separate framebuffer initialization into separate file

4 files changed, 39 insertions, 16 deletions

diff --git a/fb.c b/fb.c
new file mode 100644
index 0000000..479808c
--- /dev/null
+++ b/fb.c
@@ -0,0 +1,30 @@
+#include <GL/glew.h>
+#include <GLFW/glfw3.h>
+
+#include "fb.h"
+#include "die.h"
+#include "consts.h"
+
+GLuint init_fb() {
+	GLuint fbo;
+	glGenFramebuffers(1, &fbo);
+
+	// configure newly created framebuffer
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+	GLuint buffer;
+	glGenTextures(1, &buffer);
+	glBindTexture(GL_TEXTURE_2D, buffer);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, RES_H, RES_V, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, buffer, 0);
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
+		die("can't initialize framebuffer??\n");
+
+	// use default framebuffer again
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+	return fbo;
+}
+
diff --git a/fb.h b/fb.h
new file mode 100644
index 0000000..cc0df69
--- /dev/null
+++ b/fb.h
@@ -0,0 +1,6 @@
+#pragma once
+
+#include <GL/glew.h>
+
+GLuint init_fb();
+
diff --git a/main.c b/main.c
index e65c829..075f264 100644
--- a/main.c
+++ b/main.c
@@ -3,6 +3,7 @@
 #include <GLFW/glfw3.h>
 
 #include "consts.h"
+#include "fb.h"
 #include "shader.h"
 #include "die.h"
 #include "uniform.h"
@@ -81,22 +82,7 @@ int main(int argc, char** argv) {
 		frag_shader(pass2_frag, pass2_frag_size)
 	);
 
-	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, RES_H, RES_V, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-	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);
-
+	GLuint fbo = init_fb();
 
 	// main draw loop
 	while (!glfwWindowShouldClose(window)) {
diff --git a/makefile b/makefile
index 719f0f0..829b235 100644
--- a/makefile
+++ b/makefile
@@ -18,6 +18,7 @@ main: pass1_frag.o
 main: fill_vert.o
 main: pass2_frag.o
 main: uniform.o
+main: fb.o
 
 # fix compile order
 main.o: fill_vert.h