Now have separate FrameBuffer and Screen structs to manage the framebuffer/screen dance.

21-framebuffers/meson.build

@@ -81,6 +81,8 @@ sources = [
   'src/model.cpp',
   'src/scene.cpp',
   'src/camera.cpp',
+  'src/framebuffer.cpp',
+  'src/screen.cpp',
 ]
 
 subdir('tests')

21-framebuffers/src/framebuffer.cpp

@@ -0,0 +1,59 @@
+#include "framebuffer.hpp"
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+
+void FrameBuffer::init() {
+  // target_fb config
+  glGenFramebuffers(1, &target_fb);
+  glBindFramebuffer(GL_FRAMEBUFFER, target_fb);
+
+  // target_fb configuration
+  // -------------------------
+  glGenFramebuffers(1, &target_fb);
+  glBindFramebuffer(GL_FRAMEBUFFER, target_fb);
+
+  // create a color attachment texture
+  glGenTextures(1, &texture_buffer);
+  glBindTexture(GL_TEXTURE_2D, texture_buffer);
+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, SCR_WIDTH, SCR_HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture_buffer, 0);
+
+  // create a renderbuffer object for depth and stencil attachment (we won't be sampling these)
+  glGenRenderbuffers(1, &target_rbo);
+  glBindRenderbuffer(GL_RENDERBUFFER, target_rbo);
+  glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, SCR_WIDTH, SCR_HEIGHT); // use a single renderbuffer object for both a depth AND stencil buffer.
+  glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, target_rbo); // now actually attach it
+  // now that we actually created the target_fb and added all attachments we want to check if it is actually complete now
+
+  dbc::check(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE, "Frame buffer not complete.");
+  glBindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
+void FrameBuffer::begin() {
+  // target_fb stuff here
+  glBindFramebuffer(GL_FRAMEBUFFER, target_fb);
+  glEnable(GL_DEPTH_TEST);
+
+  glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+}
+
+void FrameBuffer::commit() {
+  // disable the frame buffer
+  glBindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
+void FrameBuffer::draw(Screen& screen) {
+  glDisable(GL_DEPTH_TEST);
+
+  glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
+  glClear(GL_COLOR_BUFFER_BIT);
+
+  // render the screen quad
+  screen.shader.use();
+  glBindVertexArray(screen.target_VAO);
+  glBindTexture(GL_TEXTURE_2D, texture_buffer);
+  glDrawArrays(GL_TRIANGLES, 0, 6);
+}

21-framebuffers/src/framebuffer.hpp

@@ -0,0 +1,15 @@
+#pragma once
+
+#include "shader.hpp"
+#include "screen.hpp"
+
+struct FrameBuffer {
+  unsigned int target_fb = 0;
+  unsigned int target_rbo = 0;
+  unsigned int texture_buffer = 0;
+
+  void init();
+  void begin();
+  void commit();
+  void draw(Screen& screen);
+};

21-framebuffers/src/scene.cpp

@@ -40,12 +40,7 @@ void Scene::render(GLFWwindow* window) {
   // fov, aspect, near plane, far plane
   projection = glm::perspective(glm::radians(camera.fov), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
 
-  // framebuffer stuff here
+  framebuffer.begin();
-  glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
-  glEnable(GL_DEPTH_TEST);
-
-  glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
-  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
   // render the scene
   shader.use();
@@ -56,18 +51,9 @@ void Scene::render(GLFWwindow* window) {
     draw_thing(shader, thing);
   }
 
-  // disable the frame buffer
+  framebuffer.commit();
-  glBindFramebuffer(GL_FRAMEBUFFER, 0);
-  glDisable(GL_DEPTH_TEST);
 
-  glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
+  framebuffer.draw(screen);
-  glClear(GL_COLOR_BUFFER_BIT);
-
-  // render the screen quad
-  screen_shader.use();
-  glBindVertexArray(quadVAO);
-  glBindTexture(GL_TEXTURE_2D, textureColorBuffer);
-  glDrawArrays(GL_TRIANGLES, 0, 6);
 }
 
 void Scene::cleanup() {

21-framebuffers/src/scene.hpp

@@ -11,6 +11,7 @@
 #include "model.hpp"
 #include "camera.hpp"
 #include "components.hpp"
+#include "framebuffer.hpp"
 #include <vector>
 #include <unordered_map>
 
@@ -26,7 +27,8 @@ struct Thing {
 
 struct Scene {
   Shader shader;
-  Shader screen_shader;
+  Screen screen;
+  FrameBuffer framebuffer;
 
   std::unordered_map<std::string, components::Material> materials;
   Camera camera;
@@ -36,27 +38,10 @@ struct Scene {
 
   float deltaTime = 0.0f;
   float lastFrame = 0.0f;
-  unsigned int framebuffer = 0;
-  unsigned int textureColorBuffer = 0;
-  unsigned int quadVAO = 0;
-  unsigned int quadVBO = 0;
-  unsigned int rbo = 0;
-
-  float quadVertices[24] = {
-    // vertex attributes for a quad that fills the entire screen in Normalized Device Coordinates.
-    // positions   // texCoords
-    -1.0f,  1.0f,  0.0f, 1.0f,
-    -1.0f, -1.0f,  0.0f, 0.0f,
-    1.0f, -1.0f,  1.0f, 0.0f,
-
-    -1.0f,  1.0f,  0.0f, 1.0f,
-    1.0f, -1.0f,  1.0f, 0.0f,
-    1.0f,  1.0f,  1.0f, 1.0f
-  };
 
   Scene(components::Scene& config):
     shader{config.shader.vertex_path, config.shader.frag_path},
-    screen_shader{config.screen_shader.vertex_path, config.shader.frag_path},
+    screen{.shader={config.screen_shader.vertex_path, config.shader.frag_path}},
     materials{config.materials},
     camera{
       .position=config.camera.position,
@@ -81,49 +66,12 @@ struct Scene {
           thing.scale);
     }
 
-    glGenVertexArrays(1, &quadVAO);
-    glGenBuffers(1, &quadVBO);
-    glBindVertexArray(quadVAO);
-    glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), &quadVertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)(2 * sizeof(float)));
-
     shader.use();
     shader.setInt("texture1", 0);
     shader.apply_lighting(light);
 
-    screen_shader.use();
+    framebuffer.init();
-    screen_shader.setInt("screenTexture", 0);
+    screen.init();
-
-    // framebuffer config
-    glGenFramebuffers(1, &framebuffer);
-    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
-
-    // framebuffer configuration
-    // -------------------------
-    glGenFramebuffers(1, &framebuffer);
-    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
-
-    // create a color attachment texture
-    glGenTextures(1, &textureColorBuffer);
-    glBindTexture(GL_TEXTURE_2D, textureColorBuffer);
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, SCR_WIDTH, SCR_HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureColorBuffer, 0);
-
-    // create a renderbuffer object for depth and stencil attachment (we won't be sampling these)
-    glGenRenderbuffers(1, &rbo);
-    glBindRenderbuffer(GL_RENDERBUFFER, rbo);
-    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, SCR_WIDTH, SCR_HEIGHT); // use a single renderbuffer object for both a depth AND stencil buffer.
-    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rbo); // now actually attach it
-    // now that we actually created the framebuffer and added all attachments we want to check if it is actually complete now
-
-    dbc::check(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE, "Frame buffer not complete.");
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
   }
 
   void update();

21-framebuffers/src/screen.cpp

@@ -0,0 +1,18 @@
+#include "screen.hpp"
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+
+void Screen::init() {
+  shader.use();
+  shader.setInt("screenTexture", 0);
+
+  glGenVertexArrays(1, &target_VAO);
+  glGenBuffers(1, &target_VBO);
+  glBindVertexArray(target_VAO);
+  glBindBuffer(GL_ARRAY_BUFFER, target_VBO);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), &vertices, GL_STATIC_DRAW);
+  glEnableVertexAttribArray(0);
+  glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void *)0);
+  glEnableVertexAttribArray(1);
+  glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)(2 * sizeof(float)));
+}

21-framebuffers/src/screen.hpp

@@ -0,0 +1,22 @@
+#pragma once
+#include "shader.hpp"
+
+struct Screen {
+  Shader shader;
+  unsigned int target_VAO = 0;
+  unsigned int target_VBO = 0;
+
+  float vertices[24] = {
+    // vertex attributes for a quad that fills the entire screen in Normalized Device Coordinates.
+    // positions   // texCoords
+    -1.0f,  1.0f,  0.0f, 1.0f,
+    -1.0f, -1.0f,  0.0f, 0.0f,
+    1.0f, -1.0f,  1.0f, 0.0f,
+
+    -1.0f,  1.0f,  0.0f, 1.0f,
+    1.0f, -1.0f,  1.0f, 0.0f,
+    1.0f,  1.0f,  1.0f, 1.0f
+  };
+
+  void init();
+};