SkChopCubicAt2 using Sk2s-- 2x faster

src/core/SkGeometry.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGeometry.h"
 #include "SkMatrix.h"
 #include "Sk2x.h"
@@ skipping 461 matching lines @@
     dst[12] = src[6];
 }
 
 void SkChopCubicAt(const SkPoint src[4], SkPoint dst[7], SkScalar t) {
     SkASSERT(t > 0 && t < SK_Scalar1);
 
     interp_cubic_coords(&src[0].fX, &dst[0].fX, t);
     interp_cubic_coords(&src[0].fY, &dst[0].fY, t);
 }
 
+void SkChopCubicAt2(const SkPoint src[4], SkPoint dst[7], SkScalar t) {
+    SkASSERT(t > 0 && t < SK_Scalar1);
+
+    Sk2s    p0 = from_point(src[0]);
+    Sk2s    p1 = from_point(src[1]);
+    Sk2s    p2 = from_point(src[2]);
+    Sk2s    p3 = from_point(src[3]);
+    Sk2s    tt(t);
+
+    Sk2s    ab = interp(p0, p1, tt);
+    Sk2s    bc = interp(p1, p2, tt);
+    Sk2s    cd = interp(p2, p3, tt);
+    Sk2s    abc = interp(ab, bc, tt);
+    Sk2s    bcd = interp(bc, cd, tt);
+    Sk2s    abcd = interp(abc, bcd, tt);
+    
+    dst[0] = src[0];
+    dst[1] = to_point(ab);
+    dst[2] = to_point(abc);
+    dst[3] = to_point(abcd);
+    dst[4] = to_point(bcd);
+    dst[5] = to_point(cd);
+    dst[6] = src[3];
+}
+
 /*  http://code.google.com/p/skia/issues/detail?id=32
 
     This test code would fail when we didn't check the return result of
     valid_unit_divide in SkChopCubicAt(... tValues[], int roots). The reason is
     that after the first chop, the parameters to valid_unit_divide are equal
     (thanks to finite float precision and rounding in the subtracts). Thus
     even though the 2nd tValue looks < 1.0, after we renormalize it, we end
     up with 1.0, hence the need to check and just return the last cubic as
     a degenerate clump of 4 points in the sampe place.
 
@@ skipping 1122 matching lines @@
         matrix.preScale(SK_Scalar1, -SK_Scalar1);
     }
     if (userMatrix) {
         matrix.postConcat(*userMatrix);
     }
     for (int i = 0; i < conicCount; ++i) {
         matrix.mapPoints(dst[i].fPts, 3);
     }
     return conicCount;
 }