From b455fb9e158ee7990f107e9d67f2bac084a460c7 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Sat, 26 Jul 2014 11:16:35 -0400
Subject: [PATCH] load GL buffers

---
 src/Window.cc | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/Window.cc b/src/Window.cc
index 9900f95..7db79bf 100644
--- a/src/Window.cc
+++ b/src/Window.cc
@@ -1,4 +1,5 @@
 #include "gl3w.h"
+#include "GLBuffer.h"
 #include "ruby.h"
 #include "Window.h"
 #include <SDL.h>
@@ -9,6 +10,7 @@
 typedef struct
 {
     SDL_Window * sdl_window;
+    GLBufferRef rect_buffer;
 } Window;
 
 static VALUE ruby_class;
@@ -30,6 +32,23 @@ static void Init_SDL()
     initialized = true;
 }
 
+static void load_gl_buffers(Window * window)
+{
+    static const GLint rect_coords[4][2] = {
+        {0, 0},
+        {1, 0},
+        {0, 1},
+        {1, 1},
+    };
+
+    window->rect_buffer = new GLBuffer();
+    if (!window->rect_buffer->create(GL_ARRAY_BUFFER, GL_STATIC_DRAW,
+                                     &rect_coords, sizeof(rect_coords)))
+    {
+        rb_raise(rb_eRuntimeError, "Failed to create rectangle VBO");
+    }
+}
+
 static void Init_OpenGL()
 {
     static bool initialized = false;
@@ -92,6 +111,8 @@ static VALUE Window_new(VALUE klass)
 
     Init_OpenGL();
 
+    load_gl_buffers(window);
+
     one_created = true;
 
     VALUE rv = Data_Wrap_Struct(ruby_class, NULL, Window_free, window);