blob: 3da753da413180de77c162092c4fc98f64d02239 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkFDot6_DEFINED
#define SkFDot6_DEFINED
#include "SkScalar.h"
#include "SkMath.h"
typedef int32_t SkFDot6;
/* This uses the magic number approach suggested here:
* http://stereopsis.com/sree/fpu2006.html and used in
* _cairo_fixed_from_double. It does banker's rounding
* (i.e. round to nearest even)
*/
inline SkFDot6 SkScalarRoundToFDot6(SkScalar x, int shift = 0)
{
union {
double fDouble;
int32_t fBits[2];
} tmp;
int fractionalBits = 6 + shift;
double magic = (1LL << (52 - (fractionalBits))) * 1.5;
tmp.fDouble = SkScalarToDouble(x) + magic;
#ifdef SK_CPU_BENDIAN
return tmp.fBits[1];
#else
return tmp.fBits[0];
#endif
}
#define SK_FDot6One (64)
#define SK_FDot6Half (32)
#ifdef SK_DEBUG
inline SkFDot6 SkIntToFDot6(S16CPU x) {
SkASSERT(SkToS16(x) == x);
return x << 6;
}
#else
#define SkIntToFDot6(x) ((x) << 6)
#endif
#define SkFDot6Floor(x) ((x) >> 6)
#define SkFDot6Ceil(x) (((x) + 63) >> 6)
#define SkFDot6Round(x) (((x) + 32) >> 6)
#define SkFixedToFDot6(x) ((x) >> 10)
inline SkFixed SkFDot6ToFixed(SkFDot6 x) {
SkASSERT((x << 10 >> 10) == x);
return x << 10;
}
#define SkScalarToFDot6(x) (SkFDot6)((x) * 64)
#define SkFDot6ToScalar(x) ((SkScalar)(x) * 0.015625f)
inline SkFixed SkFDot6Div(SkFDot6 a, SkFDot6 b) {
SkASSERT(b != 0);
if (a == (int16_t)a) {
return (a << 16) / b;
} else {
return SkFixedDiv(a, b);
}
}
#endif
|
