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path: root/modules/ffpoly.c
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 ```1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 ``` ``````/* * ffpoly.c - compute a finite field polynomial * Copyright (c) by Tom Schouten * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include "m_pd.h" #include typedef struct ffpoly_struct { t_object x_obj; t_float x_f; t_outlet *x_outlet; t_int *x_coef; t_int x_poly_order; t_int x_field_order; t_int x_lastpackedcoef; } t_ffpoly; static void ffpoly_compute(t_ffpoly *x, t_floatarg fcoef) { int in = (int)fcoef; int fo = x->x_field_order; int po = x->x_poly_order; t_int* c = x->x_coef; int i, out; in %= fo; if (in < 0) in += fo; out = c[po]; for (i=po-1; i>=0; i--){ out *= in; out += c[i]; out %= fo; } outlet_float(x->x_outlet, (float)out); } /* this sets all coefficients given one float */ static void ffpoly_coefficients(t_ffpoly *x, t_floatarg fcoef) { int coef = (int)fcoef; int i; if (coef < 0) coef = -coef; x->x_lastpackedcoef = coef; for (i=0; ix_poly_order + 1; i++){ x->x_coef[i] = coef % x->x_field_order; coef = coef / x->x_field_order; } } /* this sets one coefficient */ static void ffpoly_coef(t_ffpoly *x, t_floatarg index, t_floatarg val) { int i = (int)index; int v = (int)val; if (i<0) return; if (i>x->x_poly_order) return; v %= x->x_field_order; if (v<0) v += x->x_field_order; x->x_coef[i] = v; } static void ffpoly_fieldorder(t_ffpoly *x, t_floatarg ffieldorder) { int i; int order = (int)ffieldorder; if (order < 2) order = 2; x->x_field_order = order; for (i=0; ix_poly_order+1; i++) x->x_coef[i] %= x->x_field_order; //ffpoly_coefficients(x, x->x_lastpackedcoef); } static void ffpoly_free(t_ffpoly *x) { free (x->x_coef); } t_class *ffpoly_class; static void *ffpoly_new(t_floatarg fpolyorder, t_floatarg ffieldorder) { t_int polyorder = (int)fpolyorder; t_int fieldorder = (int)ffieldorder; t_ffpoly *x = (t_ffpoly *)pd_new(ffpoly_class); if (polyorder < 1) polyorder = 1; if (fieldorder < 2) fieldorder = 2; x->x_poly_order = polyorder; x->x_field_order = fieldorder; x->x_coef = (t_int *)malloc((x->x_poly_order + 1) * sizeof(int)); /* set poly to f(x) = x */ ffpoly_coefficients(x, x->x_field_order); x->x_outlet = outlet_new(&x->x_obj, &s_float); return (void *)x; } #ifdef __cplusplus extern "C" { #endif void ffpoly_setup(void) { ffpoly_class = class_new(gensym("ffpoly"), (t_newmethod)ffpoly_new, (t_method)ffpoly_free, sizeof(t_ffpoly), 0, A_DEFFLOAT, A_DEFFLOAT, A_NULL); class_addmethod(ffpoly_class, (t_method)ffpoly_coefficients, gensym("coefficients"), A_FLOAT, A_NULL); class_addmethod(ffpoly_class, (t_method)ffpoly_coef, gensym("coef"), A_FLOAT, A_FLOAT, A_NULL); class_addmethod(ffpoly_class, (t_method)ffpoly_fieldorder, gensym("order"), A_FLOAT, A_NULL); class_addfloat(ffpoly_class, (t_method)ffpoly_compute); } #ifdef __cplusplus } #endif ``````