sdl_video.c

Simple DirectMedia Layer - Simple DirectMedia Layer 是一个跨平台的多媒体库设计用来提供快速图形framebuffer和音频驱动。应用MPEG为软件

 * Update a specific portion of the physical screen
 */
void SDL_UpdateRect(SDL_Surface *screen, Sint32 x, Sint32 y, Uint32 w, Uint32 h)
{
	if ( screen ) {
		SDL_Rect rect;

		/* Perform some checking */
		if ( w == 0 )
			w = screen->w;
		if ( h == 0 )
			h = screen->h;
		if ( (int)(x+w) > screen->w )
			return;
		if ( (int)(y+h) > screen->h )
			return;

		/* Fill the rectangle */
		rect.x = x;
		rect.y = y;
		rect.w = w;
		rect.h = h;
		SDL_UpdateRects(screen, 1, &rect);
	}
}
void SDL_UpdateRects (SDL_Surface *screen, int numrects, SDL_Rect *rects)
{
	int i;
	SDL_VideoDevice *video = current_video;
	SDL_VideoDevice *this = current_video;

	if ( screen == SDL_ShadowSurface ) {
		/* Blit the shadow surface using saved mapping */
		SDL_Palette *pal = screen->format->palette;
		SDL_Color *saved_colors = NULL;
		if ( pal && !(SDL_VideoSurface->flags & SDL_HWPALETTE) ) {
			/* simulated 8bpp, use correct physical palette */
			saved_colors = pal->colors;
			if ( video->gammacols ) {
				/* gamma-corrected palette */
				pal->colors = video->gammacols;
			} else if ( video->physpal ) {
				/* physical palette different from logical */
				pal->colors = video->physpal->colors;
			}
		}
		if ( SHOULD_DRAWCURSOR(SDL_cursorstate) ) {
			SDL_LockCursor();
			SDL_DrawCursor(SDL_ShadowSurface);
			for ( i=0; i<numrects; ++i ) {
				SDL_LowerBlit(SDL_ShadowSurface, &rects[i], 
						SDL_VideoSurface, &rects[i]);
			}
			SDL_EraseCursor(SDL_ShadowSurface);
			SDL_UnlockCursor();
		} else {
			for ( i=0; i<numrects; ++i ) {
				SDL_LowerBlit(SDL_ShadowSurface, &rects[i], 
						SDL_VideoSurface, &rects[i]);
			}
		}
		if ( saved_colors ) {
			pal->colors = saved_colors;
		}

		/* Fall through to video surface update */
		screen = SDL_VideoSurface;
	}
	if ( screen == SDL_VideoSurface ) {
		/* Update the video surface */
		if ( screen->offset ) {
			for ( i=0; i<numrects; ++i ) {
				rects[i].x += video->offset_x;
				rects[i].y += video->offset_y;
			}
			video->UpdateRects(this, numrects, rects);
			for ( i=0; i<numrects; ++i ) {
				rects[i].x -= video->offset_x;
				rects[i].y -= video->offset_y;
			}
		} else {
			video->UpdateRects(this, numrects, rects);
		}
	}
}

/*
 * Performs hardware double buffering, if possible, or a full update if not.
 */
int SDL_Flip(SDL_Surface *screen)
{
	SDL_VideoDevice *video = current_video;
	/* Copy the shadow surface to the video surface */
	if ( screen == SDL_ShadowSurface ) {
		SDL_Rect rect;
		SDL_Palette *pal = screen->format->palette;
		SDL_Color *saved_colors = NULL;
		if ( pal && !(SDL_VideoSurface->flags & SDL_HWPALETTE) ) {
			/* simulated 8bpp, use correct physical palette */
			saved_colors = pal->colors;
			if ( video->gammacols ) {
				/* gamma-corrected palette */
				pal->colors = video->gammacols;
			} else if ( video->physpal ) {
				/* physical palette different from logical */
				pal->colors = video->physpal->colors;
			}
		}

		rect.x = 0;
		rect.y = 0;
		rect.w = screen->w;
		rect.h = screen->h;
		if ( SHOULD_DRAWCURSOR(SDL_cursorstate) ) {
			SDL_LockCursor();
			SDL_DrawCursor(SDL_ShadowSurface);
			SDL_LowerBlit(SDL_ShadowSurface, &rect,
					SDL_VideoSurface, &rect);
			SDL_EraseCursor(SDL_ShadowSurface);
			SDL_UnlockCursor();
		} else {
			SDL_LowerBlit(SDL_ShadowSurface, &rect,
					SDL_VideoSurface, &rect);
		}
		if ( saved_colors ) {
			pal->colors = saved_colors;
		}

		/* Fall through to video surface update */
		screen = SDL_VideoSurface;
	}
	if ( (screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF ) {
		SDL_VideoDevice *this  = current_video;
		return(video->FlipHWSurface(this, SDL_VideoSurface));
	} else {
		SDL_UpdateRect(screen, 0, 0, 0, 0);
	}
	return(0);
}

static void SetPalette_logical(SDL_Surface *screen, SDL_Color *colors,
			       int firstcolor, int ncolors)
{
        SDL_Palette *pal = screen->format->palette;
	SDL_Palette *vidpal;

	if ( colors != (pal->colors + firstcolor) ) {
	        memcpy(pal->colors + firstcolor, colors,
		       ncolors * sizeof(*colors));
	}

	vidpal = SDL_VideoSurface->format->palette;
	if ( (screen == SDL_ShadowSurface) && vidpal ) {
	        /*
		 * This is a shadow surface, and the physical
		 * framebuffer is also indexed. Propagate the
		 * changes to its logical palette so that
		 * updates are always identity blits
		 */
		memcpy(vidpal->colors + firstcolor, colors,
		       ncolors * sizeof(*colors));
	}
	SDL_FormatChanged(screen);
}

static int SetPalette_physical(SDL_Surface *screen,
                               SDL_Color *colors, int firstcolor, int ncolors)
{
	SDL_VideoDevice *video = current_video;
	int gotall = 1;

	if ( video->physpal ) {
		/* We need to copy the new colors, since we haven't
		 * already done the copy in the logical set above.
		 */
		memcpy(video->physpal->colors + firstcolor,
		       colors, ncolors * sizeof(*colors));
	}
	if ( screen == SDL_ShadowSurface ) {
		if ( SDL_VideoSurface->flags & SDL_HWPALETTE ) {
			/*
			 * The real screen is also indexed - set its physical
			 * palette. The physical palette does not include the
			 * gamma modification, we apply it directly instead,
			 * but this only happens if we have hardware palette.
			 */
			screen = SDL_VideoSurface;
		} else {
			/*
			 * The video surface is not indexed - invalidate any
			 * active shadow-to-video blit mappings.
			 */
			if ( screen->map->dst == SDL_VideoSurface ) {
				SDL_InvalidateMap(screen->map);
			}
			if ( video->gamma ) {
				if( ! video->gammacols ) {
					SDL_Palette *pp = video->physpal;
					if(!pp)
						pp = screen->format->palette;
					video->gammacols = malloc(pp->ncolors
							  * sizeof(SDL_Color));
					SDL_ApplyGamma(video->gamma,
						       pp->colors,
						       video->gammacols,
						       pp->ncolors);
				} else {
					SDL_ApplyGamma(video->gamma, colors,
						       video->gammacols
						       + firstcolor,
						       ncolors);
				}
			}
			SDL_UpdateRect(screen, 0, 0, 0, 0);
		}
	}

	if ( screen == SDL_VideoSurface ) {
		SDL_Color gcolors[256];

	        if ( video->gamma ) {
		        SDL_ApplyGamma(video->gamma, colors, gcolors, ncolors);
			colors = gcolors;
		}
		gotall = video->SetColors(video, firstcolor, ncolors, colors);
		if ( ! gotall ) {
			/* The video flags shouldn't have SDL_HWPALETTE, and
			   the video driver is responsible for copying back the
			   correct colors into the video surface palette.
			*/
			;
		}
		SDL_CursorPaletteChanged();
	}
	return gotall;
}

/*
 * Set the physical and/or logical colormap of a surface:
 * Only the screen has a physical colormap. It determines what is actually
 * sent to the display.
 * The logical colormap is used to map blits to/from the surface.
 * 'which' is one or both of SDL_LOGPAL, SDL_PHYSPAL
 *
 * Return nonzero if all colours were set as requested, or 0 otherwise.
 */
int SDL_SetPalette(SDL_Surface *screen, int which,
		   SDL_Color *colors, int firstcolor, int ncolors)
{
        SDL_Palette *pal;
	int gotall;
	int palsize;

	if ( ! current_video ) {
		return 0;
	}
	if ( screen != SDL_PublicSurface ) {
	        /* only screens have physical palettes */
	        which &= ~SDL_PHYSPAL;
	} else if( (screen->flags & SDL_HWPALETTE) != SDL_HWPALETTE ) {
	        /* hardware palettes required for split colormaps */
	        which |= SDL_PHYSPAL | SDL_LOGPAL;
	}

	/* Verify the parameters */
	pal = screen->format->palette;
	if( !pal ) {
	        return 0;	/* not a palettized surface */
	}
	gotall = 1;
	palsize = 1 << screen->format->BitsPerPixel;
	if ( ncolors > (palsize - firstcolor) ) {
	        ncolors = (palsize - firstcolor);
		gotall = 0;
	}

	if ( which & SDL_LOGPAL ) {
		/*
		 * Logical palette change: The actual screen isn't affected,
		 * but the internal colormap is altered so that the
		 * interpretation of the pixel values (for blits etc) is
		 * changed.
		 */
	        SetPalette_logical(screen, colors, firstcolor, ncolors);
	}
	if ( which & SDL_PHYSPAL ) {
		SDL_VideoDevice *video = current_video;
	        /*
		 * Physical palette change: This doesn't affect the
		 * program's idea of what the screen looks like, but changes
		 * its actual appearance.
		 */
	        if(!video)
		        return gotall;	/* video not yet initialized */
		if(!video->physpal && !(which & SDL_LOGPAL) ) {
			/* Lazy physical palette allocation */
		        int size;
			SDL_Palette *pp = malloc(sizeof(*pp));
			current_video->physpal = pp;
			pp->ncolors = pal->ncolors;
			size = pp->ncolors * sizeof(SDL_Color);
			pp->colors = malloc(size);
			memcpy(pp->colors, pal->colors, size);
		}
		if ( ! SetPalette_physical(screen,
		                           colors, firstcolor, ncolors) ) {
			gotall = 0;
		}
	}
	return gotall;
}

int SDL_SetColors(SDL_Surface *screen, SDL_Color *colors, int firstcolor,
		  int ncolors)
{
        return SDL_SetPalette(screen, SDL_LOGPAL | SDL_PHYSPAL,
			      colors, firstcolor, ncolors);
}

/*
 * Clean up the video subsystem
 */
void SDL_VideoQuit (void)
{
	SDL_Surface *ready_to_go;

	if ( current_video ) {
		SDL_VideoDevice *video = current_video;
		SDL_VideoDevice *this  = current_video;

		/* Halt event processing before doing anything else */
		SDL_StopEventLoop();

		/* Clean up allocated window manager items */
		if ( SDL_PublicSurface ) {
			SDL_PublicSurface = NULL;
		}
		SDL_CursorQuit();

		/* Just in case... */
		SDL_WM_GrabInputOff();

		/* Clean up the system video */
		video->VideoQuit(this);

		/* Free any lingering surfaces */
		ready_to_go = SDL_ShadowSurface;
		SDL_ShadowSurface = NULL;
		SDL_FreeSurface(ready_to_go);
		if ( SDL_VideoSurface != NULL ) {
			ready_to_go = SDL_VideoSurface;
			SDL_VideoSurface = NULL;
			SDL_FreeSurface(ready_to_go);
		}
		SDL_PublicSurface = NULL;

		/* Clean up miscellaneous memory */
		if ( video->physpal ) {
			free(video->physpal->colors);
			free(video->physpal);
			video->physpal = NULL;
		}
		if ( video->gammacols ) {
			free(video->gammacols);
			video->gammacols = NULL;
		}
		if ( video->gamma ) {
			free(video->gamma);
			video->gamma = NULL;
		}
		if ( video->wm_title != NULL ) {
			free(video->wm_title);
			video->wm_title = NULL;
		}
		if ( video->wm_icon != NULL ) {
			free(video->wm_icon);
			video->wm_icon = NULL;
		}

		/* Finish cleaning up video subsystem */
		video->free(this);
		current_video = NULL;
	}
	return;
}

/* Load the GL driver library */
int SDL_GL_LoadLibrary(const char *path)
{
	SDL_VideoDevice *video = current_video;
	SDL_VideoDevice *this = current_video;
	int retval;

	retval = -1;
	if ( video == NULL ) {
		SDL_SetError("Video subsystem has not been initialized");
	} else {
		if ( video->GL_LoadLibrary ) {
			retval = video->GL_LoadLibrary(this, path);
		} else {
			SDL_SetError("No dynamic GL support in video driver");
		}
	}
	return(retval);
}

void *SDL_GL_GetProcAddress(const char* proc)
{
	SDL_VideoDevice *video = current_video;
	SDL_VideoDevice *this = current_video;
	void *func;

	func = NULL;
	if ( video->GL_GetProcAddress ) {
		if ( video->gl_config.driver_loaded ) {
			func = video->GL_GetProcAddress(this, proc);
		} else {
			SDL_SetError("No GL driver has been loaded");
		}
	} else {
		SDL_SetError("No dynamic GL support in video driver");
	}
	return func;
}

/* Set the specified GL attribute for setting up a GL video mode */
int SDL_GL_SetAttribute( SDL_GLattr attr, int value )
{
	int retval;
	SDL_VideoDevice *video = current_video;

	retval = 0;
	switch (attr) {
		case SDL_GL_RED_SIZE:
			video->gl_config.red_size = value;
			break;
		case SDL_GL_GREEN_SIZE:
			video->gl_config.green_size = value;
			break;
		case SDL_GL_BLUE_SIZE:
			video->gl_config.blue_size = value;
			break;
		case SDL_GL_ALPHA_SIZE:
			video->gl_config.alpha_size = value;
			break;
		case SDL_GL_DOUBLEBUFFER:
			video->gl_config.double_buffer = value;
			break;
        	case SDL_GL_BUFFER_SIZE:
	        	video->gl_config.buffer_size = value;
			break;
		case SDL_GL_DEPTH_SIZE:
			video->gl_config.depth_size = value;
			break;
		case SDL_GL_STENCIL_SIZE:
			video->gl_config.stencil_size = value;
			break;
		case SDL_GL_ACCUM_RED_SIZE:
			video->gl_config.accum_red_size = value;
			break;
		case SDL_GL_ACCUM_GREEN_SIZE:
			video->gl_config.accum_green_size = value;
			break;
		case SDL_GL_ACCUM_BLUE_SIZE:
			video->gl_config.accum_blue_size = value;
			break;
		case SDL_GL_ACCUM_ALPHA_SIZE:
			video->gl_config.accum_alpha_size = value;
			break;