cocos.particle module

Particle system engine

exception ExceptionNoEmptyParticle

Bases: Exception

Particle system has no room for another particle.

class Color(r, g, b, a)

Bases: object

Representation of a rgba color

Parameters

  • r (float) – red component

  • g (float) – green component

  • b (float) – blue component

  • a (float) – alpha component

to_array()

Convert Color to a tuple.

Returns

tuple – r, g, b and a components.

class ParticleSystem(fallback=None, texture=None)

Bases: cocos.cocosnode.CocosNode

Base class for many flavors of cocos particle systems.

The easiest way to customize is to subclass and redefine some class attributes; see cocos.particle_systems for examples.

To define a per-class custom texture, override load_texture(). To use a per-instance custom texture, pass it in the __init__ texture kw-param

Parameters

  • fallback (Optional[None, True, False]) –

    Defaults to None.

    • False: use point sprites, faster, not always available

    • True: use quads, slower but always available

    • None: autodetect, use the fastest available

  • texture (Optional[pyglet.image.Texture]) – The texture image to be used for the particles.

add_particle()
Code calling add_particle must either:

It is acceptable to try: ... except...: pass

draw()

Draw the particles system

draw_fallback()

Called instead of draw() when quads are used instead of Point Sprite.

init_particle()

Set initial particles state.

load_texture()

Sets the default texture used by all instances of this particles system.

Override this method to change the default texture.

Note

By issue #168 the texture should hold only one image, so don’t use:

texture = pyglet.resource.image('z.png').texture # (produces an atlas, ie multiple images in a texture)

You can use instead:

texture = pyglet.image.load(...).get_texture()
# Or using pyglet resource mechanism
texture = pyglet.image.load('filename.png', file=pyglet.resource.file('filename.png')).get_texture()
make_delta_pos_to_vertex()

Helper function creating quad vertices based on particles position.

on_cocos_resize(usable_width, usable_height)

Handler for windows resize.

Parameters

  • usable_width (int) – New window width.

  • usable_height (int) – New window height.

on_enter()

Called everytime the Particle system enters the stage.

on_exit()

Called everytime the Particle system exits the stage.

reset_system()

Resets the particle system.

step(delta)

Called every frame to create new particles if needed and update the particles position.

If a duration was given to this particle system, the method will check if it needs to remove itself from its parent node when its time has arrived.

Parameters

delta (float) – time in seconds since last frame.

stop_system()

Stop the particle system.

update_particles(delta)

Updates particles position.

Parameters

delta (float) – time in seconds since last frame.

update_per_vertex_colors()

Helper function to update particle quad colors based on particle color.

update_vertexs_from_pos()

Helper function to update particle quad vertices based on particle position.

POSITION_FREE = 0

type of particle

POSITION_GROUPED = 1

type of particle

active = True

is the particle system active ?

angle = 0.0

The angle (direction) of the particles measured in degrees

angle_var = 0.0

Angle variance measured in degrees

blend_additive = False

blend additive

color_modulate = True

color modulate

duration = 0

duration in seconds of the system. -1 is infinity

elapsed = 0

time elapsed since the start of the system (in seconds)

emit_counter

How many particles can be emitted per second

end_color = Color(0.00, 0.00, 0.00, 0.00)

End color of the particles

end_color_var = Color(0.00, 0.00, 0.00, 0.00)

End color variance

gravity = Point2(0.00, 0.00)

Gravity of the particles

life = 0

How many seconds will the particle live

life_var = 0

Life variance

particle_count

Count of particles

pos_var = Point2(0.00, 0.00)

Position variance

position_type = 1

position type. Defaults to POSITION_GROUPED

radial_accel = 0.0

Radial acceleration in degrees per second

radial_accel_var = 0.0

Radial acceleration variance

property scale

The scaling factor of the object.

Type

float

size = 0.0

Size of the particles

size_var = 0.0

Size variance

speed = 0.0

The speed the particles will have.

speed_var = 0.0

The speed variance

start_color = Color(0.00, 0.00, 0.00, 0.00)

Start color of the particles

start_color_var = Color(0.00, 0.00, 0.00, 0.00)

Start color variance

tangential_accel = 0.0

Tangential acceleration

tangential_accel_var = 0.0

Tangential acceleration variance

texture = None

texture for the particles, will be loaded in __init__ because Intel weakness, #235. Either override the load_texture() method in a subclass to define a common texture for all particles system of this class, or provide a texture argument to the __init__ method to define a custom texture for that instance.

total_particles = 0

Maximum particles

PointerToNumpy(a, ptype=ctypes.c_float)

Provides a ctype pointer to a Numpy array.

Parameters

  • a (numpy.array) – The Numpy array.

  • ptype (ctypes) – The ctypes type contained in the array.

Returns

Pointer to the Numpy array.

point_sprites_available()
Returns

bool – tells if point sprites are available.

For development and diagonostic cocos.particle.forced_point_sprites could be set to force the desired return value.

rand()

Function generating a random float beween -1.0 and 1.0.