2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Sam Lantinga
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 of the License, or (at your option) any later version.
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with this library; if not, write to the Free
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 "@(#) $Id: SDL_video.h,v 1.12 2002/08/19 17:58:08 slouken Exp $";
28 /* Header file for access to the SDL raw framebuffer window */
35 #include "SDL_types.h"
36 #include "SDL_mutex.h"
37 #include "SDL_rwops.h"
39 #include "begin_code.h"
40 /* Set up for C function definitions, even when using C++ */
45 /* Transparency definitions: These define alpha as the opacity of a surface */
46 #define SDL_ALPHA_OPAQUE 255
47 #define SDL_ALPHA_TRANSPARENT 0
49 /* Useful data types */
67 /* Everything in the pixel format structure is read-only */
68 typedef struct SDL_PixelFormat {
85 /* RGB color key information */
87 /* Alpha value information (per-surface alpha) */
91 /* typedef for private surface blitting functions */
93 typedef int (*SDL_blit)(struct SDL_Surface *src, SDL_Rect *srcrect,
94 struct SDL_Surface *dst, SDL_Rect *dstrect);
96 /* This structure should be treated as read-only, except for 'pixels',
97 which, if not NULL, contains the raw pixel data for the surface.
99 typedef struct SDL_Surface {
100 Uint32 flags; /* Read-only */
101 SDL_PixelFormat *format; /* Read-only */
102 int w, h; /* Read-only */
103 Uint16 pitch; /* Read-only */
104 void *pixels; /* Read-write */
105 int offset; /* Private */
107 /* Hardware-specific surface info */
108 struct private_hwdata *hwdata;
110 /* clipping information */
111 SDL_Rect clip_rect; /* Read-only */
112 Uint32 unused1; /* for binary compatibility */
114 /* Allow recursive locks */
115 Uint32 locked; /* Private */
117 /* info for fast blit mapping to other surfaces */
118 struct SDL_BlitMap *map; /* Private */
120 /* format version, bumped at every change to invalidate blit maps */
121 unsigned int format_version; /* Private */
123 /* Reference count -- used when freeing surface */
124 int refcount; /* Read-mostly */
127 /* These are the currently supported flags for the SDL_surface */
128 /* Available for SDL_CreateRGBSurface() or SDL_SetVideoMode() */
129 #define SDL_SWSURFACE 0x00000000 /* Surface is in system memory */
130 #define SDL_HWSURFACE 0x00000001 /* Surface is in video memory */
131 #define SDL_ASYNCBLIT 0x00000004 /* Use asynchronous blits if possible */
132 /* Available for SDL_SetVideoMode() */
133 #define SDL_ANYFORMAT 0x10000000 /* Allow any video depth/pixel-format */
134 #define SDL_HWPALETTE 0x20000000 /* Surface has exclusive palette */
135 #define SDL_DOUBLEBUF 0x40000000 /* Set up double-buffered video mode */
136 #define SDL_FULLSCREEN 0x80000000 /* Surface is a full screen display */
137 #define SDL_OPENGL 0x00000002 /* Create an OpenGL rendering context */
138 #define SDL_OPENGLBLIT 0x0000000A /* Create an OpenGL rendering context and use it for blitting */
139 #define SDL_RESIZABLE 0x00000010 /* This video mode may be resized */
140 #define SDL_NOFRAME 0x00000020 /* No window caption or edge frame */
141 /* Used internally (read-only) */
142 #define SDL_HWACCEL 0x00000100 /* Blit uses hardware acceleration */
143 #define SDL_SRCCOLORKEY 0x00001000 /* Blit uses a source color key */
144 #define SDL_RLEACCELOK 0x00002000 /* Private flag */
145 #define SDL_RLEACCEL 0x00004000 /* Surface is RLE encoded */
146 #define SDL_SRCALPHA 0x00010000 /* Blit uses source alpha blending */
147 #define SDL_PREALLOC 0x01000000 /* Surface uses preallocated memory */
149 /* Evaluates to true if the surface needs to be locked before access */
150 #define SDL_MUSTLOCK(surface) \
151 (surface->offset || \
152 ((surface->flags & (SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_RLEACCEL)) != 0))
155 /* Useful for determining the video hardware capabilities */
157 Uint32 hw_available :1; /* Flag: Can you create hardware surfaces? */
158 Uint32 wm_available :1; /* Flag: Can you talk to a window manager? */
159 Uint32 UnusedBits1 :6;
160 Uint32 UnusedBits2 :1;
161 Uint32 blit_hw :1; /* Flag: Accelerated blits HW --> HW */
162 Uint32 blit_hw_CC :1; /* Flag: Accelerated blits with Colorkey */
163 Uint32 blit_hw_A :1; /* Flag: Accelerated blits with Alpha */
164 Uint32 blit_sw :1; /* Flag: Accelerated blits SW --> HW */
165 Uint32 blit_sw_CC :1; /* Flag: Accelerated blits with Colorkey */
166 Uint32 blit_sw_A :1; /* Flag: Accelerated blits with Alpha */
167 Uint32 blit_fill :1; /* Flag: Accelerated color fill */
168 Uint32 UnusedBits3 :16;
169 Uint32 video_mem; /* The total amount of video memory (in K) */
170 SDL_PixelFormat *vfmt; /* Value: The format of the video surface */
174 /* The most common video overlay formats.
175 For an explanation of these pixel formats, see:
176 http://www.webartz.com/fourcc/indexyuv.htm
178 For information on the relationship between color spaces, see:
179 http://www.neuro.sfc.keio.ac.jp/~aly/polygon/info/color-space-faq.html
181 #define SDL_YV12_OVERLAY 0x32315659 /* Planar mode: Y + V + U (3 planes) */
182 #define SDL_IYUV_OVERLAY 0x56555949 /* Planar mode: Y + U + V (3 planes) */
183 #define SDL_YUY2_OVERLAY 0x32595559 /* Packed mode: Y0+U0+Y1+V0 (1 plane) */
184 #define SDL_UYVY_OVERLAY 0x59565955 /* Packed mode: U0+Y0+V0+Y1 (1 plane) */
185 #define SDL_YVYU_OVERLAY 0x55595659 /* Packed mode: Y0+V0+Y1+U0 (1 plane) */
187 /* The YUV hardware video overlay */
188 typedef struct SDL_Overlay {
189 Uint32 format; /* Read-only */
190 int w, h; /* Read-only */
191 int planes; /* Read-only */
192 Uint16 *pitches; /* Read-only */
193 Uint8 **pixels; /* Read-write */
195 /* Hardware-specific surface info */
196 struct private_yuvhwfuncs *hwfuncs;
197 struct private_yuvhwdata *hwdata;
200 Uint32 hw_overlay :1; /* Flag: This overlay hardware accelerated? */
201 Uint32 UnusedBits :31;
205 /* Public enumeration for setting the OpenGL window attributes. */
215 SDL_GL_ACCUM_RED_SIZE,
216 SDL_GL_ACCUM_GREEN_SIZE,
217 SDL_GL_ACCUM_BLUE_SIZE,
218 SDL_GL_ACCUM_ALPHA_SIZE,
220 SDL_GL_MULTISAMPLEBUFFERS,
221 SDL_GL_MULTISAMPLESAMPLES
225 /* flags for SDL_SetPalette() */
226 #define SDL_LOGPAL 0x01
227 #define SDL_PHYSPAL 0x02
229 /* Function prototypes */
231 /* These functions are used internally, and should not be used unless you
232 * have a specific need to specify the video driver you want to use.
233 * You should normally use SDL_Init() or SDL_InitSubSystem().
235 * SDL_VideoInit() initializes the video subsystem -- sets up a connection
236 * to the window manager, etc, and determines the current video mode and
237 * pixel format, but does not initialize a window or graphics mode.
238 * Note that event handling is activated by this routine.
240 * If you use both sound and video in your application, you need to call
241 * SDL_Init() before opening the sound device, otherwise under Win32 DirectX,
242 * you won't be able to set full-screen display modes.
244 extern DECLSPEC int SDLCALL SDL_VideoInit(const char *driver_name, Uint32 flags);
245 extern DECLSPEC void SDLCALL SDL_VideoQuit(void);
247 /* This function fills the given character buffer with the name of the
248 * video driver, and returns a pointer to it if the video driver has
249 * been initialized. It returns NULL if no driver has been initialized.
251 extern DECLSPEC char * SDLCALL SDL_VideoDriverName(char *namebuf, int maxlen);
254 * This function returns a pointer to the current display surface.
255 * If SDL is doing format conversion on the display surface, this
256 * function returns the publicly visible surface, not the real video
259 extern DECLSPEC SDL_Surface * SDLCALL SDL_GetVideoSurface(void);
262 * This function returns a read-only pointer to information about the
263 * video hardware. If this is called before SDL_SetVideoMode(), the 'vfmt'
264 * member of the returned structure will contain the pixel format of the
267 extern DECLSPEC const SDL_VideoInfo * SDLCALL SDL_GetVideoInfo(void);
270 * Check to see if a particular video mode is supported.
271 * It returns 0 if the requested mode is not supported under any bit depth,
272 * or returns the bits-per-pixel of the closest available mode with the
273 * given width and height. If this bits-per-pixel is different from the
274 * one used when setting the video mode, SDL_SetVideoMode() will succeed,
275 * but will emulate the requested bits-per-pixel with a shadow surface.
277 * The arguments to SDL_VideoModeOK() are the same ones you would pass to
280 extern DECLSPEC int SDLCALL SDL_VideoModeOK(int width, int height, int bpp, Uint32 flags);
283 * Return a pointer to an array of available screen dimensions for the
284 * given format and video flags, sorted largest to smallest. Returns
285 * NULL if there are no dimensions available for a particular format,
286 * or (SDL_Rect **)-1 if any dimension is okay for the given format.
288 * If 'format' is NULL, the mode list will be for the format given
289 * by SDL_GetVideoInfo()->vfmt
291 extern DECLSPEC SDL_Rect ** SDLCALL SDL_ListModes(SDL_PixelFormat *format, Uint32 flags);
294 * Set up a video mode with the specified width, height and bits-per-pixel.
296 * If 'bpp' is 0, it is treated as the current display bits per pixel.
298 * If SDL_ANYFORMAT is set in 'flags', the SDL library will try to set the
299 * requested bits-per-pixel, but will return whatever video pixel format is
300 * available. The default is to emulate the requested pixel format if it
301 * is not natively available.
303 * If SDL_HWSURFACE is set in 'flags', the video surface will be placed in
304 * video memory, if possible, and you may have to call SDL_LockSurface()
305 * in order to access the raw framebuffer. Otherwise, the video surface
306 * will be created in system memory.
308 * If SDL_ASYNCBLIT is set in 'flags', SDL will try to perform rectangle
309 * updates asynchronously, but you must always lock before accessing pixels.
310 * SDL will wait for updates to complete before returning from the lock.
312 * If SDL_HWPALETTE is set in 'flags', the SDL library will guarantee
313 * that the colors set by SDL_SetColors() will be the colors you get.
314 * Otherwise, in 8-bit mode, SDL_SetColors() may not be able to set all
315 * of the colors exactly the way they are requested, and you should look
316 * at the video surface structure to determine the actual palette.
317 * If SDL cannot guarantee that the colors you request can be set,
318 * i.e. if the colormap is shared, then the video surface may be created
319 * under emulation in system memory, overriding the SDL_HWSURFACE flag.
321 * If SDL_FULLSCREEN is set in 'flags', the SDL library will try to set
322 * a fullscreen video mode. The default is to create a windowed mode
323 * if the current graphics system has a window manager.
324 * If the SDL library is able to set a fullscreen video mode, this flag
325 * will be set in the surface that is returned.
327 * If SDL_DOUBLEBUF is set in 'flags', the SDL library will try to set up
328 * two surfaces in video memory and swap between them when you call
329 * SDL_Flip(). This is usually slower than the normal single-buffering
330 * scheme, but prevents "tearing" artifacts caused by modifying video
331 * memory while the monitor is refreshing. It should only be used by
332 * applications that redraw the entire screen on every update.
334 * If SDL_RESIZABLE is set in 'flags', the SDL library will allow the
335 * window manager, if any, to resize the window at runtime. When this
336 * occurs, SDL will send a SDL_VIDEORESIZE event to you application,
337 * and you must respond to the event by re-calling SDL_SetVideoMode()
338 * with the requested size (or another size that suits the application).
340 * If SDL_NOFRAME is set in 'flags', the SDL library will create a window
341 * without any title bar or frame decoration. Fullscreen video modes have
342 * this flag set automatically.
344 * This function returns the video framebuffer surface, or NULL if it fails.
346 * If you rely on functionality provided by certain video flags, check the
347 * flags of the returned surface to make sure that functionality is available.
348 * SDL will fall back to reduced functionality if the exact flags you wanted
351 extern DECLSPEC SDL_Surface * SDLCALL SDL_SetVideoMode
352 (int width, int height, int bpp, Uint32 flags);
355 * Makes sure the given list of rectangles is updated on the given screen.
356 * If 'x', 'y', 'w' and 'h' are all 0, SDL_UpdateRect will update the entire
358 * These functions should not be called while 'screen' is locked.
360 extern DECLSPEC void SDLCALL SDL_UpdateRects
361 (SDL_Surface *screen, int numrects, SDL_Rect *rects);
362 extern DECLSPEC void SDLCALL SDL_UpdateRect
363 (SDL_Surface *screen, Sint32 x, Sint32 y, Uint32 w, Uint32 h);
366 * On hardware that supports double-buffering, this function sets up a flip
367 * and returns. The hardware will wait for vertical retrace, and then swap
368 * video buffers before the next video surface blit or lock will return.
369 * On hardware that doesn not support double-buffering, this is equivalent
370 * to calling SDL_UpdateRect(screen, 0, 0, 0, 0);
371 * The SDL_DOUBLEBUF flag must have been passed to SDL_SetVideoMode() when
372 * setting the video mode for this function to perform hardware flipping.
373 * This function returns 0 if successful, or -1 if there was an error.
375 extern DECLSPEC int SDLCALL SDL_Flip(SDL_Surface *screen);
378 * Set the gamma correction for each of the color channels.
379 * The gamma values range (approximately) between 0.1 and 10.0
381 * If this function isn't supported directly by the hardware, it will
382 * be emulated using gamma ramps, if available. If successful, this
383 * function returns 0, otherwise it returns -1.
385 extern DECLSPEC int SDLCALL SDL_SetGamma(float red, float green, float blue);
388 * Set the gamma translation table for the red, green, and blue channels
389 * of the video hardware. Each table is an array of 256 16-bit quantities,
390 * representing a mapping between the input and output for that channel.
391 * The input is the index into the array, and the output is the 16-bit
392 * gamma value at that index, scaled to the output color precision.
394 * You may pass NULL for any of the channels to leave it unchanged.
395 * If the call succeeds, it will return 0. If the display driver or
396 * hardware does not support gamma translation, or otherwise fails,
397 * this function will return -1.
399 extern DECLSPEC int SDLCALL SDL_SetGammaRamp(Uint16 *red, Uint16 *green, Uint16 *blue);
402 * Retrieve the current values of the gamma translation tables.
404 * You must pass in valid pointers to arrays of 256 16-bit quantities.
405 * Any of the pointers may be NULL to ignore that channel.
406 * If the call succeeds, it will return 0. If the display driver or
407 * hardware does not support gamma translation, or otherwise fails,
408 * this function will return -1.
410 extern DECLSPEC int SDLCALL SDL_GetGammaRamp(Uint16 *red, Uint16 *green, Uint16 *blue);
413 * Sets a portion of the colormap for the given 8-bit surface. If 'surface'
414 * is not a palettized surface, this function does nothing, returning 0.
415 * If all of the colors were set as passed to SDL_SetColors(), it will
416 * return 1. If not all the color entries were set exactly as given,
417 * it will return 0, and you should look at the surface palette to
418 * determine the actual color palette.
420 * When 'surface' is the surface associated with the current display, the
421 * display colormap will be updated with the requested colors. If
422 * SDL_HWPALETTE was set in SDL_SetVideoMode() flags, SDL_SetColors()
423 * will always return 1, and the palette is guaranteed to be set the way
424 * you desire, even if the window colormap has to be warped or run under
427 extern DECLSPEC int SDLCALL SDL_SetColors(SDL_Surface *surface,
428 SDL_Color *colors, int firstcolor, int ncolors);
431 * Sets a portion of the colormap for a given 8-bit surface.
432 * 'flags' is one or both of:
433 * SDL_LOGPAL -- set logical palette, which controls how blits are mapped
434 * to/from the surface,
435 * SDL_PHYSPAL -- set physical palette, which controls how pixels look on
437 * Only screens have physical palettes. Separate change of physical/logical
438 * palettes is only possible if the screen has SDL_HWPALETTE set.
440 * The return value is 1 if all colours could be set as requested, and 0
443 * SDL_SetColors() is equivalent to calling this function with
444 * flags = (SDL_LOGPAL|SDL_PHYSPAL).
446 extern DECLSPEC int SDLCALL SDL_SetPalette(SDL_Surface *surface, int flags,
447 SDL_Color *colors, int firstcolor,
451 * Maps an RGB triple to an opaque pixel value for a given pixel format
453 extern DECLSPEC Uint32 SDLCALL SDL_MapRGB
454 (SDL_PixelFormat *format, Uint8 r, Uint8 g, Uint8 b);
457 * Maps an RGBA quadruple to a pixel value for a given pixel format
459 extern DECLSPEC Uint32 SDLCALL SDL_MapRGBA(SDL_PixelFormat *format,
460 Uint8 r, Uint8 g, Uint8 b, Uint8 a);
463 * Maps a pixel value into the RGB components for a given pixel format
465 extern DECLSPEC void SDLCALL SDL_GetRGB(Uint32 pixel, SDL_PixelFormat *fmt,
466 Uint8 *r, Uint8 *g, Uint8 *b);
469 * Maps a pixel value into the RGBA components for a given pixel format
471 extern DECLSPEC void SDLCALL SDL_GetRGBA(Uint32 pixel, SDL_PixelFormat *fmt,
472 Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a);
475 * Allocate and free an RGB surface (must be called after SDL_SetVideoMode)
476 * If the depth is 4 or 8 bits, an empty palette is allocated for the surface.
477 * If the depth is greater than 8 bits, the pixel format is set using the
479 * If the function runs out of memory, it will return NULL.
481 * The 'flags' tell what kind of surface to create.
482 * SDL_SWSURFACE means that the surface should be created in system memory.
483 * SDL_HWSURFACE means that the surface should be created in video memory,
484 * with the same format as the display surface. This is useful for surfaces
485 * that will not change much, to take advantage of hardware acceleration
486 * when being blitted to the display surface.
487 * SDL_ASYNCBLIT means that SDL will try to perform asynchronous blits with
488 * this surface, but you must always lock it before accessing the pixels.
489 * SDL will wait for current blits to finish before returning from the lock.
490 * SDL_SRCCOLORKEY indicates that the surface will be used for colorkey blits.
491 * If the hardware supports acceleration of colorkey blits between
492 * two surfaces in video memory, SDL will try to place the surface in
493 * video memory. If this isn't possible or if there is no hardware
494 * acceleration available, the surface will be placed in system memory.
495 * SDL_SRCALPHA means that the surface will be used for alpha blits and
496 * if the hardware supports hardware acceleration of alpha blits between
497 * two surfaces in video memory, to place the surface in video memory
498 * if possible, otherwise it will be placed in system memory.
499 * If the surface is created in video memory, blits will be _much_ faster,
500 * but the surface format must be identical to the video surface format,
501 * and the only way to access the pixels member of the surface is to use
502 * the SDL_LockSurface() and SDL_UnlockSurface() calls.
503 * If the requested surface actually resides in video memory, SDL_HWSURFACE
504 * will be set in the flags member of the returned surface. If for some
505 * reason the surface could not be placed in video memory, it will not have
506 * the SDL_HWSURFACE flag set, and will be created in system memory instead.
508 #define SDL_AllocSurface SDL_CreateRGBSurface
509 extern DECLSPEC SDL_Surface * SDLCALL SDL_CreateRGBSurface
510 (Uint32 flags, int width, int height, int depth,
511 Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
512 extern DECLSPEC SDL_Surface * SDLCALL SDL_CreateRGBSurfaceFrom(void *pixels,
513 int width, int height, int depth, int pitch,
514 Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
515 extern DECLSPEC void SDLCALL SDL_FreeSurface(SDL_Surface *surface);
518 * SDL_LockSurface() sets up a surface for directly accessing the pixels.
519 * Between calls to SDL_LockSurface()/SDL_UnlockSurface(), you can write
520 * to and read from 'surface->pixels', using the pixel format stored in
521 * 'surface->format'. Once you are done accessing the surface, you should
522 * use SDL_UnlockSurface() to release it.
524 * Not all surfaces require locking. If SDL_MUSTLOCK(surface) evaluates
525 * to 0, then you can read and write to the surface at any time, and the
526 * pixel format of the surface will not change. In particular, if the
527 * SDL_HWSURFACE flag is not given when calling SDL_SetVideoMode(), you
528 * will not need to lock the display surface before accessing it.
530 * No operating system or library calls should be made between lock/unlock
531 * pairs, as critical system locks may be held during this time.
533 * SDL_LockSurface() returns 0, or -1 if the surface couldn't be locked.
535 extern DECLSPEC int SDLCALL SDL_LockSurface(SDL_Surface *surface);
536 extern DECLSPEC void SDLCALL SDL_UnlockSurface(SDL_Surface *surface);
539 * Load a surface from a seekable SDL data source (memory or file.)
540 * If 'freesrc' is non-zero, the source will be closed after being read.
541 * Returns the new surface, or NULL if there was an error.
542 * The new surface should be freed with SDL_FreeSurface().
544 extern DECLSPEC SDL_Surface * SDLCALL SDL_LoadBMP_RW(SDL_RWops *src, int freesrc);
546 /* Convenience macro -- load a surface from a file */
547 #define SDL_LoadBMP(file) SDL_LoadBMP_RW(SDL_RWFromFile(file, "rb"), 1)
550 * Save a surface to a seekable SDL data source (memory or file.)
551 * If 'freedst' is non-zero, the source will be closed after being written.
552 * Returns 0 if successful or -1 if there was an error.
554 extern DECLSPEC int SDLCALL SDL_SaveBMP_RW
555 (SDL_Surface *surface, SDL_RWops *dst, int freedst);
557 /* Convenience macro -- save a surface to a file */
558 #define SDL_SaveBMP(surface, file) \
559 SDL_SaveBMP_RW(surface, SDL_RWFromFile(file, "wb"), 1)
562 * Sets the color key (transparent pixel) in a blittable surface.
563 * If 'flag' is SDL_SRCCOLORKEY (optionally OR'd with SDL_RLEACCEL),
564 * 'key' will be the transparent pixel in the source image of a blit.
565 * SDL_RLEACCEL requests RLE acceleration for the surface if present,
566 * and removes RLE acceleration if absent.
567 * If 'flag' is 0, this function clears any current color key.
568 * This function returns 0, or -1 if there was an error.
570 extern DECLSPEC int SDLCALL SDL_SetColorKey
571 (SDL_Surface *surface, Uint32 flag, Uint32 key);
574 * This function sets the alpha value for the entire surface, as opposed to
575 * using the alpha component of each pixel. This value measures the range
576 * of transparency of the surface, 0 being completely transparent to 255
577 * being completely opaque. An 'alpha' value of 255 causes blits to be
578 * opaque, the source pixels copied to the destination (the default). Note
579 * that per-surface alpha can be combined with colorkey transparency.
581 * If 'flag' is 0, alpha blending is disabled for the surface.
582 * If 'flag' is SDL_SRCALPHA, alpha blending is enabled for the surface.
583 * OR:ing the flag with SDL_RLEACCEL requests RLE acceleration for the
584 * surface; if SDL_RLEACCEL is not specified, the RLE accel will be removed.
586 * The 'alpha' parameter is ignored for surfaces that have an alpha channel.
588 extern DECLSPEC int SDLCALL SDL_SetAlpha(SDL_Surface *surface, Uint32 flag, Uint8 alpha);
591 * Sets the clipping rectangle for the destination surface in a blit.
593 * If the clip rectangle is NULL, clipping will be disabled.
594 * If the clip rectangle doesn't intersect the surface, the function will
595 * return SDL_FALSE and blits will be completely clipped. Otherwise the
596 * function returns SDL_TRUE and blits to the surface will be clipped to
597 * the intersection of the surface area and the clipping rectangle.
599 * Note that blits are automatically clipped to the edges of the source
600 * and destination surfaces.
602 extern DECLSPEC SDL_bool SDLCALL SDL_SetClipRect(SDL_Surface *surface, const SDL_Rect *rect);
605 * Gets the clipping rectangle for the destination surface in a blit.
606 * 'rect' must be a pointer to a valid rectangle which will be filled
607 * with the correct values.
609 extern DECLSPEC void SDLCALL SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect);
612 * Creates a new surface of the specified format, and then copies and maps
613 * the given surface to it so the blit of the converted surface will be as
614 * fast as possible. If this function fails, it returns NULL.
616 * The 'flags' parameter is passed to SDL_CreateRGBSurface() and has those
617 * semantics. You can also pass SDL_RLEACCEL in the flags parameter and
618 * SDL will try to RLE accelerate colorkey and alpha blits in the resulting
621 * This function is used internally by SDL_DisplayFormat().
623 extern DECLSPEC SDL_Surface * SDLCALL SDL_ConvertSurface
624 (SDL_Surface *src, SDL_PixelFormat *fmt, Uint32 flags);
627 * This performs a fast blit from the source surface to the destination
628 * surface. It assumes that the source and destination rectangles are
629 * the same size. If either 'srcrect' or 'dstrect' are NULL, the entire
630 * surface (src or dst) is copied. The final blit rectangles are saved
631 * in 'srcrect' and 'dstrect' after all clipping is performed.
632 * If the blit is successful, it returns 0, otherwise it returns -1.
634 * The blit function should not be called on a locked surface.
636 * The blit semantics for surfaces with and without alpha and colorkey
637 * are defined as follows:
641 * alpha-blend (using alpha-channel).
642 * SDL_SRCCOLORKEY ignored.
643 * SDL_SRCALPHA not set:
645 * if SDL_SRCCOLORKEY set, only copy the pixels matching the
646 * RGB values of the source colour key, ignoring alpha in the
651 * alpha-blend (using the source per-surface alpha value);
652 * set destination alpha to opaque.
653 * SDL_SRCALPHA not set:
654 * copy RGB, set destination alpha to source per-surface alpha value.
656 * if SDL_SRCCOLORKEY set, only copy the pixels matching the
661 * alpha-blend (using the source alpha channel) the RGB values;
662 * leave destination alpha untouched. [Note: is this correct?]
663 * SDL_SRCCOLORKEY ignored.
664 * SDL_SRCALPHA not set:
665 * copy all of RGBA to the destination.
666 * if SDL_SRCCOLORKEY set, only copy the pixels matching the
667 * RGB values of the source colour key, ignoring alpha in the
672 * alpha-blend (using the source per-surface alpha value).
673 * SDL_SRCALPHA not set:
676 * if SDL_SRCCOLORKEY set, only copy the pixels matching the
679 * If either of the surfaces were in video memory, and the blit returns -2,
680 * the video memory was lost, so it should be reloaded with artwork and
682 while ( SDL_BlitSurface(image, imgrect, screen, dstrect) == -2 ) {
683 while ( SDL_LockSurface(image) < 0 )
685 -- Write image pixels to image->pixels --
686 SDL_UnlockSurface(image);
688 * This happens under DirectX 5.0 when the system switches away from your
689 * fullscreen application. The lock will also fail until you have access
690 * to the video memory again.
692 /* You should call SDL_BlitSurface() unless you know exactly how SDL
693 blitting works internally and how to use the other blit functions.
695 #define SDL_BlitSurface SDL_UpperBlit
697 /* This is the public blit function, SDL_BlitSurface(), and it performs
698 rectangle validation and clipping before passing it to SDL_LowerBlit()
700 extern DECLSPEC int SDLCALL SDL_UpperBlit
701 (SDL_Surface *src, SDL_Rect *srcrect,
702 SDL_Surface *dst, SDL_Rect *dstrect);
703 /* This is a semi-private blit function and it performs low-level surface
706 extern DECLSPEC int SDLCALL SDL_LowerBlit
707 (SDL_Surface *src, SDL_Rect *srcrect,
708 SDL_Surface *dst, SDL_Rect *dstrect);
711 * This function performs a fast fill of the given rectangle with 'color'
712 * The given rectangle is clipped to the destination surface clip area
713 * and the final fill rectangle is saved in the passed in pointer.
714 * If 'dstrect' is NULL, the whole surface will be filled with 'color'
715 * The color should be a pixel of the format used by the surface, and
716 * can be generated by the SDL_MapRGB() function.
717 * This function returns 0 on success, or -1 on error.
719 extern DECLSPEC int SDLCALL SDL_FillRect
720 (SDL_Surface *dst, SDL_Rect *dstrect, Uint32 color);
723 * This function takes a surface and copies it to a new surface of the
724 * pixel format and colors of the video framebuffer, suitable for fast
725 * blitting onto the display surface. It calls SDL_ConvertSurface()
727 * If you want to take advantage of hardware colorkey or alpha blit
728 * acceleration, you should set the colorkey and alpha value before
729 * calling this function.
731 * If the conversion fails or runs out of memory, it returns NULL
733 extern DECLSPEC SDL_Surface * SDLCALL SDL_DisplayFormat(SDL_Surface *surface);
736 * This function takes a surface and copies it to a new surface of the
737 * pixel format and colors of the video framebuffer (if possible),
738 * suitable for fast alpha blitting onto the display surface.
739 * The new surface will always have an alpha channel.
741 * If you want to take advantage of hardware colorkey or alpha blit
742 * acceleration, you should set the colorkey and alpha value before
743 * calling this function.
745 * If the conversion fails or runs out of memory, it returns NULL
747 extern DECLSPEC SDL_Surface * SDLCALL SDL_DisplayFormatAlpha(SDL_Surface *surface);
750 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
751 /* YUV video surface overlay functions */
752 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
754 /* This function creates a video output overlay
755 Calling the returned surface an overlay is something of a misnomer because
756 the contents of the display surface underneath the area where the overlay
757 is shown is undefined - it may be overwritten with the converted YUV data.
759 extern DECLSPEC SDL_Overlay * SDLCALL SDL_CreateYUVOverlay(int width, int height,
760 Uint32 format, SDL_Surface *display);
762 /* Lock an overlay for direct access, and unlock it when you are done */
763 extern DECLSPEC int SDLCALL SDL_LockYUVOverlay(SDL_Overlay *overlay);
764 extern DECLSPEC void SDLCALL SDL_UnlockYUVOverlay(SDL_Overlay *overlay);
766 /* Blit a video overlay to the display surface.
767 The contents of the video surface underneath the blit destination are
769 The width and height of the destination rectangle may be different from
770 that of the overlay, but currently only 2x scaling is supported.
772 extern DECLSPEC int SDLCALL SDL_DisplayYUVOverlay(SDL_Overlay *overlay, SDL_Rect *dstrect);
774 /* Free a video overlay */
775 extern DECLSPEC void SDLCALL SDL_FreeYUVOverlay(SDL_Overlay *overlay);
778 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
779 /* OpenGL support functions. */
780 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
783 * Dynamically load a GL driver, if SDL is built with dynamic GL.
785 * SDL links normally with the OpenGL library on your system by default,
786 * but you can compile it to dynamically load the GL driver at runtime.
787 * If you do this, you need to retrieve all of the GL functions used in
788 * your program from the dynamic library using SDL_GL_GetProcAddress().
790 * This is disabled in default builds of SDL.
792 extern DECLSPEC int SDLCALL SDL_GL_LoadLibrary(const char *path);
795 * Get the address of a GL function (for extension functions)
797 extern DECLSPEC void * SDLCALL SDL_GL_GetProcAddress(const char* proc);
800 * Set an attribute of the OpenGL subsystem before intialization.
802 extern DECLSPEC int SDLCALL SDL_GL_SetAttribute(SDL_GLattr attr, int value);
805 * Get an attribute of the OpenGL subsystem from the windowing
806 * interface, such as glX. This is of course different from getting
807 * the values from SDL's internal OpenGL subsystem, which only
808 * stores the values you request before initialization.
810 * Developers should track the values they pass into SDL_GL_SetAttribute
811 * themselves if they want to retrieve these values.
813 extern DECLSPEC int SDLCALL SDL_GL_GetAttribute(SDL_GLattr attr, int* value);
816 * Swap the OpenGL buffers, if double-buffering is supported.
818 extern DECLSPEC void SDLCALL SDL_GL_SwapBuffers(void);
821 * Internal functions that should not be called unless you have read
822 * and understood the source code for these functions.
824 extern DECLSPEC void SDLCALL SDL_GL_UpdateRects(int numrects, SDL_Rect* rects);
825 extern DECLSPEC void SDLCALL SDL_GL_Lock(void);
826 extern DECLSPEC void SDLCALL SDL_GL_Unlock(void);
828 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
829 /* These functions allow interaction with the window manager, if any. */
830 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
833 * Sets/Gets the title and icon text of the display window
835 extern DECLSPEC void SDLCALL SDL_WM_SetCaption(const char *title, const char *icon);
836 extern DECLSPEC void SDLCALL SDL_WM_GetCaption(char **title, char **icon);
839 * Sets the icon for the display window.
840 * This function must be called before the first call to SDL_SetVideoMode().
841 * It takes an icon surface, and a mask in MSB format.
842 * If 'mask' is NULL, the entire icon surface will be used as the icon.
844 extern DECLSPEC void SDLCALL SDL_WM_SetIcon(SDL_Surface *icon, Uint8 *mask);
847 * This function iconifies the window, and returns 1 if it succeeded.
848 * If the function succeeds, it generates an SDL_APPACTIVE loss event.
849 * This function is a noop and returns 0 in non-windowed environments.
851 extern DECLSPEC int SDLCALL SDL_WM_IconifyWindow(void);
854 * Toggle fullscreen mode without changing the contents of the screen.
855 * If the display surface does not require locking before accessing
856 * the pixel information, then the memory pointers will not change.
858 * If this function was able to toggle fullscreen mode (change from
859 * running in a window to fullscreen, or vice-versa), it will return 1.
860 * If it is not implemented, or fails, it returns 0.
862 * The next call to SDL_SetVideoMode() will set the mode fullscreen
863 * attribute based on the flags parameter - if SDL_FULLSCREEN is not
864 * set, then the display will be windowed by default where supported.
866 * This is currently only implemented in the X11 video driver.
868 extern DECLSPEC int SDLCALL SDL_WM_ToggleFullScreen(SDL_Surface *surface);
871 * This function allows you to set and query the input grab state of
872 * the application. It returns the new input grab state.
878 SDL_GRAB_FULLSCREEN /* Used internally */
881 * Grabbing means that the mouse is confined to the application window,
882 * and nearly all keyboard input is passed directly to the application,
883 * and not interpreted by a window manager, if any.
885 extern DECLSPEC SDL_GrabMode SDLCALL SDL_WM_GrabInput(SDL_GrabMode mode);
887 /* Not in public API at the moment - do not use! */
888 extern DECLSPEC int SDLCALL SDL_SoftStretch(SDL_Surface *src, SDL_Rect *srcrect,
889 SDL_Surface *dst, SDL_Rect *dstrect);
891 /* Ends C function definitions when using C++ */
895 #include "close_code.h"
897 #endif /* _SDL_video_h */