From e2e3323a409d47204410b808b756c3cb70ed1078 Mon Sep 17 00:00:00 2001
From: Brad Werth <bwerth@mozilla.com>
Date: Tue, 29 Nov 2022 02:31:18 +0000
Subject: [PATCH] Bug 1798067 Part 1: Add SupportsHDR to gfxPlatform, refactor
 macOS to use it. r=gfx-reviewers,lsalzman

Differential Revision: https://phabricator.services.mozilla.com/D161364
---
 gfx/thebes/gfxPlatform.h      |  2 ++
 gfx/thebes/gfxPlatformMac.cpp | 18 ++++++++++++++++++
 gfx/thebes/gfxPlatformMac.h   |  2 ++
 widget/cocoa/nsLookAndFeel.mm | 16 ++++++++--------
 4 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/gfx/thebes/gfxPlatform.h b/gfx/thebes/gfxPlatform.h
index 7ce11d08e67b..f484b8e5126a 100644
--- a/gfx/thebes/gfxPlatform.h
+++ b/gfx/thebes/gfxPlatform.h
@@ -805,6 +805,8 @@ class gfxPlatform : public mozilla::layers::MemoryPressureListener {
 
   static bool UseDesktopZoomingScrollbars();
 
+  virtual bool SupportsHDR() { return false; }
+
  protected:
   gfxPlatform();
   virtual ~gfxPlatform();
diff --git a/gfx/thebes/gfxPlatformMac.cpp b/gfx/thebes/gfxPlatformMac.cpp
index c1dbd2b7823e..af4de9217845 100644
--- a/gfx/thebes/gfxPlatformMac.cpp
+++ b/gfx/thebes/gfxPlatformMac.cpp
@@ -996,6 +996,24 @@ gfxPlatformMac::CreateGlobalHardwareVsyncSource() {
   return osxVsyncSource.forget();
 }
 
+bool gfxPlatformMac::SupportsHDR() {
+  // HDR has 3 requirements:
+  // 1) high peak brightness
+  // 2) high contrast ratio
+  // 3) color depth > 24
+  if (GetScreenDepth() <= 24) {
+    return false;
+  }
+  // Screen is capable. Is the OS capable?
+#ifdef EARLY_BETA_OR_EARLIER
+  // More-or-less supported in Catalina.
+  return nsCocoaFeatures::OnCatalinaOrLater();
+#else
+  // Definitely supported in Big Sur.
+  return nsCocoaFeatures::OnBigSurOrLater();
+#endif
+}
+
 nsTArray<uint8_t> gfxPlatformMac::GetPlatformCMSOutputProfileData() {
   nsTArray<uint8_t> prefProfileData = GetPrefCMSOutputProfileData();
   if (!prefProfileData.IsEmpty()) {
diff --git a/gfx/thebes/gfxPlatformMac.h b/gfx/thebes/gfxPlatformMac.h
index 00ab2c1ca864..29bbd7e877f7 100644
--- a/gfx/thebes/gfxPlatformMac.h
+++ b/gfx/thebes/gfxPlatformMac.h
@@ -76,6 +76,8 @@ class gfxPlatformMac : public gfxPlatform {
 
   static bool CheckVariationFontSupport();
 
+  bool SupportsHDR() override;
+
  protected:
   bool AccelerateLayersByDefault() override;
 
diff --git a/widget/cocoa/nsLookAndFeel.mm b/widget/cocoa/nsLookAndFeel.mm
index 23085324b244..7d9222566d66 100644
--- a/widget/cocoa/nsLookAndFeel.mm
+++ b/widget/cocoa/nsLookAndFeel.mm
@@ -484,13 +484,13 @@ nsresult nsLookAndFeel::NativeGetInt(IntID aID, int32_t& aResult) {
     case IntID::UseAccessibilityTheme:
       aResult = NSWorkspace.sharedWorkspace.accessibilityDisplayShouldIncreaseContrast;
       break;
-    case IntID::VideoDynamicRange:
-#ifdef EARLY_BETA_OR_EARLIER
-      aResult = nsCocoaFeatures::OnCatalinaOrLater();
-#else
-      aResult = nsCocoaFeatures::OnBigSurOrLater();
-#endif
+    case IntID::VideoDynamicRange: {
+      // If the platform says it supports HDR, then we claim to support video-dynamic-range.
+      gfxPlatform* platform = gfxPlatform::GetPlatform();
+      MOZ_ASSERT(platform);
+      aResult = platform->SupportsHDR();
       break;
+    }
     case IntID::PanelAnimations:
       aResult = 1;
       break;
@@ -687,8 +687,8 @@ void nsLookAndFeel::RecordAccessibilityTelemetry() {
 }
 
 - (void)cachedValuesChanged {
-  // We only need to re-cache (and broadcast) updated LookAndFeel values, so that they're up-to-date
-  // the next time they're queried. No further change handling is needed.
+  // We only need to re-cache (and broadcast) updated LookAndFeel values, so that they're
+  // up-to-date the next time they're queried. No further change handling is needed.
   // TODO: Add a change hint for this which avoids the unnecessary media query invalidation.
   LookAndFeel::NotifyChangedAllWindows(widget::ThemeChangeKind::MediaQueriesOnly);
 }