mami/src/mami.js/animate.js

135 lines
3.5 KiB
JavaScript

#include easings.js
// This probably need a bit of a rewrite at some point to allow starting for arbitrary time points
const MamiAnimate = info => {
if(typeof info !== 'object')
throw 'info must be an object';
let onUpdate;
if('update' in info && typeof info.update === 'function')
onUpdate = info.update;
if(onUpdate === undefined)
throw 'update is a required parameter for info';
let duration;
if('duration' in info)
duration = parseFloat(info.duration);
if(duration <= 0)
throw 'duration is a required parameter for info and must be greater than 0';
let onStart;
if('start' in info && typeof info.start === 'function')
onStart = info.start;
let onEnd;
if('end' in info && typeof info.end === 'function')
onEnd = info.end;
let onCancel;
if('cancel' in info && typeof info.cancel === 'function')
onCancel = info.cancel;
let easing;
if('easing' in info)
easing = info.easing;
let delayed;
if('delayed' in info)
delayed = !!info.delayed;
let async;
if('async' in info)
async = !!info.async;
const easingType = typeof easing;
if(easingType !== 'function') {
if(easingType === 'string' && easing in MamiEasings)
easing = MamiEasings[easing];
else
easing = MamiEasings.linear;
}
let tStart, tLast,
cancel = false,
tRawCompletion = 0,
tCompletion = 0,
started = !delayed;
const update = tCurrent => {
if(tStart === undefined) {
tStart = tCurrent;
if(onStart !== undefined)
onStart();
}
const tElapsed = tCurrent - tStart;
tRawCompletion = Math.min(1, Math.max(0, tElapsed / duration));
tCompletion = easing(tRawCompletion);
onUpdate(tCompletion, tRawCompletion);
if(tElapsed < duration) {
if(cancel) {
if(onCancel !== undefined)
onCancel(tCompletion, tRawCompletion);
return;
}
tLast = tCurrent;
requestAnimationFrame(update);
} else if(onEnd !== undefined)
onEnd();
};
let promise;
if(async)
promise = new Promise((resolve, reject) => {
if(onCancel === undefined) {
onCancel = reject;
} else {
const realOnCancel = onCancel;
onCancel = (...args) => {
realOnCancel(...args);
reject(...args);
};
}
if(onEnd === undefined) {
onEnd = resolve;
} else {
const realOnEnd = onEnd;
onEnd = (...args) => {
realOnEnd(...args);
resolve(...args);
};
}
if(!delayed)
requestAnimationFrame(update);
});
if(!delayed) {
if(promise !== undefined)
return promise;
requestAnimationFrame(update);
}
return {
getCompletion: () => tCompletion,
getRawCompletion: () => tRawCompletion,
start: () => {
if(!started) {
started = true;
requestAnimationFrame(update);
}
if(promise !== undefined)
return promise;
},
cancel: () => {
cancel = true;
},
};
};