obj loader

src/engine/obj_loader.cpp

@@ -0,0 +1,84 @@
+#include "engine/obj_loader.hpp"
+#include <fstream>
+#include <sstream>
+
+OBJLoader::OBJLoader(std::string filepath) : filepath(filepath), loaded(true) {
+    std::ifstream file(filepath);
+    if (!file.is_open()) {
+        loaded = false;
+        return;
+    }
+
+    std::vector<glm::vec3> temp_positions;
+    std::vector<glm::vec3> temp_normals;
+    std::vector<glm::vec2> temp_texCoords;
+
+    std::string line;
+    while (std::getline(file, line)) {
+        std::istringstream ss(line);
+        std::string prefix;
+        ss >> prefix;
+
+        if (prefix == "v") {
+            glm::vec3 position;
+            ss >> position.x >> position.y >> position.z;
+            temp_positions.push_back(position);
+        } else if (prefix == "vn") {
+            glm::vec3 normal;
+            ss >> normal.x >> normal.y >> normal.z;
+            temp_normals.push_back(normal);
+        } else if (prefix == "vt") {
+            glm::vec2 texCoord;
+            ss >> texCoord.x >> texCoord.y;
+            temp_texCoords.push_back(texCoord);
+        } else if (prefix == "f") {
+            unsigned int posIdx[3], texIdx[3], normIdx[3];
+            char slash; // to consume the '/' characters
+
+            for (int i = 0; i < 3; ++i) {
+                ss >> posIdx[i] >> slash >> texIdx[i] >> slash >> normIdx[i];
+                Vertex vertex;
+                vertex.position = temp_positions[posIdx[i] - 1];
+                vertex.texCoord = temp_texCoords[texIdx[i] - 1];
+                vertex.normal = temp_normals[normIdx[i] - 1];
+                vertices.push_back(vertex);
+                indices.push_back(static_cast<unsigned int>(vertices.size() - 1));
+            }
+        }
+    }
+}
+
+// Convert loaded vertex data to a contiguous float array
+float* OBJLoader::getVertexData() {
+    size_t vertexCount = vertices.size();
+    float* vertexData = new float[vertexCount * 8]; // 3 pos + 3 normal + 2 texCoord
+    for (size_t i = 0; i < vertexCount; ++i) {
+        vertexData[i * 8 + 0] = vertices[i].position.x;
+        vertexData[i * 8 + 1] = vertices[i].position.y;
+        vertexData[i * 8 + 2] = vertices[i].position.z;
+        vertexData[i * 8 + 3] = vertices[i].normal.x;
+        vertexData[i * 8 + 4] = vertices[i].normal.y;
+        vertexData[i * 8 + 5] = vertices[i].normal.z;
+        vertexData[i * 8 + 6] = vertices[i].texCoord.x;
+        vertexData[i * 8 + 7] = vertices[i].texCoord.y;
+    }
+    return vertexData;
+}
+
+// Convert loaded index data to a contiguous unsigned int array
+unsigned int* OBJLoader::getIndexData() {
+    size_t indexCount = indices.size();
+    unsigned int* indexData = new unsigned int[indexCount];
+    for (size_t i = 0; i < indexCount; ++i) {
+        indexData[i] = indices[i];
+    }
+    return indexData;
+}
+
+size_t OBJLoader::getVertexCount() {
+    return vertices.size();
+}
+
+size_t OBJLoader::getIndexCount() {
+    return indices.size();
+}

src/main.cpp

@@ -1,10 +1,6 @@
-#define GL_GLEXT_PROTOTYPES
 #include "engine/sdl.hpp"
 #include "engine/opengl.hpp"
-
-#include <glm/glm.hpp>
-#include <glm/gtc/matrix_transform.hpp>
-#include <iostream>
+#include "engine/obj_loader.hpp"
 
 int main(int argc, char* argv[]) {
     SDLWindow window("My SDL Application", 800, 600);
@@ -12,9 +8,8 @@ int main(int argc, char* argv[]) {
     OpenGLContext glContext(window);
     if (!glContext.isInitialized()) { return -1; }
 
-
     Camera camera(
-        glm::vec3(0.0f, 0.0f, 3.0f), // Position
+        glm::vec3(2.0f, 1.0f, 3.0f), // Position
         glm::vec3(0.0f, 0.0f, 0.0f), // Target
         glm::vec3(0.0f, 1.0f, 0.0f)  // Up vector
     );
@@ -28,29 +23,25 @@ int main(int argc, char* argv[]) {
 
     Shader shader_program("shaders/triangle.vert", "shaders/triangle.frag");
 
-    // vertex, color
-    float vertexData[] = {
-        0.5f,  0.5f, 0.0f, 1.0f, 0.0f, 0.0f, // top right
-        0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom right
-        -0.5f,  0.5f, 0.0f, 0.0f, 1.0f, 0.0f, // top left
-        -0.5f, -0.5f, 0.0f, 1.0f, 1.0f, 0.0f  // bottom left
-    };
-
-    unsigned int indexData[] = {
-        0, 1, 2,  // first triangle
-        1, 3, 2   // second triangle
-    };
-    
-    // glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+    OBJLoader objLoader("assets/models/suzanne.obj");
+    if (!objLoader.isLoaded()) {
+        SDL_Log("Failed to load OBJ model.");
+        return -1;
+    }
 
     VertexArrayObject VAO;
-    VAO.bufferVertexData(vertexData, sizeof(vertexData));
-    VAO.bufferElementData(indexData, sizeof(indexData));
-    VAO.setAttributePointer(0, 3, GL_FLOAT, false, 6 * sizeof(float), 0); // position
-    VAO.setAttributePointer(1, 3, GL_FLOAT, false, 6 * sizeof(float), 3 * sizeof(float)); // color
+    VAO.bufferVertexData(objLoader.getVertexData(), objLoader.getVertexCount() * sizeof(float) * 8);
+    VAO.bufferElementData(objLoader.getIndexData(), objLoader.getIndexCount() * sizeof(unsigned int));
+    VAO.setAttributePointer(0, 3, GL_FLOAT, false, 8 * sizeof(float), 0); // position
+    VAO.setAttributePointer(1, 3, GL_FLOAT, false, 8 * sizeof(float), 3 * sizeof(float)); // normal
+    VAO.setAttributePointer(2, 2, GL_FLOAT, false, 8 * sizeof(float), 6 * sizeof(float)); // texCoord
+
+    // Wireframe mode
+    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 
     window.setPosition(SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
     window.showWindow();
+
     while (window.isRunning()) {
         window.pollEvents();