Elements/Chipmunk/Documentation

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)