Batched implementation of drawLattice() for GPU

Bechmarks (Nexus 6P):

Src=100x100, Dst=250x250, NumRects=9
Android              77.7us
Skia (without patch) 57.2us
Skia (with patch)    30.9us

Src=100x100, Dst=500x500, NumRects=9
Android              77.0us
Skia (without patch) 56.9us
Skia (with patch)    31.8us

Src=100x100, Dst=1000x1000, NumRects=9
Android              180us
Skia (without patch) 96.8us
Skia (with patch)    70.5us

Src=100x100, Dst=250x250, NumRects=15
Android              208us
Skia (without patch) 155us
Skia (with patch)    38.2us

Src=100x100, Dst=500x500, NumRects=15
Android              207us
Skia (without patch) 152us
Skia (with patch)    38.4us

Src=100x100, Dst=1000x1000, NumRects=15
Android              233us
Skia (without patch) 156us
Skia (with patch)    99.9us

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2255963002

Committed: https://skia.googlesource.com/skia/+/93242c4ae50dfcc0d922cdb3ba80bbc7b4bbe93d
Review-Url: https://codereview.chromium.org/2255963002

1 files changed, 13 insertions, 0 deletions

diff --git a/include/private/SkTArray.h b/include/private/SkTArray.h
index 1fe2c3857c..1c06bf331a 100644
--- a/include/private/SkTArray.h
+++ b/include/private/SkTArray.h
@@ -238,6 +238,19 @@ public:
     }
 
     /**
+     * Version of above that uses the move constructor to set n items.
+     */
+    T* move_back_n(int n, T* t) {
+        SkASSERT(n >= 0);
+        this->checkRealloc(n);
+        for (int i = 0; i < n; ++i) {
+            new (fItemArray + fCount + i) T(std::move(t[i]));
+        }
+        fCount += n;
+        return fItemArray + fCount - n;
+    }
+
+    /**
      * Removes the last element. Not safe to call when count() == 0.
      */
     void pop_back() {