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- /*
- * Copyright (C) 2020 Christopher J. Howard
- *
- * This file is part of Antkeeper source code.
- *
- * Antkeeper source code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Antkeeper source code is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #include "resources/resource-loader.hpp"
- #include "resources/resource-manager.hpp"
- #include "renderer/model.hpp"
- #include "renderer/vertex-attributes.hpp"
- #include "rasterizer/vertex-attribute-type.hpp"
- #include "rasterizer/drawing-mode.hpp"
- #include "utility/fundamental-types.hpp"
- #include <sstream>
- #include <stdexcept>
- #include <limits>
- #include <physfs.h>
-
- struct material_group
- {
- std::string name;
- material* material;
- std::size_t start_index;
- std::size_t index_count;
- };
-
- static const float3 barycentric_coords[3] =
- {
- float3{1, 0, 0},
- float3{0, 1, 0},
- float3{0, 0, 1}
- };
-
- template <>
- model* resource_loader<model>::load(resource_manager* resource_manager, PHYSFS_File* file)
- {
- std::string line;
- std::vector<float3> positions;
- std::vector<float2> uvs;
- std::vector<float3> normals;
- std::vector<std::vector<std::size_t>> faces;
- std::vector<material_group> material_groups;
- material_group* current_material_group = nullptr;
- aabb<float> bounds =
- {
- {std::numeric_limits<float>::infinity(), std::numeric_limits<float>::infinity(), std::numeric_limits<float>::infinity()},
- {-std::numeric_limits<float>::infinity(), -std::numeric_limits<float>::infinity(), -std::numeric_limits<float>::infinity()}
- };
-
- while (!PHYSFS_eof(file))
- {
- // Read line
- physfs_getline(file, line);
-
- // Tokenize line
- std::vector<std::string> tokens;
- std::string token;
- std::istringstream linestream(line);
- while (linestream >> token)
- tokens.push_back(token);
-
- // Skip empty lines and comments
- if (tokens.empty() || tokens[0][0] == '#')
- continue;
-
- if (tokens[0] == "v")
- {
- if (tokens.size() != 4)
- {
- std::stringstream stream;
- stream << "resource_loader<mesh>::load(): Invalid line \"" << line << "\"" << std::endl;
- throw std::runtime_error(stream.str());
- }
-
- float3 position;
-
- std::stringstream(tokens[1]) >> position[0];
- std::stringstream(tokens[2]) >> position[1];
- std::stringstream(tokens[3]) >> position[2];
-
- positions.push_back(position);
-
- // Add position to bounds
- for (int i = 0; i < 3; ++i)
- {
- bounds.min_point[i] = std::min<float>(bounds.min_point[i], position[i]);
- bounds.max_point[i] = std::max<float>(bounds.max_point[i], position[i]);
- }
- }
- else if (tokens[0] == "vt")
- {
- if (tokens.size() != 3)
- {
- std::stringstream stream;
- stream << "resource_loader<mesh>::load(): Invalid line \"" << line << "\"" << std::endl;
- throw std::runtime_error(stream.str());
- }
-
- float2 uv;
-
- std::stringstream(tokens[1]) >> uv[0];
- std::stringstream(tokens[2]) >> uv[1];
-
- uvs.push_back(uv);
- }
- else if (tokens[0] == "vn")
- {
- if (tokens.size() != 4)
- {
- std::stringstream stream;
- stream << "resource_loader<mesh>::load(): Invalid line \"" << line << "\"" << std::endl;
- throw std::runtime_error(stream.str());
- }
-
- float3 normal;
-
- std::stringstream(tokens[1]) >> normal[0];
- std::stringstream(tokens[2]) >> normal[1];
- std::stringstream(tokens[3]) >> normal[2];
-
- normals.push_back(normal);
- }
- else if (tokens[0] == "f")
- {
- if (tokens.size() != 4)
- {
- std::stringstream stream;
- stream << "resource_loader<mesh>::load(): Invalid line \"" << line << "\"" << std::endl;
- throw std::runtime_error(stream.str());
- }
-
- std::vector<std::size_t> face;
-
- for (std::size_t i = 0; i < 3; ++i)
- {
- std::stringstream ss(tokens[i + 1]);
- while (ss.good())
- {
- std::string substring;
- std::getline(ss, substring, '/');
-
- if (!substring.empty())
- {
- std::size_t index = std::stoul(substring) - 1;
- face.push_back(index);
- }
- }
- }
-
- faces.push_back(face);
- }
- else if (tokens[0] == "usemtl")
- {
- if (tokens.size() != 2)
- {
- std::stringstream stream;
- stream << "resource_loader<mesh>::load(): Invalid line \"" << line << "\"" << std::endl;
- throw std::runtime_error(stream.str());
- }
-
- if (current_material_group)
- {
- current_material_group->index_count = faces.size() * 3 - current_material_group->start_index;
- }
-
- material_groups.push_back(material_group());
- current_material_group = &material_groups.back();
- current_material_group->name = tokens[1];
- current_material_group->start_index = faces.size() * 3;
- current_material_group->index_count = 0;
- }
- }
-
- if (current_material_group)
- {
- current_material_group->index_count = faces.size() * 3 - current_material_group->start_index;
- }
-
- // Load material group materials
- for (material_group& material_group: material_groups)
- {
- material_group.material = resource_manager->load<material>(material_group.name + ".mtl");
- }
-
- bool has_uvs = (!uvs.empty());
- bool has_normals = (!normals.empty());
- bool has_barycentric = true;
-
- std::size_t vertex_size = 3;
- if (has_uvs)
- vertex_size += 2;
- if (has_normals)
- vertex_size += 3;
- if (has_barycentric)
- vertex_size += 3;
-
- std::size_t vertex_stride = sizeof(float) * vertex_size;
-
- // Generate vertex buffer
- float* vertex_data = new float[vertex_size * faces.size() * 3];
- float* v = &vertex_data[0];
- for (std::size_t i = 0; i < faces.size(); ++i)
- {
- const std::vector<std::size_t>& face = faces[i];
-
- std::size_t k = 0;
- for (std::size_t j = 0; j < 3; ++j)
- {
- const float3& position = positions[face[k++]];
- *(v++) = position[0];
- *(v++) = position[1];
- *(v++) = position[2];
-
- if (has_uvs)
- {
- const float2& uv = uvs[face[k++]];
- *(v++) = uv[0];
- *(v++) = uv[1];
- }
-
- if (has_normals)
- {
- const float3& normal = normals[face[k++]];
- *(v++) = normal[0];
- *(v++) = normal[1];
- *(v++) = normal[2];
- }
-
- if (has_barycentric)
- {
- *(v++) = barycentric_coords[j][0];
- *(v++) = barycentric_coords[j][1];
- *(v++) = barycentric_coords[j][2];
- }
- }
- }
-
- // Allocate a model
- model* model = new ::model();
- model->set_bounds(bounds);
- vertex_buffer* vbo = model->get_vertex_buffer();
- vertex_array* vao = model->get_vertex_array();
- vbo->resize(sizeof(float) * vertex_size * faces.size() * 3, vertex_data);
- std::size_t offset = 0;
- vao->bind_attribute(VERTEX_POSITION_LOCATION, *vbo, 3, vertex_attribute_type::float_32, vertex_stride, 0);
- offset += 3;
- if (has_uvs)
- {
- vao->bind_attribute(VERTEX_TEXCOORD_LOCATION, *vbo, 2, vertex_attribute_type::float_32, vertex_stride, sizeof(float) * offset);
- offset += 2;
- }
- if (has_normals)
- {
- vao->bind_attribute(VERTEX_NORMAL_LOCATION, *vbo, 3, vertex_attribute_type::float_32, vertex_stride, sizeof(float) * offset);
- offset += 3;
- }
- if (has_barycentric)
- {
- vao->bind_attribute(VERTEX_BARYCENTRIC_LOCATION, *vbo, 3, vertex_attribute_type::float_32, vertex_stride, sizeof(float) * offset);
- offset += 3;
- }
-
- // Add model groups for each material
- for (const material_group& material_group: material_groups)
- {
- model_group* model_group = model->add_group(material_group.name);
- model_group->set_material(material_group.material);
- model_group->set_drawing_mode(drawing_mode::triangles);
- model_group->set_start_index(material_group.start_index);
- model_group->set_index_count(material_group.index_count);
- }
-
- // Deallocate vertex data
- delete[] vertex_data;
-
- return model;
- }
-
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