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//
// CVPixelBufferRef+SDLUtil.m
// SmartDeviceLink-iOS
//
// Created by Muller, Alexander (A.) on 3/16/17.
// Copyright © 2017 smartdevicelink. All rights reserved.
//
#import "CVPixelBufferRef+SDLUtil.h"
#import "SDLLogMacros.h"
NS_ASSUME_NONNULL_BEGIN
// Video stream string message padding is 5% of the screen size. Padding is added to the message so the text is not flush with the edge of the screen.
CGFloat const SDLVideoStringMessagePadding = .05;
UIFont * _Nullable sdl_findFontSizeToFitText(CGSize size, NSString *text) {
CGFloat fontSize = 300;
do {
CGFloat padding = SDLVideoStringMessagePadding * size.width * 2;
CGSize textSize = [text boundingRectWithSize:CGSizeMake((size.width - padding), CGFLOAT_MAX)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName : [UIFont systemFontOfSize:fontSize]}
context:nil].size;
if (textSize.height <= (size.height - padding)) {
break;
}
fontSize -= (CGFloat)1.0;
} while (fontSize > 0.0);
return (fontSize > 0) ? [UIFont systemFontOfSize:fontSize] : nil;
}
UIImage * _Nullable sdl_createTextImage(NSString *text, CGSize size) {
UIFont *font = sdl_findFontSizeToFitText(size, text);
if (!font) {
SDLLogW(@"Text cannot fit inside frame");
return nil;
}
CGRect frame = CGRectMake(0, 0, size.width, size.height);
UIGraphicsBeginImageContextWithOptions(frame.size, NO, 1.0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [UIColor blackColor].CGColor);
CGContextFillRect(context, frame);
CGContextSaveGState(context);
NSMutableParagraphStyle* textStyle = NSMutableParagraphStyle.defaultParagraphStyle.mutableCopy;
textStyle.alignment = NSTextAlignmentLeft;
NSDictionary* textAttributes = @{
NSFontAttributeName: font,
NSForegroundColorAttributeName: [UIColor whiteColor],
NSParagraphStyleAttributeName: textStyle
};
CGRect textFrame = [text boundingRectWithSize:size
options:NSStringDrawingUsesLineFragmentOrigin
attributes:textAttributes
context:nil];
CGFloat padding = SDLVideoStringMessagePadding * size.width;
CGRect textInset = CGRectMake(0 + padding,
(frame.size.height - CGRectGetHeight(textFrame)) / 2.0,
frame.size.width - (padding * 2),
frame.size.height - (padding * 2));
[text drawInRect:textInset
withAttributes:textAttributes];
CGContextRestoreGState(context);
UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
return image;
}
Boolean CVPixelBufferAddText(CVPixelBufferRef CV_NONNULL pixelBuffer, NSString *text) {
size_t width = CVPixelBufferGetWidth(pixelBuffer);
size_t height = CVPixelBufferGetHeight(pixelBuffer);
UIImage *image = sdl_createTextImage(text, CGSizeMake(width, height));
if (!image) {
SDLLogE(@"Could not create text image.");
return false;
}
CVPixelBufferLockBaseAddress(pixelBuffer, 0);
void *data = CVPixelBufferGetBaseAddress(pixelBuffer);
CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(data, width, height,
8, CVPixelBufferGetBytesPerRow(pixelBuffer), rgbColorSpace,
kCGBitmapByteOrder32Little |
kCGImageAlphaPremultipliedFirst);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), image.CGImage);
CGColorSpaceRelease(rgbColorSpace);
CGContextRelease(context);
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
return true;
}
NS_ASSUME_NONNULL_END
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