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annotate libs/vmath/vmath.inl @ 27:3d082c566b53

fixed all the bugs, pc version works
author John Tsiombikas <nuclear@member.fsf.org>
date Thu, 18 Jun 2015 04:32:25 +0300
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nuclear@10 1 /*
nuclear@10 2 libvmath - a vector math library
nuclear@10 3 Copyright (C) 2004-2015 John Tsiombikas <nuclear@member.fsf.org>
nuclear@10 4
nuclear@10 5 This program is free software: you can redistribute it and/or modify
nuclear@10 6 it under the terms of the GNU Lesser General Public License as published
nuclear@10 7 by the Free Software Foundation, either version 3 of the License, or
nuclear@10 8 (at your option) any later version.
nuclear@10 9
nuclear@10 10 This program is distributed in the hope that it will be useful,
nuclear@10 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@10 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
nuclear@10 13 GNU Lesser General Public License for more details.
nuclear@10 14
nuclear@10 15 You should have received a copy of the GNU Lesser General Public License
nuclear@10 16 along with this program. If not, see <http://www.gnu.org/licenses/>.
nuclear@10 17 */
nuclear@10 18
nuclear@10 19 #include <stdlib.h>
nuclear@10 20
nuclear@10 21 static inline scalar_t smoothstep(float a, float b, float x)
nuclear@10 22 {
nuclear@10 23 if(x < a) return 0.0;
nuclear@10 24 if(x >= b) return 1.0;
nuclear@10 25
nuclear@10 26 x = (x - a) / (b - a);
nuclear@10 27 return x * x * (3.0 - 2.0 * x);
nuclear@10 28 }
nuclear@10 29
nuclear@10 30 /** Generates a random number in [0, range) */
nuclear@10 31 static inline scalar_t frand(scalar_t range)
nuclear@10 32 {
nuclear@10 33 return range * (scalar_t)rand() / (scalar_t)RAND_MAX;
nuclear@10 34 }
nuclear@10 35
nuclear@10 36 /** Generates a random vector on the surface of a sphere */
nuclear@10 37 static inline vec3_t sphrand(scalar_t rad)
nuclear@10 38 {
nuclear@10 39 scalar_t u = (scalar_t)rand() / RAND_MAX;
nuclear@10 40 scalar_t v = (scalar_t)rand() / RAND_MAX;
nuclear@10 41
nuclear@10 42 scalar_t theta = 2.0 * M_PI * u;
nuclear@10 43 scalar_t phi = acos(2.0 * v - 1.0);
nuclear@10 44
nuclear@10 45 vec3_t res;
nuclear@10 46 res.x = rad * cos(theta) * sin(phi);
nuclear@10 47 res.y = rad * sin(theta) * sin(phi);
nuclear@10 48 res.z = rad * cos(phi);
nuclear@10 49 return res;
nuclear@10 50 }
nuclear@10 51
nuclear@10 52 /** linear interpolation */
nuclear@10 53 static inline scalar_t lerp(scalar_t a, scalar_t b, scalar_t t)
nuclear@10 54 {
nuclear@10 55 return a + (b - a) * t;
nuclear@10 56 }