1 /*
2 * Copyright (c) 2012-2015 Etnaviv Project
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sub license,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the
12 * next paragraph) shall be included in all copies or substantial portions
13 * of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24 /* Misc util */
25 #ifndef H_ETNA_UTIL
26 #define H_ETNA_UTIL
27
28 #include <math.h>
29
30 /* for conditionally setting boolean flag(s): */
31 #define COND(bool, val) ((bool) ? (val) : 0)
32
33 /* clamped float [0.0 .. 1.0] -> [0 .. 255] */
34 static inline uint8_t
etna_cfloat_to_uint8(float f)35 etna_cfloat_to_uint8(float f)
36 {
37 if (f <= 0.0f)
38 return 0;
39
40 if (f >= (1.0f - 1.0f / 256.0f))
41 return 255;
42
43 return f * 256.0f;
44 }
45
46 /* clamped float [0.0 .. 1.0] -> [0 .. (1<<bits)-1] */
47 static inline uint32_t
etna_cfloat_to_uintN(float f,int bits)48 etna_cfloat_to_uintN(float f, int bits)
49 {
50 if (f <= 0.0f)
51 return 0;
52
53 if (f >= (1.0f - 1.0f / (1 << bits)))
54 return (1 << bits) - 1;
55
56 return f * (1 << bits);
57 }
58
59 /* 1/log10(2) */
60 #define RCPLOG2 (1.4426950408889634f)
61
62 /* float to fixp 5.5 */
63 static inline uint32_t
etna_float_to_fixp55(float f)64 etna_float_to_fixp55(float f)
65 {
66 if (f >= 15.953125f)
67 return 511;
68
69 if (f < -16.0f)
70 return 512;
71
72 return (int32_t)(f * 32.0f + 0.5f);
73 }
74
75 /* float to fixp 8.8 */
76 static inline uint32_t
etna_float_to_fixp88(float f)77 etna_float_to_fixp88(float f)
78 {
79 if (f >= (32767.0 - 1.0f) / 256.0f)
80 return 32767;
81
82 if (f < -16.0f)
83 return 32768;
84
85 return (int32_t)(f * 256.0f + 0.5f);
86 }
87
88 /* texture size to log2 in fixp 5.5 format */
89 static inline uint32_t
etna_log2_fixp55(unsigned width)90 etna_log2_fixp55(unsigned width)
91 {
92 return etna_float_to_fixp55(logf((float)width) * RCPLOG2);
93 }
94
95 /* texture size to log2 in fixp 8.8 format */
96 static inline uint32_t
etna_log2_fixp88(unsigned width)97 etna_log2_fixp88(unsigned width)
98 {
99 return etna_float_to_fixp88(logf((float)width) * RCPLOG2);
100 }
101
102 /* float to fixp 16.16 */
103 static inline uint32_t
etna_f32_to_fixp16(float f)104 etna_f32_to_fixp16(float f)
105 {
106 if (f >= (32768.0f - 1.0f / 65536.0f))
107 return 0x7fffffff;
108
109 if (f < -32768.0f)
110 return 0x80000000;
111
112 return (int32_t)(f * 65536.0f + 0.5f);
113 }
114
115 #endif
116