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 "include/core/SkPoint.h" |
12 | |
13 | struct SK_API SkPoint3 { |
14 | SkScalar fX, fY, fZ; |
15 | |
16 | static SkPoint3 Make(SkScalar x, SkScalar y, SkScalar z) { |
17 | SkPoint3 pt; |
18 | pt.set(x, y, z); |
19 | return pt; |
20 | } |
21 | |
22 | SkScalar x() const { return fX; } |
23 | SkScalar y() const { return fY; } |
24 | SkScalar z() const { return fZ; } |
25 | |
26 | 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 | */ |
42 | 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 | */ |
52 | 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 | */ |
60 | 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 | return { a.fX - b.fX, a.fY - b.fY, a.fZ - b.fZ }; |
82 | } |
83 | |
84 | /** Returns a new point whose coordinates are the sum of a and b (a + b) |
85 | */ |
86 | friend SkPoint3 operator+(const SkPoint3& a, const SkPoint3& b) { |
87 | return { a.fX + b.fX, a.fY + b.fY, a.fZ + b.fZ }; |
88 | } |
89 | |
90 | /** Add v's coordinates to the point's |
91 | */ |
92 | void operator+=(const SkPoint3& v) { |
93 | fX += v.fX; |
94 | fY += v.fY; |
95 | fZ += v.fZ; |
96 | } |
97 | |
98 | /** Subtract v's coordinates from the point's |
99 | */ |
100 | void operator-=(const SkPoint3& v) { |
101 | fX -= v.fX; |
102 | fY -= v.fY; |
103 | fZ -= v.fZ; |
104 | } |
105 | |
106 | friend SkPoint3 operator*(SkScalar t, SkPoint3 p) { |
107 | return { t * p.fX, t * p.fY, t * p.fZ }; |
108 | } |
109 | |
110 | /** Returns true if fX, fY, and fZ are measurable values. |
111 | |
112 | @return true for values other than infinities and NaN |
113 | */ |
114 | bool isFinite() const { |
115 | SkScalar accum = 0; |
116 | accum *= fX; |
117 | accum *= fY; |
118 | accum *= fZ; |
119 | |
120 | // accum is either NaN or it is finite (zero). |
121 | SkASSERT(0 == accum || SkScalarIsNaN(accum)); |
122 | |
123 | // value==value will be true iff value is not NaN |
124 | // TODO: is it faster to say !accum or accum==accum? |
125 | return !SkScalarIsNaN(accum); |
126 | } |
127 | |
128 | /** Returns the dot product of a and b, treating them as 3D vectors |
129 | */ |
130 | static SkScalar DotProduct(const SkPoint3& a, const SkPoint3& b) { |
131 | return a.fX * b.fX + a.fY * b.fY + a.fZ * b.fZ; |
132 | } |
133 | |
134 | SkScalar dot(const SkPoint3& vec) const { |
135 | return DotProduct(*this, vec); |
136 | } |
137 | |
138 | /** Returns the cross product of a and b, treating them as 3D vectors |
139 | */ |
140 | static SkPoint3 CrossProduct(const SkPoint3& a, const SkPoint3& b) { |
141 | SkPoint3 result; |
142 | result.fX = a.fY*b.fZ - a.fZ*b.fY; |
143 | result.fY = a.fZ*b.fX - a.fX*b.fZ; |
144 | result.fZ = a.fX*b.fY - a.fY*b.fX; |
145 | |
146 | return result; |
147 | } |
148 | |
149 | SkPoint3 cross(const SkPoint3& vec) const { |
150 | return CrossProduct(*this, vec); |
151 | } |
152 | }; |
153 | |
154 | typedef SkPoint3 SkVector3; |
155 | typedef SkPoint3 SkColor3f; |
156 | |
157 | #endif |
158 | |