1 /* Copyright  (C) 2010-2018 The RetroArch team
2  *
3  * ---------------------------------------------------------------------------------------
4  * The following license statement only applies to this file (retro_math.h).
5  * ---------------------------------------------------------------------------------------
6  *
7  * Permission is hereby granted, free of charge,
8  * to any person obtaining a copy of this software and associated documentation files (the "Software"),
9  * to deal in the Software without restriction, including without limitation the rights to
10  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
11  * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
16  * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
19  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21  */
22 
23 #ifndef _LIBRETRO_COMMON_MATH_H
24 #define _LIBRETRO_COMMON_MATH_H
25 
26 #include <stdint.h>
27 
28 #if defined(_WIN32) && !defined(_XBOX)
29 #define WIN32_LEAN_AND_MEAN
30 #include <windows.h>
31 #elif defined(_WIN32) && defined(_XBOX)
32 #include <Xtl.h>
33 #endif
34 
35 #include <limits.h>
36 
37 #ifdef _MSC_VER
38 #include <compat/msvc.h>
39 #endif
40 #include <retro_inline.h>
41 
42 #ifndef M_PI
43 #if !defined(USE_MATH_DEFINES)
44 #define M_PI 3.14159265358979323846264338327
45 #endif
46 #endif
47 
48 #ifndef MAX
49 #define MAX(a, b) ((a) > (b) ? (a) : (b))
50 #endif
51 
52 #ifndef MIN
53 #define MIN(a, b) ((a) < (b) ? (a) : (b))
54 #endif
55 
56 /**
57  * next_pow2:
58  * @v         : initial value
59  *
60  * Get next power of 2 value based on  initial value.
61  *
62  * Returns: next power of 2 value (derived from @v).
63  **/
next_pow2(uint32_t v)64 INLINE uint32_t next_pow2(uint32_t v)
65 {
66    v--;
67    v |= v >> 1;
68    v |= v >> 2;
69    v |= v >> 4;
70    v |= v >> 8;
71    v |= v >> 16;
72    v++;
73    return v;
74 }
75 
76 /**
77  * prev_pow2:
78  * @v         : initial value
79  *
80  * Get previous power of 2 value based on initial value.
81  *
82  * Returns: previous power of 2 value (derived from @v).
83  **/
prev_pow2(uint32_t v)84 INLINE uint32_t prev_pow2(uint32_t v)
85 {
86    v |= v >> 1;
87    v |= v >> 2;
88    v |= v >> 4;
89    v |= v >> 8;
90    v |= v >> 16;
91    return v - (v >> 1);
92 }
93 
94 #endif
95