1 | #pragma once |
---|
2 | #include <math.hfa> |
---|
3 | #include <iostream.hfa> |
---|
4 | |
---|
5 | //---------------------- Vector Types ---------------------- |
---|
6 | // TODO: make generic, as per glm |
---|
7 | |
---|
8 | struct vec2 { |
---|
9 | float x, y; |
---|
10 | }; |
---|
11 | |
---|
12 | void ?{}( vec2 & v, float x, float y) { |
---|
13 | v.[x, y] = [x, y]; |
---|
14 | } |
---|
15 | |
---|
16 | forall( dtype ostype | ostream( ostype ) ) { |
---|
17 | ostype & ?|?( ostype & os, const vec2& v) with (v) { |
---|
18 | if ( sepPrt( os ) ) fmt( os, "%s", sepGetCur( os ) ); |
---|
19 | fmt( os, "<%g,%g>", x, y); |
---|
20 | return os; |
---|
21 | } |
---|
22 | void ?|?( ostype & os, const vec2& v ) { |
---|
23 | (ostype &)(os | v); ends( os ); |
---|
24 | } |
---|
25 | } |
---|
26 | |
---|
27 | void ?{}(vec2& vec, zero_t) with (vec) { |
---|
28 | x = y = 0; |
---|
29 | } |
---|
30 | void ?{}(vec2& vec, vec2& other) with (vec) { |
---|
31 | [x,y] = other.[x,y]; |
---|
32 | } |
---|
33 | |
---|
34 | vec2 ?-?(const vec2& u, const vec2& v) { |
---|
35 | return [u.x - v.x, u.y - v.y]; |
---|
36 | } |
---|
37 | vec2 ?*?(const vec2& v, float scalar) with (v) { |
---|
38 | return [x * scalar, y * scalar]; |
---|
39 | } |
---|
40 | vec2 ?*?(float scalar, const vec2& v) { |
---|
41 | return v * scalar; |
---|
42 | } |
---|
43 | vec2 ?/?(const vec2& v, float scalar) with (v) { |
---|
44 | return [x / scalar, y / scalar]; |
---|
45 | } |
---|
46 | vec2 -?(const vec2& v) with (v) { |
---|
47 | return [-x, -y]; |
---|
48 | } |
---|
49 | |
---|
50 | /* //---------------------- Geometric Functions ---------------------- */ |
---|
51 | /* // These functions implement the Geometric Functions section of GLSL */ |
---|
52 | |
---|
53 | static inline float dot(const vec2& u, const vec2& v) { |
---|
54 | return u.x * v.x + u.y * v.y; |
---|
55 | } |
---|
56 | |
---|
57 | static inline float length(const vec2& v) { |
---|
58 | return sqrt(dot(v, v)); |
---|
59 | } |
---|
60 | |
---|
61 | // Returns the distance betwwen v1 and v2, i.e., length(p0 - p1). |
---|
62 | static inline float distance(const vec2& v1, const vec2& v2) { |
---|
63 | return length(v1 - v2); |
---|
64 | } |
---|
65 | |
---|
66 | static inline vec2 normalize(const vec2& v) { |
---|
67 | // TODO(dkobets) -- show them inversesqrt |
---|
68 | // https://github.com/g-truc/glm/blob/269ae641283426f7f84116f2fe333472b9c914c9/glm/detail/func_exponential.inl |
---|
69 | /* return v * inversesqrt(dot(v, v)); */ |
---|
70 | return v / sqrt(dot(v, v)); |
---|
71 | } |
---|
72 | |
---|
73 | // project vector u onto vector v |
---|
74 | static inline vec2 project(const vec2& u, const vec2& v) { |
---|
75 | vec2 v_norm = normalize(v); |
---|
76 | return v_norm * dot(u, v_norm); |
---|
77 | } |
---|
78 | |
---|
79 | /* returns the reflection direction : v - 2.0 * project(v, n) |
---|
80 | * for incident vector v and surface normal n |
---|
81 | */ |
---|
82 | static inline vec2 reflect(const vec2& v, const vec2& n) { |
---|
83 | return v - 2 * project(v, n); |
---|
84 | } |
---|
85 | |
---|
86 | // incident vector v, surface normal n |
---|
87 | // eta = ratio of indices of refraction between starting material and |
---|
88 | // entering material (i.e., from air to water, eta = 1/1.33) |
---|
89 | static inline vec2 refract(const vec2& v, const vec2& n, float eta) { |
---|
90 | float dotValue = dot(n, v); |
---|
91 | float k = 1 - eta * eta * (1 - dotValue * dotValue); |
---|
92 | if (k < 0) { |
---|
93 | return 0; |
---|
94 | } |
---|
95 | return eta * v - (eta * dotValue + sqrt(k)) * n; |
---|
96 | } |
---|
97 | |
---|
98 | // TODO: I don't quite understand the use-case for faceforward |
---|