react-native/Libraries/NativeAnimation/RCTAnimationUtils.m

96 lines
3.0 KiB
Objective-C

/**
* Copyright (c) 2015-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#import "RCTAnimationUtils.h"
#import <React/RCTLog.h>
static NSUInteger _RCTFindIndexOfNearestValue(CGFloat value, NSArray<NSNumber *> *range)
{
NSUInteger index;
NSUInteger rangeCount = range.count;
for (index = 1; index < rangeCount - 1; index++) {
NSNumber *inputValue = range[index];
if (inputValue.doubleValue >= value) {
break;
}
}
return index - 1;
}
/**
* Interpolates value by remapping it linearly fromMin->fromMax to toMin->toMax
*/
CGFloat RCTInterpolateValue(CGFloat value,
CGFloat inputMin,
CGFloat inputMax,
CGFloat outputMin,
CGFloat outputMax,
NSString *extrapolateLeft,
NSString *extrapolateRight)
{
if (value < inputMin) {
if ([extrapolateLeft isEqualToString:EXTRAPOLATE_TYPE_IDENTITY]) {
return value;
} else if ([extrapolateLeft isEqualToString:EXTRAPOLATE_TYPE_CLAMP]) {
value = inputMin;
} else if ([extrapolateLeft isEqualToString:EXTRAPOLATE_TYPE_EXTEND]) {
// noop
} else {
RCTLogError(@"Invalid extrapolation type %@ for left extrapolation", extrapolateLeft);
}
}
if (value > inputMax) {
if ([extrapolateRight isEqualToString:EXTRAPOLATE_TYPE_IDENTITY]) {
return value;
} else if ([extrapolateRight isEqualToString:EXTRAPOLATE_TYPE_CLAMP]) {
value = inputMax;
} else if ([extrapolateRight isEqualToString:EXTRAPOLATE_TYPE_EXTEND]) {
// noop
} else {
RCTLogError(@"Invalid extrapolation type %@ for right extrapolation", extrapolateRight);
}
}
return outputMin + (value - inputMin) * (outputMax - outputMin) / (inputMax - inputMin);
}
/**
* Interpolates value by mapping it from the inputRange to the outputRange.
*/
CGFloat RCTInterpolateValueInRange(CGFloat value,
NSArray<NSNumber *> *inputRange,
NSArray<NSNumber *> *outputRange,
NSString *extrapolateLeft,
NSString *extrapolateRight)
{
NSUInteger rangeIndex = _RCTFindIndexOfNearestValue(value, inputRange);
CGFloat inputMin = inputRange[rangeIndex].doubleValue;
CGFloat inputMax = inputRange[rangeIndex + 1].doubleValue;
CGFloat outputMin = outputRange[rangeIndex].doubleValue;
CGFloat outputMax = outputRange[rangeIndex + 1].doubleValue;
return RCTInterpolateValue(value,
inputMin,
inputMax,
outputMin,
outputMax,
extrapolateLeft,
extrapolateRight);
}
CGFloat RCTRadiansToDegrees(CGFloat radians)
{
return radians * 180.0 / M_PI;
}
CGFloat RCTDegreesToRadians(CGFloat degrees)
{
return degrees / 180.0 * M_PI;
}