1 | //roarfloat.c: |
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2 | |
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3 | /* |
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4 | * Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2010-2012 |
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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, 51 Franklin Street, Fifth Floor, |
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22 | * Boston, MA 02110-1301, USA. |
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23 | * |
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24 | * NOTE for everyone want's to change something and send patches: |
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25 | * read README and HACKING! There a addition information on |
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26 | * the license of this document you need to read before you send |
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27 | * any patches. |
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28 | * |
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29 | * NOTE for uses of non-GPL (LGPL,...) software using libesd, libartsc |
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30 | * or libpulse*: |
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31 | * The libs libroaresd, libroararts and libroarpulse link this lib |
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32 | * and are therefore GPL. Because of this it may be illigal to use |
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33 | * them with any software that uses libesd, libartsc or libpulse*. |
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34 | */ |
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35 | |
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36 | #include "libroar.h" |
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37 | |
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38 | #ifdef ROAR_HAVE_LIBM |
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39 | #include <math.h> |
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40 | #endif |
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41 | |
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42 | union c4f { |
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43 | unsigned char c[4]; |
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44 | roarfloat32 f; |
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45 | }; |
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46 | |
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47 | roarfloat32 roar_ufloat32_build(const uint16_t mul, const uint16_t scale) { |
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48 | union c4f ret; |
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49 | |
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50 | ROAR_DBG("roar_ufloat32_build(mul=%u, scale=%u) = ?", (unsigned int)mul, (unsigned int)scale); |
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51 | |
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52 | ret.c[0] = (scale & 0xFF00) >> 8; |
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53 | ret.c[1] = (scale & 0x00FF) >> 0; |
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54 | ret.c[2] = (mul & 0xFF00) >> 8; |
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55 | ret.c[3] = (mul & 0x00FF) >> 0; |
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56 | |
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57 | return ret.f; |
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58 | } |
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59 | |
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60 | uint16_t roar_ufloat32_scale(const roarfloat32 f) { |
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61 | const union c4f p = {.f = f}; |
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62 | |
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63 | ROAR_DBG("roar_ufloat32_scale(f=?): p.c[] = {%u, %u, %u, %u}", (unsigned int)p.c[0], (unsigned int)p.c[1], (unsigned int)p.c[2], (unsigned int)p.c[3]); |
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64 | |
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65 | return (p.c[0] << 8) | p.c[1]; |
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66 | } |
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67 | |
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68 | uint16_t roar_ufloat32_mul(const roarfloat32 f) { |
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69 | const union c4f p = {.f = f}; |
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70 | |
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71 | return (p.c[2] << 8) | p.c[3]; |
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72 | } |
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73 | |
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74 | roarfloat32 roar_ufloat32_from_float(const float f) { |
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75 | uint16_t scale; |
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76 | |
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77 | if ( f < 0 ) |
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78 | return ROAR_UFLOAT32_NNAN; |
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79 | |
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80 | if ( f == 0 ) |
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81 | return ROAR_UFLOAT32_ZERO; |
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82 | |
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83 | if ( f > ROAR_UFLOAT32_MAX ) |
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84 | return ROAR_UFLOAT32_PINF; |
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85 | |
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86 | if ( f <= 1 ) { |
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87 | scale = ROAR_UFLOAT32_MAX; |
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88 | } else { |
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89 | scale = (float)ROAR_UFLOAT32_MAX/f; |
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90 | } |
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91 | |
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92 | ROAR_DBG("roar_ufloat32_from_float(f=%f): scale=%u", f, (unsigned int)scale); |
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93 | |
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94 | return roar_ufloat32_build(f*(float)scale, scale); |
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95 | } |
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96 | |
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97 | float roar_ufloat32_to_float (const roarfloat32 f) { |
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98 | float mul = roar_ufloat32_mul(f); |
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99 | float scale = roar_ufloat32_scale(f); |
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100 | |
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101 | ROAR_DBG("roar_ufloat32_to_float(f=?): mul=%f, scale=%f", mul, scale); |
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102 | |
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103 | if ( roar_float32_iszero(f) ) |
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104 | return 0; |
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105 | |
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106 | #ifdef INFINITY |
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107 | if ( roar_float32_isinf(f) ) |
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108 | return INFINITY; |
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109 | #endif |
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110 | |
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111 | #ifdef NAN |
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112 | if ( roar_float32_isnan(f) ) |
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113 | return NAN; |
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114 | #endif |
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115 | |
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116 | return mul/scale; |
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117 | } |
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118 | |
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119 | int roar_float32_iszero(const roarfloat32 f) { |
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120 | const union c4f p = {.f = f}; |
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121 | |
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122 | return p.c[2] == 0 && p.c[3] == 0; |
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123 | } |
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124 | |
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125 | int roar_float32_isinf(const roarfloat32 f) { |
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126 | const union c4f p = {.f = f}; |
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127 | |
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128 | if ( p.c[0] != 0 || p.c[1] != 0 ) |
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129 | return 0; |
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130 | |
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131 | if ( p.c[2] == 0x00 && p.c[3] == 0x01 ) { |
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132 | return 1; |
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133 | } else if ( p.c[2] == 0xFF && p.c[3] == 0xFF ) { |
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134 | return -1; |
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135 | } else { |
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136 | return 0; |
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137 | } |
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138 | } |
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139 | |
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140 | int roar_float32_isnan(const roarfloat32 f) { |
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141 | const union c4f p = {.f = f}; |
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142 | |
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143 | if ( p.c[0] != 0 || p.c[1] != 0 ) |
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144 | return 0; |
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145 | |
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146 | if ( p.c[2] == 0x7F && p.c[3] == 0xFF ) { |
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147 | return 1; |
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148 | } else if ( p.c[2] == 0x80 && p.c[3] == 0x00 ) { |
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149 | return -1; |
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150 | } else { |
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151 | return 0; |
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152 | } |
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153 | } |
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154 | |
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155 | //ll |
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