Batched implementation of drawLattice() for GPU

src/core/SkLatticeIter.cpp

Index: src/core/SkLatticeIter.cpp
diff --git a/src/core/SkLatticeIter.cpp b/src/core/SkLatticeIter.cpp
index 24ab3f1cbc29a11af6ded16de3965c93ac76b292..ba6ac97a5b4395807a22c482b05e95ccc985eb0c 100644
--- a/src/core/SkLatticeIter.cpp
+++ b/src/core/SkLatticeIter.cpp
@@ -159,6 +159,7 @@ SkLatticeIter::SkLatticeIter(int srcWidth, int srcHeight, const SkCanvas::Lattic
 
     fCurrX = fCurrY = 0;
     fDone = false;
+    fNumRects = (xCount + 1) * (yCount + 1);
 }
 
 bool SkLatticeIter::Valid(int width, int height, const SkIRect& center) {
@@ -205,6 +206,7 @@ SkLatticeIter::SkLatticeIter(int w, int h, const SkIRect& c, const SkRect& dst)
 
     fCurrX = fCurrY = 0;
     fDone = false;
+    fNumRects = 9;
 }
 
 bool SkLatticeIter::next(SkRect* src, SkRect* dst) {
@@ -228,3 +230,18 @@ bool SkLatticeIter::next(SkRect* src, SkRect* dst) {
     }
     return true;
 }
+
+void SkLatticeIter::mapDstScaleTranslate(const SkMatrix& matrix) {
+    SkASSERT(matrix.isScaleTranslate());
+    SkScalar tx = matrix.getTranslateX();
+    SkScalar sx = matrix.getScaleX();
+    for (int i = 0; i < fDstX.count(); i++) {
+        fDstX[i] = fDstX[i] * sx + tx;
+    }
+
+    SkScalar ty = matrix.getTranslateY();
+    SkScalar sy = matrix.getScaleY();
+    for (int i = 0; i < fDstY.count(); i++) {
+        fDstY[i] = fDstY[i] * sy + ty;
+    }
+}