react-native/Libraries/ART/Brushes/ARTRadialGradient.m

57 lines
1.7 KiB
Objective-C

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
#import "ARTRadialGradient.h"
#import "RCTConvert+ART.h"
#import "RCTLog.h"
@implementation ARTRadialGradient
{
CGGradientRef _gradient;
CGPoint _focusPoint;
CGPoint _centerPoint;
CGFloat _radius;
CGFloat _radiusRatio;
}
- (instancetype)initWithArray:(NSArray<NSNumber *> *)array
{
if ((self = [super initWithArray:array])) {
if (array.count < 7) {
RCTLogError(@"-[%@ %@] expects 7 elements, received %@",
self.class, NSStringFromSelector(_cmd), array);
return nil;
}
_radius = [RCTConvert CGFloat:array[3]];
_radiusRatio = [RCTConvert CGFloat:array[4]] / _radius;
_focusPoint.x = [RCTConvert CGFloat:array[1]];
_focusPoint.y = [RCTConvert CGFloat:array[2]] / _radiusRatio;
_centerPoint.x = [RCTConvert CGFloat:array[5]];
_centerPoint.y = [RCTConvert CGFloat:array[6]] / _radiusRatio;
_gradient = CGGradientRetain([RCTConvert CGGradient:array offset:7]);
}
return self;
}
- (void)dealloc
{
CGGradientRelease(_gradient);
}
- (void)paint:(CGContextRef)context
{
CGAffineTransform transform = CGAffineTransformMakeScale(1, _radiusRatio);
CGContextConcatCTM(context, transform);
CGGradientDrawingOptions extendOptions = kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation;
CGContextDrawRadialGradient(context, _gradient, _focusPoint, 0, _centerPoint, _radius, extendOptions);
}
@end