1/*
2 * Copyright 2010 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkImageInfo.h"
9#include "SkReadBuffer.h"
10#include "SkWriteBuffer.h"
11
12static bool alpha_type_is_valid(SkAlphaType alphaType) {
13    return (alphaType >= 0) && (alphaType <= kLastEnum_SkAlphaType);
14}
15
16static bool color_type_is_valid(SkColorType colorType) {
17    return (colorType >= 0) && (colorType <= kLastEnum_SkColorType);
18}
19
20void SkImageInfo::unflatten(SkReadBuffer& buffer) {
21    fWidth = buffer.read32();
22    fHeight = buffer.read32();
23
24    uint32_t packed = buffer.read32();
25    SkASSERT(0 == (packed >> 16));
26    fAlphaType = (SkAlphaType)((packed >> 8) & 0xFF);
27    fColorType = (SkColorType)((packed >> 0) & 0xFF);
28    buffer.validate(alpha_type_is_valid(fAlphaType) &&
29                    color_type_is_valid(fColorType));
30}
31
32void SkImageInfo::flatten(SkWriteBuffer& buffer) const {
33    buffer.write32(fWidth);
34    buffer.write32(fHeight);
35
36    SkASSERT(0 == (fAlphaType & ~0xFF));
37    SkASSERT(0 == (fColorType & ~0xFF));
38    uint32_t packed = (fAlphaType << 8) | fColorType;
39    buffer.write32(packed);
40}
41
42bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType,
43                                  SkAlphaType* canonical) {
44    switch (colorType) {
45        case kUnknown_SkColorType:
46            alphaType = kIgnore_SkAlphaType;
47            break;
48        case kAlpha_8_SkColorType:
49            if (kUnpremul_SkAlphaType == alphaType) {
50                alphaType = kPremul_SkAlphaType;
51            }
52            // fall-through
53        case kIndex_8_SkColorType:
54        case kARGB_4444_SkColorType:
55        case kRGBA_8888_SkColorType:
56        case kBGRA_8888_SkColorType:
57            if (kIgnore_SkAlphaType == alphaType) {
58                return false;
59            }
60            break;
61        case kRGB_565_SkColorType:
62            alphaType = kOpaque_SkAlphaType;
63            break;
64        default:
65            return false;
66    }
67    if (canonical) {
68        *canonical = alphaType;
69    }
70    return true;
71}
72