Swiftgram/lottie-ios/Classes/AnimatableProperties/LOTAnimatableShapeValue.m
2017-03-01 09:59:52 -05:00

307 lines
11 KiB
Objective-C

//
// LOTAnimatableShapeValue.m
// LottieAnimator
//
// Created by brandon_withrow on 6/23/16.
// Copyright © 2016 Brandon Withrow. All rights reserved.
//
#import "LOTAnimatableShapeValue.h"
#import "CGGeometry+LOTAdditions.h"
@interface LOTAnimatableShapeValue ()
@property (nonatomic, readonly) NSArray *shapeKeyframes;
@property (nonatomic, readonly) NSArray<NSNumber *> *keyTimes;
@property (nonatomic, readonly) NSArray<CAMediaTimingFunction *> *timingFunctions;
@property (nonatomic, readonly) NSTimeInterval delay;
@property (nonatomic, readonly) NSTimeInterval duration;
@property (nonatomic, readonly) NSNumber *startFrame;
@property (nonatomic, readonly) NSNumber *durationFrames;
@property (nonatomic, readonly) NSNumber *frameRate;
@end
@implementation LOTAnimatableShapeValue
- (instancetype)initWithShapeValues:(NSDictionary *)shapeValues frameRate:(NSNumber *)frameRate closed:(BOOL)closed {
self = [super init];
if (self) {
_frameRate = frameRate;
id value = shapeValues[@"k"];
if ([value isKindOfClass:[NSArray class]] &&
[[(NSArray *)value firstObject] isKindOfClass:[NSDictionary class]] &&
[(NSArray *)value firstObject][@"t"]) {
//Keframes
NSDictionary *first = [(NSArray *)value firstObject];
NSDictionary *start = ([first[@"s"] isKindOfClass:[NSDictionary class]] ?
first[@"s"] :
[(NSArray *)first[@"s"] firstObject]);
if ([(start[@"c"]) isKindOfClass:[NSNumber class]]) {
closed = [(start[@"c"]) boolValue];
}
[self _buildAnimationForKeyframes:value closed:closed];
} else if ([value isKindOfClass:[NSDictionary class]]) {
//Single Value, no animation
if ([value[@"c"] isKindOfClass:[NSNumber class]]) {
closed = [value[@"c"] boolValue];
}
_initialShape = [self _bezierShapeFromValue:value closed:closed];
}
if (shapeValues[@"x"]) {
NSLog(@"%s: Warning: expressions are not supported", __PRETTY_FUNCTION__);
}
}
return self;
}
- (void)_buildAnimationForKeyframes:(NSArray<NSDictionary *> *)keyframes closed:(BOOL)closed {
NSMutableArray *keyTimes = [NSMutableArray array];
NSMutableArray *timingFunctions = [NSMutableArray array];
NSMutableArray *shapeValues = [NSMutableArray array];
_startFrame = keyframes.firstObject[@"t"];
NSNumber *endFrame = keyframes.lastObject[@"t"];
NSAssert((_startFrame && endFrame && _startFrame.integerValue < endFrame.integerValue),
@"Lottie: Keyframe animation has incorrect time values or invalid number of keyframes");
// Calculate time duration
_durationFrames = @(endFrame.floatValue - _startFrame.floatValue);
_duration = _durationFrames.floatValue / _frameRate.floatValue;
_delay = _startFrame.floatValue / _frameRate.floatValue;
BOOL addStartValue = YES;
BOOL addTimePadding = NO;
NSDictionary *outShape = nil;
for (NSDictionary *keyframe in keyframes) {
// Get keyframe time value
NSNumber *frame = keyframe[@"t"];
// Calculate percentage value for keyframe.
//CA Animations accept time values of 0-1 as a percentage of animation completed.
NSNumber *timePercentage = @((frame.floatValue - _startFrame.floatValue) / _durationFrames.floatValue);
if (outShape) {
//add out value
[shapeValues addObject:(id)[[self _bezierShapeFromValue:outShape closed:closed] CGPath]];
[timingFunctions addObject:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];
outShape = nil;
}
NSDictionary *startShape = keyframe[@"s"];
if (addStartValue) {
// Add start value
if (startShape) {
if (keyframe == keyframes.firstObject) {
_initialShape = [self _bezierShapeFromValue:startShape closed:closed];
}
[shapeValues addObject:(id)[[self _bezierShapeFromValue:startShape closed:closed] CGPath]];
if (timingFunctions.count) {
[timingFunctions addObject:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];
}
}
addStartValue = NO;
}
if (addTimePadding) {
// add time padding
NSNumber *holdPercentage = @(timePercentage.floatValue - 0.00001);
[keyTimes addObject:[holdPercentage copy]];
addTimePadding = NO;
}
// add end value if present for keyframe
NSDictionary *endShape = keyframe[@"e"];
if (endShape) {
[shapeValues addObject:(id)[[self _bezierShapeFromValue:endShape closed:closed] CGPath]];
/*
* Timing Function for time interpolations between keyframes
* Should be n-1 where n is the number of keyframes
*/
CAMediaTimingFunction *timingFunction;
NSDictionary *timingControlPoint1 = keyframe[@"o"];
NSDictionary *timingControlPoint2 = keyframe[@"i"];
if (timingControlPoint1 && timingControlPoint2) {
// Easing function
CGPoint cp1 = [self _pointFromValueDict:timingControlPoint1];
CGPoint cp2 = [self _pointFromValueDict:timingControlPoint2];
timingFunction = [CAMediaTimingFunction functionWithControlPoints:cp1.x :cp1.y :cp2.x :cp2.y];
} else {
// No easing function specified, fallback to linear
timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
}
[timingFunctions addObject:timingFunction];
}
// add time
[keyTimes addObject:timePercentage];
// Check if keyframe is a hold keyframe
if ([keyframe[@"h"] boolValue]) {
// set out value as start and flag next frame accordinly
outShape = startShape;
addStartValue = YES;
addTimePadding = YES;
}
}
_shapeKeyframes = shapeValues;
_keyTimes = keyTimes;
_timingFunctions = timingFunctions;
}
- (UIBezierPath *)_bezierShapeFromValue:(id)value closed:(BOOL)closedPath {
NSDictionary *pointsData = nil;
if ([value isKindOfClass:[NSArray class]] &&
[[(NSArray *)value firstObject] isKindOfClass:[NSDictionary class]] &&
[(NSDictionary *)[(NSArray *)value firstObject] objectForKey:@"v"]) {
pointsData = [(NSArray *)value firstObject];
} else if ([value isKindOfClass:[NSDictionary class]] &&
[(NSDictionary *)value objectForKey:@"v"]) {
pointsData = value;
}
if (!pointsData) {
return nil;
}
NSArray *pointsArray = pointsData[@"v"];
NSArray *inTangents = pointsData[@"i"];
NSArray *outTangents = pointsData[@"o"];
NSAssert((pointsArray.count == inTangents.count &&
pointsArray.count == outTangents.count),
@"Lottie: Incorrect number of points and tangents");
UIBezierPath *shape = [UIBezierPath bezierPath];
[shape moveToPoint:[self _vertexAtIndex:0 inArray:pointsArray]];
for (int i = 1; i < pointsArray.count; i ++) {
CGPoint vertex = [self _vertexAtIndex:i inArray:pointsArray];
CGPoint previousVertex = [self _vertexAtIndex:i - 1 inArray:pointsArray];
CGPoint cp1 = LOT_PointAddedToPoint(previousVertex, [self _vertexAtIndex:i - 1 inArray:outTangents]);
CGPoint cp2 = LOT_PointAddedToPoint(vertex, [self _vertexAtIndex:i inArray:inTangents]);
if (CGPointEqualToPoint(previousVertex, cp1) &&
CGPointEqualToPoint(vertex, cp2)) {
// Straight Line
[shape addLineToPoint:vertex];
} else {
if (CGPointEqualToPoint(previousVertex, cp1)) {
// Missing out tan
cp1 = LOT_PointByLerpingPoints(previousVertex, cp2, 0.01);
}
if (CGPointEqualToPoint(vertex, cp2)) {
// Missing in tan
cp2 = LOT_PointByLerpingPoints(cp1, vertex, 0.99);
}
[shape addCurveToPoint:vertex
controlPoint1:cp1
controlPoint2:cp2];
}
}
if (closedPath) {
CGPoint vertex = [self _vertexAtIndex:0 inArray:pointsArray];
CGPoint previousVertex = [self _vertexAtIndex:pointsArray.count - 1 inArray:pointsArray];
CGPoint cp1 = LOT_PointAddedToPoint(previousVertex, [self _vertexAtIndex:pointsArray.count - 1 inArray:outTangents]);
CGPoint cp2 = LOT_PointAddedToPoint(vertex, [self _vertexAtIndex:0 inArray:inTangents]);
if (CGPointEqualToPoint(previousVertex, cp1) &&
CGPointEqualToPoint(vertex, cp2)) {
// Straight Line
cp1 = LOT_PointByLerpingPoints(previousVertex, vertex, 0.01);
cp2 = LOT_PointByLerpingPoints(previousVertex, vertex, 0.99);
} else {
if (CGPointEqualToPoint(previousVertex, cp1)) {
// Missing out tan
cp1 = LOT_PointByLerpingPoints(previousVertex, cp2, 0.01);
}
if (CGPointEqualToPoint(vertex, cp2)) {
// Missing in tan
cp2 = LOT_PointByLerpingPoints(cp1, vertex, 0.99);
}
}
[shape addCurveToPoint:vertex
controlPoint1:cp1
controlPoint2:cp2];
[shape closePath];
}
// Double up shape for trim offsets.
// TODO Remove this heavy solution by refactoring the drawing tree.
[shape appendPath:[shape copy]];
return shape;
}
- (CGPoint)_vertexAtIndex:(NSInteger)idx inArray:(NSArray *)points {
NSAssert((idx < points.count),
@"Lottie: Vertex Point out of bounds");
NSArray *pointArray = points[idx];
NSAssert((pointArray.count >= 2 &&
[pointArray.firstObject isKindOfClass:[NSNumber class]]),
@"Lottie: Point Data Malformed");
return CGPointMake([pointArray[0] floatValue], [pointArray[1] floatValue]);
}
- (NSNumber *)_numberValueFromObject:(id)valueObject {
if ([valueObject isKindOfClass:[NSNumber class]]) {
return valueObject;
}
if ([valueObject isKindOfClass:[NSArray class]]) {
return [(NSArray *)valueObject firstObject];
}
return nil;
}
- (CGPoint)_pointFromValueDict:(NSDictionary *)values {
NSNumber *xValue = @0, *yValue = @0;
if ([values[@"x"] isKindOfClass:[NSNumber class]]) {
xValue = values[@"x"];
} else if ([values[@"x"] isKindOfClass:[NSArray class]]) {
xValue = values[@"x"][0];
}
if ([values[@"y"] isKindOfClass:[NSNumber class]]) {
yValue = values[@"y"];
} else if ([values[@"y"] isKindOfClass:[NSArray class]]) {
yValue = values[@"y"][0];
}
return CGPointMake([xValue floatValue], [yValue floatValue]);
}
- (BOOL)hasAnimation {
return (self.shapeKeyframes.count > 0);
}
- (nullable CAKeyframeAnimation *)animationForKeyPath:(nonnull NSString *)keypath {
if (self.hasAnimation == NO) {
return nil;
}
CAKeyframeAnimation *keyframeAnimation = [CAKeyframeAnimation animationWithKeyPath:keypath];
keyframeAnimation.keyTimes = self.keyTimes;
keyframeAnimation.values = self.shapeKeyframes;
keyframeAnimation.timingFunctions = self.timingFunctions;
keyframeAnimation.duration = self.duration;
keyframeAnimation.beginTime = self.delay;
keyframeAnimation.fillMode = kCAFillModeForwards;
return keyframeAnimation;
}
- (NSString *)description {
return self.initialShape.description;
}
@end