remotion
Version:
Make videos programmatically
153 lines (152 loc) • 5.75 kB
JavaScript
;
// Taken from https://github.com/facebook/react-native/blob/0b9ea60b4fee8cacc36e7160e31b91fc114dbc0d/Libraries/Animated/src/nodes/AnimatedInterpolation.js
Object.defineProperty(exports, "__esModule", { value: true });
exports.assertValidInterpolateEasingOption = assertValidInterpolateEasingOption;
exports.interpolate = interpolate;
function interpolateFunction(input, inputRange, outputRange, options) {
const { extrapolateLeft, extrapolateRight, easing } = options;
let result = input;
const [inputMin, inputMax] = inputRange;
const [outputMin, outputMax] = outputRange;
if (result < inputMin) {
if (extrapolateLeft === 'identity') {
return result;
}
if (extrapolateLeft === 'clamp') {
result = inputMin;
}
else if (extrapolateLeft === 'wrap') {
const range = inputMax - inputMin;
result = ((((result - inputMin) % range) + range) % range) + inputMin;
}
else if (extrapolateLeft === 'extend') {
// Noop
}
}
if (result > inputMax) {
if (extrapolateRight === 'identity') {
return result;
}
if (extrapolateRight === 'clamp') {
result = inputMax;
}
else if (extrapolateRight === 'wrap') {
const range = inputMax - inputMin;
result = ((((result - inputMin) % range) + range) % range) + inputMin;
}
else if (extrapolateRight === 'extend') {
// Noop
}
}
if (outputMin === outputMax) {
return outputMin;
}
// Input Range
result = (result - inputMin) / (inputMax - inputMin);
// Easing
result = easing(result);
// Output Range
result = result * (outputMax - outputMin) + outputMin;
return result;
}
function findRange(input, inputRange) {
let i;
for (i = 1; i < inputRange.length - 1; ++i) {
if (inputRange[i] >= input) {
break;
}
}
return i - 1;
}
function checkValidInputRange(arr) {
for (let i = 1; i < arr.length; ++i) {
if (!(arr[i] > arr[i - 1])) {
throw new Error(`inputRange must be strictly monotonically increasing but got [${arr.join(',')}]`);
}
}
}
function checkInfiniteRange(name, arr) {
if (arr.length < 2) {
throw new Error(name + ' must have at least 2 elements');
}
for (const element of arr) {
if (typeof element !== 'number') {
throw new Error(`${name} must contain only numbers`);
}
if (!Number.isFinite(element)) {
throw new Error(`${name} must contain only finite numbers, but got [${arr.join(',')}]`);
}
}
}
function assertValidInterpolateEasingOption(easing, inputRangeLength) {
if (easing === undefined) {
return;
}
if (typeof easing === 'function') {
return;
}
const expectedLength = inputRangeLength - 1;
if (easing.length !== expectedLength) {
throw new Error(`When easing is an array, it must have one entry per segment between keyframes (length inputRange.length - 1 = ${expectedLength}), but got length ${easing.length}`);
}
for (let i = 0; i < easing.length; i++) {
if (typeof easing[i] !== 'function') {
throw new Error(`easing[${i}] must be a function`);
}
}
}
/*
* @description Allows you to map a range of values to another using a concise syntax.
* @see [Documentation](https://remotion.dev/docs/interpolate)
*/
function interpolate(input, inputRange, outputRange, options) {
if (typeof input === 'undefined') {
throw new Error('input can not be undefined');
}
if (typeof inputRange === 'undefined') {
throw new Error('inputRange can not be undefined');
}
if (typeof outputRange === 'undefined') {
throw new Error('outputRange can not be undefined');
}
if (inputRange.length !== outputRange.length) {
throw new Error('inputRange (' +
inputRange.length +
') and outputRange (' +
outputRange.length +
') must have the same length');
}
checkInfiniteRange('inputRange', inputRange);
checkInfiniteRange('outputRange', outputRange);
checkValidInputRange(inputRange);
assertValidInterpolateEasingOption(options === null || options === void 0 ? void 0 : options.easing, inputRange.length);
const easingOption = options === null || options === void 0 ? void 0 : options.easing;
const defaultEasing = (num) => num;
const resolveEasingForSegment = (segmentIndex) => {
if (easingOption === undefined) {
return defaultEasing;
}
if (typeof easingOption === 'function') {
return easingOption;
}
// `segmentIndex` is in [0, inputRange.length - 2]; array length was validated above.
return easingOption[segmentIndex];
};
let extrapolateLeft = 'extend';
if ((options === null || options === void 0 ? void 0 : options.extrapolateLeft) !== undefined) {
extrapolateLeft = options.extrapolateLeft;
}
let extrapolateRight = 'extend';
if ((options === null || options === void 0 ? void 0 : options.extrapolateRight) !== undefined) {
extrapolateRight = options.extrapolateRight;
}
if (typeof input !== 'number') {
throw new TypeError('Cannot interpolate an input which is not a number');
}
const range = findRange(input, inputRange);
return interpolateFunction(input, [inputRange[range], inputRange[range + 1]], [outputRange[range], outputRange[range + 1]], {
easing: resolveEasingForSegment(range),
extrapolateLeft,
extrapolateRight,
});
}