[31] | 1 | //math.c: |
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| 2 | |
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[690] | 3 | /* |
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| 4 | * Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2008 |
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| 5 | * |
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| 6 | * This file is part of libroar a part of RoarAudio, |
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| 7 | * a cross-platform sound system for both, home and professional use. |
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| 8 | * See README for details. |
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| 9 | * |
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| 10 | * This file is free software; you can redistribute it and/or modify |
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| 11 | * it under the terms of the GNU General Public License version 3 |
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| 12 | * as published by the Free Software Foundation. |
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| 13 | * |
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| 14 | * libroar is distributed in the hope that it will be useful, |
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| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 17 | * GNU General Public License for more details. |
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| 18 | * |
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| 19 | * You should have received a copy of the GNU General Public License |
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| 20 | * along with this software; see the file COPYING. If not, write to |
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| 21 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. |
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| 22 | * |
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| 23 | * NOTE for everyone want's to change something and send patches: |
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| 24 | * read README and HACKING! There a addition information on |
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| 25 | * the license of this document you need to read before you send |
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| 26 | * any patches. |
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| 27 | * |
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| 28 | * NOTE for uses of non-GPL (LGPL,...) software using libesd, libartsc |
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| 29 | * or libpulse*: |
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| 30 | * The libs libroaresd, libroararts and libroarpulse link this lib |
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| 31 | * and are therefore GPL. Because of this it may be illigal to use |
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| 32 | * them with any software that uses libesd, libartsc or libpulse*. |
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| 33 | */ |
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| 34 | |
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[1369] | 35 | #include "libroardsp.h" |
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[31] | 36 | |
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[34] | 37 | int roar_math_mkpoly (float * poly, float * data, int len) { |
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| 38 | if ( len == 2 ) |
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| 39 | return roar_math_mkpoly_2x2(poly, data); |
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| 40 | if ( len == 3 ) |
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| 41 | return roar_math_mkpoly_3x3(poly, data); |
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| 42 | if ( len == 4 ) |
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| 43 | return roar_math_mkpoly_4x4(poly, data); |
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| 44 | if ( len == 5 ) |
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| 45 | return roar_math_mkpoly_5x5(poly, data); |
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| 46 | |
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| 47 | return -1; |
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| 48 | } |
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| 49 | |
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| 50 | int roar_math_mkpoly_2x2 (float * poly, float * data) { |
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| 51 | /* |
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| 52 | A B |
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| 53 | 0 1 x |
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| 54 | 1 1 y |
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| 55 | |
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| 56 | B = x |
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| 57 | A = y - x |
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| 58 | */ |
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| 59 | |
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| 60 | poly[0] = data[0]; |
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| 61 | poly[1] = data[1] - data[0]; |
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| 62 | |
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| 63 | return 0; |
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| 64 | } |
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[31] | 65 | |
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[34] | 66 | int roar_math_mkpoly_3x3 (float * poly, float * data) { |
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| 67 | /* |
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| 68 | A B C |
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| 69 | 0 0 1 x |
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| 70 | 1 1 1 y |
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| 71 | 4 2 1 z |
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| 72 | */ |
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| 73 | |
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| 74 | poly[0] = data[0]; |
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| 75 | poly[1] = 2*data[1] - 2*data[0] - (data[2]-data[0])/2; |
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| 76 | poly[2] = (data[2]-data[0])/2 - data[1] + data[0]; |
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| 77 | |
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| 78 | |
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| 79 | return 0; |
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| 80 | } |
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| 81 | |
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| 82 | int roar_math_mkpoly_4x4 (float * poly, float * data) { |
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| 83 | /* |
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| 84 | a b c d |
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| 85 | 0 0 0 1 A X 0 |
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| 86 | 1 1 1 1 B Y 1 |
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| 87 | 8 4 2 1 C Z 2 |
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| 88 | 27 9 3 1 D Q 3 |
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| 89 | */ |
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| 90 | |
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| 91 | |
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| 92 | // { a = -(3z-3y+x-q)/6, b = (4z-5y+2x-q)/2, c = -(9z-18y+11x-2q)/6, d = x }. |
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| 93 | |
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| 94 | poly[0] = data[0]; |
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| 95 | poly[1] = -(11*data[0] - 18*data[1] + 9*data[2] - 2*data[3])/6; |
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| 96 | poly[2] = (2 *data[0] - 5*data[1] + 4*data[2] - data[3])/2; |
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| 97 | poly[3] = -( data[0] - 3*data[1] + 3*data[2] - data[3])/6; |
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| 98 | |
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| 99 | return 0; |
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| 100 | } |
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| 101 | |
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[49] | 102 | int roar_math_mkpoly_5x5 (float * poly, float * data) { |
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| 103 | return -1; |
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| 104 | } |
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[31] | 105 | |
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[383] | 106 | |
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[2442] | 107 | float roar_math_cvpoly (float * poly, float t, int len) { |
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| 108 | float ret = 0; |
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| 109 | float ct = 1; |
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| 110 | int i; |
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| 111 | |
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| 112 | if ( poly == NULL ) |
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| 113 | return 0; |
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| 114 | |
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| 115 | switch (len) { |
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| 116 | case 4: return roar_math_cvpoly_4x4(poly, t); |
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| 117 | } |
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| 118 | |
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| 119 | for (i = 0; i < len; i++) { |
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| 120 | ret += poly[i] * ct; |
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| 121 | ct *= t; |
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| 122 | } |
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| 123 | |
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| 124 | return ret; |
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| 125 | } |
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| 126 | |
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[383] | 127 | float roar_math_cvpoly_4x4 (float * poly, float t) { |
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| 128 | float ret = poly[0]; |
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| 129 | float ct = t; |
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| 130 | |
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| 131 | ret += poly[1] * ct; |
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| 132 | ct *= t; |
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| 133 | ret += poly[2] * ct; |
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| 134 | ct *= t; |
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| 135 | ret += poly[3] * ct; |
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| 136 | |
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| 137 | // printf("ret=%f\n", ret); |
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| 138 | |
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| 139 | return ret; |
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| 140 | } |
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| 141 | |
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[31] | 142 | //ll |
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