Bug 1875670 - Create a refcounted object for resolved color-font palette, instead of just a bare nsTArray. r=gfx-reviewers,lsalzman

This does not change behavior for users; it is preparation for the
following patch, which will want the ability to hold an additional
strong reference to a resolved palette. So we can no longer just own it
via a UniquePtr; we make it a RefPtr instead.

Differential Revision: https://phabricator.services.mozilla.com/D200138

gfx/thebes/COLRFonts.cpp

@@ -2576,7 +2576,7 @@ uint16_t COLRFonts::GetColrTableVersion(hb_blob_t* aCOLR) {
   return colr->version;
 }
 
-UniquePtr<nsTArray<sRGBColor>> COLRFonts::SetupColorPalette(
+nsTArray<sRGBColor> COLRFonts::CreateColorPalette(
     hb_face_t* aFace, const FontPaletteValueSet* aPaletteValueSet,
     nsAtom* aFontPalette, const nsACString& aFamilyName) {
   // Find the base color palette to use, if there are multiple available;
@@ -2631,10 +2631,10 @@ UniquePtr<nsTArray<sRGBColor>> COLRFonts::SetupColorPalette(
   hb_ot_color_palette_get_colors(aFace, paletteIndex, 0, &count,
                                  colors.Elements());
 
-  auto palette = MakeUnique<nsTArray<sRGBColor>>();
-  palette->SetCapacity(count);
+  nsTArray<sRGBColor> palette;
+  palette.SetCapacity(count);
   for (const auto c : colors) {
-    palette->AppendElement(
+    palette.AppendElement(
         sRGBColor(hb_color_get_red(c) / 255.0, hb_color_get_green(c) / 255.0,
                   hb_color_get_blue(c) / 255.0, hb_color_get_alpha(c) / 255.0));
   }
@@ -2642,8 +2642,8 @@ UniquePtr<nsTArray<sRGBColor>> COLRFonts::SetupColorPalette(
   // Apply @font-palette-values overrides, if present.
   if (fpv) {
     for (const auto overrideColor : fpv->mOverrides) {
-      if (overrideColor.mIndex < palette->Length()) {
-        (*palette)[overrideColor.mIndex] = overrideColor.mColor;
+      if (overrideColor.mIndex < palette.Length()) {
+        palette[overrideColor.mIndex] = overrideColor.mColor;
       }
     }
   }

gfx/thebes/COLRFonts.h

@@ -126,7 +126,7 @@ class COLRFonts {
 
   static uint16_t GetColrTableVersion(hb_blob_t* aCOLR);
 
-  static UniquePtr<nsTArray<sRGBColor>> SetupColorPalette(
+  static nsTArray<sRGBColor> CreateColorPalette(
       hb_face_t* aFace, const FontPaletteValueSet* aPaletteValueSet,
       nsAtom* aFontPalette, const nsACString& aFamilyName);
 };

gfx/thebes/FontPaletteCache.cpp

@@ -5,6 +5,7 @@
 
 #include "FontPaletteCache.h"
 #include "COLRFonts.h"
+#include "gfxFontEntry.h"
 
 using namespace mozilla;
 
@@ -14,7 +15,7 @@ void gfx::PaletteCache::SetPaletteValueSet(
   Clear();
 }
 
-nsTArray<gfx::sRGBColor>* gfx::PaletteCache::GetPaletteFor(
+already_AddRefed<gfx::FontPalette> gfx::PaletteCache::GetPaletteFor(
     gfxFontEntry* aFontEntry, nsAtom* aPaletteName) {
   auto entry = Lookup(std::pair(aFontEntry, aPaletteName));
   if (!entry) {
@@ -22,10 +23,11 @@ nsTArray<gfx::sRGBColor>* gfx::PaletteCache::GetPaletteFor(
     newData.mKey = std::pair(aFontEntry, aPaletteName);
 
     gfxFontEntry::AutoHBFace face = aFontEntry->GetHBFace();
-    newData.mPalette = gfx::COLRFonts::SetupColorPalette(
-        face, mPaletteValueSet, aPaletteName, aFontEntry->FamilyName());
+    newData.mPalette = new FontPalette(gfx::COLRFonts::CreateColorPalette(
+        face, mPaletteValueSet, aPaletteName, aFontEntry->FamilyName()));
 
     entry.Set(std::move(newData));
   }
-  return entry.Data().mPalette.get();
+  RefPtr result = entry.Data().mPalette;
+  return result.forget();
 }

gfx/thebes/FontPaletteCache.h

@@ -6,23 +6,43 @@
 #ifndef FONT_PALETTE_CACHE_H
 #define FONT_PALETTE_CACHE_H
 
-#include "gfxFontEntry.h"
 #include "mozilla/gfx/Types.h"
 #include "mozilla/MruCache.h"
 #include "mozilla/HashFunctions.h"
+#include "mozilla/RefPtr.h"
 #include "nsAtom.h"
+#include "nsTArray.h"
 #include <utility>
 
+class gfxFontEntry;
+
 namespace mozilla::gfx {
 
 class FontPaletteValueSet;
 
+// A resolved font palette as an array of colors.
+class FontPalette {
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(FontPalette);
+
+ public:
+  FontPalette() = default;
+  explicit FontPalette(nsTArray<mozilla::gfx::sRGBColor>&& aColors)
+      : mColors(std::move(aColors)) {}
+
+  const nsTArray<mozilla::gfx::sRGBColor>* Colors() const { return &mColors; }
+
+ private:
+  ~FontPalette() = default;
+
+  nsTArray<mozilla::gfx::sRGBColor> mColors;
+};
+
 // MRU cache used for resolved color-font palettes, to avoid reconstructing
 // the palette for each glyph rendered with a given font.
 using CacheKey = std::pair<RefPtr<gfxFontEntry>, RefPtr<nsAtom>>;
 struct CacheData {
   CacheKey mKey;
-  mozilla::UniquePtr<nsTArray<mozilla::gfx::sRGBColor>> mPalette;
+  RefPtr<FontPalette> mPalette;
 };
 
 class PaletteCache
@@ -33,8 +53,8 @@ class PaletteCache
 
   void SetPaletteValueSet(const FontPaletteValueSet* aSet);
 
-  nsTArray<mozilla::gfx::sRGBColor>* GetPaletteFor(gfxFontEntry* aFontEntry,
-                                                   nsAtom* aPaletteName);
+  already_AddRefed<FontPalette> GetPaletteFor(gfxFontEntry* aFontEntry,
+                                              nsAtom* aPaletteName);
 
   static mozilla::HashNumber Hash(const CacheKey& aKey) {
     return mozilla::HashGeneric(aKey.first.get(), aKey.second.get());

gfx/thebes/gfxFont.cpp

@@ -2676,7 +2676,7 @@ bool gfxFont::RenderColorGlyph(DrawTarget* aDrawTarget, gfxContext* aContext,
           GetFontEntry()->GetCOLR(), hbShaper->GetHBFont(), paintGraph,
           aDrawTarget, aTextDrawer, aFontParams.scaledFont,
           aFontParams.drawOptions, aPoint, aFontParams.currentColor,
-          aFontParams.palette, aGlyphId, mFUnitsConvFactor);
+          aFontParams.palette->Colors(), aGlyphId, mFUnitsConvFactor);
     }
   }
 
@@ -2686,7 +2686,7 @@ bool gfxFont::RenderColorGlyph(DrawTarget* aDrawTarget, gfxContext* aContext,
     bool ok = COLRFonts::PaintGlyphLayers(
         GetFontEntry()->GetCOLR(), face, layers, aDrawTarget, aTextDrawer,
         aFontParams.scaledFont, aFontParams.drawOptions, aPoint,
-        aFontParams.currentColor, aFontParams.palette);
+        aFontParams.currentColor, aFontParams.palette->Colors());
     return ok;
   }
 

gfx/thebes/gfxFont.h

@@ -10,7 +10,6 @@
 #include <new>
 #include <utility>
 #include <functional>
-#include "FontPaletteCache.h"
 #include "PLDHashTable.h"
 #include "ThebesRLBoxTypes.h"
 #include "gfxFontVariations.h"
@@ -27,6 +26,7 @@
 #include "mozilla/RWLock.h"
 #include "mozilla/TypedEnumBits.h"
 #include "mozilla/UniquePtr.h"
+#include "mozilla/gfx/FontPaletteCache.h"
 #include "mozilla/gfx/MatrixFwd.h"
 #include "mozilla/gfx/Point.h"
 #include "mozilla/gfx/2D.h"
@@ -2338,7 +2338,7 @@ struct MOZ_STACK_CLASS FontDrawParams {
   mozilla::gfx::DrawOptions drawOptions;
   gfxFloat advanceDirection;
   mozilla::gfx::sRGBColor currentColor;
-  nsTArray<mozilla::gfx::sRGBColor>* palette;  // owned by TextRunDrawParams
+  RefPtr<mozilla::gfx::FontPalette> palette;
   mozilla::gfx::Rect fontExtents;
   bool isVerticalFont;
   bool haveSVGGlyphs;

gfx/thebes/moz.build

@@ -19,7 +19,6 @@ XPIDL_MODULE = "gfx"
 EXPORTS += [
     "COLRFonts.h",
     "DrawMode.h",
-    "FontPaletteCache.h",
     "gfx2DGlue.h",
     "gfxAlphaRecovery.h",
     "gfxASurface.h",
@@ -71,6 +70,7 @@ EXPORTS.mozilla.gfx += [
     "D3D11Checks.h",
     "DeviceManagerDx.h",
     "DisplayConfigWindows.h",
+    "FontPaletteCache.h",
     "PrintPromise.h",
     "PrintTarget.h",
     "PrintTargetThebes.h",