Speeup hairline curves (quads and cubics) (patchset #7 id:120001 of https://codereview.chromium.org…

src/core/SkGeometry.h

Index: src/core/SkGeometry.h
diff --git a/src/core/SkGeometry.h b/src/core/SkGeometry.h
index bafde61155bed86bcc79287daad9ce53fdb4c325..9ddd91f7504f1c0f1ef3ddea4feb2820e96d08a5 100644
--- a/src/core/SkGeometry.h
+++ b/src/core/SkGeometry.h
@@ -9,6 +9,22 @@
 #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.
@@ -25,6 +41,16 @@ SkPoint SkEvalQuadTangentAt(const SkPoint src[3], SkScalar t);
 */
 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]