const all the things

Having the glyph run list be const as it passes through the stack means
that future change can't be introduced in the device code that changes
behavior. Try to force all text changes into the SkGylphRun system.

Change-Id: I9412bc094c7adb8554887c725a6264af306e1d42
Reviewed-on: https://skia-review.googlesource.com/143702
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>

1 files changed, 19 insertions, 20 deletions

diff --git a/src/core/SkGlyphRun.h b/src/core/SkGlyphRun.h
index 8348fe9013..b2d1aad265 100644
--- a/src/core/SkGlyphRun.h
+++ b/src/core/SkGlyphRun.h
@@ -56,7 +56,7 @@ public:
     SkGlyphRun() = default;
     SkGlyphRun(SkPaint&& runPaint,
                SkSpan<const uint16_t> denseIndices,
-               SkSpan<SkPoint> positions,
+               SkSpan<const SkPoint> positions,
                SkSpan<const SkGlyphID> glyphIDs,
                SkSpan<const SkGlyphID> uniqueGlyphIDs,
                SkSpan<const char> text,
@@ -65,7 +65,6 @@ public:
     // A function that turns an SkGlyphRun into an SkGlyphRun for each glyph.
     using PerGlyph = std::function<void (SkGlyphRun*, SkPaint*)>;
     void eachGlyphToGlyphRun(PerGlyph perGlyph);
-    void mapPositions(const SkMatrix& matrix);
 
     // The following made a ~5% speed improvement over not using a template.
     //using PerGlyphPos = std::function<void (SkGlyphID glyphID, SkPoint positions)>;
@@ -91,7 +90,7 @@ private:
     //
     const SkSpan<const uint16_t> fUniqueGlyphIDIndices;
     //
-    const SkSpan<SkPoint> fPositions;
+    const SkSpan<const SkPoint> fPositions;
     // This is temporary while converting from the old per glyph code to the bulk code.
     const SkSpan<const SkGlyphID> fGlyphIDs;
     // The unique glyphs from fGlyphIDs.
@@ -115,21 +114,21 @@ public:
     using PerPath = std::function<void(const SkPath&, const SkMatrix&)>;
     using PerPathCreator = std::function<PerPath(const SkPaint&, SkArenaAlloc* alloc)>;
     void drawForBitmap(
-            SkGlyphRunList* glyphRunList, const SkMatrix& deviceMatrix,
+            const SkGlyphRunList& glyphRunList, const SkMatrix& deviceMatrix,
             PerMaskCreator perMaskCreator, PerPathCreator perPathCreator);
 
 private:
     static bool ShouldDrawAsPath(const SkPaint& paint, const SkMatrix& matrix);
     bool ensureBitmapBuffers(size_t runSize);
     void drawGlyphRunAsPaths(
-            SkGlyphRun* glyphRun, SkPoint origin,
+            const SkGlyphRun& glyphRun, SkPoint origin,
             const SkSurfaceProps& props, PerPath perPath) const;
     void drawGlyphRunAsSubpixelMask(
-            SkGlyphCache* cache, SkGlyphRun* glyphRun,
+            SkGlyphCache* cache, const SkGlyphRun& glyphRun,
             SkPoint origin, const SkMatrix& deviceMatrix,
             PerMask perMask);
     void drawGlyphRunAsFullpixelMask(
-            SkGlyphCache* cache, SkGlyphRun* glyphRun,
+            SkGlyphCache* cache, const SkGlyphRun& glyphRun,
             SkPoint origin, const SkMatrix& deviceMatrix,
             PerMask perMask);
     // The props as on the actual device.
@@ -179,22 +178,23 @@ public:
     const SkPaint& paint() const { return *fOriginalPaint; }
     const SkTextBlob* blob() const { return fOriginalTextBlob; }
 
-    auto begin() -> decltype(fGlyphRuns.begin())               { return fGlyphRuns.begin(); }
-    auto end()   -> decltype(fGlyphRuns.end())                 { return fGlyphRuns.end();   }
-    auto size()  -> decltype(fGlyphRuns.size())                { return fGlyphRuns.size();  }
-    auto empty() -> decltype(fGlyphRuns.empty())               { return fGlyphRuns.empty(); }
-    auto operator [] (size_t i) -> decltype(fGlyphRuns[i])     { return fGlyphRuns[i];      }
-    void temporaryShuntToDrawPosText(SkBaseDevice* device, SkPoint origin) {
+    auto begin() -> decltype(fGlyphRuns.begin())               { return fGlyphRuns.begin();  }
+    auto end()   -> decltype(fGlyphRuns.end())                 { return fGlyphRuns.end();    }
+    auto begin() const -> decltype(fGlyphRuns.cbegin())        { return fGlyphRuns.cbegin(); }
+    auto end()   const -> decltype(fGlyphRuns.cend())          { return fGlyphRuns.cend();   }
+    auto size()  const -> decltype(fGlyphRuns.size())          { return fGlyphRuns.size();   }
+    auto empty() const -> decltype(fGlyphRuns.empty())         { return fGlyphRuns.empty();  }
+    auto operator [] (size_t i) const -> decltype(fGlyphRuns[i]) { return fGlyphRuns[i];     }
+    void temporaryShuntToDrawPosText(SkBaseDevice* device, SkPoint origin) const {
         for (auto& run : fGlyphRuns) {
             run.temporaryShuntToDrawPosText(device, origin);
         }
     }
-
 };
 
 class SkGlyphRunListIterator {
 public:
-    explicit SkGlyphRunListIterator(SkGlyphRunList* list) : fList{*list} {}
+    explicit SkGlyphRunListIterator(const SkGlyphRunList& list) : fList{list} {}
 
     bool done() const { return fIndex == fList.size(); }
     void next() { fIndex += 1;}
@@ -213,7 +213,7 @@ public:
 private:
     static constexpr SkPoint fZero{0, 0};
     size_t fIndex{0};
-    SkGlyphRunList& fList;
+    const SkGlyphRunList& fList;
 };
 
 class SkGlyphIDSet {
@@ -238,7 +238,7 @@ public:
             const SkPaint& paint, const void* bytes, size_t byteLength, const SkPoint* pos);
     void drawTextBlob(const SkPaint& paint, const SkTextBlob& blob, SkPoint origin);
 
-    SkGlyphRunList* useGlyphRunList();
+    const SkGlyphRunList& useGlyphRunList();
 
 private:
     void initialize(size_t totalRunSize);
@@ -255,7 +255,7 @@ private:
     void makeGlyphRun(
             const SkPaint& runPaint,
             SkSpan<const SkGlyphID> glyphIDs,
-            SkSpan<SkPoint> positions,
+            SkSpan<const SkPoint> positions,
             SkSpan<const uint16_t> uniqueGlyphIDIndices,
             SkSpan<const SkGlyphID> uniqueGlyphIDs,
             SkSpan<const char> text,
@@ -280,7 +280,6 @@ private:
             SkSpan<const char> text = SkSpan<const char>{},
             SkSpan<const uint32_t> clusters = SkSpan<const uint32_t>{});
 
-
     size_t fMaxTotalRunSize{0};
     SkAutoTMalloc<uint16_t> fUniqueGlyphIDIndices;
     SkAutoTMalloc<SkPoint> fPositions;
@@ -303,7 +302,7 @@ private:
 
 template <typename PerGlyphPos>
 inline void SkGlyphRun::forEachGlyphAndPosition(PerGlyphPos perGlyph) const {
-    SkPoint* ptCursor = fPositions.data();
+    const SkPoint* ptCursor = fPositions.data();
     for (auto glyphID : fGlyphIDs) {
         perGlyph(glyphID, *ptCursor++);
     }