dungeon_crawler
annotate prototype/vmath/vmath.inl @ 80:a373b36ffc17
better
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Sat, 27 Oct 2012 01:59:39 +0300 |
| parents | |
| children |
| rev | line source |
|---|---|
| nuclear@1 | 1 /* |
| nuclear@1 | 2 libvmath - a vector math library |
| nuclear@1 | 3 Copyright (C) 2004-2011 John Tsiombikas <nuclear@member.fsf.org> |
| nuclear@1 | 4 |
| nuclear@1 | 5 This program is free software: you can redistribute it and/or modify |
| nuclear@1 | 6 it under the terms of the GNU Lesser General Public License as published |
| nuclear@1 | 7 by the Free Software Foundation, either version 3 of the License, or |
| nuclear@1 | 8 (at your option) any later version. |
| nuclear@1 | 9 |
| nuclear@1 | 10 This program is distributed in the hope that it will be useful, |
| nuclear@1 | 11 but WITHOUT ANY WARRANTY; without even the implied warranty of |
| nuclear@1 | 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| nuclear@1 | 13 GNU Lesser General Public License for more details. |
| nuclear@1 | 14 |
| nuclear@1 | 15 You should have received a copy of the GNU Lesser General Public License |
| nuclear@1 | 16 along with this program. If not, see <http://www.gnu.org/licenses/>. |
| nuclear@1 | 17 */ |
| nuclear@1 | 18 |
| nuclear@1 | 19 #include <stdlib.h> |
| nuclear@1 | 20 |
| nuclear@1 | 21 /** Generates a random number in [0, range) */ |
| nuclear@1 | 22 static inline scalar_t frand(scalar_t range) |
| nuclear@1 | 23 { |
| nuclear@1 | 24 return range * (scalar_t)rand() / (scalar_t)RAND_MAX; |
| nuclear@1 | 25 } |
| nuclear@1 | 26 |
| nuclear@1 | 27 /** Generates a random vector on the surface of a sphere */ |
| nuclear@1 | 28 static inline vec3_t sphrand(scalar_t rad) |
| nuclear@1 | 29 { |
| nuclear@1 | 30 scalar_t u = (scalar_t)rand() / RAND_MAX; |
| nuclear@1 | 31 scalar_t v = (scalar_t)rand() / RAND_MAX; |
| nuclear@1 | 32 |
| nuclear@1 | 33 scalar_t theta = 2.0 * M_PI * u; |
| nuclear@1 | 34 scalar_t phi = acos(2.0 * v - 1.0); |
| nuclear@1 | 35 |
| nuclear@1 | 36 vec3_t res; |
| nuclear@1 | 37 res.x = rad * cos(theta) * sin(phi); |
| nuclear@1 | 38 res.y = rad * sin(theta) * sin(phi); |
| nuclear@1 | 39 res.z = rad * cos(phi); |
| nuclear@1 | 40 return res; |
| nuclear@1 | 41 } |
| nuclear@1 | 42 |
| nuclear@1 | 43 /** linear interpolation */ |
| nuclear@1 | 44 static inline scalar_t lerp(scalar_t a, scalar_t b, scalar_t t) |
| nuclear@1 | 45 { |
| nuclear@1 | 46 return a + (b - a) * t; |
| nuclear@1 | 47 } |