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A CCurve represents an animation curve that stores and interpolates animation keys. A CCurve is stored in a CTrack 对象。

CCurve objects are an instance of CSbase .

// This code loops through all tracks and all keys of the given object.

CTrack * track = activeObject-> GetFirstCTrack ();

while (track != nullptr ) { CCurve * const curve = track-> GetCurve (); if (curve == nullptr ) continue ; const Int32 keyCount = curve-> GetKeyCount (); for ( Int32 i = 0; i < keyCount; ++i) { CKey * const key = curve-> GetKey (i); if (key) { // do something with the key ApplicationOutput ( "Found a key!" ); } } track = track-> GetNext (); }

Access

CCurve objects cannot be created on their own. They are created with a CTrack that contains the CCurve 对象。

CTrack::GetCurve() ：返回 CCurve object stored with a CTrack . See example above.
CCurve::GetTrack() ：返回 CTrack that stores the CCurve .

键

Access Keys

The CCurve objects stores the animation keys and provides access to these:

CCurve::GetKeyCount() : Returns the number of keys.
CCurve::GetKey() ：返回 CKey at the given index.
CCurve::FindKey() : Returns the (next) CKey at the given time.
- FINDANIM::EXACT : Searches for a CKey at the exact given time.
- FINDANIM::LEFT : Searches for a CKey on the left side of the given time.
- FINDANIM::RIGHT : Searches for a CKey on the right side of the given time.

// This example searches for a key left from the given time. const BaseTime time = doc-> GetTime (); CKey * const leftKey = curve-> FindKey (time, nullptr , FINDANIM::LEFT ); if (leftKey) { // move this key to the current time leftKey-> SetTime (curve, time); }

Add Keys

A CCurve object can create and receive keys:

CCurve::AddKey() : Adds a new key to the CCurve .
CCurve::AddKeyAdaptTangent() : Adds a new key to the CCurve but retains the curve's current curvature.
CCurve::InsertKey() : Inserts a key into the CCurve 。 CCurve takes ownership.

// This example creates keys along the timeline. const Int32 fps = doc-> GetFps (); const Int32 min = doc-> GetMinTime (). GetFrame (fps); const Int32 max = doc-> GetMaxTime (). GetFrame (fps); const Int32 range = max - min; const Int32 step = range / 10; const BaseTime stepTime = BaseTime (step, fps); BaseTime keyTime = doc-> GetMinTime (); for ( Int32 i = 0; i <= 10; ++i) { if (curve-> AddKey (keyTime, nullptr ) == nullptr ) return maxon::OutOfMemoryError( MAXON_SOURCE_LOCATION ); keyTime = keyTime + stepTime; }

另请参阅 CKey Allocation/Deallocation .

Handle Keys

A CCurve object can be used to manipulate its keys:

CCurve::DelKey() : Deletes the key at the given index.
CCurve::MoveKey() : Moves the key at the given index.
CCurve::FlushKeys() : Removes all keys from the curve.
CCurve::SetKeyDirty() : Sets the key dirty.
CCurve::SetKeyDefault() : Sets the default settings for the key at the given index.

// This example creates a new key and sets the default values. Int32 index; CKey * const newKey = curve-> AddKey (time, &index); if (newKey == nullptr ) return maxon::OutOfMemoryError( MAXON_SOURCE_LOCATION ); track-> FillKey (doc, obj, newKey); curve-> SetKeyDefault (doc, index);

Unmuted Keys

A key can be muted so it is ignored.

CCurve::FindNextUnmuted() : Returns the next unmuted key searching from the given index.
CCurve::FindPrevUnmuted() : Returns the previous unmuted key searching from the given index.

// This example searches for the first unmuted key. const CKey * const key = curve-> FindNextUnmuted (0); if (key) { const Float time = key-> GetTime (). Get (); ApplicationOutput ( "Found unmuted key at " + String::FloatToString (time)); }

另请参阅 CKey Bits .

动画

The interpolation between the keys defines the dynamics of an animation. This interpolation is refined with the tangents.

CCurve::CalcHermite() : Calculates the Hermite spline between two sets of key values.
CCurve::CalcSoftTangents() : Calculates the soft tangents (i.e. auto interpolation) around the key of the given index.
CCurve::GetTangents() : Computes the tangents of a key, taking into account all options like zero slope, link slope etc.
CCurve::GetValue() : Returns the value calculated at the given time, taking into account things like time curves.

// This example samples the curve. BaseTime time(0.0); const BaseTime step(0.1); for ( Int32 i = 0; i < 10; ++i) { const Float value = curve-> GetValue (time); ApplicationOutput ( "Value: " + String::FloatToString (value)); time = time + step; }

时间

A CCurve is confined by a first and a last key:

CCurve::GetStartTime() : Returns the start time of the curve.
CCurve::GetEndTime() : Returns the end time of the curve.

// This example sets the loop time dimensions based on the start // and end time of the given curve. const BaseTime start = curve-> GetStartTime (); const BaseTime end = curve-> GetEndTime (); doc-> SetLoopMinTime (start); doc-> SetLoopMaxTime ( end );