1 /*
2 * Copyright 2017 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 #ifndef SkImageInfoPriv_DEFINED
9 #define SkImageInfoPriv_DEFINED
10
11 #include "SkImageInfo.h"
12
13 enum SkColorTypeComponentFlag {
14 kRed_SkColorTypeComponentFlag = 0x1,
15 kGreen_SkColorTypeComponentFlag = 0x2,
16 kBlue_SkColorTypeComponentFlag = 0x4,
17 kAlpha_SkColorTypeComponentFlag = 0x8,
18 kGray_SkColorTypeComponentFlag = 0x10,
19 kRGB_SkColorTypeComponentFlags = kRed_SkColorTypeComponentFlag |
20 kGreen_SkColorTypeComponentFlag |
21 kBlue_SkColorTypeComponentFlag,
22 kRGBA_SkColorTypeComponentFlags = kRGB_SkColorTypeComponentFlags |
23 kAlpha_SkColorTypeComponentFlag,
24 };
25
SkColorTypeComponentFlags(SkColorType ct)26 static inline uint32_t SkColorTypeComponentFlags(SkColorType ct) {
27 switch (ct) {
28 case kUnknown_SkColorType: return 0;
29 case kAlpha_8_SkColorType: return kAlpha_SkColorTypeComponentFlag;
30 case kRGB_565_SkColorType: return kRGB_SkColorTypeComponentFlags;
31 case kARGB_4444_SkColorType: return kRGBA_SkColorTypeComponentFlags;
32 case kRGBA_8888_SkColorType: return kRGBA_SkColorTypeComponentFlags;
33 case kRGB_888x_SkColorType: return kRGB_SkColorTypeComponentFlags;
34 case kBGRA_8888_SkColorType: return kRGBA_SkColorTypeComponentFlags;
35 case kRGBA_1010102_SkColorType: return kRGBA_SkColorTypeComponentFlags;
36 case kRGB_101010x_SkColorType: return kRGB_SkColorTypeComponentFlags;
37 case kGray_8_SkColorType: return kGray_SkColorTypeComponentFlag;
38 case kRGBA_F16Norm_SkColorType: return kRGBA_SkColorTypeComponentFlags;
39 case kRGBA_F16_SkColorType: return kRGBA_SkColorTypeComponentFlags;
40 case kRGBA_F32_SkColorType: return kRGBA_SkColorTypeComponentFlags;
41 }
42 return 0;
43 }
44
SkColorTypeIsAlphaOnly(SkColorType ct)45 static inline bool SkColorTypeIsAlphaOnly(SkColorType ct) {
46 return kAlpha_SkColorTypeComponentFlag == SkColorTypeComponentFlags(ct);
47 }
48
SkAlphaTypeIsValid(unsigned value)49 static inline bool SkAlphaTypeIsValid(unsigned value) {
50 return value <= kLastEnum_SkAlphaType;
51 }
52
SkColorTypeIsGray(SkColorType ct)53 static inline bool SkColorTypeIsGray(SkColorType ct) {
54 auto flags = SkColorTypeComponentFlags(ct);
55 // Currently assuming that a color type has only gray or does not have gray.
56 SkASSERT(!(kGray_SkColorTypeComponentFlag & flags) || kGray_SkColorTypeComponentFlag == flags);
57 return kGray_SkColorTypeComponentFlag == flags;
58 }
59
SkColorTypeShiftPerPixel(SkColorType ct)60 static int SkColorTypeShiftPerPixel(SkColorType ct) {
61 switch (ct) {
62 case kUnknown_SkColorType: return 0;
63 case kAlpha_8_SkColorType: return 0;
64 case kRGB_565_SkColorType: return 1;
65 case kARGB_4444_SkColorType: return 1;
66 case kRGBA_8888_SkColorType: return 2;
67 case kRGB_888x_SkColorType: return 2;
68 case kBGRA_8888_SkColorType: return 2;
69 case kRGBA_1010102_SkColorType: return 2;
70 case kRGB_101010x_SkColorType: return 2;
71 case kGray_8_SkColorType: return 0;
72 case kRGBA_F16Norm_SkColorType: return 3;
73 case kRGBA_F16_SkColorType: return 3;
74 case kRGBA_F32_SkColorType: return 4;
75 }
76 return 0;
77 }
78
SkColorTypeMinRowBytes(SkColorType ct,int width)79 static inline size_t SkColorTypeMinRowBytes(SkColorType ct, int width) {
80 return width * SkColorTypeBytesPerPixel(ct);
81 }
82
SkColorTypeIsValid(unsigned value)83 static inline bool SkColorTypeIsValid(unsigned value) {
84 return value <= kLastEnum_SkColorType;
85 }
86
SkColorTypeComputeOffset(SkColorType ct,int x,int y,size_t rowBytes)87 static inline size_t SkColorTypeComputeOffset(SkColorType ct, int x, int y, size_t rowBytes) {
88 if (kUnknown_SkColorType == ct) {
89 return 0;
90 }
91 return y * rowBytes + (x << SkColorTypeShiftPerPixel(ct));
92 }
93
94 /**
95 * Returns true if |info| contains a valid combination of width, height, colorType, and alphaType.
96 */
SkImageInfoIsValid(const SkImageInfo & info)97 static inline bool SkImageInfoIsValid(const SkImageInfo& info) {
98 if (info.width() <= 0 || info.height() <= 0) {
99 return false;
100 }
101
102 const int kMaxDimension = SK_MaxS32 >> 2;
103 if (info.width() > kMaxDimension || info.height() > kMaxDimension) {
104 return false;
105 }
106
107 if (kUnknown_SkColorType == info.colorType() || kUnknown_SkAlphaType == info.alphaType()) {
108 return false;
109 }
110
111 return true;
112 }
113
114 /**
115 * Returns true if Skia has defined a pixel conversion from the |src| to the |dst|.
116 * Returns false otherwise.
117 */
SkImageInfoValidConversion(const SkImageInfo & dst,const SkImageInfo & src)118 static inline bool SkImageInfoValidConversion(const SkImageInfo& dst, const SkImageInfo& src) {
119 return SkImageInfoIsValid(dst) && SkImageInfoIsValid(src);
120 }
121 #endif // SkImageInfoPriv_DEFINED
122