gfx/skia/trunk/include/core/SkFloatBits.h@129ffea94266
gfx/skia/trunk/include/core/SkFloatBits.h
Sat, 03 Jan 2015 20:18:00 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Sat, 03 Jan 2015 20:18:00 +0100
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
- permissions
- -rw-r--r--
Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.
2 /*
3 * Copyright 2008 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
10 #ifndef SkFloatBits_DEFINED
11 #define SkFloatBits_DEFINED
13 #include "SkTypes.h"
15 /** Convert a sign-bit int (i.e. float interpreted as int) into a 2s compliement
16 int. This also converts -0 (0x80000000) to 0. Doing this to a float allows
17 it to be compared using normal C operators (<, <=, etc.)
18 */
19 static inline int32_t SkSignBitTo2sCompliment(int32_t x) {
20 if (x < 0) {
21 x &= 0x7FFFFFFF;
22 x = -x;
23 }
24 return x;
25 }
27 /** Convert a 2s compliment int to a sign-bit (i.e. int interpreted as float).
28 This undoes the result of SkSignBitTo2sCompliment().
29 */
30 static inline int32_t Sk2sComplimentToSignBit(int32_t x) {
31 int sign = x >> 31;
32 // make x positive
33 x = (x ^ sign) - sign;
34 // set the sign bit as needed
35 x |= sign << 31;
36 return x;
37 }
39 /** Given the bit representation of a float, return its value cast to an int.
40 If the value is out of range, or NaN, return return +/- SK_MaxS32
41 */
42 int32_t SkFloatBits_toIntCast(int32_t floatBits);
44 /** Given the bit representation of a float, return its floor as an int.
45 If the value is out of range, or NaN, return return +/- SK_MaxS32
46 */
47 SK_API int32_t SkFloatBits_toIntFloor(int32_t floatBits);
49 /** Given the bit representation of a float, return it rounded to an int.
50 If the value is out of range, or NaN, return return +/- SK_MaxS32
51 */
52 SK_API int32_t SkFloatBits_toIntRound(int32_t floatBits);
54 /** Given the bit representation of a float, return its ceiling as an int.
55 If the value is out of range, or NaN, return return +/- SK_MaxS32
56 */
57 SK_API int32_t SkFloatBits_toIntCeil(int32_t floatBits);
60 union SkFloatIntUnion {
61 float fFloat;
62 int32_t fSignBitInt;
63 };
65 // Helper to see a float as its bit pattern (w/o aliasing warnings)
66 static inline int32_t SkFloat2Bits(float x) {
67 SkFloatIntUnion data;
68 data.fFloat = x;
69 return data.fSignBitInt;
70 }
72 // Helper to see a bit pattern as a float (w/o aliasing warnings)
73 static inline float SkBits2Float(int32_t floatAsBits) {
74 SkFloatIntUnion data;
75 data.fSignBitInt = floatAsBits;
76 return data.fFloat;
77 }
79 /** Return the float as a 2s compliment int. Just to be used to compare floats
80 to each other or against positive float-bit-constants (like 0). This does
81 not return the int equivalent of the float, just something cheaper for
82 compares-only.
83 */
84 static inline int32_t SkFloatAs2sCompliment(float x) {
85 return SkSignBitTo2sCompliment(SkFloat2Bits(x));
86 }
88 /** Return the 2s compliment int as a float. This undos the result of
89 SkFloatAs2sCompliment
90 */
91 static inline float Sk2sComplimentAsFloat(int32_t x) {
92 return SkBits2Float(Sk2sComplimentToSignBit(x));
93 }
95 /** Return x cast to a float (i.e. (float)x)
96 */
97 float SkIntToFloatCast(int x);
98 float SkIntToFloatCast_NoOverflowCheck(int x);
100 /** Return the float cast to an int.
101 If the value is out of range, or NaN, return +/- SK_MaxS32
102 */
103 static inline int32_t SkFloatToIntCast(float x) {
104 return SkFloatBits_toIntCast(SkFloat2Bits(x));
105 }
107 /** Return the floor of the float as an int.
108 If the value is out of range, or NaN, return +/- SK_MaxS32
109 */
110 static inline int32_t SkFloatToIntFloor(float x) {
111 return SkFloatBits_toIntFloor(SkFloat2Bits(x));
112 }
114 /** Return the float rounded to an int.
115 If the value is out of range, or NaN, return +/- SK_MaxS32
116 */
117 static inline int32_t SkFloatToIntRound(float x) {
118 return SkFloatBits_toIntRound(SkFloat2Bits(x));
119 }
121 /** Return the ceiling of the float as an int.
122 If the value is out of range, or NaN, return +/- SK_MaxS32
123 */
124 static inline int32_t SkFloatToIntCeil(float x) {
125 return SkFloatBits_toIntCeil(SkFloat2Bits(x));
126 }
128 // Scalar wrappers for float-bit routines
130 #define SkScalarAs2sCompliment(x) SkFloatAs2sCompliment(x)
131 #define Sk2sComplimentAsScalar(x) Sk2sComplimentAsFloat(x)
133 #endif
