PyClutter recipes.

Here are a few scripts using pyClutter 1.0 that I have recently finished. They are only for demonstrating some of the abilities of Clutter -- which I must say is just awesome!

Clipping actors (and groups of groups of... etc.) into a path shape
So, you have a shape and you want to force all the children in that Group (groups are Actors) to show within that path? Here you go:

import clutter
from clutter import cogl

"""
pyClutter 1.0
Demonstration of how to clip groups to a path.
"""

zoom = 1
def zoomify(obj,evt):
 global zoom
 if evt.direction == clutter.SCROLL_UP:
  zoom += .1
 else:
  zoom -= .1
 # When the zoom gets small, the cogl clip goes all wonky...
 obj.set_scale(zoom, zoom)

class ClipGroup(clutter.Group):
 """ Custom Group to perform clipping from a path."""
 # Vital line.
 # Registers the specified Python class as a PyGTK type.
 # Also enables the do_paint method. I am not sure why...
 __gtype_name__ = 'ClipGroup'

 def __init__(self,w,h):
  clutter.Group.__init__(self)#,*args)
  self.width, self.height = w, h

 def do_paint(self):
  # Draw a triangle.
  cogl.path_move_to(self.width / 2, 0)
  cogl.path_line_to(self.width, self.height)
  cogl.path_line_to(0, self.height)
  cogl.path_line_to(self.width / 2, 0)
  cogl.path_close()
  # Start the clip
  cogl.clip_push_from_path()

  # errr.. the idea is to have the other stuff in the group
  # get painted -- I assume Group knows what to do.
  clutter.Group.do_paint(self)

  # Finish the clip
  cogl.clip_pop()

def main():
 stage = clutter.Stage()
 stage.set_size(500, 500)
 stage.set_color(clutter.color_from_string("#000"))

 rect_red, rect_green, rect_blue, rect_bounce = \
  clutter.Rectangle(), clutter.Rectangle(), clutter.Rectangle(), clutter.Rectangle()
 
 # We make two of our special groups.
 clipped_group = ClipGroup(300,300)
 inner_group = ClipGroup(100,100)

 rect_red.set_position(0, 0)
 rect_red.set_size(550, 550) #Big to be backdrop.
 rect_red.set_color(clutter.color_from_string("#FF0000FF"))
 
 rect_green.set_position(120, 10)
 rect_green.set_size(50, 50)
 rect_green.set_color(clutter.color_from_string("#00FF0090"))

 rect_bounce.set_position(0,0)
 rect_bounce.set_size(500,20)
 rect_bounce.set_color(clutter.color_from_string("#AABBCCFF"))

 clipped_group.add(rect_red, rect_green)
 clipped_group.add(inner_group) # Add entire inner_group into clipped_group

 rect_blue.set_color(clutter.color_from_string("#0000FF90"))
 rect_blue.set_size(50, 50)
 rect_blue.set_position(50,50) #relative to inner_group...
 inner_group.add(rect_blue) # even though this comes after set_position...

 clipped_group.set_position(100, 100)
 inner_group.set_position(100,50)

 stage.add(rect_bounce)
 stage.add(clipped_group)

 # Make rect_blue move around somewhat.
 path = clutter.Path('M 0 0 L 40 0 L 40 40 L 0 40 Z')
 timeline = clutter.Timeline(4000)
 timeline.set_loop(True)
 alpha = clutter.Alpha(timeline,clutter.EASE_OUT_SINE)
 p_behaviour = clutter.BehaviourPath(alpha, path)
 p_behaviour.apply(rect_blue) 
 timeline.start()

 # Make rect_bounce go up and down
 animation = rect_bounce.animate(clutter.EASE_IN_OUT_BOUNCE, 2000, "y", 500)
 animation.set_loop(True)

 # Start the main clipped_group rotating around the Y axis. For giggles.
 timeline = clutter.Timeline(15000)
 timeline.set_loop(True)
 alpha = clutter.Alpha(timeline, clutter.LINEAR)
 r_behave = clutter.BehaviourRotate(clutter.Y_AXIS, 0.0, 360.0, alpha=alpha)
 r_behave.set_center(150, 0, 0)
 r_behave.apply(clipped_group)
 timeline.start()

 stage.show_all()

 stage.connect('key-press-event', clutter.main_quit)
 stage.connect('destroy', clutter.main_quit)
 stage.connect('scroll-event', zoomify)

 clutter.main()

if __name__ == '__main__':
 main()

Adventures in Time(line)
I wanted to see for myself how Timelines could be controlled from a Score. This is very cool. Here, three rectangles fire in sequence given markers in their timelines. It sounds complicated, but the code should be easy to follow:

import clutter
from clutter import cogl

def main():
 stage = clutter.Stage()
 stage.set_size(500, 500)
 stage.set_color(clutter.color_from_string("#000"))

 rect_red, rect_green, rect_blue = \
  clutter.Rectangle(), clutter.Rectangle(), clutter.Rectangle()
 
 rect_red.set_position(30, 30)
 rect_red.set_size(20, 20)
 rect_red.set_color(clutter.color_from_string("#FF0000FF"))
 
 rect_green.set_position(100, 100)
 rect_green.set_size(50, 50)
 rect_green.set_color(clutter.color_from_string("#00FF0090"))

 rect_blue.set_color(clutter.color_from_string("#0000FF90"))
 rect_blue.set_size(80, 80)
 rect_blue.set_position(200,200)

 stage.add(rect_red, rect_green, rect_blue)

 t_red=clutter.Timeline(10000)
 t_green=clutter.Timeline(5000)
 t_blue=clutter.Timeline(5000)

 a_blue=clutter.Alpha(t_blue,clutter.EASE_OUT_SINE)
 a_green=clutter.Alpha(t_green,clutter.EASE_OUT_SINE)
 a_red=clutter.Alpha(t_red,clutter.EASE_OUT_SINE)

 b_red = clutter.BehaviourRotate(clutter.Z_AXIS, 0.0, 360.0, alpha=a_red)
 b_green = clutter.BehaviourRotate(clutter.Z_AXIS, 0.0, 360.0, alpha=a_green)
 b_blue = clutter.BehaviourRotate(clutter.Z_AXIS, 0.0, 360.0, alpha=a_blue)
 
 b_blue.apply(rect_blue)
 b_green.apply(rect_green)
 b_red.apply(rect_red)

 s=clutter.Score()

 t_red.set_loop(True)
 s.append(t_red)
 t_red.add_marker_at_time("go_green",2000)
 s.append_at_marker(t_red,"go_green",t_green)
 t_green.add_marker_at_time("go_blue",5000)
 s.append_at_marker(t_green,"go_blue", t_blue)

 stage.show_all()
 s.start()

 stage.connect('key-press-event', clutter.main_quit)
 stage.connect('destroy', clutter.main_quit)

 clutter.main()

if __name__ == '__main__':
 main()