1 /*
2 * Copyright (C) 2006 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef SkEndian_DEFINED
18 #define SkEndian_DEFINED
19
20 #include "SkTypes.h"
21
22 /** \file SkEndian.h
23
24 Macros and helper functions for handling 16 and 32 bit values in
25 big and little endian formats.
26 */
27
28 #if defined(SK_CPU_LENDIAN) && defined(SK_CPU_BENDIAN)
29 #error "can't have both LENDIAN and BENDIAN defined"
30 #endif
31
32 #if !defined(SK_CPU_LENDIAN) && !defined(SK_CPU_BENDIAN)
33 #error "need either LENDIAN or BENDIAN defined"
34 #endif
35
36 /** Swap the two bytes in the low 16bits of the parameters.
37 e.g. 0x1234 -> 0x3412
38 */
SkEndianSwap16(U16CPU value)39 inline uint16_t SkEndianSwap16(U16CPU value)
40 {
41 SkASSERT(value == (uint16_t)value);
42 return (uint16_t)((value >> 8) | (value << 8));
43 }
44
45 /** Vector version of SkEndianSwap16(), which swaps the
46 low two bytes of each value in the array.
47 */
SkEndianSwap16s(uint16_t array[],int count)48 inline void SkEndianSwap16s(uint16_t array[], int count)
49 {
50 SkASSERT(count == 0 || array != NULL);
51
52 while (--count >= 0)
53 {
54 *array = SkEndianSwap16(*array);
55 array += 1;
56 }
57 }
58
59 /** Reverse all 4 bytes in a 32bit value.
60 e.g. 0x12345678 -> 0x78563412
61 */
SkEndianSwap32(uint32_t value)62 inline uint32_t SkEndianSwap32(uint32_t value)
63 {
64 return ((value & 0xFF) << 24) |
65 ((value & 0xFF00) << 8) |
66 ((value & 0xFF0000) >> 8) |
67 (value >> 24);
68 }
69
70 /** Vector version of SkEndianSwap16(), which swaps the
71 bytes of each value in the array.
72 */
SkEndianSwap32s(uint32_t array[],int count)73 inline void SkEndianSwap32s(uint32_t array[], int count)
74 {
75 SkASSERT(count == 0 || array != NULL);
76
77 while (--count >= 0)
78 {
79 *array = SkEndianSwap32(*array);
80 array += 1;
81 }
82 }
83
84 #ifdef SK_CPU_LENDIAN
85 #define SkEndian_SwapBE16(n) SkEndianSwap16(n)
86 #define SkEndian_SwapBE32(n) SkEndianSwap32(n)
87 #define SkEndian_SwapLE16(n) (n)
88 #define SkEndian_SwapLE32(n) (n)
89 #else // SK_CPU_BENDIAN
90 #define SkEndian_SwapBE16(n) (n)
91 #define SkEndian_SwapBE32(n) (n)
92 #define SkEndian_SwapLE16(n) SkEndianSwap16(n)
93 #define SkEndian_SwapLE32(n) SkEndianSwap32(n)
94 #endif
95
96
97 #endif
98
99