Create mesh abstraction

src/main.cc

@@ -69,18 +69,38 @@ class Shader {
 
 class Texture2D {
   public:
-    Texture2D(const char *filename, GLint texture_unit);
+    Texture2D(const char *filename, GLint texture_unit, const char *name);
     ~Texture2D();
-    void activate();
+    void activate() const;
     int width;
     int height;
     int channels;
+    GLint texture_unit;
+    std::string name;
   private:
     GLuint texture;
-    GLint texture_unit;
     GLint format;
 };
 
+struct Vertex {
+  glm::vec3 position;
+  glm::vec3 normal;
+  glm::vec2 tex_coord;
+};
+
+class Mesh {
+  public:
+    std::vector<Vertex> vertices;
+    std::vector<GLuint> indices;
+    std::vector<Texture2D> textures;
+
+    Mesh(std::vector<Vertex> vertices, std::vector<GLuint> indices, std::vector<Texture2D> textures);
+    void draw(Shader &Shader);
+  private:
+    GLuint vao, vbo, ebo;
+    void setup_mesh();
+};
+
 int main() {
   if (SDL_Init(SDL_INIT_EVERYTHING) != 0) {
     return EXIT_CODE_SDL_INIT_FAILED;
@@ -116,32 +136,32 @@ int main() {
 
   glEnable(GL_DEPTH_TEST);
 
-  std::vector<GLfloat> vertices = {
+  std::vector<Vertex> vertices = {
-    // positions         // normals           // texture coords
+    // positions                    // normals                      // texture coords
-   -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f, 1.0f,
+    Vertex{glm::vec3(-0.5f, -0.5f, -0.5f), glm::vec3(-1.0f,  0.0f,  0.0f), glm::vec2(0.0f, 1.0f)},
-    0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f,
+    Vertex{glm::vec3( 0.5f,  0.5f,  0.5f), glm::vec3( 1.0f,  0.0f,  0.0f), glm::vec2(1.0f, 0.0f)},
-    0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f,
+    Vertex{glm::vec3( 0.5f,  0.5f, -0.5f), glm::vec3( 1.0f,  0.0f,  0.0f), glm::vec2(1.0f, 1.0f)},
-   -0.5f,  0.5f,  0.5f,  0.0f,  0.0f, 1.0f,   0.0f, 1.0f,
+    Vertex{glm::vec3(-0.5f,  0.5f,  0.5f), glm::vec3( 0.0f,  0.0f,  1.0f), glm::vec2(0.0f, 1.0f)},
-    0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f, 0.0f,
+    Vertex{glm::vec3( 0.5f, -0.5f,  0.5f), glm::vec3( 1.0f,  0.0f,  0.0f), glm::vec2(0.0f, 0.0f)},
-    0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f, 1.0f,
+    Vertex{glm::vec3( 0.5f, -0.5f, -0.5f), glm::vec3( 0.0f, -1.0f,  0.0f), glm::vec2(1.0f, 1.0f)},
-   -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f, 0.0f,
+    Vertex{glm::vec3(-0.5f, -0.5f, -0.5f), glm::vec3( 0.0f,  0.0f, -1.0f), glm::vec2(0.0f, 0.0f)},
-    0.5f, -0.5f,  0.5f,  0.0f,  0.0f, 1.0f,   1.0f, 0.0f,
+    Vertex{glm::vec3( 0.5f, -0.5f,  0.5f), glm::vec3( 0.0f,  0.0f,  1.0f), glm::vec2(1.0f, 0.0f)},
-   -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f, 1.0f,
+    Vertex{glm::vec3(-0.5f, -0.5f, -0.5f), glm::vec3( 0.0f, -1.0f,  0.0f), glm::vec2(0.0f, 1.0f)},
-    0.5f,  0.5f,  0.5f,  0.0f,  0.0f, 1.0f,   1.0f, 1.0f,
+    Vertex{glm::vec3( 0.5f,  0.5f,  0.5f), glm::vec3( 0.0f,  0.0f,  1.0f), glm::vec2(1.0f, 1.0f)},
-    0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f, 0.0f,
+    Vertex{glm::vec3( 0.5f, -0.5f,  0.5f), glm::vec3( 0.0f, -1.0f,  0.0f), glm::vec2(1.0f, 0.0f)},
-   -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f, 0.0f,
+    Vertex{glm::vec3(-0.5f, -0.5f,  0.5f), glm::vec3( 0.0f, -1.0f,  0.0f), glm::vec2(0.0f, 0.0f)},
-    0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f, 1.0f,
+    Vertex{glm::vec3( 0.5f,  0.5f, -0.5f), glm::vec3( 0.0f,  0.0f, -1.0f), glm::vec2(1.0f, 1.0f)},
-    0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f, 0.0f,
+    Vertex{glm::vec3( 0.5f,  0.5f,  0.5f), glm::vec3( 0.0f,  1.0f,  0.0f), glm::vec2(1.0f, 0.0f)},
-    0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f, 0.0f,
+    Vertex{glm::vec3( 0.5f, -0.5f, -0.5f), glm::vec3( 0.0f,  0.0f, -1.0f), glm::vec2(1.0f, 0.0f)},
-   -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f, 0.0f,
+    Vertex{glm::vec3(-0.5f,  0.5f,  0.5f), glm::vec3( 0.0f,  1.0f,  0.0f), glm::vec2(0.0f, 0.0f)},
-   -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f, 1.0f,
+    Vertex{glm::vec3(-0.5f,  0.5f, -0.5f), glm::vec3( 0.0f,  1.0f,  0.0f), glm::vec2(0.0f, 1.0f)},
-   -0.5f, -0.5f,  0.5f,  0.0f,  0.0f, 1.0f,   0.0f, 0.0f,
+    Vertex{glm::vec3(-0.5f, -0.5f,  0.5f), glm::vec3( 0.0f,  0.0f,  1.0f), glm::vec2(0.0f, 0.0f)},
-   -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f, 0.0f,
+    Vertex{glm::vec3(-0.5f, -0.5f,  0.5f), glm::vec3(-1.0f,  0.0f,  0.0f), glm::vec2(0.0f, 0.0f)},
-   -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f, 1.0f,
+    Vertex{glm::vec3(-0.5f,  0.5f, -0.5f), glm::vec3( 0.0f,  0.0f, -1.0f), glm::vec2(0.0f, 1.0f)},
-   -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f, 1.0f,
+    Vertex{glm::vec3(-0.5f,  0.5f, -0.5f), glm::vec3(-1.0f,  0.0f,  0.0f), glm::vec2(1.0f, 1.0f)},
-    0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f, 1.0f,
+    Vertex{glm::vec3( 0.5f,  0.5f, -0.5f), glm::vec3( 0.0f,  1.0f,  0.0f), glm::vec2(1.0f, 1.0f)},
-   -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f, 0.0f,
+    Vertex{glm::vec3(-0.5f,  0.5f,  0.5f), glm::vec3(-1.0f,  0.0f,  0.0f), glm::vec2(1.0f, 0.0f)},
-    0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f, 1.0f,
+    Vertex{glm::vec3( 0.5f, -0.5f, -0.5f), glm::vec3( 1.0f,  0.0f,  0.0f), glm::vec2(0.0f, 1.0f)},
   };
 
   std::vector<GLuint> indices = {
@@ -159,48 +179,17 @@ int main() {
     13, 15, 16
   };
 
-  GLuint vao = 0;
+  std::vector<Texture2D> textures = {
-  glGenVertexArrays(1, &vao);
+    Texture2D("images/container2.png", GL_TEXTURE0, "material.diffuse"),
-  glBindVertexArray(vao);
+    Texture2D("images/container2_specular.png", GL_TEXTURE1, "material.specular"),
+  };
 
-  GLuint ebo = 0;
+  Mesh container = {vertices, indices, textures};
-  glGenBuffers(1, &ebo);
+  Mesh light     = {vertices, indices, {}};
-  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
-  glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(GLuint), indices.data(), GL_STATIC_DRAW);
-
-  GLuint vbo = 0;
-  glGenBuffers(1, &vbo);
-  glBindBuffer(GL_ARRAY_BUFFER, vbo);
-  glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(GLfloat), vertices.data(), GL_STATIC_DRAW);
-
-  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (void *)0);
-  glEnableVertexAttribArray(0);
-  glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (void *)(3 * sizeof(GLfloat)));
-  glEnableVertexAttribArray(1);
-  glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (void *)(6 * sizeof(GLfloat)));
-  glEnableVertexAttribArray(2);
-
-  GLuint light_vao = 0;
-  glGenVertexArrays(1, &light_vao);
-  glBindVertexArray(light_vao);
-  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
-  glBindBuffer(GL_ARRAY_BUFFER, vbo);
-
-  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (void *)0);
-  glEnableVertexAttribArray(0);
-
-  glBindVertexArray(0);
-  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
-  glBindBuffer(GL_ARRAY_BUFFER, 0);
 
   Shader main_shader  {"shaders/vert.glsl", "shaders/frag.glsl"};
   Shader light_shader {"shaders/vert.glsl", "shaders/light_frag.glsl"};
 
-  Texture2D diffuse_map  = Texture2D("images/container2.png", GL_TEXTURE0);
-  Texture2D specular_map = Texture2D("images/container2_specular.png", GL_TEXTURE1);
-  main_shader.set_int("material.diffuse", 0);
-  main_shader.set_int("material.specular", 1);
-
   const float camera_speed   = 25.0f;
   glm::vec3 camera_position  = glm::vec3(-2.0f, 0.0f, 6.0f);
   glm::vec3 camera_forward   = glm::vec3(0.0f);
@@ -382,10 +371,7 @@ int main() {
       main_shader.activate();
       main_shader.set_mat4("model", model);
       main_shader.set_mat3("normal_mat", normal_mat);
-      diffuse_map.activate();
+      container.draw(main_shader);
-      specular_map.activate();
-      glBindVertexArray(vao);
-      glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, (void *)0);
     }
 
     // Draw light source
@@ -395,8 +381,7 @@ int main() {
       light_shader.activate();
       light_shader.set_mat4("model", model);
       light_shader.set_vec3("light_diffuse", light_diffuse);
-      glBindVertexArray(light_vao);
+      light.draw(light_shader);
-      glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, (void *)0);
     }
 
     SDL_GL_SwapWindow(window);
@@ -546,7 +531,7 @@ const char *Shader::get_shader_type_string(GLenum shader_type) {
   return output;
 }
 
-Texture2D::Texture2D(const char *filename, GLint texture_unit) : texture_unit(texture_unit) {
+Texture2D::Texture2D(const char *filename, GLint texture_unit, const char *name) : texture_unit(texture_unit), name(name) {
   uint8_t *image = stbi_load(filename, &width, &height, &channels, 0);
   if (!image) {
     return;
@@ -572,7 +557,45 @@ Texture2D::Texture2D(const char *filename, GLint texture_unit) : texture_unit(te
 
 Texture2D::~Texture2D() {}
 
-void Texture2D::activate() {
+void Texture2D::activate() const {
   glActiveTexture(texture_unit);
   glBindTexture(GL_TEXTURE_2D, texture);
 }
+
+Mesh::Mesh(std::vector<Vertex> vertices, std::vector<GLuint> indices, std::vector<Texture2D> textures)
+  : vertices(vertices), indices(indices), textures(textures) {
+    setup_mesh();
+}
+
+void Mesh::setup_mesh() {
+  glGenVertexArrays(1, &vao);
+  glGenBuffers(1, &ebo);
+  glGenBuffers(1, &vbo);
+
+  glBindVertexArray(vao);
+
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
+  glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(GLuint), indices.data(), GL_STATIC_DRAW);
+
+  glBindBuffer(GL_ARRAY_BUFFER, vbo);
+  glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex), vertices.data(), GL_STATIC_DRAW);
+
+  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)0);
+  glEnableVertexAttribArray(0);
+  glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)(offsetof(Vertex, normal)));
+  glEnableVertexAttribArray(1);
+  glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)(offsetof(Vertex, tex_coord)));
+  glEnableVertexAttribArray(2);
+}
+
+void Mesh::draw(Shader &shader) {
+  for (int i = 0; i < textures.size(); ++i) {
+    const Texture2D &texture = textures[i];
+    shader.set_int(texture.name.c_str(), texture.texture_unit - GL_TEXTURE0);
+    texture.activate();
+  }
+
+  glBindVertexArray(vao);
+  glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, (void *)0);
+  glBindVertexArray(0);
+}