1/*
2Copyright (c) 2012, Broadcom Europe Ltd
3All rights reserved.
4
5Redistribution and use in source and binary forms, with or without
6modification, are permitted provided that the following conditions are met:
7 * Redistributions of source code must retain the above copyright
8 notice, this list of conditions and the following disclaimer.
9 * Redistributions in binary form must reproduce the above copyright
10 notice, this list of conditions and the following disclaimer in the
11 documentation and/or other materials provided with the distribution.
12 * Neither the name of the copyright holder nor the
13 names of its contributors may be used to endorse or promote products
14 derived from this software without specific prior written permission.
15
16THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
17ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
20DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26*/
27
28static INLINE bool clean_boolean(int b)
29{
30 return !!b;
31}
32
33/*
34 clean_float(float f)
35
36 Implementation notes:
37
38 'Cleans' a floating point number by converting -INF to -FLT_MAX, INF to FLT_MAX and
39 any NaN to zero. Khronos spec says nothing about what happens if an unclean float is
40 passed to a function, so this at least guarantees reasonable behaviour.
41
42 Preconditions:
43
44 -
45
46 Postconditions:
47
48 result r is not NaN or infinite
49*/
50
51static INLINE float clean_float(float f)
52{
53 uint32_t u = float_to_bits(f);
54
55 if (u == 0x7f800000)
56 return FLT_MAX;
57 if (u == (uint32_t)0xff800000)
58 return -FLT_MAX;
59 if ((u & 0x7f800000) == 0x7f800000)
60 return 0; // force NaN to zero
61
62 return f;
63}
64
65/*
66 clampf(float x, float l, float u)
67
68 Implementation notes:
69
70 Khronos makes frequent use of the datatype clampf, which is defined as
71
72 floating-point value clamped to [0, 1]
73
74 This function is used in many places to clamp a floating point value to lie in a range
75 (almost always 0..1) and also to implicitly remove any NaNs or infinities.
76
77 Preconditions:
78
79 l and u are not NaN or infinity and l <= u
80
81 Postconditions:
82
83 result r is not NaN or an infinity, and l <= r <= u
84*/
85
86static INLINE float clampf(float x, float l, float u)
87{
88 vcos_assert(l <= u);
89
90 x = clean_float(x);
91
92 return _maxf(_minf(x, u), l);
93}
94
95/*
96 fixed_to_float(int f)
97
98 Implementation notes:
99
100 OpenGL ES 1.1 makes use of the datatype 'fixed' which is defined as a:
101
102 signed 2s complement 16.16 scaled integer
103
104 This function is used to convert a fixed value to its floating point equivalent, with
105 some loss of precision. We believe this is justified as the state tables in the spec
106 talk about storing all these values as type R (floating-point number).
107
108 Preconditions:
109
110 -
111
112 Postconditions:
113
114 result r is not NaN or an infinity
115*/
116
117static INLINE float fixed_to_float(int f)
118{
119 return (float)f / 65536.0f;
120}
121
122/*
123 clampi(int x, int l, int u)
124
125 Implementation notes:
126
127 Preconditions:
128
129 l <= u
130
131 Postconditions:
132
133 result r satisfies l <= r <= u
134*/
135
136static INLINE int clampi(int x, int l, int u)
137{
138 vcos_assert(l <= u);
139
140 return (int) _max(_min( (int32_t)x, (int32_t)u), (int32_t)l);
141}
142