cocos.cocosnode module¶
CocosNode: the basic element of cocos2d
-
class
CocosNode
¶ Bases:
object
Cocosnode is the main element. Anything that gets drawn or contains things that gets drawn is a
CocosNode
. The most popularCocosNode
arecocos.scene.Scene
,cocos.layer.base_layers.Layer
andcocos.sprite.Sprite
.- The main features of a
CocosNode
are: - They can contain other
CocosNode
(add()
,get()
,remove()
, etc) - They can schedule periodic callback (
schedule()
,schedule_interval()
, etc) - They can execute actions (
do()
,pause()
,stop()
, etc)
- They can contain other
Some
CocosNode
provide extra functionality for them or their children.- Subclassing a
CocosNode
usually means (one/all) of: - overriding
__init__
to initialize resources and schedule callbacks - create callbacks to handle the advancement of time
- overriding
draw()
to render the node
- overriding
-
add
(child, z=0, name=None)¶ Adds a child and if it becomes part of the active scene, it calls its
on_enter()
method.Parameters: - child (CocosNode) – object to be added
- z (Optional[float]) – the child z index. Defaults to 0.
- name (Optional[str]) – Name of the child. Defaults to
None
Returns: CocosNode – self
-
are_actions_running
()¶ Determine whether any actions are running.
-
do
(action, target=None)¶ Executes an
Action
. When the action is finished, it will be removed from the node’s actions container.To remove an action you must use the
do()
return value to callremove_action()
.Parameters: action (Action) – Action that will be executed. Returns: Action – A clone of action
-
draw
(*args, **kwargs)¶ This is the function you will have to override if you want your subclassed
CocosNode
to draw something on screen.You must respect the position, scale, rotation and anchor attributes. If you want OpenGL to do the scaling for you, you can:
def draw(self): glPushMatrix() self.transform() # ... draw .. glPopMatrix()
-
get
(name)¶ Gets a child given its name.
Parameters: name (str) – name of the reference to retrieve. Returns: CocosNode – The child named ‘name’. Will raise an Exception
if not present.Warning
If a node is added with name, then removing it differently than by name will prevent the name to be recycled: attempting to add another node with this name will produce an Exception.
-
get_ancestor
(klass)¶ Walks the nodes tree upwards until it finds a node of the class
klass
or returns None.Returns: CocosNode or None
-
get_children
()¶ Return a list with the node’s children, order is back to front.
Returns: list[CocosNode] – children of this node, ordered back to front.
-
get_local_inverse
()¶ Returns an
euclid.Matrix3
with the local inverse transformation matrix.Returns: euclid.Matrix3
-
get_local_transform
()¶ Returns an
euclid.Matrix3
with the local transformation matrixReturns: euclid.Matrix3
-
get_world_inverse
()¶ returns an
euclid.Matrix3
with the world inverse transformation matrix.Returns: euclid.Matrix3
-
get_world_transform
()¶ Returns an
euclid.Matrix3
with the world transformation matrixReturns: euclid.Matrix3
-
kill
()¶ Remove this object from its parent, and thus most likely from everything.
-
on_enter
()¶ Called every time just before the node enters the stage.
Scheduled calls and worker actions begin or continue to perform.
Good point to do
push_handlers()
if you have custom onesNote
A handler pushed there is near certain to require a
pop_handlers()
in theon_exit()
method (else it will be called even after being removed from the active scene, or if going on stage again it will be called multiple times for each event ocurrences).
-
on_exit
()¶ Called every time just before the node leaves the stage.
Scheduled calls and worker actions are suspended, that is, they will not be called until an
on_enter()
event happens.Most of the time you will want to
pop_handlers()
for all explicitpush_handlers()
found in meth:on_enter.Consider to release here openGL resources created by this node, like compiled vertex lists.
-
pause
()¶ Suspends the execution of actions.
-
pause_scheduler
()¶ Time will stop for this node: scheduled callbacks will not be called, worker actions will not be called.
-
point_to_local
(p)¶ returns an
euclid.Vector2
converted to local space.Parameters: p (Vector2) – Vector to convert. Returns: Vector2 – p
vector converted to local coordinates.
-
point_to_world
(p)¶ Returns an
euclid.Vector2
converted to world space.Parameters: p (Vector2) – Vector to convert Returns: Vector2 – p
vector converted to world coordinates.
-
remove
(obj)¶ Removes a child given its name or object
If the node was added with name, it is better to remove by name, else the name will be unavailable for further adds (and will raise an Exception if add with this same name is attempted)
If the node was part of the active scene, its
on_exit()
method will be called.Parameters: obj (str or object) – Name of the reference to be removed or object to be removed.
-
remove_action
(action)¶ Removes an action from the node actions container, potentially calling
action.stop()
.If action was running,
Action.stop()
is called. Mandatory interface to remove actions in the node actions container. When skipping this there is the posibility to double call theaction.stop
Parameters: action (Action) – Action to be removed. Must be the return value for a do()
call
-
resume
()¶ Resumes the execution of actions.
-
resume_scheduler
()¶ Time will continue/start passing for this node and callbacks will be called, worker actions will be called.
-
schedule
(callback, *args, **kwargs)¶ Schedule a function to be called every frame.
The function should have a prototype that includes
dt
as the first argument, which gives the elapsed time, in seconds, since the last clock tick. Any additional arguments given to this function are passed on to the callback:def callback(dt, *args, **kwargs): pass
This function is a wrapper to
pyglet.clock.schedule
. It has the additional benefit that all calllbacks are paused and resumed when the node leaves or enters a scene.You should not have to schedule things using pyglet by yourself.
Parameters: - callback (a function) – The function to call each frame.
- *args – Variable length argument list passed to the
callback
. - **kwargs – Arbitrary keyword arguments passed to the
callback
.
-
schedule_interval
(callback, interval, *args, **kwargs)¶ Schedule a function to be called every
interval
seconds.Specifying an interval of 0 prevents the function from being called again (see
schedule()
to call a function as often as possible).The callback function prototype is the same as for
schedule()
.This function is a wrapper to
pyglet.clock.schedule_interval
. It has the additional benefit that all calllbacks are paused and resumed when the node leaves or enters a scene.You should not have to schedule things using pyglet by yourself.
Parameters: - callback (a function) – The function to call when the timer elapsed.
- interval (float) – The number of seconds to wait between each call.
- *args – Variable length argument list passed to the
callback
. - **kwargs – Arbitrary keyword arguments passed to the
callback
.
-
stop
()¶ Removes all actions from the running action list.
For each action running, the stop method will be called, and the action will be removed from the actions container.
-
transform
()¶ Apply ModelView transformations.
You will most likely want to wrap calls to this function with
glPushMatrix()
/glPopMatrix()
-
unschedule
(callback)¶ Remove a function from the schedule.
If the function appears in the schedule more than once, all occurances are removed. If the function was not scheduled, no error is raised.
This function is a wrapper to pyglet.clock.unschedule. It has the additional benefit that all calllbacks are paused and resumed when the node leaves or enters a scene.
You should not unschedule things using pyglet that where scheduled by
schedule()
/schedule_interval()
.Parameters: callback (a function) – The function to remove from the schedule.
-
visit
()¶ This function visits its children in a recursive way.
It will first visit the children that that have a z-order value less than 0.
Then it will call the
draw()
method to draw itself.And finally it will visit the rest of the children (the ones with a z-value bigger or equal than 0)
Before visiting any children it will call the
transform()
method to apply any possible transformations.
-
walk
(callback, collect=None)¶ Executes callback on all the subtree starting at self. returns a list of all return values that are not
None
.Parameters: - callback (a function) – Callable that takes a
CocosNode
as an argument. - collect (list) – List of non-None returned values from visited nodes.
Returns: list – The list of non-None return values.
- callback (a function) – Callable that takes a
-
actions
= None¶ list of Action objects that are running
-
anchor
¶ Anchor point of the object. Alias for
transform_anchor
Children will be added at this point and transformations like scaling and rotation will use this point as the center.
-
anchor_x
¶ Anchor x value for transformations and adding children. Alias for
transform_anchor_x
-
anchor_y
¶ Anchor y value for transformations and adding children. Alias for
transform_anchor_y
-
camera
= None¶ eye, center and up vector for the
Camera
. gluLookAt() is used with these values. Default: FOV 60, center of the screen.Note
The camera can perform exactly the same transformation as
scale
,rotation
and thex
,y
attributes (with the exception that the camera can modify also the z-coordinate) In fact, they all transform the same matrix, so use either the camera or the other attributes, but not both since the camera will be overridden by the transformations done by the other attributes.You can change the camera manually or by using the
Camera3DAction
action.
-
children
= None¶ list of (int, child-reference) where int is the z-order, sorted by ascending z (back to front order)
-
children_names
= None¶ dictionary that maps children names with children references
-
grid
= None¶ the grid object for the grid actions. This can be a Grid3D or a TiledGrid3D object depending on the action.
-
is_running
= None¶ whether of not the object is running
-
parent
¶ The parent of this object.
Returns: CocosNode or None
-
position
¶ The (x, y) coordinates of the object.
Type: tuple[int, int]
-
rotation
¶ The rotation of this object in degrees. Defaults to 0.0.
Type: float
-
scale
¶ The scaling factor of the object.
Type: float
-
scale_x
¶ The scale x of this object.
Type: float
-
scale_y
¶ The scale y of this object.
Type: float
-
scheduled_calls
= None¶ list of scheduled callbacks
-
scheduled_interval_calls
= None¶ list of scheduled interval callbacks
-
skip_frame
= None¶ whether or not the next frame will be skipped
-
to_remove
= None¶ list of Action objects to be removed
-
transform_anchor
¶ Transformation anchor point. Children will be added at this point and transformations like scaling and rotation will use this point as its center.
-
transform_anchor_x
= None¶ offset from (x,0) from where rotation and scale will be applied. Default: 0
-
transform_anchor_y
= None¶ offset from (0,y) from where rotation and scale will be applied. Default: 0
-
visible
= None¶ whether of not the object and his childrens are visible. Default: True
-
x
¶ The x coordinate of the CocosNode
-
y
¶ The y coordinate of the CocosNode
- The main features of a