clean up uniform init/update code + fix window resizing

5 files changed, 87 insertions, 36 deletions

diff --git a/main.c b/main.c
index c4da904..00f5723 100644
--- a/main.c
+++ b/main.c
@@ -1,17 +1,42 @@
 #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 "uniform.h"
 
 #include "fill_vert.h"
 #include "visuals_frag.h"
 
-void prepare_tri() {
+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,
@@ -39,46 +64,21 @@ void prepare_tri() {
 
 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
+	GLFWwindow* window = init_window();
 	glewInit();
 
-	// create single triangle
-	prepare_tri();
-
-	// prepare shaders
+	init_tri();
 	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);
+	init_uniform(shader, window);
 
 	// 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);
+		update_uniform();
 
 		glUseProgram(shader);
 		glDrawArrays(GL_TRIANGLES, 0, 3);
diff --git a/makefile b/makefile
index daf3750..ef01ae8 100644
--- a/makefile
+++ b/makefile
@@ -17,6 +17,7 @@ main: die.o
 main: shader.o
 main: visuals_frag.o
 main: fill_vert.o
+main: uniform.o
 
 # fix compile order
 main.o: fill_vert.h
diff --git a/uniform.c b/uniform.c
new file mode 100644
index 0000000..6c66b7a
--- /dev/null
+++ b/uniform.c
@@ -0,0 +1,40 @@
+#include <sys/time.h>
+#include <time.h>
+#include <GL/glew.h>
+
+#include "uniform.h"
+
+int time_start = 0;
+GLFWwindow* window = NULL;
+GLint u_time, u_window;
+
+void init_uniform(GLuint shader, GLFWwindow* _window) {
+	window = _window;
+
+	u_time = glGetUniformLocation(shader, "time");
+	u_window = glGetUniformLocation(shader, "window");
+
+	time_start = time(NULL);
+}
+
+/** @brief update `uniform float time` */
+static void update_u_time() {
+	struct timeval t;
+	gettimeofday(&t, NULL);
+	t.tv_sec -= time_start;
+	float time = t.tv_sec + (t.tv_usec / 1e6);
+	glUniform1f(u_time, time);
+}
+
+/** @brief update `uniform ivec2 window` */
+static void update_u_window() {
+	int width, height;
+	glfwGetWindowSize(window, &width, &height);
+	glUniform2i(u_window, width, height);
+}
+
+void update_uniform() {
+	update_u_time();
+	update_u_window();
+}
+
diff --git a/uniform.h b/uniform.h
new file mode 100644
index 0000000..d7c58b3
--- /dev/null
+++ b/uniform.h
@@ -0,0 +1,10 @@
+#pragma once
+
+#include <stdlib.h>
+#include <GL/glew.h>
+#include <GLFW/glfw3.h>
+#include <GL/gl.h>
+
+void init_uniform(GLuint shader, GLFWwindow* window);
+void update_uniform();
+
diff --git a/visuals.frag b/visuals.frag
index 16e7712..d680834 100644
--- a/visuals.frag
+++ b/visuals.frag
@@ -1,8 +1,7 @@
 #version 330 core
 
-#include "config.h"
-
 uniform float time;
+uniform ivec2 window;
 
 // adapted from <https://www.shadertoy.com/view/4djSRW>
 float hash12(vec2 p) {
@@ -12,7 +11,8 @@ float hash12(vec2 p) {
 }
 
 void main() {
+	vec2 uv = gl_FragCoord.xy / window;
 	vec2 pos = gl_FragCoord.xy + time;
-	gl_FragColor = vec4(vec3(hash12(pos)), 1.0);
+	gl_FragColor = vec4(hash12(pos), uv.xy, 1.0);
 }