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#include <stdlib.h>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <sys/time.h>
#include <time.h>
#include "shader.h"
#include "die.h"
#include "config.h"
#include "fill_vert.h"
#include "visuals_frag.h"
void prepare_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();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
// force floating window w/ i3
glfwWindowHint(GLFW_FLOATING, GL_TRUE);
glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
// initialize window
GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "vis", NULL, NULL);
if (window == NULL)
die("error: could not create window\n");
glfwMakeContextCurrent(window);
// initialize GLEW
glewInit();
// create single triangle
prepare_tri();
// prepare shaders
GLuint shader = link_shaders(
vert_shader(fill_vert, fill_vert_size),
frag_shader(visuals_frag, visuals_frag_size)
);
// prepare uniform variables
GLint u_time = glGetUniformLocation(shader, "time");
int time_start = time(NULL);
// main draw loop
while (!glfwWindowShouldClose(window)) {
glfwPollEvents();
// set `time` uniform
struct timeval t;
gettimeofday(&t, NULL);
t.tv_sec -= time_start;
float time = t.tv_sec + (t.tv_usec / 1e6);
glUniform1f(u_time, time);
glUseProgram(shader);
glDrawArrays(GL_TRIANGLES, 0, 3);
glfwSwapBuffers(window);
}
return EXIT_SUCCESS;
}
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