1 // Copyright (C) 2002-2005 Nikolaus Gebhardt
2 // This file is part of the "Irrlicht Engine" and the "irrXML" project.
3 // For conditions of distribution and use, see copyright notice in irrlicht.h and irrXML.h
4 // ----------------------------------------------------------------------------
5 // Copyright (C) 2014
6 // David Freese, W1HKJ
7 //
8 // This file is part of fldigi
9 //
10 // fldigi is free software; you can redistribute it and/or modify
11 // it under the terms of the GNU General Public License as published by
12 // the Free Software Foundation; either version 3 of the License, or
13 // (at your option) any later version.
14 //
15 // fldigi is distributed in the hope that it will be useful,
16 // but WITHOUT ANY WARRANTY; without even the implied warranty of
17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 // GNU General Public License for more details.
19 //
20 // You should have received a copy of the GNU General Public License
21 // along with this program. If not, see <http://www.gnu.org/licenses/>.
22 // ----------------------------------------------------------------------------
23
24
25 #ifndef __FAST_A_TO_F_H_INCLUDED__
26 #define __FAST_A_TO_F_H_INCLUDED__
27
28 #include <stdlib.h>
29 #include <math.h>
30
31 namespace irr
32 {
33 namespace core
34 {
35
36 // Disable the use of powf(3) on mingw32 because it breaks cross compilation
37 // on Debian unstable.
38 #ifndef __MINGW32__
39 const float fast_atof_table[] = {
40 0.f,
41 0.1f,
42 0.01f,
43 0.001f,
44 0.0001f,
45 0.00001f,
46 0.000001f,
47 0.0000001f,
48 0.00000001f,
49 0.000000001f,
50 0.0000000001f,
51 0.00000000001f,
52 0.000000000001f,
53 0.0000000000001f,
54 0.00000000000001f,
55 0.000000000000001f
56 };
57
58 //! Provides a fast function for converting a string into a float,
59 //! about 6 times faster than atof in win32.
60 // If you find any bugs, please send them to me, niko (at) irrlicht3d.org.
fast_atof_move(char * c,float & out)61 inline char* fast_atof_move(char* c, float& out)
62 {
63 bool inv = false;
64 char *t;
65 float f;
66
67 if (*c=='-')
68 {
69 c++;
70 inv = true;
71 }
72
73 f = (float)strtol(c, &t, 10);
74
75 c = t;
76
77 if (*c == '.')
78 {
79 c++;
80
81 float pl = (float)strtol(c, &t, 10);
82 pl *= fast_atof_table[t-c];
83
84 f += pl;
85
86 c = t;
87
88 if (*c == 'e')
89 {
90 ++c;
91 float exp = (float)strtol(c, &t, 10);
92 f *= (float)pow(10.0f, exp);
93 c = t;
94 }
95 }
96
97 if (inv)
98 f *= -1.0f;
99
100 out = f;
101 return c;
102 }
103
104 //! Provides a fast function for converting a string into a float,
105 //! about 6 times faster than atof in win32.
106 // If you find any bugs, please send them to me, niko (at) irrlicht3d.org.
fast_atof_move_const(const char * c,float & out)107 inline const char* fast_atof_move_const(const char* c, float& out)
108 {
109 bool inv = false;
110 char *t;
111 float f;
112
113 if (*c=='-')
114 {
115 c++;
116 inv = true;
117 }
118
119 f = (float)strtol(c, &t, 10);
120
121 c = t;
122
123 if (*c == '.')
124 {
125 c++;
126
127 float pl = (float)strtol(c, &t, 10);
128 pl *= fast_atof_table[t-c];
129
130 f += pl;
131
132 c = t;
133
134 if (*c == 'e')
135 {
136 ++c;
137 f32 exp = (f32)strtol(c, &t, 10);
138 f *= (f32)powf(10.0f, exp);
139 c = t;
140 }
141 }
142
143 if (inv)
144 f *= -1.0f;
145
146 out = f;
147 return c;
148 }
149
150
fast_atof(const char * c)151 inline float fast_atof(const char* c)
152 {
153 float ret;
154 fast_atof_move_const(c, ret);
155 return ret;
156 }
157 #else // __MINGW32__
158 inline float fast_atof(const char* c)
159 {
160 return atof(c);
161 }
162 #endif // !__MINGW32__
163
164 } // end namespace core
165 }// end namespace irr
166
167 #endif
168
169