learn-opengl/09-basic-light-materials/src/main.cpp
2026-08-21 13:15:55 -04:00

319 lines
8.8 KiB
C++

#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"
#include "model.hpp"
#include "camera.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;
Shader light;
Model model;
glm::vec3 lightPos{1.2f, 1.0f, 2.0f};
glm::vec3 boxPos{2.0f, 0.0f, 0.0f};
unsigned int cubeVAO = 0;
unsigned int lightCubeVAO = 0;
unsigned int VBO = 0;
Camera camera{};
float deltaTime = 0.0f;
float lastFrame = 0.0f;
void updateDelta() {
float currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
}
};
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);
}
void mouse_callback(GLFWwindow *window, double xpos, double ypos) {
Camera* camera = static_cast<Camera*>(glfwGetWindowUserPointer(window));
camera->mouse_move(xpos, ypos);
}
void scroll_callback(GLFWwindow *window, double xoffset, double yoffset) {
Camera* camera = static_cast<Camera*>(glfwGetWindowUserPointer(window));
camera->mouse_scroll(xoffset, yoffset);
}
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");
glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
glfwSetCursorPosCallback(window, mouse_callback);
glfwSetScrollCallback(window, scroll_callback);
return window;
}
void processInput(GLFWwindow *window, BoxTest &box, Camera& camera) {
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);
}
}
if(glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS) {
camera.forward();
}
if(glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS) {
camera.back();
}
if(glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS) {
camera.left();
}
if(glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS) {
camera.right();
}
}
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{
.shader={"shaders/08-vert.glsl", "shaders/08-frag.glsl"},
.light={"shaders/08-vert.glsl", "shaders/08-lightsource.frag.glsl"},
.model={"assets/popcorn_model_a.glb"}
};
unsigned int VBO = 0;
unsigned int lightCubeVAO = 0;
unsigned int cubeVAO = 0;
// cube vao configure, this is the light target
glGenVertexArrays(1, &cubeVAO);
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glBindVertexArray(cubeVAO);
// position attribute
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void *)0);
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void *)(3 * sizeof(float)));
glEnableVertexAttribArray(1);
// light vao configure, this is the light source
glGenVertexArrays(1, &lightCubeVAO);
glBindVertexArray(lightCubeVAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
config.lightCubeVAO = lightCubeVAO;
config.cubeVAO = cubeVAO;
config.VBO = VBO;
return config;
}
void draw_popcorn(Config& config, BoxTest& box, size_t box_i, glm::mat4& projection, glm::mat4& view)
{
config.shader.use();
config.shader.setVec3("objectColor", 1.0f, 0.5f, 0.31f);
config.shader.setVec3("lightColor", 1.0f, 1.0f, 1.0f);
// THIS WAS MISSING
config.shader.setVec3("lightPos", config.lightPos);
config.shader.setMat4("view", view);
config.shader.setMat4("projection", projection);
config.shader.setVec3("viewPos", config.camera.pos);
float time = glfwGetTime();
// get position from box
b2Vec2 position = box.bodies[box_i]->GetPosition();
float angle = box.bodies[box_i]->GetAngle();
glm::mat4 model = glm::mat4(1.0f);
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);
config.model.Draw(config.shader);
}
void draw_cube(Config& config, glm::mat4& projection, glm::mat4& view) {
config.shader.use();
config.shader.setVec3("objectColor", 1.0f, 0.5f, 0.31f);
config.shader.setVec3("lightColor", 1.0f, 1.0f, 1.0f);
// THIS WAS MISSING
config.shader.setVec3("lightPos", config.lightPos);
config.shader.setMat4("view", view);
config.shader.setMat4("projection", projection);
config.shader.setVec3("viewPos", config.camera.pos);
glm::mat4 model = glm::mat4(1.0f);
model = glm::translate(model, config.boxPos);
config.shader.setMat4("model", model);
glBindVertexArray(config.cubeVAO);
glDrawArrays(GL_TRIANGLES, 0, 36);
}
void draw_light(Config& config, glm::mat4& projection, glm::mat4& view) {
config.light.use();
config.light.setVec3("lightPos", config.lightPos);
config.light.setMat4("projection", projection);
config.light.setMat4("view", view);
glm::mat4 model = glm::mat4(1.0f);
model = glm::translate(model, config.lightPos);
model = glm::scale(model, glm::vec3(0.2f));
config.light.setMat4("model", model);
glBindVertexArray(config.lightCubeVAO);
glDrawArrays(GL_TRIANGLES, 0, 36);
}
void render(GLFWwindow* window, Config& config, BoxTest& box, b2World& world) {
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
config.shader.use();
Box2d_step_world(world);
// time is used for fake 3d rotation
float time = glfwGetTime();
config.camera.update(config.deltaTime);
glm::mat4 view = config.camera.lookAt();
glm::mat4 projection = glm::mat4(1.0f);
// fov, aspect, near plane, far plane
projection = glm::perspective(glm::radians(config.camera.fov), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
// update light color
draw_cube(config, projection, view);
// the 0 is for which popcorn, so later when we have N for-loop
draw_popcorn(config, box, 0, projection, view);
draw_light(config, projection, view);
glfwSwapBuffers(window);
glfwPollEvents();
}
void cleanup(Config& config) {
glDeleteVertexArrays(1, &config.lightCubeVAO);
glDeleteBuffers(1, &config.lightCubeVAO);
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();
glfwSetWindowUserPointer(window, &config.camera);
while(!glfwWindowShouldClose(window)) {
processInput(window, box, config.camera);
render(window, config, box, world);
config.updateDelta();
}
cleanup(config);
glfwTerminate();
return 0;
}