Merge lp:~oly/python-snippets/gtk-opengl-triangle into lp:python-snippets

[Oliver Marks]

OpenGL gtk3 example, seperated from the other example tested on 13.10 and 12.04 in a virtual machine.

requires these libraries only

python-opengl
python-xlib
libx11-dev

Unmerged revisions

101. By Oliver Marks on 2013-10-15

gtk 3 opengl triangle example

=== modified file 'CATEGORIES'
--- CATEGORIES	2010-04-24 18:34:32 +0000
+++ CATEGORIES	2013-10-15 07:57:04 +0000
@@ -30,6 +30,7 @@
     launchpadlib            Samples using launchpadlib.
     Notify OSD              Notify OSD examples.
     os			            os Python module OS related snippets.
+    OpenGL		    Examples of working with OpenGL.
     OpenOffice.org	    Snippets the handle OpenOffice.org files.
     PyGTK                   PyGTK widget and framework examples.
     PyGTKSourceView         PyGTKSourceView widget and framework examples.

=== added directory 'opengl'
=== added file 'opengl/draw-simple-triangle-using-opengl-gtk3.py'
--- opengl/draw-simple-triangle-using-opengl-gtk3.py	1970-01-01 00:00:00 +0000
+++ opengl/draw-simple-triangle-using-opengl-gtk3.py	2013-10-15 07:57:04 +0000
@@ -0,0 +1,129 @@
+#!/usr/bin/env python
+# [SNIPPET_NAME: gtk3 opengl example]
+# [SNIPPET_CATEGORIES: opengl]
+# [SNIPPET_TAGS: opengl, gtk3]
+# [SNIPPET_DESCRIPTION: using gtk3 library lets draw using opengl]
+# [SNIPPET_AUTHOR: Oliver Marks ]
+# [SNIPPET_LICENSE: GPL]
+
+import sys
+from OpenGL.GL import *
+from OpenGL.GLU import *
+from OpenGL import GLX
+from OpenGL.raw._GLX import struct__XDisplay
+from OpenGL import GL
+from ctypes import *
+
+import Xlib
+from Xlib.display import Display
+from gi.repository import Gtk, GdkX11, Gdk
+
+
+class gtkgl:
+    """ these method do not seem to exist in python x11 library lets exploit the c methods """
+    xlib = cdll.LoadLibrary('libX11.so')
+    xlib.XOpenDisplay.argtypes = [c_char_p]
+    xlib.XOpenDisplay.restype = POINTER(struct__XDisplay)
+    xdisplay = xlib.XOpenDisplay("")
+    display = Xlib.display.Display()
+    attrs = []
+
+    xwindow_id = None
+    width = height = 200
+
+    def __init__(self):
+        """ lets setup are opengl settings and create the context for our window """
+        self.add_attribute(GLX.GLX_RGBA, True)
+        self.add_attribute(GLX.GLX_RED_SIZE, 1)
+        self.add_attribute(GLX.GLX_GREEN_SIZE, 1)
+        self.add_attribute(GLX.GLX_BLUE_SIZE, 1)
+        self.add_attribute(GLX.GLX_DOUBLEBUFFER, 0)
+
+        xvinfo = GLX.glXChooseVisual(self.xdisplay, self.display.get_default_screen(), self.get_attributes())
+        configs = GLX.glXChooseFBConfig(self.xdisplay, 0, None, byref(c_int()))
+        self.context = GLX.glXCreateContext(self.xdisplay, xvinfo, None, True)
+
+    def add_attribute(self, setting, value):
+        """just to nicely add opengl parameters"""
+        self.attrs.append(setting)
+        self.attrs.append(value)
+
+    def get_attributes(self):
+        """ return our parameters in the expected structure"""
+        attrs = self.attrs + [0, 0]
+        return (c_int * len(attrs))(*attrs)
+
+    def configure(self, wid):
+        """  """
+        self.xwindow_id = GdkX11.X11Window.get_xid(wid)
+        if(not GLX.glXMakeCurrent(self.xdisplay, self.xwindow_id, self.context)):
+            print 'failed'
+        glViewport(0, 0, self.width, self.height)
+
+    def draw_start(self):
+        """make cairo context current for drawing"""
+        if(not GLX.glXMakeCurrent(self.xdisplay, self.xwindow_id, self.context)):
+            print "failed"
+
+    def draw_finish(self):
+        """swap buffer when we have finished drawing"""
+        GLX.glXSwapBuffers(self.xdisplay, self.xwindow_id)
+
+    def test(self):
+        """Test method to draw something so we can make sure opengl is working and we can see something"""
+        self.draw_start()
+
+        glClearColor(0.0, 0.0, 0.0, 0.0)
+        glClear(GL_COLOR_BUFFER_BIT)
+        glBegin(GL_TRIANGLES)
+        glIndexi(0)
+        glColor3f(1.0, 0.0, 0.0)
+        glVertex2i(0, 1)
+        glIndexi(0)
+        glColor3f(0.0, 1.0, 0.0)
+        glVertex2i(-1, -1)
+        glIndexi(0)
+        glColor3f(0.0, 0.0, 1.0)
+        glVertex2i(1, -1)
+        glEnd()
+
+        self.draw_finish()
+
+
+class gui():
+    glwrap = gtkgl()
+
+    def __init__(self):
+        self.window = Gtk.Window()
+        self.window.realize()
+        self.window.resize(self.glwrap.width, self.glwrap.height)
+        self.window.set_resizable(True)
+        self.window.set_reallocate_redraws(True)
+        self.window.set_title("GTK3 with opengl")
+        self.window.connect('delete_event', Gtk.main_quit)
+        self.window.connect('destroy', lambda quit: Gtk.main_quit())
+
+        self.drawing_area = Gtk.DrawingArea()
+        self.drawing_area.connect('configure_event', self.on_configure_event)
+        self.drawing_area.connect('draw', self.on_draw)
+        self.drawing_area.set_double_buffered(False)
+        self.drawing_area.set_size_request(self.glwrap.width, self.glwrap.height)
+
+        self.window.add(self.drawing_area)
+        self.window.show_all()
+
+    def on_configure_event(self, widget, event):
+        self.glwrap.configure(widget.get_window())
+        self.glwrap.test()
+        return True
+
+    def on_draw(self, widget, context):
+        self.glwrap.test()
+
+
+def main():
+    g = gui()
+    Gtk.main()
+
+if __name__ == '__main__':
+    main()