new file mode 100644
--- /dev/null
+++ b/pytouhou/ui/opengl/backend.pyx
@@ -0,0 +1,63 @@
+from pytouhou.lib cimport sdl
+from pytouhou.lib.sdl cimport Window
+
+from pytouhou.lib.opengl cimport \
+         (glEnable, glHint, glEnableClientState, GL_TEXTURE_2D, GL_BLEND,
+          GL_PERSPECTIVE_CORRECTION_HINT, GL_FOG_HINT, GL_NICEST,
+          GL_COLOR_ARRAY, GL_VERTEX_ARRAY, GL_TEXTURE_COORD_ARRAY)
+
+IF USE_GLEW:
+    from pytouhou.lib.opengl cimport glewInit
+
+
+GameRenderer = None
+
+
+def init(options):
+    global flavor, version, major, minor, double_buffer, is_legacy, GameRenderer
+
+    flavor = options['flavor']
+    assert flavor in ('core', 'es', 'compatibility', 'legacy')
+
+    version = options['version']
+    major = int(version)
+    minor = <int>(version * 10) % 10
+
+    double_buffer = options['double-buffer']
+    is_legacy = flavor == 'legacy'
+
+    #TODO: check for framebuffer/renderbuffer support.
+
+    from pytouhou.ui.opengl.gamerenderer import GameRenderer
+
+
+def create_window(title, x, y, width, height):
+    sdl.gl_set_attribute(sdl.GL_CONTEXT_MAJOR_VERSION, major)
+    sdl.gl_set_attribute(sdl.GL_CONTEXT_MINOR_VERSION, minor)
+    sdl.gl_set_attribute(sdl.GL_DOUBLEBUFFER, double_buffer)
+    sdl.gl_set_attribute(sdl.GL_DEPTH_SIZE, 24)
+
+    flags = sdl.WINDOW_SHOWN | sdl.WINDOW_OPENGL
+
+    #TODO: legacy can support one of the framebuffer extensions.
+    if not is_legacy:
+        flags |= sdl.WINDOW_RESIZABLE
+
+    window = Window(title, x, y, width, height, flags)
+    window.gl_create_context()
+
+    if USE_GLEW:
+        if glewInit() != 0:
+            raise Exception('GLEW init fail!')
+
+    # Initialize OpenGL
+    glEnable(GL_BLEND)
+    if is_legacy:
+        glEnable(GL_TEXTURE_2D)
+        glHint(GL_FOG_HINT, GL_NICEST)
+        glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST)
+        glEnableClientState(GL_COLOR_ARRAY)
+        glEnableClientState(GL_VERTEX_ARRAY)
+        glEnableClientState(GL_TEXTURE_COORD_ARRAY)
+
+    return window