react-native/Libraries/Image/RCTImageUtils.m

290 lines
8.9 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 "RCTImageUtils.h"
#import <ImageIO/ImageIO.h>
#import <MobileCoreServices/UTCoreTypes.h>
#import <tgmath.h>
#import "RCTLog.h"
#import "RCTUtils.h"
static CGFloat RCTCeilValue(CGFloat value, CGFloat scale)
{
return ceil(value * scale) / scale;
}
static CGFloat RCTFloorValue(CGFloat value, CGFloat scale)
{
return floor(value * scale) / scale;
}
static CGSize RCTCeilSize(CGSize size, CGFloat scale)
{
return (CGSize){
RCTCeilValue(size.width, scale),
RCTCeilValue(size.height, scale)
};
}
CGRect RCTTargetRect(CGSize sourceSize, CGSize destSize,
CGFloat destScale, UIViewContentMode resizeMode)
{
if (CGSizeEqualToSize(destSize, CGSizeZero)) {
// Assume we require the largest size available
return (CGRect){CGPointZero, sourceSize};
}
CGFloat aspect = sourceSize.width / sourceSize.height;
// If only one dimension in destSize is non-zero (for example, an Image
// with `flex: 1` whose height is indeterminate), calculate the unknown
// dimension based on the aspect ratio of sourceSize
if (destSize.width == 0) {
destSize.width = destSize.height * aspect;
}
if (destSize.height == 0) {
destSize.height = destSize.width / aspect;
}
// Calculate target aspect ratio if needed (don't bother if resizeMode == stretch)
CGFloat targetAspect = 0.0;
if (resizeMode != UIViewContentModeScaleToFill) {
targetAspect = destSize.width / destSize.height;
if (aspect == targetAspect) {
resizeMode = UIViewContentModeScaleToFill;
}
}
switch (resizeMode) {
case UIViewContentModeScaleToFill: // stretch
return (CGRect){CGPointZero, RCTCeilSize(destSize, destScale)};
case UIViewContentModeScaleAspectFit: // contain
if (targetAspect <= aspect) { // target is taller than content
sourceSize.width = destSize.width = destSize.width;
sourceSize.height = sourceSize.width / aspect;
} else { // target is wider than content
sourceSize.height = destSize.height = destSize.height;
sourceSize.width = sourceSize.height * aspect;
}
return (CGRect){CGPointZero, RCTCeilSize(sourceSize, destScale)};
case UIViewContentModeScaleAspectFill: // cover
if (targetAspect <= aspect) { // target is taller than content
sourceSize.height = destSize.height = destSize.height;
sourceSize.width = sourceSize.height * aspect;
destSize.width = destSize.height * targetAspect;
return (CGRect){
{RCTFloorValue((destSize.width - sourceSize.width) / 2, destScale), 0},
RCTCeilSize(sourceSize, destScale)
};
} else { // target is wider than content
sourceSize.width = destSize.width = destSize.width;
sourceSize.height = sourceSize.width / aspect;
destSize.height = destSize.width / targetAspect;
return (CGRect){
{0, RCTFloorValue((destSize.height - sourceSize.height) / 2, destScale)},
RCTCeilSize(sourceSize, destScale)
};
}
default:
RCTLogError(@"A resizeMode value of %zd is not supported", resizeMode);
return (CGRect){CGPointZero, RCTCeilSize(destSize, destScale)};
}
}
CGSize RCTTargetSize(CGSize sourceSize, CGFloat sourceScale,
CGSize destSize, CGFloat destScale,
UIViewContentMode resizeMode,
BOOL allowUpscaling)
{
switch (resizeMode) {
case UIViewContentModeScaleToFill: // stretch
if (!allowUpscaling) {
CGFloat scale = sourceScale / destScale;
destSize.width = MIN(sourceSize.width * scale, destSize.width);
destSize.height = MIN(sourceSize.height * scale, destSize.height);
}
return RCTCeilSize(destSize, destScale);
default: {
// Get target size
CGSize size = RCTTargetRect(sourceSize, destSize, destScale, resizeMode).size;
if (!allowUpscaling) {
// return sourceSize if target size is larger
if (sourceSize.width * sourceScale < size.width * destScale) {
return sourceSize;
}
}
return size;
}
}
}
BOOL RCTUpscalingRequired(CGSize sourceSize, CGFloat sourceScale,
CGSize destSize, CGFloat destScale,
UIViewContentMode resizeMode)
{
if (CGSizeEqualToSize(destSize, CGSizeZero)) {
// Assume we require the largest size available
return YES;
}
// Precompensate for scale
CGFloat scale = sourceScale / destScale;
sourceSize.width *= scale;
sourceSize.height *= scale;
// Calculate aspect ratios if needed (don't bother if resizeMode == stretch)
CGFloat aspect = 0.0, targetAspect = 0.0;
if (resizeMode != UIViewContentModeScaleToFill) {
aspect = sourceSize.width / sourceSize.height;
targetAspect = destSize.width / destSize.height;
if (aspect == targetAspect) {
resizeMode = UIViewContentModeScaleToFill;
}
}
switch (resizeMode) {
case UIViewContentModeScaleToFill: // stretch
return destSize.width > sourceSize.width || destSize.height > sourceSize.height;
case UIViewContentModeScaleAspectFit: // contain
if (targetAspect <= aspect) { // target is taller than content
return destSize.width > sourceSize.width;
} else { // target is wider than content
return destSize.height > sourceSize.height;
}
case UIViewContentModeScaleAspectFill: // cover
if (targetAspect <= aspect) { // target is taller than content
return destSize.height > sourceSize.height;
} else { // target is wider than content
return destSize.width > sourceSize.width;
}
default:
RCTLogError(@"A resizeMode value of %zd is not supported", resizeMode);
return NO;
}
}
CGSize RCTSizeInPixels(CGSize pointSize, CGFloat scale)
{
return (CGSize){
ceil(pointSize.width * scale),
ceil(pointSize.height * scale),
};
}
UIImage *RCTDecodeImageWithData(NSData *data,
CGSize destSize,
CGFloat destScale,
UIViewContentMode resizeMode)
{
CGImageSourceRef sourceRef = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
if (!sourceRef) {
return nil;
}
// get original image size
CGSize sourceSize;
CFDictionaryRef imageProperties = CGImageSourceCopyPropertiesAtIndex(sourceRef, 0, NULL);
if (!imageProperties) {
CFRelease(sourceRef);
return nil;
}
NSNumber *width = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelWidth);
NSNumber *height = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelHeight);
sourceSize = (CGSize){width.doubleValue, height.doubleValue};
CFRelease(imageProperties);
if (CGSizeEqualToSize(destSize, CGSizeZero)) {
destSize = sourceSize;
}
// calculate target size
CGSize targetSize = RCTTargetSize(sourceSize, 1, destSize, destScale, resizeMode, YES);
CGSize targetPixelSize = RCTSizeInPixels(targetSize, destScale);
CGFloat maxPixelSize = fmax(fmin(sourceSize.width, targetPixelSize.width),
fmin(sourceSize.height, targetPixelSize.height));
NSDictionary<NSString *, NSNumber *> *options = @{
(id)kCGImageSourceShouldAllowFloat: @YES,
(id)kCGImageSourceCreateThumbnailWithTransform: @YES,
(id)kCGImageSourceCreateThumbnailFromImageAlways: @YES,
(id)kCGImageSourceThumbnailMaxPixelSize: @(maxPixelSize),
};
// get thumbnail
CGImageRef imageRef = CGImageSourceCreateThumbnailAtIndex(sourceRef, 0, (__bridge CFDictionaryRef)options);
CFRelease(sourceRef);
if (!imageRef) {
return nil;
}
// adjust scale
size_t actualWidth = CGImageGetWidth(imageRef);
CGFloat scale = actualWidth / targetSize.width * destScale;
// return image
UIImage *image = [UIImage imageWithCGImage:imageRef
scale:scale
orientation:UIImageOrientationUp];
CGImageRelease(imageRef);
return image;
}
NSData *RCTGetImageData(CGImageRef image, float quality)
{
NSDictionary *properties;
CGImageDestinationRef destination;
CFMutableDataRef imageData = CFDataCreateMutable(NULL, 0);
if (RCTImageHasAlpha(image)) {
// get png data
destination = CGImageDestinationCreateWithData(imageData, kUTTypePNG, 1, NULL);
} else {
// get jpeg data
destination = CGImageDestinationCreateWithData(imageData, kUTTypeJPEG, 1, NULL);
properties = @{(NSString *)kCGImageDestinationLossyCompressionQuality: @(quality)};
}
CGImageDestinationAddImage(destination, image, (__bridge CFDictionaryRef)properties);
if (!CGImageDestinationFinalize(destination))
{
CFRelease(imageData);
imageData = NULL;
}
CFRelease(destination);
return (__bridge_transfer NSData *)imageData;
}