Implement AnalyticAA for convex shapes.

Design doc: go/analyticAA

A performance test can be found here: https://docs.google.com/a/google.com/spreadsheets/d/1n9LSjFzrQzx0hovFddWey0GSMXNRjl1oFuSypMlHWZk/edit?usp=sharing

Our best case is filling big triangles, which according to our experiment has ~2.9x speedup. Our worst case is filling small ovals/circles, which has a ~1.06x slowdown.

To see how our new algorithm changes the DM images, see: https://x20web.corp.google.com/~liyuqian/dmdiff/index.html
The most significant changes are in convexpaths and analytic_antialias_convex

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2221103002

Review-Url: https://codereview.chromium.org/2221103002

1 files changed, 22 insertions, 0 deletions

diff --git a/src/core/SkScan.h b/src/core/SkScan.h
index 4aa8e44399..1e3d60a290 100644
--- a/src/core/SkScan.h
+++ b/src/core/SkScan.h
@@ -22,6 +22,24 @@ class SkPath;
 */
 typedef SkIRect SkXRect;
 
+class GlobalAAConfig {
+private:
+    GlobalAAConfig() {}
+
+public:
+    bool fUseAnalyticAA = false;
+
+    GlobalAAConfig(const GlobalAAConfig&) = delete;
+    void operator=(const GlobalAAConfig&) = delete;
+
+    static GlobalAAConfig& getInstance() {
+        static GlobalAAConfig instance;
+        return instance;
+    }
+};
+
+class AdditiveBlitter;
+
 class SkScan {
 public:
     /*
@@ -45,6 +63,7 @@ public:
     static void AntiFillXRect(const SkXRect&, const SkRasterClip&, SkBlitter*);
     static void FillPath(const SkPath&, const SkRasterClip&, SkBlitter*);
     static void AntiFillPath(const SkPath&, const SkRasterClip&, SkBlitter*);
+    static void AAAFillPath(const SkPath&, const SkRasterClip&, SkBlitter*);
     static void FrameRect(const SkRect&, const SkPoint& strokeSize,
                           const SkRasterClip&, SkBlitter*);
     static void AntiFrameRect(const SkRect&, const SkPoint& strokeSize,
@@ -79,6 +98,9 @@ private:
                               const SkRegion*, SkBlitter*);
     static void HairLineRgn(const SkPoint[], int count, const SkRegion*, SkBlitter*);
     static void AntiHairLineRgn(const SkPoint[], int count, const SkRegion*, SkBlitter*);
+    static void AAAFillPath(const SkPath& path, const SkRegion& origClip, SkBlitter* blitter);
+    static void aaa_fill_path(const SkPath& path, const SkIRect* clipRect, AdditiveBlitter*,
+                   int start_y, int stop_y, const SkRegion& clipRgn, bool isUsingMask);
 };
 
 /** Assign an SkXRect from a SkIRect, by promoting the src rect's coordinates