add SubRunType for each SubRun to facilitate deserialization

Change-Id: I058eb13d4efc20197d81f15d2261906950d6e92e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/509397
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>

src/gpu/text/GrTextBlob.cpp

@@ -50,6 +50,16 @@ using AtlasTextOp = skgpu::v1::AtlasTextOp;
 // Note:
 //   In order to use GrSlugs, you need to set the fSupportBilerpFromGlyphAtlas on GrContextOptions.
 
+enum GrSubRun::SubRunType : int {
+    kBad = 0,  // Make this 0 to line up with errors from readInt.
+    kDirectMask,
+    kSDFT,
+    kTransformMask,
+    kPath,
+    kDrawable,
+    kSubRunTypeCount,
+};
+
 // -- GrBlobSubRun ---------------------------------------------------------------------------------
 class GrBlobSubRun {
 public:
@@ -509,6 +519,9 @@ public:
     }
     const GrAtlasSubRun* testingOnly_atlasSubRun() const override { return nullptr; }
 
+protected:
+    SubRunType subRunType() const override { return kPath; }
+
 private:
     PathOpSubmitter fPathDrawing;
 };
@@ -636,6 +649,9 @@ public:
 
     int unflattenSize() const override { return 0; }
 
+protected:
+    SubRunType subRunType() const override { return kDrawable; }
+
 private:
     DrawableOpSubmitter fDrawingDrawing;
 };
@@ -707,6 +723,10 @@ public:
                         GrColor color,
                         const SkMatrix& drawMatrix, SkPoint drawOrigin,
                         SkIRect clip) const override;
+
+protected:
+    SubRunType subRunType() const override { return kDirectMask; }
+
 private:
     // The rectangle that surrounds all the glyph bounding boxes in device space.
     SkRect deviceRect(const SkMatrix& drawMatrix, SkPoint drawOrigin) const;
@@ -1113,6 +1133,9 @@ public:
     size_t vertexStride(const SkMatrix& drawMatrix) const override;
     int glyphCount() const override;
 
+protected:
+    SubRunType subRunType() const override { return kTransformMask; }
+
 private:
     // The rectangle that surrounds all the glyph bounding boxes in device space.
     SkRect deviceRect(const SkMatrix& drawMatrix, SkPoint drawOrigin) const;
@@ -1324,6 +1347,9 @@ public:
     size_t vertexStride(const SkMatrix& drawMatrix) const override;
     int glyphCount() const override;
 
+protected:
+    SubRunType subRunType() const override { return kSDFT; }
+
 private:
     // The rectangle that surrounds all the glyph bounding boxes in device space.
     SkRect deviceRect(const SkMatrix& drawMatrix, SkPoint drawOrigin) const;
@@ -2725,6 +2751,9 @@ public:
                         const SkMatrix& drawMatrix, SkPoint drawOrigin,
                         SkIRect clip) const override;
 
+protected:
+    SubRunType subRunType() const override { return kDirectMask; }
+
 private:
     // Return true if the positionMatrix represents an integer translation. Return the device
     // bounding box of all the glyphs. If the bounding box is empty, then something went singular

src/gpu/text/GrTextBlob.h

@@ -38,7 +38,7 @@ class SkSurfaceProps;
 class SkTextBlob;
 class SkTextBlobRunIterator;
 
-namespace skgpu { namespace v1 { class SurfaceDrawContext; }}
+namespace skgpu::v1 { class SurfaceDrawContext; }
 
 // -- GrAtlasSubRun --------------------------------------------------------------------------------
 // GrAtlasSubRun is the API that AtlasTextOp uses to generate vertex data for drawing.
@@ -110,6 +110,10 @@ public:
     // of the slug. If it's off then there may be more allocations needed to unflatten.
     virtual int unflattenSize() const = 0;
 
+protected:
+    enum SubRunType : int;
+    virtual SubRunType subRunType() const = 0;
+
 private:
     friend class GrSubRunList;
     GrSubRunOwner fNext;
@@ -172,7 +176,6 @@ private:
 //
 class GrTextBlob final : public GrTextReferenceFrame, public SkGlyphRunPainterInterface {
 public:
-
     // Key is not used as part of a hash map, so the hash is never taken. It's only used in a
     // list search using operator =().
     struct Key {