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#include <stdlib.h>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include "shader.h"
#include "die.h"
#include "uniform.h"
#include "fill_vert.h"
#include "visuals_frag.h"
#include "output_frag.h"
void resize_handler(GLFWwindow* window, int width, int height) {
glViewport(0, 0, width, height);
}
GLFWwindow* init_window() {
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
// creating a non-resizable floating window makes the window float with i3
glfwWindowHint(GLFW_FLOATING, GL_TRUE);
glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
// initialize window
int width = 800, height = 600; // default size
GLFWwindow* window = glfwCreateWindow(width, height, "vis", NULL, NULL);
if (window == NULL)
die("error: could not create window\n");
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, resize_handler);
// but i still want a resizable window
glfwSetWindowAttrib(window, GLFW_RESIZABLE, GL_TRUE);
return window;
}
void init_tri() {
const float vertices[] = {
0, 1, 0,
1, -1, 0,
-1, -1, 0,
};
// initialize vertex {buffer,attribute} object buffers
GLuint VBO, VAO;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
// copy vertex data into VBO
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
// set VAO pointers
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
// draw (only) this triangle
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(VAO);
}
int main(int argc, char** argv) {
glfwInit();
GLFWwindow* window = init_window();
glewInit();
init_tri();
GLuint visuals = link_shaders(
vert_shader(fill_vert, fill_vert_size),
frag_shader(visuals_frag, visuals_frag_size)
);
uniforms_t * visuals_uniforms = init_uniforms(visuals, window);
GLuint output = link_shaders(
vert_shader(fill_vert, fill_vert_size),
frag_shader(output_frag, output_frag_size)
);
uniforms_t * output_uniforms = init_uniforms(output, window);
GLuint fbo;
glGenFramebuffers(1, &fbo);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
GLuint last_frame;
glGenTextures(1, &last_frame);
glBindTexture(GL_TEXTURE_2D, last_frame);
// todo: what to do when the size changes?
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 800, 600, 0, GL_RGBA, 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, last_frame, 0);
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
die("can't initialize framebuffer??\n");
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glUseProgram(visuals);
// main draw loop
while (!glfwWindowShouldClose(window)) {
glfwPollEvents();
update_uniforms(visuals_uniforms);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glDrawArrays(GL_TRIANGLES, 0, 3);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glDrawArrays(GL_TRIANGLES, 0, 3);
glfwSwapBuffers(window);
}
return EXIT_SUCCESS;
}
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