Elements/Chipmunk/Documentation

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elements

Physics API for easy usage of chipmunk physics engine in pygame (with pymunk)
elements.__init__ Init function: pymunk, get flags, get screen size, init space
elements.init_colors Init the random color array
elements.set_color Set a fixed color for new elements
elements.reset_color Set random colors for new elements
elements.get_color Get either fixed or random color (in rgb)
elements.toggle_help
elements.set_info Set the info-text (for the upper left corner)
elements.messagebox_show
elements.messagebox_hide
elements.screenshot
elements.screencast_start
elements.screencast_stop
elements.screencast_encode_callback
elements.save_surface
elements.clear Clear & Restart the Physics Space
elements.flipy Convert pygame y-coordinate to chipmunk's
elements.vec2df Convert a pygame pos to a vec2d (with flipped y coordinate)
elements.autoset_screen_size Get screensize from pygame or set manually. Call on resize
elements.is_inside Check if pos is inside screen + tolerance
elements.update Update the physics space
elements.draw Call draw_shape for each element and remove outside ones
elements.draw_shape Draw a given shape (circle, segment, poly)
elements.add_wall Add a fixed wall
elements.add_ball Add a Ball
elements.add_square Add a Square (Box)
elements.add_poly Add a Polygon
elements.apply_impulse Apply an Impulse to a given Shape's body
elements.get_element_count Returns the current element count
(bold are the functions you'll likely want to use :)


elements.__init__

elements.__init__ (gravity= (0.0,-900.0))
  • Init function: init pymunk, get screen size, init space, ...
  • Parameter: gravity == (int(x), int(y))
  • Returns: Elements()


elements.init_colors

elements.init_colors ()
  • Init self.colors with a fix set of hex colors
  • Returns: -


elements.set_color

elements.set_color (clr)
  • Set a color for all future Elements, until reset_color() is called
  • Parameter: clr == (Hex or RGB)
  • Returns: -


elements.reset_color

elements.reset_color ()
  • All Elements from now on will be drawn in random colors
  • Returns: -


elements.get_color

elements.get_color ()
  • Get a color - either the fixed one or the next from self.colors
  • Returns: clr = ((R), (G), (B))


elements.toggle_help

elements.toggle_help ()
  • Toggle Help on and off
  • Returns: -


elements.set_info

elements.set_info (txt)
  • Create the Surface for the Infotext at the Upper Left Corner
  • Parameter: txt == str()
  • Returns: -


elements.messagebox_show

elements.messagebox_show (txt, delay=None)
  • Add a message box at the center on drawing
  • Parameter: txt == str()
  • Optional: delay (in seconds, until box disappears)
  • Returns: -


elements.messagebox_hide

elements.messagebox_hide ()
  • Hide the message box
  • Returns: -


elements.screenshot

elements.screenshot (filename='elements.screenshot', ext='tga')
  • Make a Screenshot in .tga format, if there is no screencast running
  • Optional: filename == str() (no extension), ext == str() (does not work -- always saves as .tga)
  • Returns: -


elements.screencast_start

elements.screencast_start (fn='screencast')
  • Starts saving one image per frame in snapshots/ (as .tga), for encoding with mencoder
  • Optional: fn == str() (filename without extension)
  • Returns: -


elements.screencast_stop

elements.screencast_stop ()
  • Stop the image saving and start encoding (mencoder) the images to a .avi video
  • Returns: -


elements.screencast_encode_callback

elements.screencast_encode_callback ()
  • Callback function when encoding is done -> remove info & resume physics
  • Returns: -


elements.save_surface

elements.save_surface (surface, fn='surface', ext='tga')
  • Saves a surface to a local file
  • Parameter: surface == pygame.Surface()
  • Optional: fn == str(fn_without_ext), ext == str()
  • Returns: fullname == str(full_name_of_file)


elements.clear

elements.clear ()
  • Clear & Reset the Physic Space (Remove all Elements)
  • Returns: -


elements.flipy

elements.flipy (y)
  • Convert pygame y-coordinate to chipmunk's
  • Parameter: y == int()
  • Returns: int(y_new)


elements.vec2df

elements.vec2df (pos)
  • pos -> vec2d (with flipped y)
  • Parameter: pos == (int(x), int(pygame_y))
  • Returns: vec2d(int(x), int(chipmunk_y))


elements.autoset_screen_size

elements.autoset_screen_size (size=None)
  • Get the current PyGame Screen Size, or sets it manually
  • Optional: size == (int(width), int(height))
  • Returns: -


elements.is_inside

elements.is_inside (pos, tolerance=3000)
  • Check if pos is inside screen + tolerance
  • Parameter: pos == (int(x), int(y))
  • Optional: tolerance == int(pixels)
  • Returns: True if inside, False if outside


elements.update

elements.update (fps=50.0, steps=5)
  • Update the Physics Space
  • Optional: fps == int(fps), steps == int(space_steps_per_udate)
  • Returns: -


elements.draw

elements.draw (surface, addtext=True)
  • Draw All Shapes, and removes the ones outside
  • Parameter: surface == pygame.Surface()
  • Optional: addtext == True/False (if True, also add Info-Text to surface)
  • Returns: -


elements.draw_shape

elements.draw_shape (surface, shape)
  • Draw a shape (can be either Circle, Segment or Poly).
  • Parameter: surface == pygame.Surface(), shape == pymunk.Shape()
  • Returns: True if shape is inside screen, else False (for removal)


elements.add_wall

elements.add_wall (p1, p2, friction=1.0, elasticity=0.1, mass=inf, inertia=inf)
  • Adds a fixed Wall pos = (int(x), int(y))
  • Parameter: p1 == pos(startpoint), p2 == pos(endpoint)
  • Optional: See #physical_parameters
  • Returns: pymunk.Shape() (=> .Segment())


elements.add_ball

elements.add_ball (pos, radius=15, density=0.1, inertia=1000, friction=0.5, elasticity=0.3)
  • Adds a Ball
  • Parameter: pos == (int(x), int(y))
  • Optional: See #physical_parameters
  • Returns: pymunk.Shape() (=> .Circle())


elements.add_square

elements.add_square (pos, a=18, density=0.1, friction=0.2, elasticity=0.3)
  • Adding a Square | Note that a is actually half a side, due to vector easyness :)
  • Parameter: pos == (int(x), int(y))
  • Optional: a == (sidelen/2) | #physical_parameters
  • Returns: pymunk.Shape() (=> .Poly())


elements.add_poly

elements.add_poly (points, density=0.1, friction=2.0, elasticity=0.3)
  • Mass will be calculated out of mass = A * density
  • Parameter: points == [(int(x), int(y)), (int(x), int(y)), ...]
  • Optional: See #physical_parameters
  • Returns: pymunk.Shape() (=> .Poly())


elements.apply_impulse

elements.apply_impulse (shape, impulse_vector)
  • Apply an Impulse to a given Shape
  • Parameter: shape == pymunk.Shape(), impulse_vector == (int(x), int(y))
  • Returns: -


elements.get_element_count

elements.get_element_count ()
  • Get the current (approx.) element count
  • Returns: int(element_count)
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