/* --------------------------------------------------------------------------- Open Asset Import Library (assimp) --------------------------------------------------------------------------- Copyright (c) 2006-2024, 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 Terragen importer class */ #ifndef ASSIMP_BUILD_NO_TERRAGEN_IMPORTER #include "TerragenLoader.h" #include #include #include #include #include #include namespace Assimp { static constexpr aiImporterDesc desc = { "Terragen Heightmap Importer", "", "", "http://www.planetside.co.uk/", aiImporterFlags_SupportBinaryFlavour, 0, 0, 0, 0, "ter" }; // ------------------------------------------------------------------------------------------------ // Constructor to be privately used by Importer TerragenImporter::TerragenImporter() : configComputeUVs(false) { // empty } // ------------------------------------------------------------------------------------------------ // Returns whether the class can handle the format of the given file. bool TerragenImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool /*checkSig*/) const { static const char *tokens[] = { "terragen" }; return SearchFileHeaderForToken(pIOHandler, pFile, tokens, AI_COUNT_OF(tokens)); } // ------------------------------------------------------------------------------------------------ // Build a string of all file extensions supported const aiImporterDesc *TerragenImporter::GetInfo() const { return &desc; } // ------------------------------------------------------------------------------------------------ // Setup import properties void TerragenImporter::SetupProperties(const Importer *pImp) { // AI_CONFIG_IMPORT_TER_MAKE_UVS configComputeUVs = (0 != pImp->GetPropertyInteger(AI_CONFIG_IMPORT_TER_MAKE_UVS, 0)); } // ------------------------------------------------------------------------------------------------ // Imports the given file into the given scene structure. void TerragenImporter::InternReadFile(const std::string &pFile, aiScene *pScene, IOSystem *pIOHandler) { IOStream *file = pIOHandler->Open(pFile, "rb"); // Check whether we can read from the file if (file == nullptr) throw DeadlyImportError("Failed to open TERRAGEN TERRAIN file ", pFile, "."); // Construct a stream reader to read all data in the correct endianness StreamReaderLE reader(file); if (reader.GetRemainingSize() < 16) throw DeadlyImportError("TER: file is too small"); // Check for the existence of the two magic strings 'TERRAGEN' and 'TERRAIN ' if (::strncmp((const char *)reader.GetPtr(), AI_TERR_BASE_STRING, 8)) throw DeadlyImportError("TER: Magic string \'TERRAGEN\' not found"); if (::strncmp((const char *)reader.GetPtr() + 8, AI_TERR_TERRAIN_STRING, 8)) throw DeadlyImportError("TER: Magic string \'TERRAIN\' not found"); unsigned int x = 0, y = 0, mode = 0; aiNode *root = pScene->mRootNode = new aiNode(); root->mName.Set(""); // Default scaling is 30 root->mTransformation.a1 = root->mTransformation.b2 = root->mTransformation.c3 = 30.f; // Now read all chunks until we're finished or an EOF marker is encountered reader.IncPtr(16); while (reader.GetRemainingSize() >= 4) { const char *head = (const char *)reader.GetPtr(); reader.IncPtr(4); // EOF, break in every case if (!::strncmp(head, AI_TERR_EOF_STRING, 4)) break; // Number of x-data points if (!::strncmp(head, AI_TERR_CHUNK_XPTS, 4)) { x = (uint16_t)reader.GetI2(); } // Number of y-data points else if (!::strncmp(head, AI_TERR_CHUNK_YPTS, 4)) { y = (uint16_t)reader.GetI2(); } // Squared terrains width-1. else if (!::strncmp(head, AI_TERR_CHUNK_SIZE, 4)) { x = y = (uint16_t)reader.GetI2() + 1; } // terrain scaling else if (!::strncmp(head, AI_TERR_CHUNK_SCAL, 4)) { root->mTransformation.a1 = reader.GetF4(); root->mTransformation.b2 = reader.GetF4(); root->mTransformation.c3 = reader.GetF4(); } // mapping == 1: earth radius else if (!::strncmp(head, AI_TERR_CHUNK_CRAD, 4)) { reader.GetF4(); } // mapping mode else if (!::strncmp(head, AI_TERR_CHUNK_CRVM, 4)) { mode = reader.GetI1(); if (0 != mode) ASSIMP_LOG_ERROR("TER: Unsupported mapping mode, a flat terrain is returned"); } // actual terrain data else if (!::strncmp(head, AI_TERR_CHUNK_ALTW, 4)) { float hscale = (float)reader.GetI2() / 65536; float bheight = (float)reader.GetI2(); if (!hscale) hscale = 1; // Ensure we have enough data if (reader.GetRemainingSize() < x * y * 2) throw DeadlyImportError("TER: ALTW chunk is too small"); if (x <= 1 || y <= 1) throw DeadlyImportError("TER: Invalid terrain size"); // Allocate the output mesh pScene->mMeshes = new aiMesh *[pScene->mNumMeshes = 1]; aiMesh *m = pScene->mMeshes[0] = new aiMesh(); // We return quads aiFace *f = m->mFaces = new aiFace[m->mNumFaces = (x - 1) * (y - 1)]; aiVector3D *pv = m->mVertices = new aiVector3D[m->mNumVertices = m->mNumFaces * 4]; aiVector3D *uv(nullptr); float step_y(0.0f), step_x(0.0f); if (configComputeUVs) { uv = m->mTextureCoords[0] = new aiVector3D[m->mNumVertices]; step_y = 1.f / y; step_x = 1.f / x; } const int16_t *data = (const int16_t *)reader.GetPtr(); for (unsigned int yy = 0, t = 0; yy < y - 1; ++yy) { for (unsigned int xx = 0; xx < x - 1; ++xx, ++f) { // make verts const float fy = (float)yy, fx = (float)xx; unsigned tmp, tmp2; *pv++ = aiVector3D(fx, fy, (float)data[(tmp2 = x * yy) + xx] * hscale + bheight); *pv++ = aiVector3D(fx, fy + 1, (float)data[(tmp = x * (yy + 1)) + xx] * hscale + bheight); *pv++ = aiVector3D(fx + 1, fy + 1, (float)data[tmp + xx + 1] * hscale + bheight); *pv++ = aiVector3D(fx + 1, fy, (float)data[tmp2 + xx + 1] * hscale + bheight); // also make texture coordinates, if necessary if (configComputeUVs) { *uv++ = aiVector3D(step_x * xx, step_y * yy, 0.f); *uv++ = aiVector3D(step_x * xx, step_y * (yy + 1), 0.f); *uv++ = aiVector3D(step_x * (xx + 1), step_y * (yy + 1), 0.f); *uv++ = aiVector3D(step_x * (xx + 1), step_y * yy, 0.f); } // make indices f->mIndices = new unsigned int[f->mNumIndices = 4]; for (unsigned int i = 0; i < 4; ++i) { f->mIndices[i] = t; t++; } } } // Add the mesh to the root node root->mMeshes = new unsigned int[root->mNumMeshes = 1]; root->mMeshes[0] = 0; } // Get to the next chunk (4 byte aligned) unsigned dtt = reader.GetCurrentPos() & 0x3; if (dtt) { reader.IncPtr(4 - dtt); } } // Check whether we have a mesh now if (pScene->mNumMeshes != 1) throw DeadlyImportError("TER: Unable to load terrain"); // Set the AI_SCENE_FLAGS_TERRAIN bit pScene->mFlags |= AI_SCENE_FLAGS_TERRAIN; } } // namespace Assimp #endif // !! ASSIMP_BUILD_NO_TERRAGEN_IMPORTER