-
-
Notifications
You must be signed in to change notification settings - Fork 1k
/
pixelformat.h
429 lines (382 loc) · 11.8 KB
/
pixelformat.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef GRAPHICS_PIXELFORMAT_H
#define GRAPHICS_PIXELFORMAT_H
#include "common/scummsys.h"
#include "common/str.h"
#include "graphics/colormasks.h"
namespace Graphics {
/**
* @defgroup graphics_pixelformat Pixel formats
* @ingroup graphics
*
* @brief Structures for managing pixel formats.
*
* @{
*/
/** Template to expand from an n-bit component to an 8-bit component. */
template<int depth>
struct ColorComponent {
};
/** Return 0 for an empty color component. */
template<>
struct ColorComponent<0> {
static inline uint expand(uint value) {
return 0;
}
};
/** Template to expand a 1-bit component into an 8-bit component. */
template<>
struct ColorComponent<1> {
static inline uint expand(uint value) {
return value ? 0xff : 0;
}
};
/** Template to expand a 2-bit component into an 8-bit component. */
template<>
struct ColorComponent<2> {
static inline uint expand(uint value) {
value &= 3;
return value |
(value << 2) |
(value << 4) |
(value << 6);
}
};
/** Template to expand a 3-bit component into an 8-bit component. */
template<>
struct ColorComponent<3> {
static inline uint expand(uint value) {
value &= 7;
return (value << 5) |
(value << 2) |
(value >> 1);
}
};
/** Template to expand a 4-bit component into an 8-bit component. */
template<>
struct ColorComponent<4> {
static inline uint expand(uint value) {
value &= 15;
return value |
(value << 4);
}
};
/** Template to expand a 5-bit component into an 8-bit component. */
template<>
struct ColorComponent<5> {
static inline uint expand(uint value) {
value &= 31;
return (value << 3) |
(value >> 2);
}
};
/** Template to expand a 6-bit component into an 8-bit component. */
template<>
struct ColorComponent<6> {
static inline uint expand(uint value) {
value &= 63;
return (value << 2) |
(value >> 4);
}
};
/** Template to expand a 7-bit component into an 8-bit component. */
template<>
struct ColorComponent<7> {
static inline uint expand(uint value) {
value &= 127;
return (value << 1) |
(value >> 6);
}
};
/** Return the given value. */
template<>
struct ColorComponent<8> {
static inline uint expand(uint value) {
return value & 255;
}
};
/**
* Pixel format description.
*
* Like ColorMasks, it includes the given values to create colors from RGB
* values and to retrieve RGB values from colors.
*
* Unlike ColorMasks, it is not dependent on knowing the exact pixel format
* on compile time.
*
* A minor difference between ColorMasks and PixelFormat is that ColorMasks
* stores the bit count per channel in @c kFooBits, while PixelFormat stores
* the loss compared to 8 bits per channel in @c \#Loss. It also does not
* contain mask values.
*/
struct PixelFormat {
byte bytesPerPixel; /**< Number of bytes used in the pixel format. */
byte rLoss, gLoss, bLoss, aLoss; /**< Precision loss of each color component. */
byte rShift, gShift, bShift, aShift; /**< Binary left shift of each color component in the pixel value. */
/** Default constructor that creates a null pixel format. */
constexpr PixelFormat() :
bytesPerPixel(0),
rLoss(0), gLoss(0), bLoss(0), aLoss(0),
rShift(0), gShift(0), bShift(0), aShift(0) {}
/** Construct a pixel format based on the provided arguments.
*
* Examples:
*
* - RGBA8888:
* @code
* BytesPerPixel = 4, RBits = GBits = BBits = ABits = 8, RShift = 24, GShift = 16, BShift = 8, AShift = 0
* @endcode
* - ABGR8888:
* @code
* BytesPerPixel = 4, RBits = GBits = BBits = ABits = 8, RShift = 0, GShift = 8, BShift = 16, AShift = 24
* @endcode
* - RGB565:
* @code
* BytesPerPixel = 2, RBits = 5, GBits = 6, BBits = 5, ABits = 0, RShift = 11, GShift = 5, BShift = 0, AShift = 0
* @endcode
*/
constexpr PixelFormat(byte BytesPerPixel,
byte RBits, byte GBits, byte BBits, byte ABits,
byte RShift, byte GShift, byte BShift, byte AShift) :
bytesPerPixel(BytesPerPixel),
rLoss(8 - RBits),
gLoss(8 - GBits),
bLoss(8 - BBits),
aLoss(8 - ABits),
rShift((RBits == 0) ? 0 : RShift),
gShift((GBits == 0) ? 0 : GShift),
bShift((BBits == 0) ? 0 : BShift),
aShift((ABits == 0) ? 0 : AShift)
{
}
/** Define a CLUT8 pixel format. */
static inline PixelFormat createFormatCLUT8() {
return PixelFormat(1, 0, 0, 0, 0, 0, 0, 0, 0);
}
/** Check if two pixel formats are the same */
inline bool operator==(const PixelFormat &fmt) const {
return bytesPerPixel == fmt.bytesPerPixel &&
rLoss == fmt.rLoss &&
gLoss == fmt.gLoss &&
bLoss == fmt.bLoss &&
aLoss == fmt.aLoss &&
rShift == fmt.rShift &&
gShift == fmt.gShift &&
bShift == fmt.bShift &&
aShift == fmt.aShift;
}
/** Check if two pixel formats are different. */
inline bool operator!=(const PixelFormat &fmt) const {
return !(*this == fmt);
}
/** Return an RGB color value from red, green, and blue values. */
inline uint32 RGBToColor(uint8 r, uint8 g, uint8 b) const {
return
((0xFF >> aLoss) << aShift) |
(( r >> rLoss) << rShift) |
(( g >> gLoss) << gShift) |
(( b >> bLoss) << bShift);
}
template<class T>
inline uint32 RGBToColorT(uint8 r, uint8 g, uint8 b) const {
return T::kAlphaMask |
(((r << T::kRedShift) >> (8 - T::kRedBits)) & T::kRedMask) |
(((g << T::kGreenShift) >> (8 - T::kGreenBits)) & T::kGreenMask) |
(((b << T::kBlueShift) >> (8 - T::kBlueBits)) & T::kBlueMask);
}
/** Return an ARGB color value from alpha, red, green, and blue values. */
inline uint32 ARGBToColor(uint8 a, uint8 r, uint8 g, uint8 b) const {
return
((a >> aLoss) << aShift) |
((r >> rLoss) << rShift) |
((g >> gLoss) << gShift) |
((b >> bLoss) << bShift);
}
template<class T>
inline uint32 ARGBToColorT(uint8 a, uint8 r, uint8 g, uint8 b) const {
return (((a << T::kAlphaShift) >> (8 - T::kAlphaBits)) & T::kAlphaMask) |
(((r << T::kRedShift) >> (8 - T::kRedBits)) & T::kRedMask) |
(((g << T::kGreenShift) >> (8 - T::kGreenBits)) & T::kGreenMask) |
(((b << T::kBlueShift) >> (8 - T::kBlueBits)) & T::kBlueMask);
}
/** Retrieve red, green, and blue values from an RGB color value. */
inline void colorToRGB(uint32 color, uint8 &r, uint8 &g, uint8 &b) const {
r = expand(rBits(), color >> rShift);
g = expand(gBits(), color >> gShift);
b = expand(bBits(), color >> bShift);
}
template<class T>
inline void colorToRGBT(uint32 color, uint8 &r, uint8 &g, uint8 &b) const {
r = ((color & T::kRedMask) >> T::kRedShift) << (8 - T::kRedBits);
g = ((color & T::kGreenMask) >> T::kGreenShift) << (8 - T::kGreenBits);
b = ((color & T::kBlueMask) >> T::kBlueShift) << (8 - T::kBlueBits);
}
/** Retrieve alpha, red, green, and blue values from an ARGB color value. */
inline void colorToARGB(uint32 color, uint8 &a, uint8 &r, uint8 &g, uint8 &b) const {
a = (aBits() == 0) ? 0xFF : expand(aBits(), color >> aShift);
r = expand(rBits(), color >> rShift);
g = expand(gBits(), color >> gShift);
b = expand(bBits(), color >> bShift);
}
template<class T>
inline void colorToARGBT(uint32 color, uint8 &a, uint8 &r, uint8 &g, uint8 &b) const {
a = ((color & T::kAlphaMask) >> T::kAlphaShift) << (8 - T::kAlphaBits);
r = ((color & T::kRedMask) >> T::kRedShift) << (8 - T::kRedBits);
g = ((color & T::kGreenMask) >> T::kGreenShift) << (8 - T::kGreenBits);
b = ((color & T::kBlueMask) >> T::kBlueShift) << (8 - T::kBlueBits);
}
/**
* @name Convenience functions for getting the number of color component bits
* @{
*/
/**
* Return the number of red component bits.
*/
inline byte rBits() const {
return (8 - rLoss);
}
/**
* Return the number of green component bits.
*/
inline byte gBits() const {
return (8 - gLoss);
}
/**
* Return the number of blue component bits.
*/
inline byte bBits() const {
return (8 - bLoss);
}
/**
* Return the number of alpha component bits.
*/
inline byte aBits() const {
return (8 - aLoss);
}
/**
* Return the total number of bits for the pixel format.
*/
inline byte bpp() const {
return rBits() + gBits() + bBits() + aBits();
}
/** @} */
/**
* @name Convenience functions for getting color components' maximum values
* @{
*/
/**
* Return the maximum value of red.
*/
inline uint rMax() const {
return (1 << rBits()) - 1;
}
/**
* Return the maximum value of green.
*/
inline uint gMax() const {
return (1 << gBits()) - 1;
}
/**
* Return the maximum value of blue.
*/
inline uint bMax() const {
return (1 << bBits()) - 1;
}
/**
* Return the maximum value of alpha.
*/
inline uint aMax() const {
return (1 << aBits()) - 1;
}
/** @} */
/** Expand a given bit-depth component to a full 8-bit component. @todo is that different from the templates at the beginning? */
static inline uint expand(uint bits, uint color) {
switch (bits) {
case 0:
return ColorComponent<0>::expand(color);
case 1:
return ColorComponent<1>::expand(color);
case 2:
return ColorComponent<2>::expand(color);
case 3:
return ColorComponent<3>::expand(color);
case 4:
return ColorComponent<4>::expand(color);
case 5:
return ColorComponent<5>::expand(color);
case 6:
return ColorComponent<6>::expand(color);
case 7:
return ColorComponent<7>::expand(color);
case 8:
return ColorComponent<8>::expand(color);
default:
break;
}
// Unsupported
return 0;
}
/** Return string representation. */
Common::String toString() const;
/** Shortcut method for checking if the current format is CLUT8 or not */
bool isCLUT8() const {
// We do not really need to check masks when all shifts equal zeroes
return bytesPerPixel == 1 && rShift == 0 && gShift == 0 && bShift == 0 && aShift == 0;
}
};
template<>
inline uint32 PixelFormat::RGBToColorT<ColorMasks<0> >(uint8 r, uint8 g, uint8 b) const {
return RGBToColor(r, g, b);
}
template<>
inline uint32 PixelFormat::ARGBToColorT<ColorMasks<0> >(uint8 a, uint8 r, uint8 g, uint8 b) const {
return ARGBToColor(a, r, g, b);
}
template<>
inline void PixelFormat::colorToRGBT<ColorMasks<0> >(uint32 color, uint8 &r, uint8 &g, uint8 &b) const {
colorToRGB(color, r, g, b);
}
template<>
inline void PixelFormat::colorToARGBT<ColorMasks<0> >(uint32 color, uint8 &a, uint8 &r, uint8 &g, uint8 &b) const {
colorToARGB(color, a, r, g, b);
}
/**
* Convert a 'bitFormat' as defined by one of the ColorMasks
* into a PixelFormat.
*/
template<int bitFormat>
PixelFormat createPixelFormat() {
PixelFormat format;
format.bytesPerPixel = ColorMasks<bitFormat>::kBytesPerPixel;
format.rLoss = 8 - ColorMasks<bitFormat>::kRedBits;
format.gLoss = 8 - ColorMasks<bitFormat>::kGreenBits;
format.bLoss = 8 - ColorMasks<bitFormat>::kBlueBits;
format.aLoss = 8 - ColorMasks<bitFormat>::kAlphaBits;
format.rShift = ColorMasks<bitFormat>::kRedShift;
format.gShift = ColorMasks<bitFormat>::kGreenShift;
format.bShift = ColorMasks<bitFormat>::kBlueShift;
format.aShift = ColorMasks<bitFormat>::kAlphaShift;
return format;
}
/** @} */
} // End of namespace Graphics
#endif