import gtk
import gtk.gtkgl

from OpenGL.GL import *

class Window:
    def __init__(self, title):
        self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
        self.window.set_size_request(600, 500)
        self.window.set_title(title)
        self.window.connect("destroy", self.destroy_event)

        try:
            # try double-buffered
            self.glconfig = gtk.gdkgl.Config(mode = (gtk.gdkgl.MODE_RGB |
                                              gtk.gdkgl.MODE_DOUBLE |
                                              gtk.gdkgl.MODE_DEPTH))
        except gtk.gdkgl.NoMatches:
            # try single-buffered
            self.glconfig = gtk.gdkgl.Config(mode = (gtk.gdkgl.MODE_RGB |
                                              gtk.gdkgl.MODE_DEPTH))

        glarea = gtk.gtkgl.DrawingArea(self.glconfig)

        glarea.connect_after('realize', self.init)
        glarea.connect('configure_event', self.reshape)
        glarea.connect('expose_event', self.draw)

        self.window.add(glarea)
        self.window.show_all()

    def main(self):
        gtk.main()

    def destroy_event(self, widget, data=None):
        gtk.main_quit()

    def init(self, glarea):
        # get GLContext and GLDrawable
        glcontext = glarea.get_gl_context()
        gldrawable = glarea.get_gl_drawable()

        # GL calls
        if not gldrawable.gl_begin(glcontext): return

        glLightfv(GL_LIGHT0, GL_POSITION, (1, 1, 1, 0))
        glEnable(GL_CULL_FACE)
        glEnable(GL_LIGHTING)
        glEnable(GL_LIGHT0)
        glEnable(GL_DEPTH_TEST)

        gldrawable.gl_end()

    def reshape(self, glarea, event):
        # get GLContext and GLDrawable
        glcontext = glarea.get_gl_context()
        gldrawable = glarea.get_gl_drawable()

        # GL calls
        if not gldrawable.gl_begin(glcontext): return

        x, y, width, height = glarea.get_allocation()

        glViewport(0, 0, width, height)
        glMatrixMode(GL_PROJECTION)
        glLoadIdentity()
        if width > height:
            w = float(width) / float(height)
            glFrustum(-w, w, -1.0, 1.0, 5.0, 60.0)
        else:
            h = float(height) / float(width)
            glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0)

        glMatrixMode(GL_MODELVIEW)
        glLoadIdentity()
        glTranslatef(0.0, 0.0, -40.0)

        gldrawable.gl_end()

        return True

    def draw(self, glarea, event):
        # get GLContext and GLDrawable
        glcontext = glarea.get_gl_context()
        gldrawable = glarea.get_gl_drawable()

        # GL calls
        if not gldrawable.gl_begin(glcontext): return

        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

        glPushMatrix()
        glTranslatef(-3.0, -2.0, -5.0)
        glBegin(GL_QUADS)
        glNormal(0, 0, 1)
        glVertex(0, 0, 0)
        glVertex(1, 0, 0)
        glVertex(1, 1, 0)
        glVertex(0, 1, 0)
        glEnd()
        glPopMatrix()

        if gldrawable.is_double_buffered():
            gldrawable.swap_buffers()
        else:
            glFlush()

        gldrawable.gl_end()

        return True