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] */
34static inline uint8_t
35etna_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] */
47static inline uint32_t
48etna_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 */
63static inline uint32_t
64etna_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 */
76static inline uint32_t
77etna_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 */
89static inline uint32_t
90etna_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 */
96static inline uint32_t
97etna_log2_fixp88(unsigned width)
98{
99   return etna_float_to_fixp88(logf((float)width) * RCPLOG2);
100}
101
102/* float to fixp 16.16 */
103static inline uint32_t
104etna_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