/** The SkeletonData to look up animations when they are specified by name. */

skeletonData: SkeletonData;

animationToMixTime: StringMap<number> = {};

/** The mix duration to use when no mix duration has been defined between two animations. */

defaultMix = 0;

constructor (skeletonData: SkeletonData) {

if (!skeletonData) throw new Error("skeletonData cannot be null.");

this.skeletonData = skeletonData;

}

/** Sets a mix duration by animation name.

*

* See {@link #setMixWith()}. */

setMix (fromName: string, toName: string, duration: number) {

let from = this.skeletonData.findAnimation(fromName);

if (!from) throw new Error("Animation not found: " + fromName);

let to = this.skeletonData.findAnimation(toName);

if (!to) throw new Error("Animation not found: " + toName);

this.setMixWith(from, to, duration);

}

/** Sets the mix duration when changing from the specified animation to the other.

*

* See {@link TrackEntry#mixDuration}. */

setMixWith (from: Animation, to: Animation, duration: number) {

if (!from) throw new Error("from cannot be null.");

if (!to) throw new Error("to cannot be null.");

let key = from.name + "." + to.name;

this.animationToMixTime[key] = duration;

}

/** Returns the mix duration to use when changing from the specified animation to the other, or the {@link #defaultMix} if

* no mix duration has been set. */

getMix (from: Animation, to: Animation) {

let key = from.name + "." + to.name;

let value = this.animationToMixTime[key];

return value === undefined ? this.defaultMix : value;

}