# CLerpInterval

from pandac.PandaModules import CLerpInterval

Class : CLerpInterval
Description : The base class for a family of intervals that linearly interpolate one or more numeric values over time.

## Inheritance:

CLerpInterval: CInterval
CInterval: TypedReferenceCount
TypedReferenceCount: TypedObject ReferenceCount
TypedObject: MemoryBase
MemoryBase:
ReferenceCount: MemoryBase

## Methods of CLerpInterval:

getBlendType
getClassType
stringBlendType

## Methods of CInterval:

clearToInitial
finish
getAutoFinish
getAutoPause
getClassType
getDoneEvent
getDuration
getManager
getName
getOpenEnded
getPlayRate
getState
getT
getWantsTCallback
isPlaying
isStopped
loop
output
pause
privDoEvent
privFinalize
privInitialize
privInstant
privInterrupt
privReverseFinalize
privReverseInitialize
privReverseInstant
privStep
resume
resumeUntil
setAutoFinish
setAutoPause
setDoneEvent
setManager
setPlayRate
setT
setupPlay
setupResume
setupResumeUntil
setWantsTCallback
start
stepPlay
write

## Methods of TypedReferenceCount:

getClassType

## Methods of TypedObject:

getClassType
getType
getTypeIndex
isExactType
isOfType

## Methods of ReferenceCount:

getClassType
getRefCount
ref
testRefCountIntegrity
testRefCountNonzero
unref

## Constants in CLerpInterval:

BTNoBlend | (BlendType)
BTEaseIn | (BlendType)
BTEaseOut | (BlendType)
BTEaseInOut | (BlendType)
BTInvalid | (BlendType)

## Constants in CInterval:

ETInitialize | (EventType)
ETInstant | (EventType)
ETStep | (EventType)
ETFinalize | (EventType)
ETReverseInitialize | (EventType)
ETReverseInstant | (EventType)
ETReverseFinalize | (EventType)
ETInterrupt | (EventType)
SInitial | (State)
SStarted | (State)
SPaused | (State)
SFinal | (State)

getBlendType CLerpInterval::BlendType CLerpInterval::get_blend_type(void) const; Description: Returns the blend type specified for the interval. This controls how the linear interpolation behaves near the beginning and end of the lerp period.

getClassType static TypeHandle CLerpInterval::get_class_type(void); Undocumented function.

stringBlendType static CLerpInterval::BlendType CLerpInterval::string_blend_type(string const &blend_type); Description: Returns the BlendType enumerated value corresponding to the indicated string, or BT_invalid if the string doesn't match anything.

clearToInitial void CInterval::clear_to_initial(void); Description: Pauses the interval, if it is playing, and resets its state to its initial state, abandoning any state changes already in progress in the middle of the interval. Calling this is like pausing the interval and discarding it, creating a new one in its place.

finish void CInterval::finish(void); Description: Stops the interval from playing and sets it to its final state.

getAutoFinish bool CInterval::get_auto_finish(void) const; Description: Returns the state of the 'auto_finish' flag. See set_auto_finish().

getAutoPause bool CInterval::get_auto_pause(void) const; Description: Returns the state of the 'auto_pause' flag. See set_auto_pause().

getClassType static TypeHandle CInterval::get_class_type(void); Undocumented function.

getDoneEvent string const &CInterval::get_done_event(void) const; Description: Returns the event that is generated whenever the interval reaches its final state, whether it is explicitly finished or whether it gets there on its own.

getDuration double CInterval::get_duration(void) const; Description: Returns the duration of the interval in seconds.

getManager CIntervalManager *CInterval::get_manager(void) const; Description: Returns the CIntervalManager object which will be responsible for playing this interval. Note that this can only return a C++ object; if the particular CIntervalManager object has been extended in the scripting language, this will return the encapsulated C++ object, not the full extended object.

getName string const &CInterval::get_name(void) const; Filename: cInterval.I Created by: drose (27Aug02) PANDA 3D SOFTWARE Copyright (c) 2001 - 2004, Disney Enterprises, Inc. All rights reserved All use of this software is subject to the terms of the Panda 3d Software license. You should have received a copy of this license along with this source code; you will also find a current copy of the license at http://etc.cmu.edu/panda3d/docs/license/ . To contact the maintainers of this program write to panda3d-general@lists.sourceforge.net . Description: Returns the interval's name.

getOpenEnded bool CInterval::get_open_ended(void) const; Description: Returns the state of the "open_ended" flag. This is primarily intended for instantaneous intervals like FunctionIntervals; it indicates true if the interval has some lasting effect that should be applied even if the interval doesn't get started until after its finish time, or false if the interval is a transitive thing that doesn't need to be called late.

getPlayRate double CInterval::get_play_rate(void) const; Description: Returns the play rate as set by the last call to start(), loop(), or set_play_rate().

getState CInterval::State CInterval::get_state(void) const; Description: Indicates the state the interval believes it is in: whether it has been started, is currently in the middle, or has been finalized.

getT double CInterval::get_t(void) const; Description: Returns the current time of the interval: the last value of t passed to priv_initialize(), priv_step(), or priv_finalize().

getWantsTCallback bool CInterval::get_wants_t_callback(void) const; Description: Returns the state of the 'wants_t_callback' flag. See set_wants_t_callback().

isPlaying bool CInterval::is_playing(void) const; Description: Returns true if the interval is currently playing, false otherwise.

isStopped bool CInterval::is_stopped(void) const; Description: Returns true if the interval is in either its initial or final states (but not in a running or paused state).

loop void CInterval::loop(double start_t = (0), double end_t = (-1), double play_rate = (1)); Description: Starts the interval playing by registering it with the current CIntervalManager. The interval will play until it is interrupted with finish() or pause(), looping back to start_t when it reaches end_t. If end_t is less than zero, it indicates the end of the interval.

output virtual void CInterval::output(ostream &out) const; Description:

pause double CInterval::pause(void); Description: Stops the interval from playing but leaves it in its current state. It may later be resumed from this point by calling resume().

privDoEvent void CInterval::priv_do_event(double t, CInterval::EventType event); These functions control the actual playback of the interval. Don't call them directly; they're intended to be called from a supervising object, e.g. the Python start() .. finish() interface. These cannot be declared private because they must be accessible to Python, but the method names are prefixed with priv_ to remind you that you probably don't want to be using them directly. Description: Calls the appropriate event function indicated by the EventType.

privFinalize virtual void CInterval::priv_finalize(void); Description: This is called to stop an interval, forcing it to whatever state it would be after it played all the way through. It's generally invoked by set_final_t().

privInitialize virtual void CInterval::priv_initialize(double t); These functions control the actual playback of the interval. Don't call them directly; they're intended to be called from a supervising object, e.g. the Python start() .. finish() interface. These cannot be declared private because they must be accessible to Python, but the method names are prefixed with priv_ to remind you that you probably don't want to be using them directly. Description: This replaces the first call to priv_step(), and indicates that the interval has just begun. This may be overridden by derived classes that need to do some explicit initialization on the first call.

privInstant virtual void CInterval::priv_instant(void); Description: This is called in lieu of priv_initialize() .. priv_step() .. priv_finalize(), when everything is to happen within one frame. The interval should initialize itself, then leave itself in the final state.

privInterrupt virtual void CInterval::priv_interrupt(void); Description: This is called while the interval is playing to indicate that it is about to be interrupted; that is, priv_step() will not be called for a length of time. But the interval should remain in its current state in anticipation of being eventually restarted when the calls to priv_step() eventually resume. The purpose of this function is to allow self-running intervals like sound intervals to stop the actual sound playback during the pause.

privReverseFinalize virtual void CInterval::priv_reverse_finalize(void); Description: Called generally following a priv_reverse_initialize(), this indicates the interval should set itself to the initial state.

privReverseInitialize virtual void CInterval::priv_reverse_initialize(double t); Description: Similar to priv_initialize(), but this is called when the interval is being played backwards; it indicates that the interval should start at the finishing state and undo any intervening intervals.

privReverseInstant virtual void CInterval::priv_reverse_instant(void); Description: This is called in lieu of priv_reverse_initialize() .. priv_step() .. priv_reverse_finalize(), when everything is to happen within one frame. The interval should initialize itself, then leave itself in the initial state.

privStep virtual void CInterval::priv_step(double t); Description: Advances the time on the interval. The time may either increase (the normal case) or decrease (e.g. if the interval is being played by a slider).

resume void CInterval::resume(void); Description: Restarts the interval from its current point after a previous call to pause(). Description: Restarts the interval from the indicated point after a previous call to pause().

resumeUntil void CInterval::resume_until(double end_t); Description: Restarts the interval from the current point after a previous call to pause() (or a previous play-to-point-and-stop), to play until the indicated point and then stop.

setAutoFinish void CInterval::set_auto_finish(bool auto_finish); Description: Changes the state of the 'auto_finish' flag. If this is true, the interval may be arbitrarily finished when the system needs to reset due to some external event by calling CIntervalManager::interrupt(). If this is false (the default), the interval must always be explicitly finished or paused.

setAutoPause void CInterval::set_auto_pause(bool auto_pause); Description: Changes the state of the 'auto_pause' flag. If this is true, the interval may be arbitrarily interrupted when the system needs to reset due to some external event by calling CIntervalManager::interrupt(). If this is false (the default), the interval must always be explicitly finished or paused.

setDoneEvent void CInterval::set_done_event(string const &event); Description: Sets the event that is generated whenever the interval reaches its final state, whether it is explicitly finished or whether it gets there on its own.

setManager void CInterval::set_manager(CIntervalManager *manager); Description: Indicates the CIntervalManager object which will be responsible for playing this interval. This defaults to the global CIntervalManager; you should need to change this only if you have special requirements for playing this interval.

setPlayRate void CInterval::set_play_rate(double play_rate); Description: Changes the play rate of the interval. If the interval is already started, this changes its speed on-the-fly. Note that since play_rate is a parameter to start() and loop(), the next call to start() or loop() will reset this parameter.

setT void CInterval::set_t(double t); Description: Explicitly sets the time within the interval. Normally, you would use start() .. finish() to let the time play normally, but this may be used to set the time to some particular value.

setupPlay void CInterval::setup_play(double start_time, double end_time, double play_rate, bool do_loop); Description: Called to prepare the interval for automatic timed playback, e.g. via a Python task. The interval will be played from start_t to end_t, at a time factor specified by play_rate. start_t must always be less than end_t (except for the exception for end_t == -1, below), but if play_rate is negative the interval will be played backwards. Specify end_t of -1 to play the entire interval from start_t. Call step_play() repeatedly to execute the interval.

setupResume void CInterval::setup_resume(void); Description: Called to prepare the interval for restarting at the current point within the interval after an interruption.

setupResumeUntil void CInterval::setup_resume_until(double end_t); Description: Called to prepare the interval for restarting from the current point after a previous call to pause() (or a previous play-to-point-and-stop), to play until the indicated point and then stop.

setWantsTCallback void CInterval::set_wants_t_callback(bool wants_t_callback); Description: Changes the state of the 'wants_t_callback' flag. If this is true, the interval will be returned by CIntervalManager::get_event() each time the interval's time value has been changed, regardless of whether it has any external events.

start void CInterval::start(double start_t = (0), double end_t = (-1), double play_rate = (1)); Description: Starts the interval playing by registering it with the current CIntervalManager. The interval will play to the end and stop. If end_t is less than zero, it indicates the end of the interval.

stepPlay bool CInterval::step_play(void); Description: Should be called once per frame to execute the automatic timed playback begun with setup_play(). Returns true if the interval should continue, false if it is done and should stop.

write virtual void CInterval::write(ostream &out, int indent_level) const; Description:

getClassType static TypeHandle TypedReferenceCount::get_class_type(void); Undocumented function.

getClassType static TypeHandle TypedObject::get_class_type(void); Undocumented function.

getType virtual TypeHandle TypedObject::get_type(void) const = 0; Derived classes should override this function to return get_class_type().

getTypeIndex int TypedObject::get_type_index(void) const; Description: Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. This is equivalent to get_type().get_index().

isExactType bool TypedObject::is_exact_type(TypeHandle handle) const; Description: Returns true if the current object is the indicated type exactly.

isOfType bool TypedObject::is_of_type(TypeHandle handle) const; Description: Returns true if the current object is or derives from the indicated type.

getClassType static TypeHandle ReferenceCount::get_class_type(void); Undocumented function.

getRefCount int ReferenceCount::get_ref_count(void) const; Description: Returns the current reference count.

ref void ReferenceCount::ref(void) const; Description: Explicitly increments the reference count. User code should avoid using ref() and unref() directly, which can result in missed reference counts. Instead, let a PointerTo object manage the reference counting automatically. This function is const, even though it changes the object, because generally fiddling with an object's reference count isn't considered part of fiddling with the object. An object might be const in other ways, but we still need to accurately count the number of references to it.

testRefCountIntegrity bool ReferenceCount::test_ref_count_integrity(void) const; Description: Does some easy checks to make sure that the reference count isn't completely bogus. Returns true if ok, false otherwise.

testRefCountNonzero bool ReferenceCount::test_ref_count_nonzero(void) const; Description: Does some easy checks to make sure that the reference count isn't zero, or completely bogus. Returns true if ok, false otherwise.

unref bool ReferenceCount::unref(void) const; Description: Explicitly decrements the reference count. Note that the object will not be implicitly deleted by unref() simply because the reference count drops to zero. (Having a member function delete itself is problematic; plus, we don't have a virtual destructor anyway.) However, see the helper function unref_delete(). User code should avoid using ref() and unref() directly, which can result in missed reference counts. Instead, let a PointerTo object manage the reference counting automatically. This function is const, even though it changes the object, because generally fiddling with an object's reference count isn't considered part of fiddling with the object. An object might be const in other ways, but we still need to accurately count the number of references to it. The return value is true if the new reference count is nonzero, false if it is zero.