1 | // [Blend2D] |
2 | // 2D Vector Graphics Powered by a JIT Compiler. |
3 | // |
4 | // [License] |
5 | // Zlib - See LICENSE.md file in the package. |
6 | |
7 | #include "./blapi-build_p.h" |
8 | #include "./blformat_p.h" |
9 | #include "./bltables_p.h" |
10 | |
11 | // ============================================================================ |
12 | // [BLFormatInfo - Globals] |
13 | // ============================================================================ |
14 | |
15 | const BLFormatInfo blFormatInfo[BL_FORMAT_RESERVED_COUNT] = { |
16 | #define U 0 // Used only to distinguish between zero and unused. |
17 | { 0 , blFormatFlagsStatic(0 ), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Public:NONE> |
18 | { 32, blFormatFlagsStatic(1 ), {{ { 8, 8, 8, 8 }, { 16, 8 , 0 , 24 } }} }, // <Public:PRGB32> |
19 | { 32, blFormatFlagsStatic(2 ), {{ { 8, 8, 8, U }, { 16, 8 , 0 , U } }} }, // <Public:XRGB32> |
20 | { 8 , blFormatFlagsStatic(3 ), {{ { U, U, U, 8 }, { U , U , U , 0 } }} }, // <Public:A8> |
21 | { 32, blFormatFlagsStatic(4 ), {{ { 8, 8, 8, U }, { 16, 8 , 0 , U } }} }, // <Internal:FRGB32> |
22 | { 32, blFormatFlagsStatic(5 ), {{ { 8, 8, 8, 8 }, { 16, 8 , 0 , 24 } }} }, // <Internal:ZERO32> |
23 | { 0 , blFormatFlagsStatic(6 ), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Reserved> |
24 | { 0 , blFormatFlagsStatic(7 ), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Reserved> |
25 | { 0 , blFormatFlagsStatic(8 ), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Reserved> |
26 | { 0 , blFormatFlagsStatic(9 ), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Reserved> |
27 | { 0 , blFormatFlagsStatic(10), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Reserved> |
28 | { 0 , blFormatFlagsStatic(11), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Reserved> |
29 | { 0 , blFormatFlagsStatic(12), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Reserved> |
30 | { 0 , blFormatFlagsStatic(13), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Reserved> |
31 | { 0 , blFormatFlagsStatic(14), {{ { U, U, U, U }, { U , U , U , U } }} }, // <Reserved> |
32 | { 0 , blFormatFlagsStatic(15), {{ { U, U, U, U }, { U , U , U , U } }} } // <Reserved> |
33 | #undef U |
34 | }; |
35 | |
36 | static_assert(BL_FORMAT_INTERNAL_COUNT == 6, |
37 | "New formats must be added to 'blFormatInfo' table" ); |
38 | |
39 | // ============================================================================ |
40 | // [BLFormatInfo - Tables] |
41 | // ============================================================================ |
42 | |
43 | // Indexes of components based on format flags that describe components. Each |
44 | // bit in the mask describes RGBA components (in order). Thus 0x1 descrines red |
45 | // component, 0x2 green 0x4 blue, and 0x8 alpha. Components can be combined so |
46 | // 0x7 describes RGB and 0xF RGBA. |
47 | struct BLPixelConverterComponentIndexesGen { |
48 | static constexpr uint8_t value(size_t i) noexcept { |
49 | return i == BL_FORMAT_FLAG_RGB ? uint8_t(0x7) : |
50 | i == BL_FORMAT_FLAG_ALPHA ? uint8_t(0x8) : |
51 | i == BL_FORMAT_FLAG_RGBA ? uint8_t(0xF) : |
52 | i == BL_FORMAT_FLAG_LUM ? uint8_t(0x7) : |
53 | i == BL_FORMAT_FLAG_LUMA ? uint8_t(0xF) : uint8_t(0); |
54 | } |
55 | }; |
56 | |
57 | static constexpr const auto blPixelConverterComponentIndexesTable = |
58 | blLookupTable<uint8_t, 16, BLPixelConverterComponentIndexesGen>(); |
59 | |
60 | // ============================================================================ |
61 | // [BLFormatInfo - Sanitize] |
62 | // ============================================================================ |
63 | |
64 | static BL_INLINE bool blFormatInfoIsDepthValid(uint32_t depth) noexcept { |
65 | switch (depth) { |
66 | case 1: |
67 | case 2: |
68 | case 4: |
69 | case 8: |
70 | case 16: |
71 | case 24: |
72 | case 32: |
73 | return true; |
74 | |
75 | default: |
76 | return false; |
77 | } |
78 | } |
79 | |
80 | BLResult blFormatInfoSanitize(BLFormatInfo* self) noexcept { |
81 | BLFormatInfo& f = *self; |
82 | |
83 | // Filter out all flags that will be computed. |
84 | f.flags &= BL_FORMAT_ALL_FLAGS; |
85 | |
86 | uint32_t i; |
87 | bool masksOverlap = false; |
88 | bool notByteAligned = false; |
89 | bool crossesByteBoundary = false; |
90 | |
91 | // Check depth. |
92 | if (!blFormatInfoIsDepthValid(f.depth)) |
93 | return blTraceError(BL_ERROR_INVALID_VALUE); |
94 | |
95 | if (f.flags & BL_FORMAT_FLAG_INDEXED) { |
96 | // In 32-bit mode shifts are not overlapping with `palette` so zero them. |
97 | if (sizeof(void*) == 4) |
98 | memset(f.shifts, 0, sizeof(f.shifts)); |
99 | |
100 | // Indexed formats are up to 8 bits-per-pixel and must have palette. |
101 | if (f.depth > 8 || !f.palette) |
102 | return blTraceError(BL_ERROR_INVALID_VALUE); |
103 | } |
104 | else { |
105 | // Check whether RGB|A components are correct. |
106 | uint64_t masksAsU64[4]; |
107 | uint64_t masksCombined = 0; |
108 | |
109 | // Check whether pixel components are specified correctly. |
110 | uint32_t componentIndexes = blPixelConverterComponentIndexesTable[f.flags & 0xF]; |
111 | if (!componentIndexes) |
112 | return blTraceError(BL_ERROR_INVALID_VALUE); |
113 | |
114 | for (i = 0; i < 4; i++) { |
115 | uint32_t size = f.sizes[i]; |
116 | uint32_t shift = f.shifts[i]; |
117 | |
118 | if (size == 0) { |
119 | // Fail if this component must be provided. |
120 | if (componentIndexes & (1u << i)) |
121 | return blTraceError(BL_ERROR_INVALID_VALUE); |
122 | |
123 | // Undefined size (0) must have zero shift as well. As it's not |
124 | // used it doesn't make sense to assign it a value. |
125 | if (shift != 0) |
126 | return blTraceError(BL_ERROR_INVALID_VALUE); |
127 | |
128 | masksAsU64[i] = 0; |
129 | } |
130 | else { |
131 | // Fail if this component must not be provided. |
132 | if (!(componentIndexes & (1u << i))) |
133 | return blTraceError(BL_ERROR_INVALID_VALUE); |
134 | |
135 | // Fail if the size is too large. |
136 | if (size > 16) |
137 | return blTraceError(BL_ERROR_INVALID_VALUE); |
138 | |
139 | // Shifted mask overflows the pixel depth? |
140 | if (shift + size > f.depth) |
141 | return blTraceError(BL_ERROR_INVALID_VALUE); |
142 | |
143 | // Byte aligned means that shifts are [0, 8, 16, 24] and mask is 0xFF. |
144 | if (size != 8 || (shift & 0x7u) != 0) |
145 | notByteAligned = true; |
146 | |
147 | // Does the mask cross a byte-boundary? |
148 | if ((shift / 8u) != ((shift + size - 1) / 8u)) |
149 | crossesByteBoundary = true; |
150 | |
151 | // Does the mask overlap with others? |
152 | uint64_t maskAsU64 = uint64_t(blTrailingBitMask<uint32_t>(size)) << shift; |
153 | if (masksCombined & maskAsU64) { |
154 | masksOverlap = true; |
155 | // Alpha channel cannot overlap. |
156 | if (i == 3) |
157 | return blTraceError(BL_ERROR_INVALID_VALUE); |
158 | } |
159 | |
160 | masksAsU64[i] = maskAsU64; |
161 | masksCombined |= maskAsU64; |
162 | } |
163 | } |
164 | |
165 | // Unset `BL_FORMAT_FLAG_PREMULTIPLIED` if the format doesn't have alpha. |
166 | if (!(f.flags & (BL_FORMAT_FLAG_ALPHA))) |
167 | f.flags &= ~BL_FORMAT_FLAG_PREMULTIPLIED; |
168 | |
169 | // It's allowed that masks overlap only when the pixel format describes a grayscale (LUM). |
170 | bool isLUM = (f.flags & BL_FORMAT_FLAG_LUM) != 0; |
171 | if (isLUM != masksOverlap) |
172 | return blTraceError(BL_ERROR_INVALID_VALUE); |
173 | |
174 | // RGB components must match in grayscale (LUM) mode. |
175 | if (isLUM && (f.rSize != f.gSize || f.rShift != f.gShift || |
176 | f.gSize != f.bSize || f.gShift != f.bShift)) |
177 | return blTraceError(BL_ERROR_INVALID_VALUE); |
178 | } |
179 | |
180 | // Switch to a native byte-order if possible. |
181 | if (f.flags & BL_FORMAT_FLAG_BYTE_SWAP) { |
182 | if (f.depth <= 8) { |
183 | // Switch to native byte-order if the depth <= 8. |
184 | f.flags &= ~BL_FORMAT_FLAG_BYTE_SWAP; |
185 | } |
186 | else if (!crossesByteBoundary) { |
187 | // Switch to native byte-order if no mask crosses a byte boundary. |
188 | for (i = 0; i < 4; i++) { |
189 | uint32_t size = f.sizes[i]; |
190 | if (!size) |
191 | continue; |
192 | f.shifts[i] = uint8_t(f.depth - f.shifts[i] - size); |
193 | } |
194 | |
195 | f.flags &= ~BL_FORMAT_FLAG_BYTE_SWAP; |
196 | } |
197 | } |
198 | |
199 | // Add computed flags. |
200 | if (!notByteAligned) |
201 | f.flags |= BL_FORMAT_FLAG_BYTE_ALIGNED; |
202 | |
203 | return BL_SUCCESS; |
204 | } |
205 | |