Bug 1740530 - patch 5 - Implement support for COLRv1 glyphs represented as acyclic graphs of paint records. r=gfx-reviewers,lsalzman

Depends on D153870

Differential Revision: https://phabricator.services.mozilla.com/D152041

gfx/thebes/COLRFonts.h

@@ -10,6 +10,7 @@
 
 struct hb_blob_t;
 struct hb_face_t;
+struct hb_font_t;
 
 namespace mozilla {
 
@@ -18,21 +19,44 @@ class TextDrawTarget;
 }
 
 namespace gfx {
-struct COLRBaseGlyphRecord;
 
 class COLRFonts {
  public:
-  // for color layer from glyph using COLR and CPAL tables
   static bool ValidateColorGlyphs(hb_blob_t* aCOLR, hb_blob_t* aCPAL);
 
-  static const COLRBaseGlyphRecord* GetGlyphLayers(hb_blob_t* aCOLR,
-                                                   uint32_t aGlyphId);
+  // COLRv0: color glyph is represented as a simple list of colored layers.
+  struct GlyphLayers;
+
+  static const GlyphLayers* GetGlyphLayers(hb_blob_t* aCOLR, uint32_t aGlyphId);
 
   static bool PaintGlyphLayers(
-      hb_blob_t* aCOLR, hb_face_t* aFace, const COLRBaseGlyphRecord* aLayers,
+      hb_blob_t* aCOLR, hb_face_t* aFace, const GlyphLayers* aLayers,
       DrawTarget* aDrawTarget, layout::TextDrawTarget* aTextDrawer,
       ScaledFont* aScaledFont, DrawOptions aDrawOptions,
       const sRGBColor& aCurrentColor, const Point& aPoint);
+
+  // COLRv1 support: color glyph is represented by a directed acyclic graph of
+  // paint records.
+  struct GlyphPaintGraph;
+
+  static const GlyphPaintGraph* GetGlyphPaintGraph(hb_blob_t* aCOLR,
+                                                   uint32_t aGlyphId);
+
+  static bool PaintGlyphGraph(hb_blob_t* aCOLR, hb_font_t* aFont,
+                              const GlyphPaintGraph* aPaintGraph,
+                              DrawTarget* aDrawTarget,
+                              layout::TextDrawTarget* aTextDrawer,
+                              ScaledFont* aScaledFont, DrawOptions aDrawOptions,
+                              const sRGBColor& aCurrentColor,
+                              const Point& aPoint, uint32_t aGlyphId,
+                              float aFontUnitsToPixels);
+
+  static Rect GetColorGlyphBounds(hb_blob_t* aCOLR, hb_font_t* aFont,
+                                  uint32_t aGlyphId, DrawTarget* aDrawTarget,
+                                  ScaledFont* aScaledFont,
+                                  float aFontUnitsToPixels);
+
+  static uint16_t GetColrTableVersion(hb_blob_t* aCOLR);
 };
 
 }  // namespace gfx

gfx/thebes/gfxFont.cpp

@@ -2466,7 +2466,7 @@ bool gfxFont::RenderColorGlyph(DrawTarget* aDrawTarget, gfxContext* aContext,
                                layout::TextDrawTarget* aTextDrawer,
                                ScaledFont* aScaledFont,
                                DrawOptions aDrawOptions, const Point& aPoint,
-                               uint32_t aGlyphId) const {
+                               uint32_t aGlyphId) {
   auto currentColor = [=]() {
     DeviceColor ctxColor;
     return aContext->GetDeviceColor(ctxColor)
@@ -2474,6 +2474,17 @@ bool gfxFont::RenderColorGlyph(DrawTarget* aDrawTarget, gfxContext* aContext,
                : sRGBColor::OpaqueBlack();
   };
 
+  if (const auto* paintGraph =
+          COLRFonts::GetGlyphPaintGraph(GetFontEntry()->GetCOLR(), aGlyphId)) {
+    const auto* hbShaper = GetHarfBuzzShaper();
+    if (hbShaper && hbShaper->IsInitialized()) {
+      return COLRFonts::PaintGlyphGraph(
+          GetFontEntry()->GetCOLR(), hbShaper->GetHBFont(), paintGraph,
+          aDrawTarget, aTextDrawer, aScaledFont, aDrawOptions, currentColor(),
+          aPoint, aGlyphId, mFUnitsConvFactor);
+    }
+  }
+
   if (const auto* layers =
           COLRFonts::GetGlyphLayers(GetFontEntry()->GetCOLR(), aGlyphId)) {
     auto face(GetFontEntry()->GetHBFace());
@@ -2509,7 +2520,8 @@ bool gfxFont::HasColorGlyphFor(uint32_t aCh, uint32_t aNextCh) {
   }
   // Check if there is a COLR/CPAL or SVG glyph for this ID.
   if (fe->TryGetColorGlyphs() &&
-      COLRFonts::GetGlyphLayers(fe->GetCOLR(), gid)) {
+      (COLRFonts::GetGlyphPaintGraph(fe->GetCOLR(), gid) ||
+       COLRFonts::GetGlyphLayers(fe->GetCOLR(), gid))) {
     return true;
   }
   if (fe->TryGetSVGData(this) && fe->HasSVGGlyph(gid)) {
@@ -3613,6 +3625,24 @@ void gfxFont::SetupGlyphExtents(DrawTarget* aDrawTarget, uint32_t aGlyphID,
     return;
   }
 
+  if (mFontEntry->TryGetColorGlyphs() && mFontEntry->mCOLR &&
+      COLRFonts::GetColrTableVersion(mFontEntry->mCOLR) == 1) {
+    auto* shaper = GetHarfBuzzShaper();
+    if (shaper && shaper->IsInitialized()) {
+      RefPtr scaledFont = GetScaledFont(aDrawTarget);
+      Rect r = COLRFonts::GetColorGlyphBounds(
+          mFontEntry->mCOLR, shaper->GetHBFont(), aGlyphID, aDrawTarget,
+          scaledFont, mFUnitsConvFactor);
+      if (!r.IsEmpty()) {
+        gfxFloat d2a = aExtents->GetAppUnitsPerDevUnit();
+        aExtents->SetTightGlyphExtents(
+            aGlyphID, gfxRect(r.X() * d2a, r.Y() * d2a, r.Width() * d2a,
+                              r.Height() * d2a));
+        return;
+      }
+    }
+  }
+
   gfxRect bounds;
   GetGlyphBounds(aGlyphID, &bounds, mAntialiasOption == kAntialiasNone);
 

gfx/thebes/gfxFont.h

@@ -2253,8 +2253,7 @@ class gfxFont {
                         mozilla::layout::TextDrawTarget* aTextDrawer,
                         mozilla::gfx::ScaledFont* scaledFont,
                         mozilla::gfx::DrawOptions drawOptions,
-                        const mozilla::gfx::Point& aPoint,
-                        uint32_t aGlyphId) const;
+                        const mozilla::gfx::Point& aPoint, uint32_t aGlyphId);
 
   // Bug 674909. When synthetic bolding text by drawing twice, need to
   // render using a pixel offset in device pixels, otherwise text

gfx/thebes/gfxHarfBuzzShaper.h

@@ -100,6 +100,9 @@ class gfxHarfBuzzShaper : public gfxFontShaper {
                                  hb_font_funcs_t* aFontFuncs = nullptr,
                                  FontCallbackData* aCallbackData = nullptr);
 
+  hb_font_t* GetHBFont() const { return mHBFont; }
+  hb_face_t* GetHBFace() const { return hb_font_get_face(mHBFont); }
+
  protected:
   nsresult SetGlyphsFromRun(gfxShapedText* aShapedText, uint32_t aOffset,
                             uint32_t aLength, const char16_t* aText,

modules/libpref/init/StaticPrefList.yaml

@@ -5702,6 +5702,11 @@
     mirror: always
 #endif
 
+- name: gfx.font_rendering.colr_v1.enabled
+  type: RelaxedAtomicBool
+  value: false
+  mirror: always
+
 - name: gfx.font_rendering.opentype_svg.enabled
   type: RelaxedAtomicBool
   value: true