Speeup hairline curves (quads and cubics)

src/core/SkGeometry.h

 /*
  * 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.
  */
 
 #ifndef SkGeometry_DEFINED
 #define SkGeometry_DEFINED
 
 #include "SkMatrix.h"
+#include "SkNx.h"
+
+static inline Sk2s from_point(const SkPoint& point) {
+    return Sk2s::Load(&point.fX);
+}
+
+static inline SkPoint to_point(const Sk2s& x) {
+    SkPoint point;
+    x.store(&point.fX);
+    return point;
+}
+
+static inline Sk2s sk2s_cubic_eval(const Sk2s& A, const Sk2s& B, const Sk2s& C, const Sk2s& D,
+                                   const Sk2s& t) {
+    return ((A * t + B) * t + C) * t + D;
+}
 
 /** Given a quadratic equation Ax^2 + Bx + C = 0, return 0, 1, 2 roots for the
     equation.
 */
 int SkFindUnitQuadRoots(SkScalar A, SkScalar B, SkScalar C, SkScalar roots[2]);
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkPoint SkEvalQuadAt(const SkPoint src[3], SkScalar t);
 SkPoint SkEvalQuadTangentAt(const SkPoint src[3], SkScalar t);
 
 /** Set pt to the point on the src quadratic specified by t. t must be
     0 <= t <= 1.0
 */
 void SkEvalQuadAt(const SkPoint src[3], SkScalar t, SkPoint* pt, SkVector* tangent = NULL);
 
+/**
+ *  output is : eval(t) == coeff[0] * t^2 + coeff[1] * t + coeff[2]
+ */
+void SkQuadToCoeff(const SkPoint pts[3], SkPoint coeff[3]);
+
+/**
+ *  output is : eval(t) == coeff[0] * t^3 + coeff[1] * t^2 + coeff[2] * t + coeff[3]
+ */
+void SkCubicToCoeff(const SkPoint pts[4], SkPoint coeff[4]);
+
 /** Given a src quadratic bezier, chop it at the specified t value,
     where 0 < t < 1, and return the two new quadratics in dst:
     dst[0..2] and dst[2..4]
 */
 void SkChopQuadAt(const SkPoint src[3], SkPoint dst[5], SkScalar t);
 
 /** Given a src quadratic bezier, chop it at the specified t == 1/2,
     The new quads are returned in dst[0..2] and dst[2..4]
 */
 void SkChopQuadAtHalf(const SkPoint src[3], SkPoint dst[5]);
@@ skipping 266 matching lines @@
 private:
     enum {
         kQuadCount = 8, // should handle most conics
         kPointCount = 1 + 2 * kQuadCount,
     };
     SkAutoSTMalloc<kPointCount, SkPoint> fStorage;
     int fQuadCount; // #quads for current usage
 };
 
 #endif