Commit of work up to day 11 of learnopengl.com.

05-coordinate_systems/src/data.hpp

@@ -0,0 +1,47 @@
+#pragma once
+#include <glm/glm.hpp>
+
+float vertices_3d[] = {
+  // vertex coords      // texture coords
+  -0.1f, -0.1f, -0.1f,  0.0f, 0.0f,
+  0.1f, -0.1f, -0.1f,  1.0f, 0.0f,
+  0.1f,  0.1f, -0.1f,  1.0f, 1.0f,
+  0.1f,  0.1f, -0.1f,  1.0f, 1.0f,
+  -0.1f,  0.1f, -0.1f,  0.0f, 1.0f,
+  -0.1f, -0.1f, -0.1f,  0.0f, 0.0f,
+
+  -0.1f, -0.1f,  0.1f,  0.0f, 0.0f,
+  0.1f, -0.1f,  0.1f,  1.0f, 0.0f,
+  0.1f,  0.1f,  0.1f,  1.0f, 1.0f,
+  0.1f,  0.1f,  0.1f,  1.0f, 1.0f,
+  -0.1f,  0.1f,  0.1f,  0.0f, 1.0f,
+  -0.1f, -0.1f,  0.1f,  0.0f, 0.0f,
+
+  -0.1f,  0.1f,  0.1f,  1.0f, 0.0f,
+  -0.1f,  0.1f, -0.1f,  1.0f, 1.0f,
+  -0.1f, -0.1f, -0.1f,  0.0f, 1.0f,
+  -0.1f, -0.1f, -0.1f,  0.0f, 1.0f,
+  -0.1f, -0.1f,  0.1f,  0.0f, 0.0f,
+  -0.1f,  0.1f,  0.1f,  1.0f, 0.0f,
+
+  0.1f,  0.1f,  0.1f,  1.0f, 0.0f,
+  0.1f,  0.1f, -0.1f,  1.0f, 1.0f,
+  0.1f, -0.1f, -0.1f,  0.0f, 1.0f,
+  0.1f, -0.1f, -0.1f,  0.0f, 1.0f,
+  0.1f, -0.1f,  0.1f,  0.0f, 0.0f,
+  0.1f,  0.1f,  0.1f,  1.0f, 0.0f,
+
+  -0.1f, -0.1f, -0.1f,  0.0f, 1.0f,
+  0.1f, -0.1f, -0.1f,  1.0f, 1.0f,
+  0.1f, -0.1f,  0.1f,  1.0f, 0.0f,
+  0.1f, -0.1f,  0.1f,  1.0f, 0.0f,
+  -0.1f, -0.1f,  0.1f,  0.0f, 0.0f,
+  -0.1f, -0.1f, -0.1f,  0.0f, 1.0f,
+
+  -0.1f,  0.1f, -0.1f,  0.0f, 1.0f,
+  0.1f,  0.1f, -0.1f,  1.0f, 1.0f,
+  0.1f,  0.1f,  0.1f,  1.0f, 0.0f,
+  0.1f,  0.1f,  0.1f,  1.0f, 0.0f,
+  -0.1f,  0.1f,  0.1f,  0.0f, 0.0f,
+  -0.1f,  0.1f, -0.1f,  0.0f, 1.0f
+};

05-coordinate_systems/src/dbc.cpp

@@ -0,0 +1,47 @@
+#include "dbc.hpp"
+#include <iostream>
+
+void dbc::log(const string &message, const std::source_location location) {
+  std::cout << '[' << location.file_name() << ':'
+     << location.line() << "|"
+     << location.function_name() << "] "
+     << message << std::endl;
+}
+
+void dbc::sentinel(const string &message, const std::source_location location) {
+  string err = $F("[SENTINEL!] {}", message);
+  dbc::log(err, location);
+  throw dbc::SentinelError(err);
+}
+
+void dbc::pre(const string &message, bool test, const std::source_location location) {
+  if(!test) {
+    string err = $F("[PRE!] {}", message);
+    dbc::log(err, location);
+    throw dbc::PreCondError(err);
+  }
+}
+
+void dbc::pre(const string &message, std::function<bool()> tester, const std::source_location location) {
+  dbc::pre(message, tester(), location);
+}
+
+void dbc::post(const string &message, bool test, const std::source_location location) {
+  if(!test) {
+    string err = $F("[POST!] {}", message);
+    dbc::log(err, location);
+    throw dbc::PostCondError(err);
+  }
+}
+
+void dbc::post(const string &message, std::function<bool()> tester, const std::source_location location) {
+  dbc::post(message, tester(), location);
+}
+
+void dbc::check(bool test, const string &message, const std::source_location location) {
+  if(!test) {
+    string err = $F("[CHECK!] {}\n", message);
+    dbc::log(err, location);
+    throw dbc::CheckError(err);
+  }
+}

05-coordinate_systems/src/dbc.hpp

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <string>
+#include <fmt/core.h>
+#include <functional>
+#include <source_location>
+
+// AKA the Fuckit macro
+#define $F(FMT, ...) fmt::format(FMT, ##__VA_ARGS__)
+
+namespace dbc {
+  using std::string;
+
+  using CheckError = std::runtime_error;
+  using SentinelError = std::runtime_error;
+  using PreCondError = std::runtime_error;
+  using PostCondError = std::runtime_error;
+
+  void log(const string &message,
+      const std::source_location location =
+      std::source_location::current());
+
+  [[noreturn]] void sentinel(const string &message,
+      const std::source_location location =
+      std::source_location::current());
+
+  void pre(const string &message, bool test,
+      const std::source_location location =
+      std::source_location::current());
+
+  void pre(const string &message, std::function<bool()> tester,
+      const std::source_location location =
+      std::source_location::current());
+
+  void post(const string &message, bool test,
+      const std::source_location location =
+      std::source_location::current());
+
+  void post(const string &message, std::function<bool()> tester,
+      const std::source_location location =
+      std::source_location::current());
+
+  void check(bool test, const string &message,
+      const std::source_location location =
+      std::source_location::current());
+}

05-coordinate_systems/src/main.cpp

@@ -0,0 +1,214 @@
+#define _USE_MATH_DEFINES
+#include <math.h>
+#include "dbc.hpp"
+#include <print>
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <vector>
+#include <functional>
+#include "shader.hpp"
+#include <stb_image.h>
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+#include "data.hpp"
+#include "physics.hpp"
+
+void framebuffer_size_callback(GLFWwindow *window, int width, int height);
+void processInput(GLFWwindow *window);
+
+const unsigned int SCR_WIDTH = 800;
+const unsigned int SCR_HEIGHT = 600;
+
+struct Config {
+  Shader shader;
+  unsigned int VAO = 0;
+  unsigned int VBO = 0;
+  unsigned int texture1 = 0;
+  unsigned int texture2 = 0;
+};
+
+void init_glfw() {
+  glfwInit();
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+}
+
+void framebuffer_size_callback(GLFWwindow *, int width, int height) {
+  glViewport(0, 0, width, height);
+}
+
+GLFWwindow* create_window() {
+  GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
+  dbc::check(window != NULL, "failed to open window");
+
+  glfwMakeContextCurrent(window);
+
+  glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+
+  auto good = gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);
+  dbc::check(good, "failed to load GLAD");
+
+  return window;
+}
+
+void processInput(GLFWwindow *window, BoxTest &box) {
+  if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) {
+    glfwSetWindowShouldClose(window, true);
+  }
+
+  if(glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_PRESS) {
+    b2Vec2 force(0.0f, 0.5f);
+    for(size_t i = 0; i < BODY_COUNT; i++) {
+      box.bodies[i]->ApplyForceToCenter(force, true);
+      box.bodies[i]->ApplyTorque(0.1f, true);
+    }
+  }
+}
+
+unsigned int load_texture(const std::string& image_file) {
+  unsigned int texture_id;
+  glGenTextures(1, &texture_id);
+  glBindTexture(GL_TEXTURE_2D, texture_id);
+
+  // set the texture wrapping parameters
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+
+  // set texture filtering parameters
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+  int width = 0;
+  int height = 0;
+  int nrChannels = 0;
+  stbi_set_flip_vertically_on_load(true);
+
+  unsigned char *data = stbi_load(image_file.c_str(), &width, &height, &nrChannels, 0);
+
+  dbc::check(data != nullptr, std::format("Failed to load texture: {}", image_file));
+
+  dbc::check(nrChannels == 3 || nrChannels == 4,
+      std::format("Image {} has invalid channels {} should be 3 or 4.", image_file, nrChannels));
+
+  auto rgb_or_a = nrChannels == 3 ? GL_RGB : GL_RGBA;
+
+  glTexImage2D(GL_TEXTURE_2D, 0, rgb_or_a, width, height, 0, rgb_or_a, GL_UNSIGNED_BYTE, data);
+  glGenerateMipmap(GL_TEXTURE_2D);
+
+  stbi_image_free(data);
+
+  return texture_id;
+}
+
+Config setup() {
+  glEnable(GL_DEPTH_TEST);
+
+  Config config{{"shaders/4.2.texture.vs", "shaders/4.2.texture.fs"}};
+
+  unsigned int VBO = 0;
+  unsigned int VAO = 0;
+
+  glGenVertexArrays(1, &VAO);
+  glGenBuffers(1, &VBO);
+
+  glBindVertexArray(VAO);
+
+  glBindBuffer(GL_ARRAY_BUFFER, VBO);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices_3d), vertices_3d, GL_STATIC_DRAW);
+
+  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
+  glEnableVertexAttribArray(0);
+
+  glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
+  glEnableVertexAttribArray(1);
+
+  config.texture1 = load_texture("resources/textures/container.jpg");
+  config.texture2 = load_texture("resources/textures/awesomeface.png");
+
+  config.shader.use();
+  config.shader.setInt("texture1", 0);
+  config.shader.setInt("texture2", 1);
+
+  config.VAO = VAO;
+  config.VBO = VBO;
+
+  return config;
+}
+
+void render(GLFWwindow* window, const Config& config, BoxTest& box, b2World& world) {
+  glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_2D, config.texture1);
+  glActiveTexture(GL_TEXTURE1);
+  glBindTexture(GL_TEXTURE_2D, config.texture2);
+
+  config.shader.use();
+
+  // this is position
+  float time = glfwGetTime();
+  Box2d_step_world(world);
+
+
+  glm::mat4 view = glm::mat4(1.0f);
+  view = glm::translate(view, glm::vec3(0.0f, 0.0f, -3.0f));
+  config.shader.setMat4("view", view);
+
+  glm::mat4 projection = glm::mat4(1.0f);
+  projection = glm::perspective(glm::radians(45.0f), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
+  config.shader.setMat4("projection", projection);
+
+  glBindVertexArray(config.VAO);
+
+  for(unsigned int i = 0; i < BODY_COUNT; i++) {
+    glm::mat4 model = glm::mat4(1.0f);
+
+    // get position from box
+    b2Vec2 position = box.bodies[i]->GetPosition();
+    float angle = box.bodies[i]->GetAngle();
+
+    model = glm::translate(model, glm::vec3(position.x, position.y, 0.0f));
+    model = glm::rotate(model, angle / 5.0f, glm::vec3(1.0f, 0.0f, 0.0f));
+    model = glm::rotate(model, glm::radians(time * 10.0f), glm::vec3(0.0f, 1.0f, 1.0f));
+
+    config.shader.setMat4("model", model);
+
+    glDrawArrays(GL_TRIANGLES, 0, 36);
+  }
+
+  glfwSwapBuffers(window);
+  glfwPollEvents();
+}
+
+void cleanup(Config& config) {
+  glDeleteVertexArrays(1, &config.VAO);
+  glDeleteBuffers(1, &config.VAO);
+  glDeleteBuffers(1, &config.VBO);
+  config.shader.cleanup();
+}
+
+int main() {
+  init_glfw();
+
+  b2Vec2 gravity(0.0f, -10.0f);
+  b2World world(gravity);
+  BoxTest box = Box2d_setup(world);
+
+  auto window = create_window();
+
+  auto config = setup();
+
+  while(!glfwWindowShouldClose(window)) {
+    processInput(window, box);
+    render(window, config, box, world);
+  }
+
+  cleanup(config);
+
+  glfwTerminate();
+
+  return 0;
+}

05-coordinate_systems/src/physics.cpp

@@ -0,0 +1,49 @@
+#include "physics.hpp"
+
+struct BoxTest Box2d_setup(b2World &world) {
+  BoxTest box;
+  float wall_x[4] = {0.0f, 0.0f, -0.99f, 0.99f};
+  float wall_y[4] = {-0.99, 0.99f, 0.0f, 0.0f};
+  float bound_w[4] = {1.0f, 1.0f, 0.1f, 0.1f};
+  float bound_h[4] = {0.1f, 0.1f, 1.0f, 1.0f};
+
+  for(size_t i = 0; i < 4; i++) {
+    b2BodyDef groundBodyDef;
+    groundBodyDef.position.Set(wall_x[i], wall_y[i]);
+    b2Body *groundBody = world.CreateBody(&groundBodyDef);
+
+    b2PolygonShape groundBox;
+    groundBox.SetAsBox(bound_w[i], bound_h[i]);
+    groundBody->CreateFixture(&groundBox, 1.0f);
+
+    box.walls[i] = groundBody;
+  }
+
+  for(size_t i = 0; i < BODY_COUNT; i++) {
+    b2BodyDef bodyDef;
+    bodyDef.type = b2_dynamicBody;
+    bodyDef.position.Set(0.0f, 0.5f);
+    box.bodies[i] = world.CreateBody(&bodyDef);
+
+    b2PolygonShape dynamicBox;
+    dynamicBox.SetAsBox(0.1f, 0.1f);
+    b2FixtureDef fixtureDef;
+    fixtureDef.shape = &dynamicBox;
+
+    fixtureDef.density = 1.0f;
+    fixtureDef.friction = 0.3f;
+
+    box.bodies[i]->CreateFixture(&fixtureDef);
+  }
+
+  return box;
+}
+
+void Box2d_step_world(b2World& world) {
+  float timeStep = 1.0f / 60.0f;
+  int velocityIterations = 6;
+  int positionIterations = 2;
+
+  // step the world
+  world.Step(timeStep, velocityIterations, positionIterations);
+}

05-coordinate_systems/src/physics.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <box2d/box2d.h>
+
+#define BODY_COUNT 20
+
+struct BoxTest {
+  b2Body *walls[4];
+  b2Body *bodies[BODY_COUNT];
+};
+
+struct BoxTest Box2d_setup(b2World &world);
+void Box2d_step_world(b2World& world);

05-coordinate_systems/src/shader.cpp

@@ -0,0 +1,109 @@
+#include "shader.hpp"
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <print>
+#include <filesystem>
+#include "dbc.hpp"
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+
+namespace fs = std::filesystem;
+
+inline std::string read_file(const std::string& filename) {
+  // load the file
+  std::ifstream in_file{filename, std::ios::binary};
+
+  // get the size of the file
+  std::stringstream in_str;
+  in_str << in_file.rdbuf();
+  return in_str.str();
+}
+
+void check_error(const std::string& what, unsigned int thing, GLenum check_type) {
+  int success = 0;
+  char infoLog[512] = {0};
+
+  if(check_type == GL_LINK_STATUS) {
+    glGetProgramiv(thing, check_type, &success);
+
+    if(!success) {
+      glGetProgramInfoLog(thing, 512, NULL, infoLog);
+      dbc::sentinel(std::format("ERROR: Program {} compile failed: {}", what, infoLog));
+    }
+  } else {
+    glGetShaderiv(thing, check_type, &success);
+
+    if(!success) {
+      glGetShaderInfoLog(thing, 512, NULL, infoLog);
+      dbc::sentinel(std::format("ERROR: Shader {} compile failed: {}", what, infoLog));
+    }
+  }
+}
+
+unsigned int Shader::load_shader(const std::string& filename, GLenum shader_type) {
+  dbc::check(fs::exists(filename),
+      std::format("shader file {} does not exist", filename));
+
+  // create the shader
+  std::string shader_code = read_file(filename);
+  const char* shader_code_ptr = shader_code.c_str();
+
+  int shader_id = glCreateShader(shader_type);
+  glShaderSource(shader_id, 1, &shader_code_ptr, NULL);
+  glCompileShader(shader_id);
+
+  check_error(filename, shader_id, GL_COMPILE_STATUS);
+
+  // check compile error
+  return shader_id;
+}
+
+Shader::Shader(const char* vertexPath, const char* fragmentPath) {
+  unsigned int vertex = load_shader(vertexPath, GL_VERTEX_SHADER);
+  unsigned int fragment = load_shader(fragmentPath, GL_FRAGMENT_SHADER);
+
+  ID = glCreateProgram();
+  glAttachShader(ID, vertex);
+  glAttachShader(ID, fragment);
+  glLinkProgram(ID);
+
+  check_error("link", ID, GL_LINK_STATUS);
+
+  glDeleteShader(vertex);
+  glDeleteShader(fragment);
+}
+
+void Shader::use() const {
+  glUseProgram(ID);
+}
+
+void Shader::cleanup() {
+  glDeleteProgram(ID);
+}
+
+void Shader::setBool(const std::string &name, bool value) const {
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform1i(uniform, (int)value);
+}
+
+void Shader::setInt(const std::string &name, int value) const {
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform1i(uniform, value);
+}
+
+void Shader::setFloat(const std::string &name, float value) const {
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform1f(uniform, value);
+}
+
+void Shader::setVec4(const std::string &name, float v1, float v2, float v3, float v4) const {
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform4f(uniform, v1, v2, v3, v4);
+}
+
+void Shader::setMat4(const std::string &name, const glm::mat4& mat) const {
+  unsigned int loc = glGetUniformLocation(ID, name.c_str());
+  glUniformMatrix4fv(loc, 1, GL_FALSE, glm::value_ptr(mat));
+}

05-coordinate_systems/src/shader.hpp

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <glad/glad.h>
+#include <string>
+#include <climits>
+#include <glm/glm.hpp>
+
+class Shader
+{
+public:
+  unsigned int ID = UINT_MAX;
+
+  Shader(const char* vertexPath, const char* fragmentPath);
+  unsigned int load_shader(const std::string& filename, GLenum shader_type);
+  void use() const;
+  void setBool(const std::string &name, bool value) const;
+  void setInt(const std::string &name, int value) const;
+  void setFloat(const std::string &name, float value) const;
+  void setVec4(const std::string &name, float v1, float v2, float v3, float v4) const;
+  void setMat4(const std::string &name, const glm::mat4& what) const;
+  void cleanup();
+};

05-coordinate_systems/src/stb_image.cpp

@@ -0,0 +1,2 @@
+#define STB_IMAGE_IMPLEMENTATION
+#include <stb_image.h>