1 /*
2  * Copyright 2015 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef SkPoint3_DEFINED
9 #define SkPoint3_DEFINED
10 
11 #include "SkScalar.h"
12 
13 struct SK_API SkPoint3 {
14     SkScalar fX, fY, fZ;
15 
MakeSkPoint316     static SkPoint3 Make(SkScalar x, SkScalar y, SkScalar z) {
17         SkPoint3 pt;
18         pt.set(x, y, z);
19         return pt;
20     }
21 
xSkPoint322     SkScalar x() const { return fX; }
ySkPoint323     SkScalar y() const { return fY; }
zSkPoint324     SkScalar z() const { return fZ; }
25 
setSkPoint326     void set(SkScalar x, SkScalar y, SkScalar z) { fX = x; fY = y; fZ = z; }
27 
28     friend bool operator==(const SkPoint3& a, const SkPoint3& b) {
29         return a.fX == b.fX && a.fY == b.fY && a.fZ == b.fZ;
30     }
31 
32     friend bool operator!=(const SkPoint3& a, const SkPoint3& b) {
33         return !(a == b);
34     }
35 
36     /** Returns the Euclidian distance from (0,0,0) to (x,y,z)
37     */
38     static SkScalar Length(SkScalar x, SkScalar y, SkScalar z);
39 
40     /** Return the Euclidian distance from (0,0,0) to the point
41     */
lengthSkPoint342     SkScalar length() const { return SkPoint3::Length(fX, fY, fZ); }
43 
44     /** Set the point (vector) to be unit-length in the same direction as it
45         already points.  If the point has a degenerate length (i.e., nearly 0)
46         then set it to (0,0,0) and return false; otherwise return true.
47     */
48     bool normalize();
49 
50     /** Return a new point whose X, Y and Z coordinates are scaled.
51     */
makeScaleSkPoint352     SkPoint3 makeScale(SkScalar scale) const {
53         SkPoint3 p;
54         p.set(scale * fX, scale * fY, scale * fZ);
55         return p;
56     }
57 
58     /** Scale the point's coordinates by scale.
59     */
scaleSkPoint360     void scale(SkScalar value) {
61         fX *= value;
62         fY *= value;
63         fZ *= value;
64     }
65 
66     /** Return a new point whose X, Y and Z coordinates are the negative of the
67         original point's
68     */
69     SkPoint3 operator-() const {
70         SkPoint3 neg;
71         neg.fX = -fX;
72         neg.fY = -fY;
73         neg.fZ = -fZ;
74         return neg;
75     }
76 
77     /** Returns a new point whose coordinates are the difference between
78         a and b (i.e., a - b)
79     */
80     friend SkPoint3 operator-(const SkPoint3& a, const SkPoint3& b) {
81         SkPoint3 v;
82         v.set(a.fX - b.fX, a.fY - b.fY, a.fZ - b.fZ);
83         return v;
84     }
85 
86     /** Returns a new point whose coordinates are the sum of a and b (a + b)
87     */
88     friend SkPoint3 operator+(const SkPoint3& a, const SkPoint3& b) {
89         SkPoint3 v;
90         v.set(a.fX + b.fX, a.fY + b.fY, a.fZ + b.fZ);
91         return v;
92     }
93 
94     /** Add v's coordinates to the point's
95     */
96     void operator+=(const SkPoint3& v) {
97         fX += v.fX;
98         fY += v.fY;
99         fZ += v.fZ;
100     }
101 
102     /** Subtract v's coordinates from the point's
103     */
104     void operator-=(const SkPoint3& v) {
105         fX -= v.fX;
106         fY -= v.fY;
107         fZ -= v.fZ;
108     }
109 
110     /** Returns the dot product of a and b, treating them as 3D vectors
111     */
DotProductSkPoint3112     static SkScalar DotProduct(const SkPoint3& a, const SkPoint3& b) {
113         return a.fX * b.fX + a.fY * b.fY + a.fZ * b.fZ;
114     }
115 
dotSkPoint3116     SkScalar dot(const SkPoint3& vec) const {
117         return DotProduct(*this, vec);
118     }
119 };
120 
121 typedef SkPoint3 SkVector3;
122 typedef SkPoint3 SkColor3f;
123 
124 #endif
125