336 lines
11 KiB
C++

// glad and GLFW
#include <glad/glad.h>
#include <GLFW/glfw3.h>
// glm math
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <iostream>
#include <fstream>
#include <sstream>
#include <stdio.h>
#include <stdlib.h>
#define VERTEX_FILE "./shaders/vertex.glsl"
#define FRAGMENT_FILE "./shaders/fragment.glsl"
#define COMPUTE_FILE "./shaders/compute.glsl"
const float SCR_WIDTH = 1200.0f;
const float SCR_HEIGHT = 1200.0f;
// Shader loader helper
std::string loadShaderSource(const std::string& filepath) {
std::ifstream file(filepath);
if (!file.is_open()) {
std::cerr << "Failed to open shader file: " << filepath << std::endl;
return "";
}
std::stringstream buffer;
std::cout << "Loaded " << filepath << " successfully!\n";
buffer << file.rdbuf();
return buffer.str();
}
GLuint compileShader(GLenum type, const std::string& source) {
GLuint shader = glCreateShader(type);
const char* src = source.c_str();
glShaderSource(shader, 1, &src, nullptr);
glCompileShader(shader);
int success;
glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
if (!success) {
char infoLog[1024];
glGetShaderInfoLog(shader, 1024, nullptr, infoLog);
std::cerr << "Shader compilation failed:\n" << infoLog << std::endl;
exit(10);
}
return shader;
}
GLuint createShaderProgram(const std::string& vertexPath, const std::string& fragmentPath) {
std::string vertexSrc = loadShaderSource(vertexPath);
std::string fragmentSrc = loadShaderSource(fragmentPath);
GLuint vertexShader = compileShader(GL_VERTEX_SHADER, vertexSrc);
GLuint fragmentShader = compileShader(GL_FRAGMENT_SHADER, fragmentSrc);
GLuint program = glCreateProgram();
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);
glLinkProgram(program);
int success;
glGetProgramiv(program, GL_LINK_STATUS, &success);
if (!success) {
char infoLog[1024];
glGetProgramInfoLog(program, 1024, nullptr, infoLog);
std::cerr << "Shader linking failed:\n" << infoLog << std::endl;
exit(11);
}
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
return program;
}
GLuint createComputeProgram(const std::string& computePath) {
std::string computeSrc = loadShaderSource(computePath);
GLuint computeShader = compileShader(GL_COMPUTE_SHADER, computeSrc);
GLuint program = glCreateProgram();
glAttachShader(program, computeShader);
glLinkProgram(program);
int success;
glGetProgramiv(program, GL_LINK_STATUS, &success);
if (!success) {
char infoLog[1024];
glGetProgramInfoLog(program, 1024, nullptr, infoLog);
std::cerr << "Compute shader linking failed:\n" << infoLog << std::endl;;
}
glDeleteShader(computeShader);
return program;
}
int main() {
// Initialize GLFW
if (!glfwInit()) return -1;
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 1);
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // REQUIRED on macOS
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwWindowHint(GLFW_SAMPLES, 8); // 8x MSAA
GLFWwindow* window = glfwCreateWindow((int)SCR_WIDTH, (int)SCR_HEIGHT, "RASTER", nullptr, nullptr);
if (!window) {
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
std::cerr << "Failed to initialize GLAD\n";
return -1;
}
glViewport(0, 0, (int)SCR_WIDTH, (int)SCR_HEIGHT);
//DEBUG
std::cout << "OpenGL Version: " << glGetString(GL_VERSION) << std::endl;
// ----- Vertex Data -----
float vertices[] = {
// positions
-1.0f, -1.0f, 0.0f,
1.0f, -1.0f, 0.0f,
1.0f, 1.0f, 0.0f,
-1.0f, 1.0f, 0.0f
};
unsigned int indices[] = {
0, 1, 2,
2, 3, 0
};
GLuint VAO, VBO, EBO;
glGenVertexArrays(1,&VAO);
glGenBuffers(1,&VBO);
glGenBuffers(1,&EBO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER,VBO);
glBufferData(GL_ARRAY_BUFFER,sizeof(vertices),vertices,GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(indices),indices,GL_STATIC_DRAW);
// position - VERTEX SHADER
glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,3*sizeof(float),(void*)0);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER,0);
// Load shaders
GLuint shaderProgram = createShaderProgram(VERTEX_FILE, FRAGMENT_FILE);
// Caulculate model, view, projection matrices
glm::mat4 model = glm::mat4(1.0f);
glm::mat4 view = glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, 0.0f, -1.0f));
glm::mat4 projection = glm::perspective(glm::radians(45.0f), SCR_WIDTH/SCR_HEIGHT, 0.1f, 100.0f);
GLuint modelLoc = (unsigned int) glGetUniformLocation(shaderProgram, "model");
GLuint viewLoc = (unsigned int) glGetUniformLocation(shaderProgram, "view");
GLuint projLoc = (unsigned int) glGetUniformLocation(shaderProgram, "projection");
glUseProgram(shaderProgram);
glUniformMatrix4fv((int) modelLoc, 1, GL_FALSE, glm::value_ptr(model));
glUniformMatrix4fv((int) viewLoc, 1, GL_FALSE, glm::value_ptr(view));
glUniformMatrix4fv((int) projLoc, 1, GL_FALSE, glm::value_ptr(projection));
// Query important uniform locations (we'll keep them around)
GLint resLoc = glGetUniformLocation(shaderProgram, "u_resolution");
GLint timeLoc = glGetUniformLocation(shaderProgram, "u_time");
GLint scaleLoc = glGetUniformLocation(shaderProgram, "u_scale");
GLint mouseLoc = glGetUniformLocation(shaderProgram, "u_mouse");
glEnable(GL_MULTISAMPLE);
// --- Supersampling FBO ---
int scaleFactor = 2; // try 2 or 4 for smoother output
int fbWidth = (int)SCR_WIDTH * scaleFactor;
int fbHeight = (int)SCR_HEIGHT * scaleFactor;
unsigned int fbo, colorTex, rbo;
glGenFramebuffers(1, &fbo);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
// Color texture
glGenTextures(1, &colorTex);
glBindTexture(GL_TEXTURE_2D, colorTex);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, fbWidth, fbHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
// filtering + wrap
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorTex, 0);
// Depth/stencil buffer
glGenRenderbuffers(1, &rbo);
glBindRenderbuffer(GL_RENDERBUFFER, rbo);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, fbWidth, fbHeight);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rbo);
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
std::cout << "ERROR: Framebuffer not complete!" << std::endl;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// --------------------------
// set the shader resolution to the FBO size (important!)
glUseProgram(shaderProgram);
glUniform2f(resLoc, SCR_WIDTH, SCR_HEIGHT);
float scale = 1.0f;
int frameCount = 0;
float mousePos[2] = {0.0f, 0.0f};
// FPS tracking
double lastTime = glfwGetTime(); // when we last printed FPS
double fps = 0.0;
// Render loop
while (!glfwWindowShouldClose(window)) {
float timeValue = (float)glfwGetTime();
double xpos, ypos;
// Get mouse positions
glfwGetCursorPos(window, &xpos, &ypos);
mousePos[0] = (float)xpos;
mousePos[1] = (float)(SCR_HEIGHT - ypos); // Invert y-axis for OpenGL coordinates
// Input
glfwPollEvents();
// Shader hot-reload
if (glfwGetKey(window, GLFW_KEY_R) == GLFW_PRESS) {
glDeleteProgram(shaderProgram);
shaderProgram = createShaderProgram(VERTEX_FILE, FRAGMENT_FILE);
modelLoc = (unsigned int) glGetUniformLocation(shaderProgram, "model");
viewLoc = (unsigned int) glGetUniformLocation(shaderProgram, "view");
projLoc = (unsigned int) glGetUniformLocation(shaderProgram, "projection");
glUseProgram(shaderProgram);
glUniformMatrix4fv((int) modelLoc, 1, GL_FALSE, glm::value_ptr(model));
glUniformMatrix4fv((int) viewLoc, 1, GL_FALSE, glm::value_ptr(view));
glUniformMatrix4fv((int) projLoc, 1, GL_FALSE, glm::value_ptr(projection));
// Re-query uniforms and set resolution to FBO size (IMPORTANT)
resLoc = glGetUniformLocation(shaderProgram, "u_resolution");
timeLoc = glGetUniformLocation(shaderProgram, "u_time");
scaleLoc = glGetUniformLocation(shaderProgram, "u_scale");
mouseLoc = glGetUniformLocation(shaderProgram, "u_mouse");
glUseProgram(shaderProgram);
glUniform2f(resLoc, (float)fbWidth, (float)fbHeight);
std::cout << "Shaders recompiled!\n";
}
// Scroll to zoom in/out
if (glfwGetKey(window, GLFW_KEY_UP) == GLFW_PRESS) {
scale += 0.01f;
if (scale > 10.0f) scale = 10.0f; // Max zoom
}
if (glfwGetKey(window, GLFW_KEY_DOWN) == GLFW_PRESS) {
scale -= 0.01f;
if (scale < 0.1f) scale = 0.1f; // Min zoom
}
// increment frame count (for FPS)
frameCount++;
// --- FPS Counter (print to console every second) ---
double currentTime = glfwGetTime();
double delta = currentTime - lastTime;
if (delta >= 1.0) { // print every ~1 second
fps = double(frameCount) / delta;
std::cout << "FPS: " << fps
<< " Time: " << timeValue
<< " Scale: " << scale
<< " Mouse: (" << mousePos[0] << ", " << mousePos[1] << ")"
<< std::endl;
frameCount = 0;
lastTime = currentTime;
}
// --- Render into high-res FBO ---
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glViewport(0, 0, fbWidth, fbHeight);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Use shader & set uniforms
glUseProgram(shaderProgram);
glUniform1f(timeLoc, timeValue);
glUniform1f(scaleLoc, scale);
glUniform2f(mouseLoc, mousePos[0], mousePos[1]);
// (u_resolution already set to fbWidth, fbHeight)
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
// --- Blit back to screen ---
glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
glBlitFramebuffer(0, 0, fbWidth, fbHeight,
0, 0, (int)SCR_WIDTH, (int)SCR_HEIGHT,
GL_COLOR_BUFFER_BIT, GL_LINEAR);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glViewport(0, 0, (int)SCR_WIDTH, (int)SCR_HEIGHT);
glfwSwapBuffers(window);
}
glDeleteVertexArrays(1,&VAO);
glDeleteBuffers(1,&VBO);
glDeleteBuffers(1,&EBO);
glDeleteProgram(shaderProgram);
glfwDestroyWindow(window);
glfwTerminate();
return 0;
}