1 /*
2   Simple DirectMedia Layer
3   Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
4 
5   This software is provided 'as-is', without any express or implied
6   warranty.  In no event will the authors be held liable for any damages
7   arising from the use of this software.
8 
9   Permission is granted to anyone to use this software for any purpose,
10   including commercial applications, and to alter it and redistribute it
11   freely, subject to the following restrictions:
12 
13   1. The origin of this software must not be misrepresented; you must not
14      claim that you wrote the original software. If you use this software
15      in a product, an acknowledgment in the product documentation would be
16      appreciated but is not required.
17   2. Altered source versions must be plainly marked as such, and must not be
18      misrepresented as being the original software.
19   3. This notice may not be removed or altered from any source distribution.
20 */
21 
22 /**
23  *  \file SDL_pixels.h
24  *
25  *  Header for the enumerated pixel format definitions.
26  */
27 
28 #ifndef SDL_pixels_h_
29 #define SDL_pixels_h_
30 
31 #include "SDL_stdinc.h"
32 #include "SDL_endian.h"
33 
34 #include "begin_code.h"
35 /* Set up for C function definitions, even when using C++ */
36 #ifdef __cplusplus
37 extern "C" {
38 #endif
39 
40 /**
41  *  \name Transparency definitions
42  *
43  *  These define alpha as the opacity of a surface.
44  */
45 /* @{ */
46 #define SDL_ALPHA_OPAQUE 255
47 #define SDL_ALPHA_TRANSPARENT 0
48 /* @} */
49 
50 /** Pixel type. */
51 typedef enum
52 {
53     SDL_PIXELTYPE_UNKNOWN,
54     SDL_PIXELTYPE_INDEX1,
55     SDL_PIXELTYPE_INDEX4,
56     SDL_PIXELTYPE_INDEX8,
57     SDL_PIXELTYPE_PACKED8,
58     SDL_PIXELTYPE_PACKED16,
59     SDL_PIXELTYPE_PACKED32,
60     SDL_PIXELTYPE_ARRAYU8,
61     SDL_PIXELTYPE_ARRAYU16,
62     SDL_PIXELTYPE_ARRAYU32,
63     SDL_PIXELTYPE_ARRAYF16,
64     SDL_PIXELTYPE_ARRAYF32
65 } SDL_PixelType;
66 
67 /** Bitmap pixel order, high bit -> low bit. */
68 typedef enum
69 {
70     SDL_BITMAPORDER_NONE,
71     SDL_BITMAPORDER_4321,
72     SDL_BITMAPORDER_1234
73 } SDL_BitmapOrder;
74 
75 /** Packed component order, high bit -> low bit. */
76 typedef enum
77 {
78     SDL_PACKEDORDER_NONE,
79     SDL_PACKEDORDER_XRGB,
80     SDL_PACKEDORDER_RGBX,
81     SDL_PACKEDORDER_ARGB,
82     SDL_PACKEDORDER_RGBA,
83     SDL_PACKEDORDER_XBGR,
84     SDL_PACKEDORDER_BGRX,
85     SDL_PACKEDORDER_ABGR,
86     SDL_PACKEDORDER_BGRA
87 } SDL_PackedOrder;
88 
89 /** Array component order, low byte -> high byte. */
90 /* !!! FIXME: in 2.1, make these not overlap differently with
91    !!! FIXME:  SDL_PACKEDORDER_*, so we can simplify SDL_ISPIXELFORMAT_ALPHA */
92 typedef enum
93 {
94     SDL_ARRAYORDER_NONE,
95     SDL_ARRAYORDER_RGB,
96     SDL_ARRAYORDER_RGBA,
97     SDL_ARRAYORDER_ARGB,
98     SDL_ARRAYORDER_BGR,
99     SDL_ARRAYORDER_BGRA,
100     SDL_ARRAYORDER_ABGR
101 } SDL_ArrayOrder;
102 
103 /** Packed component layout. */
104 typedef enum
105 {
106     SDL_PACKEDLAYOUT_NONE,
107     SDL_PACKEDLAYOUT_332,
108     SDL_PACKEDLAYOUT_4444,
109     SDL_PACKEDLAYOUT_1555,
110     SDL_PACKEDLAYOUT_5551,
111     SDL_PACKEDLAYOUT_565,
112     SDL_PACKEDLAYOUT_8888,
113     SDL_PACKEDLAYOUT_2101010,
114     SDL_PACKEDLAYOUT_1010102
115 } SDL_PackedLayout;
116 
117 #define SDL_DEFINE_PIXELFOURCC(A, B, C, D) SDL_FOURCC(A, B, C, D)
118 
119 #define SDL_DEFINE_PIXELFORMAT(type, order, layout, bits, bytes) \
120     ((1 << 28) | ((type) << 24) | ((order) << 20) | ((layout) << 16) | \
121      ((bits) << 8) | ((bytes) << 0))
122 
123 #define SDL_PIXELFLAG(X)    (((X) >> 28) & 0x0F)
124 #define SDL_PIXELTYPE(X)    (((X) >> 24) & 0x0F)
125 #define SDL_PIXELORDER(X)   (((X) >> 20) & 0x0F)
126 #define SDL_PIXELLAYOUT(X)  (((X) >> 16) & 0x0F)
127 #define SDL_BITSPERPIXEL(X) (((X) >> 8) & 0xFF)
128 #define SDL_BYTESPERPIXEL(X) \
129     (SDL_ISPIXELFORMAT_FOURCC(X) ? \
130         ((((X) == SDL_PIXELFORMAT_YUY2) || \
131           ((X) == SDL_PIXELFORMAT_UYVY) || \
132           ((X) == SDL_PIXELFORMAT_YVYU)) ? 2 : 1) : (((X) >> 0) & 0xFF))
133 
134 #define SDL_ISPIXELFORMAT_INDEXED(format)   \
135     (!SDL_ISPIXELFORMAT_FOURCC(format) && \
136      ((SDL_PIXELTYPE(format) == SDL_PIXELTYPE_INDEX1) || \
137       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_INDEX4) || \
138       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_INDEX8)))
139 
140 #define SDL_ISPIXELFORMAT_PACKED(format) \
141     (!SDL_ISPIXELFORMAT_FOURCC(format) && \
142      ((SDL_PIXELTYPE(format) == SDL_PIXELTYPE_PACKED8) || \
143       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_PACKED16) || \
144       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_PACKED32)))
145 
146 #define SDL_ISPIXELFORMAT_ARRAY(format) \
147     (!SDL_ISPIXELFORMAT_FOURCC(format) && \
148      ((SDL_PIXELTYPE(format) == SDL_PIXELTYPE_ARRAYU8) || \
149       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_ARRAYU16) || \
150       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_ARRAYU32) || \
151       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_ARRAYF16) || \
152       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_ARRAYF32)))
153 
154 #define SDL_ISPIXELFORMAT_ALPHA(format)   \
155     ((SDL_ISPIXELFORMAT_PACKED(format) && \
156      ((SDL_PIXELORDER(format) == SDL_PACKEDORDER_ARGB) || \
157       (SDL_PIXELORDER(format) == SDL_PACKEDORDER_RGBA) || \
158       (SDL_PIXELORDER(format) == SDL_PACKEDORDER_ABGR) || \
159       (SDL_PIXELORDER(format) == SDL_PACKEDORDER_BGRA))) || \
160     (SDL_ISPIXELFORMAT_ARRAY(format) && \
161      ((SDL_PIXELORDER(format) == SDL_ARRAYORDER_ARGB) || \
162       (SDL_PIXELORDER(format) == SDL_ARRAYORDER_RGBA) || \
163       (SDL_PIXELORDER(format) == SDL_ARRAYORDER_ABGR) || \
164       (SDL_PIXELORDER(format) == SDL_ARRAYORDER_BGRA))))
165 
166 /* The flag is set to 1 because 0x1? is not in the printable ASCII range */
167 #define SDL_ISPIXELFORMAT_FOURCC(format)    \
168     ((format) && (SDL_PIXELFLAG(format) != 1))
169 
170 /* Note: If you modify this list, update SDL_GetPixelFormatName() */
171 typedef enum
172 {
173     SDL_PIXELFORMAT_UNKNOWN,
174     SDL_PIXELFORMAT_INDEX1LSB =
175         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_INDEX1, SDL_BITMAPORDER_4321, 0,
176                                1, 0),
177     SDL_PIXELFORMAT_INDEX1MSB =
178         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_INDEX1, SDL_BITMAPORDER_1234, 0,
179                                1, 0),
180     SDL_PIXELFORMAT_INDEX4LSB =
181         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_INDEX4, SDL_BITMAPORDER_4321, 0,
182                                4, 0),
183     SDL_PIXELFORMAT_INDEX4MSB =
184         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_INDEX4, SDL_BITMAPORDER_1234, 0,
185                                4, 0),
186     SDL_PIXELFORMAT_INDEX8 =
187         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_INDEX8, 0, 0, 8, 1),
188     SDL_PIXELFORMAT_RGB332 =
189         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED8, SDL_PACKEDORDER_XRGB,
190                                SDL_PACKEDLAYOUT_332, 8, 1),
191     SDL_PIXELFORMAT_XRGB4444 =
192         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_XRGB,
193                                SDL_PACKEDLAYOUT_4444, 12, 2),
194     SDL_PIXELFORMAT_RGB444 = SDL_PIXELFORMAT_XRGB4444,
195     SDL_PIXELFORMAT_XBGR4444 =
196         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_XBGR,
197                                SDL_PACKEDLAYOUT_4444, 12, 2),
198     SDL_PIXELFORMAT_BGR444 = SDL_PIXELFORMAT_XBGR4444,
199     SDL_PIXELFORMAT_XRGB1555 =
200         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_XRGB,
201                                SDL_PACKEDLAYOUT_1555, 15, 2),
202     SDL_PIXELFORMAT_RGB555 = SDL_PIXELFORMAT_XRGB1555,
203     SDL_PIXELFORMAT_XBGR1555 =
204         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_XBGR,
205                                SDL_PACKEDLAYOUT_1555, 15, 2),
206     SDL_PIXELFORMAT_BGR555 = SDL_PIXELFORMAT_XBGR1555,
207     SDL_PIXELFORMAT_ARGB4444 =
208         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_ARGB,
209                                SDL_PACKEDLAYOUT_4444, 16, 2),
210     SDL_PIXELFORMAT_RGBA4444 =
211         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_RGBA,
212                                SDL_PACKEDLAYOUT_4444, 16, 2),
213     SDL_PIXELFORMAT_ABGR4444 =
214         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_ABGR,
215                                SDL_PACKEDLAYOUT_4444, 16, 2),
216     SDL_PIXELFORMAT_BGRA4444 =
217         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_BGRA,
218                                SDL_PACKEDLAYOUT_4444, 16, 2),
219     SDL_PIXELFORMAT_ARGB1555 =
220         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_ARGB,
221                                SDL_PACKEDLAYOUT_1555, 16, 2),
222     SDL_PIXELFORMAT_RGBA5551 =
223         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_RGBA,
224                                SDL_PACKEDLAYOUT_5551, 16, 2),
225     SDL_PIXELFORMAT_ABGR1555 =
226         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_ABGR,
227                                SDL_PACKEDLAYOUT_1555, 16, 2),
228     SDL_PIXELFORMAT_BGRA5551 =
229         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_BGRA,
230                                SDL_PACKEDLAYOUT_5551, 16, 2),
231     SDL_PIXELFORMAT_RGB565 =
232         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_XRGB,
233                                SDL_PACKEDLAYOUT_565, 16, 2),
234     SDL_PIXELFORMAT_BGR565 =
235         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED16, SDL_PACKEDORDER_XBGR,
236                                SDL_PACKEDLAYOUT_565, 16, 2),
237     SDL_PIXELFORMAT_RGB24 =
238         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_ARRAYU8, SDL_ARRAYORDER_RGB, 0,
239                                24, 3),
240     SDL_PIXELFORMAT_BGR24 =
241         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_ARRAYU8, SDL_ARRAYORDER_BGR, 0,
242                                24, 3),
243     SDL_PIXELFORMAT_XRGB8888 =
244         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_XRGB,
245                                SDL_PACKEDLAYOUT_8888, 24, 4),
246     SDL_PIXELFORMAT_RGB888 = SDL_PIXELFORMAT_XRGB8888,
247     SDL_PIXELFORMAT_RGBX8888 =
248         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_RGBX,
249                                SDL_PACKEDLAYOUT_8888, 24, 4),
250     SDL_PIXELFORMAT_XBGR8888 =
251         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_XBGR,
252                                SDL_PACKEDLAYOUT_8888, 24, 4),
253     SDL_PIXELFORMAT_BGR888 = SDL_PIXELFORMAT_XBGR8888,
254     SDL_PIXELFORMAT_BGRX8888 =
255         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_BGRX,
256                                SDL_PACKEDLAYOUT_8888, 24, 4),
257     SDL_PIXELFORMAT_ARGB8888 =
258         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_ARGB,
259                                SDL_PACKEDLAYOUT_8888, 32, 4),
260     SDL_PIXELFORMAT_RGBA8888 =
261         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_RGBA,
262                                SDL_PACKEDLAYOUT_8888, 32, 4),
263     SDL_PIXELFORMAT_ABGR8888 =
264         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_ABGR,
265                                SDL_PACKEDLAYOUT_8888, 32, 4),
266     SDL_PIXELFORMAT_BGRA8888 =
267         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_BGRA,
268                                SDL_PACKEDLAYOUT_8888, 32, 4),
269     SDL_PIXELFORMAT_ARGB2101010 =
270         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_ARGB,
271                                SDL_PACKEDLAYOUT_2101010, 32, 4),
272 
273     /* Aliases for RGBA byte arrays of color data, for the current platform */
274 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
275     SDL_PIXELFORMAT_RGBA32 = SDL_PIXELFORMAT_RGBA8888,
276     SDL_PIXELFORMAT_ARGB32 = SDL_PIXELFORMAT_ARGB8888,
277     SDL_PIXELFORMAT_BGRA32 = SDL_PIXELFORMAT_BGRA8888,
278     SDL_PIXELFORMAT_ABGR32 = SDL_PIXELFORMAT_ABGR8888,
279 #else
280     SDL_PIXELFORMAT_RGBA32 = SDL_PIXELFORMAT_ABGR8888,
281     SDL_PIXELFORMAT_ARGB32 = SDL_PIXELFORMAT_BGRA8888,
282     SDL_PIXELFORMAT_BGRA32 = SDL_PIXELFORMAT_ARGB8888,
283     SDL_PIXELFORMAT_ABGR32 = SDL_PIXELFORMAT_RGBA8888,
284 #endif
285 
286     SDL_PIXELFORMAT_YV12 =      /**< Planar mode: Y + V + U  (3 planes) */
287         SDL_DEFINE_PIXELFOURCC('Y', 'V', '1', '2'),
288     SDL_PIXELFORMAT_IYUV =      /**< Planar mode: Y + U + V  (3 planes) */
289         SDL_DEFINE_PIXELFOURCC('I', 'Y', 'U', 'V'),
290     SDL_PIXELFORMAT_YUY2 =      /**< Packed mode: Y0+U0+Y1+V0 (1 plane) */
291         SDL_DEFINE_PIXELFOURCC('Y', 'U', 'Y', '2'),
292     SDL_PIXELFORMAT_UYVY =      /**< Packed mode: U0+Y0+V0+Y1 (1 plane) */
293         SDL_DEFINE_PIXELFOURCC('U', 'Y', 'V', 'Y'),
294     SDL_PIXELFORMAT_YVYU =      /**< Packed mode: Y0+V0+Y1+U0 (1 plane) */
295         SDL_DEFINE_PIXELFOURCC('Y', 'V', 'Y', 'U'),
296     SDL_PIXELFORMAT_NV12 =      /**< Planar mode: Y + U/V interleaved  (2 planes) */
297         SDL_DEFINE_PIXELFOURCC('N', 'V', '1', '2'),
298     SDL_PIXELFORMAT_NV21 =      /**< Planar mode: Y + V/U interleaved  (2 planes) */
299         SDL_DEFINE_PIXELFOURCC('N', 'V', '2', '1'),
300     SDL_PIXELFORMAT_EXTERNAL_OES =      /**< Android video texture format */
301         SDL_DEFINE_PIXELFOURCC('O', 'E', 'S', ' ')
302 } SDL_PixelFormatEnum;
303 
304 typedef struct SDL_Color
305 {
306     Uint8 r;
307     Uint8 g;
308     Uint8 b;
309     Uint8 a;
310 } SDL_Color;
311 #define SDL_Colour SDL_Color
312 
313 typedef struct SDL_Palette
314 {
315     int ncolors;
316     SDL_Color *colors;
317     Uint32 version;
318     int refcount;
319 } SDL_Palette;
320 
321 /**
322  *  \note Everything in the pixel format structure is read-only.
323  */
324 typedef struct SDL_PixelFormat
325 {
326     Uint32 format;
327     SDL_Palette *palette;
328     Uint8 BitsPerPixel;
329     Uint8 BytesPerPixel;
330     Uint8 padding[2];
331     Uint32 Rmask;
332     Uint32 Gmask;
333     Uint32 Bmask;
334     Uint32 Amask;
335     Uint8 Rloss;
336     Uint8 Gloss;
337     Uint8 Bloss;
338     Uint8 Aloss;
339     Uint8 Rshift;
340     Uint8 Gshift;
341     Uint8 Bshift;
342     Uint8 Ashift;
343     int refcount;
344     struct SDL_PixelFormat *next;
345 } SDL_PixelFormat;
346 
347 /**
348  * Get the human readable name of a pixel format.
349  *
350  * \param format the pixel format to query
351  * \returns the human readable name of the specified pixel format or
352  *          `SDL_PIXELFORMAT_UNKNOWN` if the format isn't recognized.
353  *
354  * \since This function is available since SDL 2.0.0.
355  */
356 extern DECLSPEC const char* SDLCALL SDL_GetPixelFormatName(Uint32 format);
357 
358 /**
359  * Convert one of the enumerated pixel formats to a bpp value and RGBA masks.
360  *
361  * \param format one of the SDL_PixelFormatEnum values
362  * \param bpp a bits per pixel value; usually 15, 16, or 32
363  * \param Rmask a pointer filled in with the red mask for the format
364  * \param Gmask a pointer filled in with the green mask for the format
365  * \param Bmask a pointer filled in with the blue mask for the format
366  * \param Amask a pointer filled in with the alpha mask for the format
367  * \returns SDL_TRUE on success or SDL_FALSE if the conversion wasn't
368  *          possible; call SDL_GetError() for more information.
369  *
370  * \since This function is available since SDL 2.0.0.
371  *
372  * \sa SDL_MasksToPixelFormatEnum
373  */
374 extern DECLSPEC SDL_bool SDLCALL SDL_PixelFormatEnumToMasks(Uint32 format,
375                                                             int *bpp,
376                                                             Uint32 * Rmask,
377                                                             Uint32 * Gmask,
378                                                             Uint32 * Bmask,
379                                                             Uint32 * Amask);
380 
381 /**
382  * Convert a bpp value and RGBA masks to an enumerated pixel format.
383  *
384  * This will return `SDL_PIXELFORMAT_UNKNOWN` if the conversion wasn't
385  * possible.
386  *
387  * \param bpp a bits per pixel value; usually 15, 16, or 32
388  * \param Rmask the red mask for the format
389  * \param Gmask the green mask for the format
390  * \param Bmask the blue mask for the format
391  * \param Amask the alpha mask for the format
392  * \returns one of the SDL_PixelFormatEnum values
393  *
394  * \since This function is available since SDL 2.0.0.
395  *
396  * \sa SDL_PixelFormatEnumToMasks
397  */
398 extern DECLSPEC Uint32 SDLCALL SDL_MasksToPixelFormatEnum(int bpp,
399                                                           Uint32 Rmask,
400                                                           Uint32 Gmask,
401                                                           Uint32 Bmask,
402                                                           Uint32 Amask);
403 
404 /**
405  * Create an SDL_PixelFormat structure corresponding to a pixel format.
406  *
407  * Returned structure may come from a shared global cache (i.e. not newly
408  * allocated), and hence should not be modified, especially the palette. Weird
409  * errors such as `Blit combination not supported` may occur.
410  *
411  * \param pixel_format one of the SDL_PixelFormatEnum values
412  * \returns the new SDL_PixelFormat structure or NULL on failure; call
413  *          SDL_GetError() for more information.
414  *
415  * \since This function is available since SDL 2.0.0.
416  *
417  * \sa SDL_FreeFormat
418  */
419 extern DECLSPEC SDL_PixelFormat * SDLCALL SDL_AllocFormat(Uint32 pixel_format);
420 
421 /**
422  * Free an SDL_PixelFormat structure allocated by SDL_AllocFormat().
423  *
424  * \param format the SDL_PixelFormat structure to free
425  *
426  * \since This function is available since SDL 2.0.0.
427  *
428  * \sa SDL_AllocFormat
429  */
430 extern DECLSPEC void SDLCALL SDL_FreeFormat(SDL_PixelFormat *format);
431 
432 /**
433  * Create a palette structure with the specified number of color entries.
434  *
435  * The palette entries are initialized to white.
436  *
437  * \param ncolors represents the number of color entries in the color palette
438  * \returns a new SDL_Palette structure on success or NULL on failure (e.g. if
439  *          there wasn't enough memory); call SDL_GetError() for more
440  *          information.
441  *
442  * \since This function is available since SDL 2.0.0.
443  *
444  * \sa SDL_FreePalette
445  */
446 extern DECLSPEC SDL_Palette *SDLCALL SDL_AllocPalette(int ncolors);
447 
448 /**
449  * Set the palette for a pixel format structure.
450  *
451  * \param format the SDL_PixelFormat structure that will use the palette
452  * \param palette the SDL_Palette structure that will be used
453  * \returns 0 on success or a negative error code on failure; call
454  *          SDL_GetError() for more information.
455  *
456  * \since This function is available since SDL 2.0.0.
457  *
458  * \sa SDL_AllocPalette
459  * \sa SDL_FreePalette
460  */
461 extern DECLSPEC int SDLCALL SDL_SetPixelFormatPalette(SDL_PixelFormat * format,
462                                                       SDL_Palette *palette);
463 
464 /**
465  * Set a range of colors in a palette.
466  *
467  * \param palette the SDL_Palette structure to modify
468  * \param colors an array of SDL_Color structures to copy into the palette
469  * \param firstcolor the index of the first palette entry to modify
470  * \param ncolors the number of entries to modify
471  * \returns 0 on success or a negative error code if not all of the colors
472  *          could be set; call SDL_GetError() for more information.
473  *
474  * \since This function is available since SDL 2.0.0.
475  *
476  * \sa SDL_AllocPalette
477  * \sa SDL_CreateRGBSurface
478  */
479 extern DECLSPEC int SDLCALL SDL_SetPaletteColors(SDL_Palette * palette,
480                                                  const SDL_Color * colors,
481                                                  int firstcolor, int ncolors);
482 
483 /**
484  * Free a palette created with SDL_AllocPalette().
485  *
486  * \param palette the SDL_Palette structure to be freed
487  *
488  * \since This function is available since SDL 2.0.0.
489  *
490  * \sa SDL_AllocPalette
491  */
492 extern DECLSPEC void SDLCALL SDL_FreePalette(SDL_Palette * palette);
493 
494 /**
495  * Map an RGB triple to an opaque pixel value for a given pixel format.
496  *
497  * This function maps the RGB color value to the specified pixel format and
498  * returns the pixel value best approximating the given RGB color value for
499  * the given pixel format.
500  *
501  * If the format has a palette (8-bit) the index of the closest matching color
502  * in the palette will be returned.
503  *
504  * If the specified pixel format has an alpha component it will be returned as
505  * all 1 bits (fully opaque).
506  *
507  * If the pixel format bpp (color depth) is less than 32-bpp then the unused
508  * upper bits of the return value can safely be ignored (e.g., with a 16-bpp
509  * format the return value can be assigned to a Uint16, and similarly a Uint8
510  * for an 8-bpp format).
511  *
512  * \param format an SDL_PixelFormat structure describing the pixel format
513  * \param r the red component of the pixel in the range 0-255
514  * \param g the green component of the pixel in the range 0-255
515  * \param b the blue component of the pixel in the range 0-255
516  * \returns a pixel value
517  *
518  * \since This function is available since SDL 2.0.0.
519  *
520  * \sa SDL_GetRGB
521  * \sa SDL_GetRGBA
522  * \sa SDL_MapRGBA
523  */
524 extern DECLSPEC Uint32 SDLCALL SDL_MapRGB(const SDL_PixelFormat * format,
525                                           Uint8 r, Uint8 g, Uint8 b);
526 
527 /**
528  * Map an RGBA quadruple to a pixel value for a given pixel format.
529  *
530  * This function maps the RGBA color value to the specified pixel format and
531  * returns the pixel value best approximating the given RGBA color value for
532  * the given pixel format.
533  *
534  * If the specified pixel format has no alpha component the alpha value will
535  * be ignored (as it will be in formats with a palette).
536  *
537  * If the format has a palette (8-bit) the index of the closest matching color
538  * in the palette will be returned.
539  *
540  * If the pixel format bpp (color depth) is less than 32-bpp then the unused
541  * upper bits of the return value can safely be ignored (e.g., with a 16-bpp
542  * format the return value can be assigned to a Uint16, and similarly a Uint8
543  * for an 8-bpp format).
544  *
545  * \param format an SDL_PixelFormat structure describing the format of the
546  *               pixel
547  * \param r the red component of the pixel in the range 0-255
548  * \param g the green component of the pixel in the range 0-255
549  * \param b the blue component of the pixel in the range 0-255
550  * \param a the alpha component of the pixel in the range 0-255
551  * \returns a pixel value
552  *
553  * \since This function is available since SDL 2.0.0.
554  *
555  * \sa SDL_GetRGB
556  * \sa SDL_GetRGBA
557  * \sa SDL_MapRGB
558  */
559 extern DECLSPEC Uint32 SDLCALL SDL_MapRGBA(const SDL_PixelFormat * format,
560                                            Uint8 r, Uint8 g, Uint8 b,
561                                            Uint8 a);
562 
563 /**
564  * Get RGB values from a pixel in the specified format.
565  *
566  * This function uses the entire 8-bit [0..255] range when converting color
567  * components from pixel formats with less than 8-bits per RGB component
568  * (e.g., a completely white pixel in 16-bit RGB565 format would return [0xff,
569  * 0xff, 0xff] not [0xf8, 0xfc, 0xf8]).
570  *
571  * \param pixel a pixel value
572  * \param format an SDL_PixelFormat structure describing the format of the
573  *               pixel
574  * \param r a pointer filled in with the red component
575  * \param g a pointer filled in with the green component
576  * \param b a pointer filled in with the blue component
577  *
578  * \since This function is available since SDL 2.0.0.
579  *
580  * \sa SDL_GetRGBA
581  * \sa SDL_MapRGB
582  * \sa SDL_MapRGBA
583  */
584 extern DECLSPEC void SDLCALL SDL_GetRGB(Uint32 pixel,
585                                         const SDL_PixelFormat * format,
586                                         Uint8 * r, Uint8 * g, Uint8 * b);
587 
588 /**
589  * Get RGBA values from a pixel in the specified format.
590  *
591  * This function uses the entire 8-bit [0..255] range when converting color
592  * components from pixel formats with less than 8-bits per RGB component
593  * (e.g., a completely white pixel in 16-bit RGB565 format would return [0xff,
594  * 0xff, 0xff] not [0xf8, 0xfc, 0xf8]).
595  *
596  * If the surface has no alpha component, the alpha will be returned as 0xff
597  * (100% opaque).
598  *
599  * \param pixel a pixel value
600  * \param format an SDL_PixelFormat structure describing the format of the
601  *               pixel
602  * \param r a pointer filled in with the red component
603  * \param g a pointer filled in with the green component
604  * \param b a pointer filled in with the blue component
605  * \param a a pointer filled in with the alpha component
606  *
607  * \since This function is available since SDL 2.0.0.
608  *
609  * \sa SDL_GetRGB
610  * \sa SDL_MapRGB
611  * \sa SDL_MapRGBA
612  */
613 extern DECLSPEC void SDLCALL SDL_GetRGBA(Uint32 pixel,
614                                          const SDL_PixelFormat * format,
615                                          Uint8 * r, Uint8 * g, Uint8 * b,
616                                          Uint8 * a);
617 
618 /**
619  * Calculate a 256 entry gamma ramp for a gamma value.
620  *
621  * \param gamma a gamma value where 0.0 is black and 1.0 is identity
622  * \param ramp an array of 256 values filled in with the gamma ramp
623  *
624  * \since This function is available since SDL 2.0.0.
625  *
626  * \sa SDL_SetWindowGammaRamp
627  */
628 extern DECLSPEC void SDLCALL SDL_CalculateGammaRamp(float gamma, Uint16 * ramp);
629 
630 
631 /* Ends C function definitions when using C++ */
632 #ifdef __cplusplus
633 }
634 #endif
635 #include "close_code.h"
636 
637 #endif /* SDL_pixels_h_ */
638 
639 /* vi: set ts=4 sw=4 expandtab: */
640