Update SkLightingShader to support rotation

include/effects/SkPoint3.h

-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkPoint3_DEFINED
-#define SkPoint3_DEFINED
-
-#include "SkScalar.h"
-
-struct SK_API SkPoint3 {
-    SkScalar fX, fY, fZ;
-
-    static SkPoint3 Make(SkScalar x, SkScalar y, SkScalar z) {
-        SkPoint3 pt;
-        pt.set(x, y, z);
-        return pt;
-    }
-
-    SkScalar x() const { return fX; }
-    SkScalar y() const { return fY; }
-    SkScalar z() const { return fZ; }
-
-    void set(SkScalar x, SkScalar y, SkScalar z) { fX = x; fY = y; fZ = z; }
-
-    friend bool operator==(const SkPoint3& a, const SkPoint3& b) {
-        return a.fX == b.fX && a.fY == b.fY && a.fZ == b.fZ;
-    }
-
-    friend bool operator!=(const SkPoint3& a, const SkPoint3& b) {
-        return !(a == b);
-    }
-
-    /** Returns the Euclidian distance from (0,0,0) to (x,y,z)
-    */
-    static SkScalar Length(SkScalar x, SkScalar y, SkScalar z);
-
-    /** Return the Euclidian distance from (0,0,0) to the point
-    */
-    SkScalar length() const { return SkPoint3::Length(fX, fY, fZ); }
-
-    /** Set the point (vector) to be unit-length in the same direction as it
-        already points.  If the point has a degenerate length (i.e., nearly 0)
-        then set it to (0,0,0) and return false; otherwise return true.
-    */
-    bool normalize();
-
-    /** Return a new point whose X, Y and Z coordinates are scaled.
-    */
-    SkPoint3 makeScale(SkScalar scale) const {
-        SkPoint3 p;
-        p.set(scale * fX, scale * fY, scale * fZ);
-        return p;
-    }
-
-    /** Scale the point's coordinates by scale.
-    */
-    void scale(SkScalar value) { 
-        fX *= value;
-        fY *= value;
-        fZ *= value;
-    }
-
-    /** Return a new point whose X, Y and Z coordinates are the negative of the
-        original point's
-    */
-    SkPoint3 operator-() const {
-        SkPoint3 neg;
-        neg.fX = -fX;
-        neg.fY = -fY;
-        neg.fZ = -fZ;
-        return neg;
-    }
-
-    /** Returns a new point whose coordinates are the difference between
-        a and b (i.e., a - b)
-    */
-    friend SkPoint3 operator-(const SkPoint3& a, const SkPoint3& b) {
-        SkPoint3 v;
-        v.set(a.fX - b.fX, a.fY - b.fY, a.fZ - b.fZ);
-        return v;
-    }
-
-    /** Returns a new point whose coordinates are the sum of a and b (a + b)
-    */
-    friend SkPoint3 operator+(const SkPoint3& a, const SkPoint3& b) {
-        SkPoint3 v;
-        v.set(a.fX + b.fX, a.fY + b.fY, a.fZ + b.fZ);
-        return v;
-    }
-
-    /** Returns the dot product of a and b, treating them as 3D vectors
-    */
-    static SkScalar DotProduct(const SkPoint3& a, const SkPoint3& b) {
-        return a.fX * b.fX + a.fY * b.fY + a.fZ * b.fZ;
-    }
-
-    SkScalar dot(const SkPoint3& vec) const {
-        return DotProduct(*this, vec);
-    }
-};
-
-typedef SkPoint3 SkVector3;
-typedef SkPoint3 SkColor3f;
-
-#endif