gpuray_glsl

annotate vmath/vmath.inl @ 5:000017955721

fixed the cone normal
author John Tsiombikas <nuclear@member.fsf.org>
date Tue, 11 Nov 2014 20:25:59 +0200
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nuclear@0 1 /*
nuclear@0 2 libvmath - a vector math library
nuclear@0 3 Copyright (C) 2004-2011 John Tsiombikas <nuclear@member.fsf.org>
nuclear@0 4
nuclear@0 5 This program is free software: you can redistribute it and/or modify
nuclear@0 6 it under the terms of the GNU Lesser General Public License as published
nuclear@0 7 by the Free Software Foundation, either version 3 of the License, or
nuclear@0 8 (at your option) any later version.
nuclear@0 9
nuclear@0 10 This program is distributed in the hope that it will be useful,
nuclear@0 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@0 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
nuclear@0 13 GNU Lesser General Public License for more details.
nuclear@0 14
nuclear@0 15 You should have received a copy of the GNU Lesser General Public License
nuclear@0 16 along with this program. If not, see <http://www.gnu.org/licenses/>.
nuclear@0 17 */
nuclear@0 18
nuclear@0 19 #include <stdlib.h>
nuclear@0 20
nuclear@0 21 static inline scalar_t smoothstep(float a, float b, float x)
nuclear@0 22 {
nuclear@0 23 if(x < a) return 0.0;
nuclear@0 24 if(x >= b) return 1.0;
nuclear@0 25
nuclear@0 26 x = (x - a) / (b - a);
nuclear@0 27 return x * x * (3.0 - 2.0 * x);
nuclear@0 28 }
nuclear@0 29
nuclear@0 30 /** Generates a random number in [0, range) */
nuclear@0 31 static inline scalar_t frand(scalar_t range)
nuclear@0 32 {
nuclear@0 33 return range * (scalar_t)rand() / (scalar_t)RAND_MAX;
nuclear@0 34 }
nuclear@0 35
nuclear@0 36 /** Generates a random vector on the surface of a sphere */
nuclear@0 37 static inline vec3_t sphrand(scalar_t rad)
nuclear@0 38 {
nuclear@0 39 scalar_t u = (scalar_t)rand() / RAND_MAX;
nuclear@0 40 scalar_t v = (scalar_t)rand() / RAND_MAX;
nuclear@0 41
nuclear@0 42 scalar_t theta = 2.0 * M_PI * u;
nuclear@0 43 scalar_t phi = acos(2.0 * v - 1.0);
nuclear@0 44
nuclear@0 45 vec3_t res;
nuclear@0 46 res.x = rad * cos(theta) * sin(phi);
nuclear@0 47 res.y = rad * sin(theta) * sin(phi);
nuclear@0 48 res.z = rad * cos(phi);
nuclear@0 49 return res;
nuclear@0 50 }
nuclear@0 51
nuclear@0 52 /** linear interpolation */
nuclear@0 53 static inline scalar_t lerp(scalar_t a, scalar_t b, scalar_t t)
nuclear@0 54 {
nuclear@0 55 return a + (b - a) * t;
nuclear@0 56 }