speedup haircubics

src/core/SkGeometry.cpp

Index: src/core/SkGeometry.cpp
diff --git a/src/core/SkGeometry.cpp b/src/core/SkGeometry.cpp
index 50af22de37d1acc968676bd581f90fe9cf5696b5..02b9eb9aa131cc45ad8820bb3218f83cabda795b 100644
--- a/src/core/SkGeometry.cpp
+++ b/src/core/SkGeometry.cpp
@@ -9,6 +9,7 @@
 #include "SkMatrix.h"
 #include "SkNx.h"
 
+#if 0
 static Sk2s from_point(const SkPoint& point) {
     return Sk2s::Load(&point.fX);
 }
@@ -18,6 +19,7 @@ static SkPoint to_point(const Sk2s& x) {
     x.store(&point.fX);
     return point;
 }
+#endif
 
 static SkVector to_vector(const Sk2s& x) {
     SkVector vector;
@@ -452,6 +454,32 @@ void SkChopCubicAt(const SkPoint src[4], SkPoint dst[7], SkScalar t) {
     dst[6] = src[3];
 }
 
+void SkCubicToPoly(const SkPoint pts[4], SkPoint coeff[4]) {
+    Sk2s p0 = from_point(pts[0]);
+    Sk2s p1 = from_point(pts[1]);
+    Sk2s p2 = from_point(pts[2]);
+    Sk2s p3 = from_point(pts[3]);
+
+    const Sk2s three(3);
+    Sk2s p1minusp2 = p1 - p2;
+
+    Sk2s D = p0;
+    Sk2s A = p3 + three * p1minusp2 - D;
+    Sk2s B = three * (D - p1minusp2 - p1);
+    Sk2s C = three * (p1 - D);
+
+    coeff[0] = to_point(A);
+    coeff[1] = to_point(B);
+    coeff[2] = to_point(C);
+    coeff[3] = to_point(D);
+}
+
+SkPoint SkEvalCubicPolyAt(const SkPoint coeff[4], SkScalar t) {
+    Sk2s pt = sk2s_cubic_eval(from_point(coeff[0]), from_point(coeff[1]),
+                              from_point(coeff[2]), from_point(coeff[3]), Sk2s(t));
+    return to_point(pt);
+}
+
 /*  http://code.google.com/p/skia/issues/detail?id=32
 
     This test code would fail when we didn't check the return result of