  						curIdx = 0;
  					}
  				}
  
  				if (curFace != faceEnd)
  					ASSIMP_LOG_ERROR("IRRMESH: Not enough indices");
  
  				// Finish processing the mesh - do some small material workarounds
  				if (curMatFlags & AI_IRRMESH_MAT_trans_vertex_alpha && !useColors) {
  					// Take the opacity value of the current material
  					// from the common vertex color alpha
  					aiMaterial *mat = (aiMaterial *)curMat;
  					mat->AddProperty(&curColors[0].a, 1, AI_MATKEY_OPACITY);
  				}
  			}
  		}
  	}
  
  	// End of the last buffer. A material and a mesh should be there
  	if (curMat || curMesh) {
  		if (!curMat || !curMesh) {
  			ASSIMP_LOG_ERROR("IRRMESH: A buffer must contain a mesh and a material");
  			releaseMaterial(&curMat);
  			releaseMesh(&curMesh);
  		} else {
  			materials.push_back(curMat);
  			meshes.push_back(curMesh);
  		}
  	}
  
  	if (materials.empty()) {
  		throw DeadlyImportError("IRRMESH: Unable to read a mesh from this file");
  	}
  
  	// now generate the output scene
  	pScene->mNumMeshes = (unsigned int)meshes.size();
  	pScene->mMeshes = new aiMesh *[pScene->mNumMeshes];
  	for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
  		pScene->mMeshes[i] = meshes[i];
  
  		// clean this value ...
  		pScene->mMeshes[i]->mNumUVComponents[3] = 0;
  	}
  
  	pScene->mNumMaterials = (unsigned int)materials.size();
  	pScene->mMaterials = new aiMaterial *[pScene->mNumMaterials];
  	::memcpy(pScene->mMaterials, &materials[0], sizeof(void *) * pScene->mNumMaterials);
  
  	pScene->mRootNode = new aiNode();
  	pScene->mRootNode->mName.Set("<IRRMesh>");
  	pScene->mRootNode->mNumMeshes = pScene->mNumMeshes;
  	pScene->mRootNode->mMeshes = new unsigned int[pScene->mNumMeshes];
  
  	for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
  		pScene->mRootNode->mMeshes[i] = i;
  	}
  }
  
  #endif // !! ASSIMP_BUILD_NO_IRRMESH_IMPORTER
  