KiCad PCB EDA Suite
3d_fastmath.h
Go to the documentation of this file.
1 /*
2  * This program source code file is part of KiCad, a free EDA CAD application.
3  *
4  * Copyright (C) 2015-2016 Mario Luzeiro <mrluzeiro@ua.pt>
5  * Copyright (C) 1992-2016 KiCad Developers, see AUTHORS.txt for contributors.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version 2
10  * of the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, you may find one here:
19  * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
20  * or you may search the http://www.gnu.org website for the version 2 license,
21  * or you may write to the Free Software Foundation, Inc.,
22  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
23  */
24 
30 #ifndef _3D_FASTMATH_H
31 #define _3D_FASTMATH_H
32 
33 #include <string.h>
34 #include <stdint.h>
35 #include <cmath>
36 
37 
38 // Define this flag to use fast math optimizations
39 #define FASTMATH_USE
40 
41 #define L1_CACHE_LINE_SIZE 64
42 
43 #ifdef FASTMATH_USE
44 #define INTFLOORF(s) (lrintf( (s) - (0.5f - FLT_EPSILON) ))
45 #else
46 #define INTFLOORF(s) ((int)( floor(s) ))
47 #endif
48 
49 
50 // Fast Float Random Numbers
51 // a small and fast implementation for random float numbers in the range [-1,1]
52 // This is not thread safe
53 float Fast_RandFloat();
54 
55 int Fast_rand( void );
56 void Fast_srand( unsigned int seed );
57 
63 /*
64  pbrt source code is Copyright(c) 1998-2015
65  Matt Pharr, Greg Humphreys, and Wenzel Jakob.
66 
67  This file is part of pbrt.
68 
69  Redistribution and use in source and binary forms, with or without
70  modification, are permitted provided that the following conditions are
71  met:
72 
73  - Redistributions of source code must retain the above copyright
74  notice, this list of conditions and the following disclaimer.
75 
76  - Redistributions in binary form must reproduce the above copyright
77  notice, this list of conditions and the following disclaimer in the
78  documentation and/or other materials provided with the distribution.
79 
80  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
81  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
82  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
83  PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
84  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
85  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
86  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
87  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
88  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
89  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
90  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
91 
92  */
93 
94 
95 // Global Inline Functions
96 inline uint32_t FloatToBits( float f )
97 {
98  uint32_t ui;
99 
100  memcpy( &ui, &f, sizeof( float ) );
101 
102  return ui;
103 }
104 
105 
106 inline float BitsToFloat( uint32_t ui )
107 {
108  float f;
109 
110  memcpy( &f, &ui, sizeof (uint32_t ) );
111 
112  return f;
113 }
114 
115 
116 inline uint64_t FloatToBits( double f )
117 {
118  uint64_t ui;
119 
120  memcpy( &ui, &f, sizeof( double ) );
121 
122  return ui;
123 }
124 
125 
126 inline double BitsToFloat( uint64_t ui )
127 {
128  double f;
129 
130  memcpy( &f, &ui, sizeof( uint64_t ) );
131 
132  return f;
133 }
134 
135 
136 inline float NextFloatUp( float v )
137 {
138  // Handle infinity and negative zero for _NextFloatUp()_
139  if( std::isinf( v ) && (v > 0.) )
140  return v;
141 
142  if( v == -0.f )
143  v = 0.f;
144 
145  // Advance _v_ to next higher float
146  uint32_t ui = FloatToBits( v );
147 
148  if( v >= 0. )
149  ++ui;
150  else
151  --ui;
152 
153  return BitsToFloat( ui );
154 }
155 
156 
157 inline float NextFloatDown( float v )
158 {
159  // Handle infinity and positive zero for _NextFloatDown()_
160  if( std::isinf( v ) && (v < 0.) )
161  return v;
162 
163  if( v == 0.f )
164  v = -0.f;
165 
166  uint32_t ui = FloatToBits( v );
167 
168  if( v > 0. )
169  --ui;
170  else
171  ++ui;
172 
173  return BitsToFloat( ui );
174 }
175 
176 #endif // 3D_FASTMATH_H
float BitsToFloat(uint32_t ui)
Definition: 3d_fastmath.h:106
float NextFloatDown(float v)
Definition: 3d_fastmath.h:157
uint32_t FloatToBits(float f)
This part contains some functions from the PBRT 3 source code.
Definition: 3d_fastmath.h:96
void Fast_srand(unsigned int seed)
Definition: 3d_fastmath.cpp:65
float Fast_RandFloat()
Definition: 3d_fastmath.cpp:45
float NextFloatUp(float v)
Definition: 3d_fastmath.h:136
int Fast_rand(void)
Definition: 3d_fastmath.cpp:58