Explore HDR rendering with EDR

// Instantiate AVPlayer with HDR Video Content

VPLayer*      player      = [AVPLayer playerWithURL:HDRVideoURL];
AVPlayerLayer* playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];

// Play HDR Video via EDR

AVPlayerViewController* controller = [[AVPlayerViewController alloc] init];

controller.player = player;

[player play];

// Opt-in to EDR

metalLayer.wantsExtendedDynamicRangeContent = YES;

// Set extended-range colorspace

metalLayer.colorspace =
              CGColorSpaceCreateWithName(kCGColorSpaceExtendedLinearDisplayP3);

// Select FP16 pixel buffer format

metalLayer.pixelFormat = MTLPixelFormatRGBA16Float;

// Create CGImage from HDR Image

CGImageSourceRef isr = CGImageSourceCreateWithURL((CFURLRef)HDRimageURL, NULL);
CGImageRef       img = CGImageSourceCreateImageAtIndex(isr, 0, NULL);

// Draw into floating point bitmap context

size_t width  = CGImageGetWidth(img);
size_t height = CGImageGetHeight(img);

CGBitmapInfo info = kCGBitmapByteOrder16Host | kCGImageAlphaPremultipliedLast |
                    kCGBitmapFloatComponents;

CGContextRef ctx = CGBitmapContextCreate(NULL, width, height, 16, 0,
                                         metalLayer.colorspace, info);

CGContextDrawImage(ctx, CGRectMake(0, 0, width, height), img);

// Create floating point texture

MTLTextureDescriptor* desc = [[MTLTextureDescriptor alloc] init];

desc.pixelFormat = MTLPixelFormatRGBA16Float;
desc.textureType = MTLTextureType2D;

id<MTLTexture> tex = [metalLayer.device newTextureWithDescriptor:desc];

// Load EDR bitmap into texture

const void* data = CGBitmapContextGetData(ctx);

[tex replaceRegion:MTLRegionMake2D(0, 0, width, height)
       mipmapLevel:0
         withBytes:data
       bytesPerRow:CGBitmapContextGetBytesPerRow(ctx)];

// Draw with the texture in your EDR enabled metal pipeline

// Opt-in to EDR

  - (void) viewWillMoveToWindow:(nullable NSWindow *)newWindow {
     self.wantsExtendedDynamicRangeOpenGLSurface = YES;
  }

// Select OpenGL float pixel buffer format

  NSOpenGLPixelFormatAttribute attribs[] = {
    NSOpenGLPFADoubleBuffer,
    NSOpenGLPFAMultiSample,
    NSOpenGLPFAColorFloat,
    NSOpenGLPFAColorSize, 64, 
    NSOpenGLPFAOpenGLProfile, NSOpenGLProfileVersion4_1Core,
    0};

  NSOpenGLPixelFormat* pf = [[NSOpenGLPixelFormat alloc] initWithAttributes:attribs];

// Draw EDR content into NSOpenGLView

// Get existing colorspace from the window 

CGColorSpaceRef color_space = [view.window.colorSpace CGColorSpace];

// Promote the colorspace to extended-range

CGColorSpaceRef color_space_extended = CGColorSpaceCreateExtended(color_space);

// Apply the extended-range colorspace to your app

NSColorSpace* extended_ns_color_space
                   = [[NSColorSpace alloc] initWithCGColorSpace:color_space_extended];

view.window.colorSpace = extended_ns_color_space;

CGColorSpaceRelease(color_space_extended);

// Read static values

NSScreen* screen = window.screen;

double maxPotentialEDR = screen.maximumPotentialExtendedDynamicRangeColorComponentValue;
double maxReferenceEDR = screen.maximumReferenceExtendedDynamicRangeColorComponentValue;

// Register for dynamic EDR notifications

NSNotificationCenter* notification = [NSNotificationCenter defaultCenter];  

[notification addObserver:self
                 selector:@selector(screenChangedEvent:)
                     name:NSApplicationDidChangeScreenParametersNotification
                   object:nil];

// Query for latest values

- (void)screenChangedEvent:(NSNotification *)notification {  
    double maxEDR = screen.maximumExtendedDynamicRangeColorComponentValue;
}

// HLG

CAEDRMetadata* edrMetaData = [CAEDRMetadata HLGMetadata];

// HDR10

CAEDRMetadata* edrMetaData
   = [CAEDRMetadata HDR10MetadataWithMinLuminance:minLuminance
                                     maxLuminance:maxContentMasteringDisplayBrightness 
                               opticalOutputScale:outputScale]; 

// Set on CAMetalLayer

metalLayer.EDRMetadata = edrMetaData;

// Create the linear pixel we want to render

double EDRmaxComponents[4] = {EDRmax, EDRmax, EDRmax, 1.0};

CGColorSpaceRef linearColorSpace =
                   CGColorSpaceCreateWithName(kCGColorSpaceExtendedLinearDisplayP3);

CGColorRef EDRmaxColorLinear = CGColorCreate(linearColorSpace, EDRmaxComponents);

// Convert from linear to application’s colorspace

CGColorSpaceRef winColorSpace = [self.window.colorSpace CGColorSpace];

CGColorRef EDRmaxColor = CGColorCreateCopyByMatchingToColorSpace(winColorSpace,
                                                                 kCGRenderingIntentDefault,
                                                                 EDRmaxColorLinear,
                                                                 NULL);