backtouvec3face

Author: archibate

include/OBJ.hpp

@@ -5,9 +5,7 @@
 
 struct OBJ {
     std::vector<glm::vec3> vertices;
-    std::vector<glm::vec2> uvs;
-    std::vector<glm::vec3> normals;
-    std::vector<glm::umat3x3> faces;
+    std::vector<glm::uvec3> faces;
 
     void load_obj(std::string path);
     void draw_obj();

src/Game.cpp

@@ -27,10 +27,10 @@ void Game::set_window(GLFWwindow *window) {
 }
 
 void Game::initialize() {
-    /* m_private->monkey.load_obj("/home/bate/Codes/opengltutor/assets/monkey.obj"); */
-    m_private->monkey.load_obj("/home/bate/Codes/opengltutor/assets/cube.obj");
+    m_private->monkey.load_obj("/home/bate/Codes/opengltutor/assets/monkey.obj");
+    /* m_private->monkey.load_obj("/home/bate/Codes/opengltutor/assets/cube.obj"); */
     CHECK_GL(glEnable(GL_DEPTH_TEST));
-    CHECK_GL(glEnable(GL_MULTISAMPLE));
+    CHECK_GL(glDisable(GL_MULTISAMPLE));
     CHECK_GL(glEnable(GL_BLEND));
     CHECK_GL(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA));
     CHECK_GL(glEnable(GL_LIGHTING));

src/OBJ.cpp

@@ -21,46 +21,22 @@ void OBJ::load_obj(std::string path) {
             s >> vertex.x >> vertex.y >> vertex.z;
             vertices.push_back(vertex);
 
-        } else if (line.substr(0, 3) == "vt ") {
-            std::istringstream s(line.substr(3));
-            glm::vec2 uv;
-            s >> uv.x >> uv.y;
-            uvs.push_back(uv);
-
-        } else if (line.substr(0, 3) == "vn ") {
-            std::istringstream s(line.substr(3));
-            glm::vec3 normal;
-            s >> normal.x >> normal.y >> normal.z;
-            normals.push_back(glm::normalize(normal));
-
         } else if (line.substr(0, 2) == "f ") {
             std::istringstream s(line.substr(2));
             std::string splitted;
-            std::vector<glm::uvec3> indices;
+            std::vector<unsigned int> indices;
             while (std::getline(s, splitted, ' ')) {
-                glm::uvec3 index(1);
-                std::istringstream ss(splitted);
-                std::string slashsplitted;
-                size_t indexsubs = 0;
-                while (std::getline(ss, slashsplitted, '/') && indexsubs < 3) {
-                    std::istringstream(slashsplitted) >> index[indexsubs++];
-                }
-                indices.push_back(index - 1u);
+                unsigned int index = 1;
+                std::istringstream(splitted) >> index;
+                indices.push_back(index - 1);
             }
             for (size_t i = 2; i < indices.size(); i++) {
-                glm::umat3x3 face = glm::umat3x3(indices[0], indices[i - 1], indices[i]);
+                glm::uvec3 face = glm::uvec3(indices[0], indices[i - 1], indices[i]);
                 faces.push_back(face);
             }
        }
     }
 
-    if (!normals.size()) {
-        normals.push_back(glm::vec3(0, 0, 1));
-    }
-    if (!uvs.size()) {
-        uvs.push_back(glm::vec3(0));
-    }
-
     file.close();
     std::cout << "Loaded " << vertices.size() << " vertices, " << faces.size() << " faces.\n";
 }
@@ -69,31 +45,28 @@ static glm::vec3 perspective_divide(glm::vec4 pos) {
     return glm::vec3(pos.x / pos.w, pos.y / pos.w, pos.z / pos.w);
 }
 
+static glm::vec3 compute_normal(glm::vec3 a, glm::vec3 b, glm::vec3 c) {
+    // jisuan sanjiaoxin faxian
+    glm::vec3 ab = b - a;
+    glm::vec3 ac = c - a;
+    return glm::normalize(glm::cross(ab, ac));
+}
+
 void OBJ::draw_obj() {
     glBegin(GL_TRIANGLES);
     glColor3f(0.9f, 0.6f, 0.1f);
 
     for (auto face : faces) {
-        auto const &a_pos = vertices.at(face[0][0]);
-        auto const &b_pos = vertices.at(face[1][0]);
-        auto const &c_pos = vertices.at(face[2][0]);
-        auto const &a_uv = uvs.at(face[0][1]);
-        auto const &b_uv = uvs.at(face[1][1]);
-        auto const &c_uv = uvs.at(face[2][1]);
-        auto const &a_norm = normals.at(face[0][2]);
-        auto const &b_norm = normals.at(face[1][2]);
-        auto const &c_norm = normals.at(face[2][2]);
-
-        glNormal3fv(glm::value_ptr(a_norm));
-
-        glVertex3fv(glm::value_ptr(a_pos));
-        glTexCoord2fv(glm::value_ptr(b_uv));
+        auto const &a = vertices.at(face[0]);
+        auto const &b = vertices.at(face[1]);
+        auto const &c = vertices.at(face[2]);
 
-        glVertex3fv(glm::value_ptr(b_pos));
-        glTexCoord2fv(glm::value_ptr(b_uv));
+        glm::vec3 norm = compute_normal(a, b, c);
+        glNormal3fv(glm::value_ptr(norm));
 
-        glVertex3fv(glm::value_ptr(c_pos));
-        glTexCoord2fv(glm::value_ptr(c_uv));
+        glVertex3fv(glm::value_ptr(a));
+        glVertex3fv(glm::value_ptr(b));
+        glVertex3fv(glm::value_ptr(c));
     }
 
     CHECK_GL(glEnd());

src/main.cpp

@@ -11,7 +11,7 @@ int main() {
         std::cerr << "failed to initialize GLFW: " << errmsg << '\n';
         return -1;
     }
-    
+
     // Hint the version required: OpenGL 2.0
     constexpr int version = 20;
     glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_API);