combine setRectFan and mapRect

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2276603002

Review-Url: https://codereview.chromium.org/2276603002

2 files changed, 34 insertions, 2 deletions

diff --git a/src/core/SkMatrixPriv.h b/src/core/SkMatrixPriv.h
index 91185f08d1..844901c011 100644
--- a/src/core/SkMatrixPriv.h
+++ b/src/core/SkMatrixPriv.h
@@ -65,6 +65,38 @@ public:
             pts = (SkPoint*)((intptr_t)pts + stride);
         }
     }
+
+    static void SetMappedRectFan(const SkMatrix& mx, const SkRect& rect, SkPoint quad[4]) {
+        SkMatrix::TypeMask tm = mx.getType();
+        SkScalar l = rect.fLeft;
+        SkScalar t = rect.fTop;
+        SkScalar r = rect.fRight;
+        SkScalar b = rect.fBottom;
+        if (tm <= (SkMatrix::kScale_Mask | SkMatrix::kTranslate_Mask)) {
+            const SkScalar tx = mx.getTranslateX();
+            const SkScalar ty = mx.getTranslateY();
+            if (tm <= SkMatrix::kTranslate_Mask) {
+                l += tx;
+                t += ty;
+                r += tx;
+                b += ty;
+            } else {
+                const SkScalar sx = mx.getScaleX();
+                const SkScalar sy = mx.getScaleY();
+                l = sx * l + tx;
+                t = sy * t + ty;
+                r = sx * r + tx;
+                b = sy * b + ty;
+            }
+            quad[0].set(l, t);
+            quad[1].set(l, b);
+            quad[2].set(r, b);
+            quad[3].set(r, t);
+        } else {
+            quad[0].setRectFan(l, t, r, b);
+            mx.mapPoints(quad, quad, 4);
+        }
+    }
 };
 
 #endif
diff --git a/src/gpu/GrQuad.h b/src/gpu/GrQuad.h
index 9a8d1f3a4a..3a202c61cb 100644
--- a/src/gpu/GrQuad.h
+++ b/src/gpu/GrQuad.h
@@ -10,6 +10,7 @@
 
 #include "SkPoint.h"
 #include "SkMatrix.h"
+#include "SkMatrixPriv.h"
 
 /**
  * GrQuad is a collection of 4 points which can be used to represent an arbitrary quadrilateral
@@ -35,8 +36,7 @@ public:
     }
 
     void setFromMappedRect(const SkRect& rect, const SkMatrix& matrix) {
-        this->set(rect);
-        matrix.mapPoints(fPoints, kNumPoints);
+        SkMatrixPriv::SetMappedRectFan(matrix, rect, fPoints);
     }
 
     const GrQuad& operator=(const GrQuad& that) {