1 2 /* 3 * M_APM - mapm_sin.c 4 * 5 * Copyright (C) 1999 - 2007 Michael C. Ring 6 * 7 * Permission to use, copy, and distribute this software and its 8 * documentation for any purpose with or without fee is hereby granted, 9 * provided that the above copyright notice appear in all copies and 10 * that both that copyright notice and this permission notice appear 11 * in supporting documentation. 12 * 13 * Permission to modify the software is granted. Permission to distribute 14 * the modified code is granted. Modifications are to be distributed by 15 * using the file 'license.txt' as a template to modify the file header. 16 * 'license.txt' is available in the official MAPM distribution. 17 * 18 * This software is provided "as is" without express or implied warranty. 19 */ 20 21 /* 22 * $Id: mapm_sin.c,v 1.17 2007/12/03 01:48:31 mike Exp $ 23 * 24 * This file contains the top level (user callable) SIN / COS / TAN 25 * functions. 26 * 27 * $Log: mapm_sin.c,v $ 28 * Revision 1.17 2007/12/03 01:48:31 mike 29 * Update license 30 * 31 * Revision 1.16 2002/11/03 21:53:47 mike 32 * Updated function parameters to use the modern style 33 * 34 * Revision 1.15 2001/03/25 20:59:46 mike 35 * move PI stuff to new file 36 * 37 * Revision 1.14 2001/02/07 19:12:14 mike 38 * eliminate MM_skip_limit_PI_check 39 * 40 * Revision 1.13 2000/11/18 11:05:36 mike 41 * minor code re-arrangement in PI AGM 42 * 43 * Revision 1.12 2000/07/11 23:34:42 mike 44 * adjust loop break-out for AGM PI algorithm 45 * 46 * Revision 1.11 2000/07/11 20:19:47 mike 47 * use new algorithm to compute PI (AGM) 48 * 49 * Revision 1.10 2000/05/21 01:07:57 mike 50 * use _sin_cos in _tan function 51 * 52 * Revision 1.9 2000/05/19 17:13:56 mike 53 * use local copies of PI variables & recompute 54 * on the fly as needed 55 * 56 * Revision 1.8 1999/09/21 21:03:06 mike 57 * make sure the sign of 'sin' from M_cos_to_sin is non-zero 58 * before assigning it from the original angle. 59 * 60 * Revision 1.7 1999/09/18 03:27:27 mike 61 * added m_apm_sin_cos 62 * 63 * Revision 1.6 1999/07/09 22:50:33 mike 64 * skip limit to PI when not needed 65 * 66 * Revision 1.5 1999/06/20 23:42:29 mike 67 * use new function for COS function 68 * 69 * Revision 1.4 1999/06/20 19:27:12 mike 70 * changed local static variables to MAPM stack variables 71 * 72 * Revision 1.3 1999/05/17 03:54:56 mike 73 * init globals in TAN function also 74 * 75 * Revision 1.2 1999/05/15 02:18:31 mike 76 * add check for number of decimal places 77 * 78 * Revision 1.1 1999/05/10 20:56:31 mike 79 * Initial revision 80 */ 81 82 #include "m_apm_lc.h" 83 84 /****************************************************************************/ 85 void m_apm_sin(M_APM r, int places, M_APM a) 86 { 87 M_APM tmp3; 88 89 tmp3 = M_get_stack_var(); 90 M_limit_angle_to_pi(tmp3, (places + 6), a); 91 M_5x_sin(r, places, tmp3); 92 M_restore_stack(1); 93 } 94 /****************************************************************************/ 95 void m_apm_cos(M_APM r, int places, M_APM a) 96 { 97 M_APM tmp3; 98 99 tmp3 = M_get_stack_var(); 100 M_limit_angle_to_pi(tmp3, (places + 6), a); 101 M_4x_cos(r, places, tmp3); 102 M_restore_stack(1); 103 } 104 /****************************************************************************/ 105 void m_apm_sin_cos(M_APM sinv, M_APM cosv, int places, M_APM aa) 106 { 107 M_APM tmp5, tmp6, tmp7; 108 109 tmp5 = M_get_stack_var(); 110 tmp6 = M_get_stack_var(); 111 tmp7 = M_get_stack_var(); 112 113 M_limit_angle_to_pi(tmp5, (places + 6), aa); 114 M_4x_cos(tmp7, (places + 6), tmp5); 115 116 /* 117 * compute sin(x) = sqrt(1 - cos(x) ^ 2). 118 * 119 * note that the sign of 'sin' will always be positive after the 120 * sqrt call. we need to adjust the sign based on what quadrant 121 * the original angle is in. 122 */ 123 124 M_cos_to_sin(tmp6, (places + 6), tmp7); 125 if (tmp6->m_apm_sign != 0) 126 tmp6->m_apm_sign = tmp5->m_apm_sign; 127 128 m_apm_round(sinv, places, tmp6); 129 m_apm_round(cosv, places, tmp7); 130 M_restore_stack(3); 131 } 132 /****************************************************************************/ 133 void m_apm_tan(M_APM r, int places, M_APM a) 134 { 135 M_APM tmps, tmpc, tmp0; 136 137 tmps = M_get_stack_var(); 138 tmpc = M_get_stack_var(); 139 tmp0 = M_get_stack_var(); 140 141 m_apm_sin_cos(tmps, tmpc, (places + 4), a); 142 143 /* tan(x) = sin(x) / cos(x) */ 144 145 m_apm_divide(tmp0, (places + 4), tmps, tmpc); 146 m_apm_round(r, places, tmp0); 147 M_restore_stack(3); 148 } 149 /****************************************************************************/ 150 void M_limit_angle_to_pi(M_APM rr, int places, M_APM aa) 151 { 152 M_APM tmp7, tmp8, tmp9; 153 154 M_check_PI_places(places); 155 156 tmp9 = M_get_stack_var(); 157 m_apm_copy(tmp9, MM_lc_PI); 158 159 if (m_apm_compare(aa, tmp9) == 1) /* > PI */ 160 { 161 tmp7 = M_get_stack_var(); 162 tmp8 = M_get_stack_var(); 163 164 m_apm_add(tmp7, aa, tmp9); 165 m_apm_integer_divide(tmp9, tmp7, MM_lc_2_PI); 166 m_apm_multiply(tmp8, tmp9, MM_lc_2_PI); 167 m_apm_subtract(tmp9, aa, tmp8); 168 m_apm_round(rr, places, tmp9); 169 170 M_restore_stack(3); 171 return; 172 } 173 174 tmp9->m_apm_sign = -1; 175 if (m_apm_compare(aa, tmp9) == -1) /* < -PI */ 176 { 177 tmp7 = M_get_stack_var(); 178 tmp8 = M_get_stack_var(); 179 180 m_apm_add(tmp7, aa, tmp9); 181 m_apm_integer_divide(tmp9, tmp7, MM_lc_2_PI); 182 m_apm_multiply(tmp8, tmp9, MM_lc_2_PI); 183 m_apm_subtract(tmp9, aa, tmp8); 184 m_apm_round(rr, places, tmp9); 185 186 M_restore_stack(3); 187 return; 188 } 189 190 m_apm_copy(rr, aa); 191 M_restore_stack(1); 192 } 193 /****************************************************************************/ 194