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/****************************************************************************/
85void	m_apm_sin(M_APM r, int places, M_APM a)
86{
87M_APM	tmp3;
88
89tmp3 = M_get_stack_var();
90M_limit_angle_to_pi(tmp3, (places + 6), a);
91M_5x_sin(r, places, tmp3);
92M_restore_stack(1);
93}
94/****************************************************************************/
95void	m_apm_cos(M_APM r, int places, M_APM a)
96{
97M_APM	tmp3;
98
99tmp3 = M_get_stack_var();
100M_limit_angle_to_pi(tmp3, (places + 6), a);
101M_4x_cos(r, places, tmp3);
102M_restore_stack(1);
103}
104/****************************************************************************/
105void	m_apm_sin_cos(M_APM sinv, M_APM cosv, int places, M_APM aa)
106{
107M_APM	tmp5, tmp6, tmp7;
108
109tmp5 = M_get_stack_var();
110tmp6 = M_get_stack_var();
111tmp7 = M_get_stack_var();
112
113M_limit_angle_to_pi(tmp5, (places + 6), aa);
114M_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
124M_cos_to_sin(tmp6, (places + 6), tmp7);
125if (tmp6->m_apm_sign != 0)
126  tmp6->m_apm_sign = tmp5->m_apm_sign;
127
128m_apm_round(sinv, places, tmp6);
129m_apm_round(cosv, places, tmp7);
130M_restore_stack(3);
131}
132/****************************************************************************/
133void	m_apm_tan(M_APM r, int places, M_APM a)
134{
135M_APM	tmps, tmpc, tmp0;
136
137tmps = M_get_stack_var();
138tmpc = M_get_stack_var();
139tmp0 = M_get_stack_var();
140
141m_apm_sin_cos(tmps, tmpc, (places + 4), a);
142
143/* tan(x) = sin(x) / cos(x) */
144
145m_apm_divide(tmp0, (places + 4), tmps, tmpc);
146m_apm_round(r, places, tmp0);
147M_restore_stack(3);
148}
149/****************************************************************************/
150void	M_limit_angle_to_pi(M_APM rr, int places, M_APM aa)
151{
152M_APM	tmp7, tmp8, tmp9;
153
154M_check_PI_places(places);
155
156tmp9 = M_get_stack_var();
157m_apm_copy(tmp9, MM_lc_PI);
158
159if (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
174tmp9->m_apm_sign = -1;
175if (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
190m_apm_copy(rr, aa);
191M_restore_stack(1);
192}
193/****************************************************************************/
194