Add SkGlyphRunList

Extend the glyph run system with a glyph run list. This
allows the processing of text blobs.

Add original text an cluster to runs for PDF.

Change-Id: If4867d000e45f8975a30e982fc8fdbe104ef4332
Reviewed-on: https://skia-review.googlesource.com/135627
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>

1 files changed, 64 insertions, 34 deletions

diff --git a/src/core/SkGlyphRun.h b/src/core/SkGlyphRun.h
index 243d5d121c..e4676d22df 100644
--- a/src/core/SkGlyphRun.h
+++ b/src/core/SkGlyphRun.h
@@ -24,36 +24,32 @@ template <typename T>
 class SkSpan {
 public:
     SkSpan() : fPtr{nullptr}, fSize{0} {}
-    SkSpan(const T* ptr, size_t size) : fPtr{ptr}, fSize{size} {}
-    explicit SkSpan(const std::vector<T>& v) : fPtr{v.data()}, fSize{v.size()} {}
-    const T& operator [] (ptrdiff_t i) const { return fPtr[i]; }
+    SkSpan(T* ptr, size_t size) : fPtr{ptr}, fSize{size} {}
+    explicit SkSpan(std::vector<T>& v) : fPtr{v.data()}, fSize{v.size()} {}
+    SkSpan& operator=( const SkSpan& other ) = default;
+    T& operator [] (ptrdiff_t i) const { return fPtr[i]; }
     T* begin() const { return fPtr; }
     T* end() const { return fPtr + fSize; }
     const T* cbegin() const { return fPtr; }
     const T* cend() const { return fPtr + fSize; }
-    const T* data() const { return fPtr; }
+    T* data() const { return fPtr; }
     ptrdiff_t size() const { return fSize; }
     bool empty() const { return fSize == 0; }
 
 private:
-    const T* fPtr;
+    T* fPtr;
     size_t fSize;
 };
 
 class SkGlyphRun {
 public:
     SkGlyphRun() = default;
-    SkGlyphRun(SkSpan<uint16_t>  denseIndex,
-               SkSpan<SkPoint>   positions,
-               SkSpan<SkGlyphID> scratchGlyphs,
-               SkSpan<SkGlyphID> uniqueGlyphIDs)
-            : fDenseIndex{denseIndex}
-            , fPositions{positions}
-            , fTemporaryShuntGlyphIDs{scratchGlyphs}
-            , fUniqueGlyphIDs{uniqueGlyphIDs} {
-        SkASSERT(denseIndex.size() == positions.size());
-        SkASSERT(denseIndex.size() == scratchGlyphs.size());
-    }
+    SkGlyphRun(SkSpan<uint16_t>   denseIndex,
+               SkSpan<SkPoint>    positions,
+               SkSpan<SkGlyphID>  scratchGlyphs,
+               SkSpan<SkGlyphID>  uniqueGlyphIDs,
+               SkSpan<const char> text,
+               SkSpan<uint32_t>   clusters);
 
     // The temporaryShunt calls are to allow inter-operating with existing code while glyph runs
     // are developed.
@@ -67,13 +63,33 @@ public:
 
 private:
     // Indices into the unique glyph IDs. On for each original glyph.
-    const SkSpan<uint16_t>  fDenseIndex;
+    const SkSpan<uint16_t>   fDenseIndex;
     // The base line position of all the glyphs in source space.
-    const SkSpan<SkPoint>   fPositions;
+    const SkSpan<SkPoint>    fPositions;
     // This is temporary while converting from the old per glyph code to the bulk code.
-    const SkSpan<SkGlyphID> fTemporaryShuntGlyphIDs;
+    const SkSpan<SkGlyphID>  fTemporaryShuntGlyphIDs;
     // The set of unique glyphs in the run.
-    const SkSpan<SkGlyphID> fUniqueGlyphIDs;
+    const SkSpan<SkGlyphID>  fUniqueGlyphIDs;
+    // Original text from SkTextBlob if present. Will be empty of not present.
+    const SkSpan<const char> fText;
+    // Original clusters from SkTextBlob if present. Will be empty if not present.
+    const SkSpan<uint32_t>   fClusters;
+};
+
+class SkGlyphRunList {
+    const uint64_t     fUniqueID{0};
+    SkSpan<SkGlyphRun> fGlyphRuns;
+
+public:
+    SkGlyphRunList() = default;
+    SkGlyphRunList(SkSpan<SkGlyphRun> glyphRuns, uint64_t uniqueID);
+
+    uint64_t uniqueID() const { return fUniqueID; }
+
+    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 operator [] (ptrdiff_t i) -> decltype(fGlyphRuns[i])  { return fGlyphRuns[i];      }
 };
 
 // A faster set implementation that does not need any initialization, and reading the set items
@@ -92,10 +108,6 @@ private:
     std::vector<SkGlyphID>*     fUniqueGlyphIDs{nullptr};
 };
 
-// Currently the old code is passing around SkGlyphRunBuilder because it facilitates working in the
-// old single glyph lookup style with the cache. When the lower level code is transitioned over to
-// the bulk glyph cache style, then the builder will only be used in the canvas, and only runs will
-// be passed around.
 class SkGlyphRunBuilder {
 public:
     SkGlyphRunBuilder() = default;
@@ -106,32 +118,50 @@ public:
             const SkScalar xpos[], SkScalar constY);
     void prepareDrawPosText(
             const SkPaint& paint, const void* bytes, size_t byteLength, const SkPoint pos[]);
+    void prepareTextBlob(const SkPaint& paint, const SkTextBlob& blob, SkPoint origin);
 
-    size_t runSize() const {return fDenseIndex.size();}
-    size_t uniqueSize() const {return fUniqueGlyphs.size();}
-
+    SkGlyphRunList* useGlyphRunList();
     SkGlyphRun* useGlyphRun();
 
 private:
-    void initializeDenseAndUnique(const SkPaint& paint, const void* bytes, size_t byteLength);
+    size_t runSize() const;
+    size_t uniqueSize() const;
+    void initialize();
+    SkGlyphID* addDenseAndUnique(const SkPaint& paint, const void* bytes, size_t byteLength);
+    void addGlyphRunToList(
+            SkGlyphID* temporaryShuntGlyphIDs, SkSpan<const char> text, SkSpan<uint32_t> clusters);
+
+    void drawText(
+            const SkPaint& paint, const void* bytes, size_t byteLength, SkPoint origin,
+            SkSpan<const char> text, SkSpan<uint32_t> clusters);
+    void drawPosTextH(
+            const SkPaint& paint, const void* bytes, size_t byteLength,
+            const SkScalar* xpos, SkScalar constY,
+            SkSpan<const char> text, SkSpan<uint32_t> clusters);
+    void drawPosText(
+            const SkPaint& paint, const void* bytes, size_t byteLength, const SkPoint* pos,
+            SkSpan<const char> text, SkSpan<uint32_t> clusters);
+
+    uint64_t               fUniqueID{0};
 
     std::vector<uint16_t>  fDenseIndex;
     std::vector<SkPoint>   fPositions;
     std::vector<SkGlyphID> fUniqueGlyphs;
 
+    size_t                 fLastDenseIndex{0};
+    size_t                 fLastUniqueIndex{0};
+
     // Used as a temporary for preparing using utfN text.
     std::vector<SkGlyphID> fScratchGlyphIDs;
 
     // Used as temporary storage for calculating positions for drawText.
     std::vector<SkPoint>   fScratchAdvances;
 
-    // Used to temporarily use of a glyph run for bulk cache API calls (just an experiment at
-    // this point).
-    SkGlyphRun             fScratchGlyphRun;
+    // Vector for accumulating runs. This is later deposited in fScratchGlyphRunList;
+    std::vector<SkGlyphRun> fGlyphRuns;
 
-    // Used as an aid to shunt from glyph runs to drawPosText. It will either be fScratchIDs or
-    // the bytes passed in.
-    const SkGlyphID*       fTemporaryShuntGlyphIDs{nullptr};
+    // Used as temporary glyph run for the rest of the Text stack.
+    SkGlyphRunList         fScratchGlyphRunList;
 
     // Used for collecting the set of unique glyphs.
     SkGlyphSet             fGlyphSet;