source:libcfa/src/vec/vec.hfa

Last change on this file was 7882c58, checked in by Peter A. Buhr <pabuhr@…>, 2 months ago

change old trait syntax to use new forall syntax

• Property mode set to `100644`
File size: 3.2 KB
Line
1//
2// Cforall Version 1.0.0 Copyright (C) 2021 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// io/types.hfa --
8//
9// Author           : Dimitry Kobets
10// Created On       :
13// Update Count     :
14//
15
16#pragma once
17
18#include <math.hfa>
19
20forall(T)
21trait fromint {
22    void ?{}(T&, int);
23};
24forall(T)
25trait zeroinit {
26    void ?{}(T&, zero_t);
27};
28forall(T)
29trait zero_assign {
30    T ?=?(T&, zero_t);
31};
32forall(T)
33trait subtract {
34    T ?-?(T, T);
35};
36forall(T)
37trait negate {
38    T -?(T);
39};
40forall(T)
42    T ?+?(T, T);
43};
44forall(T)
45trait multiply {
46    T ?*?(T, T);
47};
48forall(T)
49trait divide {
50    T ?/?(T, T);
51};
52forall(T)
53trait lessthan {
54    int ?<?(T, T);
55};
56forall(T)
57trait equality {
58    int ?==?(T, T);
59};
60forall(T)
61trait sqrt {
62    T sqrt(T);
63};
64
65static inline {
66// int
67int ?=?(int& n, zero_t) { return n = 0.f; }
68// unsigned int
69int ?=?(unsigned int& n, zero_t) { return n = 0.f; }
70/* float */
71void ?{}(float& a, int b) { a = b; }
72float ?=?(float& n, zero_t) { return n = 0.f; }
73/* double */
74void ?{}(double& a, int b) { a = b; }
75double ?=?(double& n, zero_t) { return n = 0L; }
76// long double
77void ?{}(long double& a, int b) { a = b; }
78long double ?=?(long double& n, zero_t) { return n = 0L; }
79}
80
81forall(V, T)
82trait dottable {
83    T dot(V, V);
84};
85
86static inline {
87
88forall(T | sqrt(T), V | dottable(V, T))
89T length(V v) {
90   return sqrt(dot(v, v));
91}
92
93forall(T, V | dottable(V, T))
94T length_squared(V v) {
95   return dot(v, v);
96}
97
98forall(T, V | { T length(V); } | subtract(V))
99T distance(V v1, V v2) {
100    return length(v1 - v2);
101}
102
103forall(T, V | { T length(V); V ?/?(V, T); })
104V normalize(V v) {
105    return v / length(v);
106}
107
108// Project vector u onto vector v
109forall(T, V | dottable(V, T) | { V normalize(V); V ?*?(V, T); })
110V project(V u, V v) {
111    V v_norm = normalize(v);
112    return v_norm * dot(u, v_norm);
113}
114
115// Reflect incident vector v with respect to surface with normal n
116forall(T | fromint(T), V | { V project(V, V); V ?*?(T, V); V ?-?(V,V); })
117V reflect(V v, V n) {
118    return v - (T){2} * project(v, n);
119}
120
121// Refract incident vector v with respect to surface with normal n
122// eta is the ratio of indices of refraction between starting material and
123// entering material (i.e., from air to water, eta = 1/1.33)
124// v and n must already be normalized
125forall(T | fromint(T) | subtract(T) | multiply(T) | add(T) | lessthan(T) | sqrt(T),
126       V | dottable(V, T) | { V ?*?(T, V); V ?-?(V,V); void ?{}(V&, zero_t); })
127V refract(V v, V n, T eta) {
128    T dotValue = dot(n, v);
129    T k = (T){1} - eta * eta * ((T){1} - dotValue * dotValue);
130    if (k < (T){0}) {
131        return 0;
132    }
133    return eta * v - (eta * dotValue + sqrt(k)) * n;
134}
135
136// Given a perturbed normal and a geometric normal,
137// flip the perturbed normal if the geometric normal is pointing away
138// from the observer.
139// n is the perturbed vector that we want to align
140// i is the incident vector
141// ng is the geometric normal of the surface
142forall(T | lessthan(T) | zeroinit(T), V | dottable(V, T) | negate(V))
143V faceforward(V n, V i, V ng) {
144    return dot(ng, i) < (T){0} ? n : -n;
145}
146
147} // inline
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