add src/coders/obj

2024-06-22 20:24:35 +03:00
parent a9640fff36
commit e4f9bd03b7
11 changed files with 241 additions and 28 deletions
@@ -0,0 +1,124 @@
+#include "obj.hpp"
+
+#include "commons.hpp"
+#include "../graphics/core/Model.hpp"
+
+using namespace model;
+
+class ObjParser : BasicParser {
+    std::vector<glm::vec3> coords {{0, 0, 0}};
+    std::vector<glm::vec2> uvs {{0, 0}};
+    std::vector<glm::vec3> normals {{0, 1, 0}};
+
+    void parseFace(Mesh& mesh) {
+        std::vector<Vertex> vertices;
+        while (hasNext()) {
+            auto c = peekInLine();
+            if (c == '\n') {
+                break;
+            } else {
+                uint indices[3] {};
+                uint i = 0;
+                do {
+                    char next = peekInLine();
+                    if (is_digit(next)) {
+                        indices[i] = parseSimpleInt(10);
+                        if (peekInLine() == '/') {
+                            pos++;
+                        }
+                    } else if (next == '/') {
+                        pos++;
+                    } else {
+                        break;
+                    }
+                } while (peekInLine() != '\n' && ++i < 3);
+
+                vertices.push_back(Vertex {
+                    coords[indices[0]], uvs[indices[1]], normals[indices[2]]
+                });
+            }
+        }
+        if (peekInLine() != '\n' && hasNext()) {
+            skipLine();
+        }
+        if (vertices.size() >= 3) {
+            for (size_t j = 0; j < vertices.size() - 2; j++) {
+                mesh.vertices.push_back(vertices[0]);
+                for (size_t i = 1; i < 3; i++) {
+                    mesh.vertices.push_back(vertices[i + j]);
+                }
+            }
+        }
+    }
+public:
+    ObjParser(const std::string_view file, const std::string_view src) : BasicParser(file, src) {
+    }
+
+    std::unique_ptr<Model> parse() {
+        // first iteration - collecting vertex data
+        while (hasNext()) {
+            if (peek() == '#') {
+                skipLine();
+                continue;
+            }
+            auto cmd = parseName();
+            if (cmd == "v") {
+                float x = dynamic::as_number(parseNumber());
+                float y = dynamic::as_number(parseNumber());
+                float z = dynamic::as_number(parseNumber());
+                coords.emplace_back(x, y, z);
+            } else if (cmd == "vt") {
+                float u = dynamic::as_number(parseNumber());
+                float v = dynamic::as_number(parseNumber());
+                uvs.emplace_back(u, v);
+            } else if (cmd == "vn") {
+                float x = dynamic::as_number(parseNumber());
+                float y = dynamic::as_number(parseNumber());
+                float z = dynamic::as_number(parseNumber());
+                normals.emplace_back(x, y, z);
+            } else {
+                skipLine();
+            }
+        }
+        // second iteration - building meshes
+        reset();
+
+        auto model = std::make_unique<Model>();
+        std::string texture;
+        while (hasNext()) {
+            if (peek() != '#' && parseName() == "usemtl") {
+                skipWhitespace();
+                texture = readUntil('\n');
+                break;
+            }
+            skipLine();
+        }
+        do {
+            Mesh* mesh = &model->addMesh(texture);
+            while (hasNext()) {
+                if (peek() == '#') {
+                    skipLine();
+                    continue;
+                }
+                auto cmd = parseName();
+                if (cmd == "usemtl") {
+                    skipWhitespace();
+                    texture = readUntil('\n');
+                    mesh = &model->addMesh(texture);
+                    break;
+                } else if (cmd == "f") {
+                    parseFace(*mesh);
+                }
+                skipLine();
+            }
+        } while(hasNext());
+        model->clean();
+        return model;
+    }
+};
+
+std::unique_ptr<Model> obj::parse(
+    const std::string_view file, const std::string_view src
+) {
+    return ObjParser(file, src).parse();
+}