sdl_cursor.c

MPEG-4编解码的实现(包括MPEG4视音频编解码)

			pixels8[0] = SDL_MapRGB(screen->format, 255, 255, 255);
			pixels8[1] = SDL_MapRGB(screen->format, 0, 0, 0);
			palette_changed = 0;
		}
		dst = (Uint8 *)screen->pixels +
                       (SDL_cursor->area.y+area->y)*screen->pitch +
                       SDL_cursor->area.x;
		dstskip = screen->pitch-area->w;

		for ( h=area->h; h; h-- ) {
			for ( w=area->w/8; w; w-- ) {
				maskb = *mask++;
				datab = *data++;
				for ( i=0; i<8; ++i ) {
					if ( maskb & 0x80 ) {
						*dst = pixels8[datab>>7];
					}
					maskb <<= 1;
					datab <<= 1;
					dst++;
				}
			}
			dst += dstskip;
		}
	    }
	    break;

	    case 2: {
		Uint16 *dst;
		int dstskip;

		dst = (Uint16 *)screen->pixels +
                       (SDL_cursor->area.y+area->y)*screen->pitch/2 +
                       SDL_cursor->area.x;
		dstskip = (screen->pitch/2)-area->w;

		for ( h=area->h; h; h-- ) {
			for ( w=area->w/8; w; w-- ) {
				maskb = *mask++;
				datab = *data++;
				for ( i=0; i<8; ++i ) {
					if ( maskb & 0x80 ) {
						*dst = pixels[datab>>7];
					}
					maskb <<= 1;
					datab <<= 1;
					dst++;
				}
			}
			dst += dstskip;
		}
	    }
	    break;

	    case 3: {
		Uint8 *dst;
		int dstskip;

		dst = (Uint8 *)screen->pixels +
                       (SDL_cursor->area.y+area->y)*screen->pitch +
                       SDL_cursor->area.x*3;
		dstskip = screen->pitch-area->w*3;

		for ( h=area->h; h; h-- ) {
			for ( w=area->w/8; w; w-- ) {
				maskb = *mask++;
				datab = *data++;
				for ( i=0; i<8; ++i ) {
					if ( maskb & 0x80 ) {
						memset(dst,pixels[datab>>7],3);
					}
					maskb <<= 1;
					datab <<= 1;
					dst += 3;
				}
			}
			dst += dstskip;
		}
	    }
	    break;

	    case 4: {
		Uint32 *dst;
		int dstskip;

		dst = (Uint32 *)screen->pixels +
                       (SDL_cursor->area.y+area->y)*screen->pitch/4 +
                       SDL_cursor->area.x;
		dstskip = (screen->pitch/4)-area->w;

		for ( h=area->h; h; h-- ) {
			for ( w=area->w/8; w; w-- ) {
				maskb = *mask++;
				datab = *data++;
				for ( i=0; i<8; ++i ) {
					if ( maskb & 0x80 ) {
						*dst = pixels[datab>>7];
					}
					maskb <<= 1;
					datab <<= 1;
					dst++;
				}
			}
			dst += dstskip;
		}
	    }
	    break;
	}
}

static void SDL_DrawCursorSlow(SDL_Surface *screen, SDL_Rect *area)
{
	const Uint32 pixels[2] = { 0xFFFFFF, 0x000000 };
	int h;
	int x, minx, maxx;
	Uint8 *data, datab = 0;
	Uint8 *mask, maskb = 0;
	Uint8 *dst;
	int dstbpp, dstskip;

	data = SDL_cursor->data + area->y * SDL_cursor->area.w/8;
	mask = SDL_cursor->mask + area->y * SDL_cursor->area.w/8;
	dstbpp = screen->format->BytesPerPixel;
	dst = (Uint8 *)screen->pixels +
                       (SDL_cursor->area.y+area->y)*screen->pitch +
                       SDL_cursor->area.x*dstbpp;
	dstskip = screen->pitch-SDL_cursor->area.w*dstbpp;

	minx = area->x;
	maxx = area->x+area->w;
	if ( screen->format->BytesPerPixel == 1 ) {
		if ( palette_changed ) {
			pixels8[0] = SDL_MapRGB(screen->format, 255, 255, 255);
			pixels8[1] = SDL_MapRGB(screen->format, 0, 0, 0);
			palette_changed = 0;
		}
		for ( h=area->h; h; h-- ) {
			for ( x=0; x<SDL_cursor->area.w; ++x ) {
				if ( (x%8) == 0 ) {
					maskb = *mask++;
					datab = *data++;
				}
				if ( (x >= minx) && (x < maxx) ) {
					if ( maskb & 0x80 ) {
						memset(dst, pixels8[datab>>7], dstbpp);
					}
				}
				maskb <<= 1;
				datab <<= 1;
				dst += dstbpp;
			}
			dst += dstskip;
		}
	} else {
		for ( h=area->h; h; h-- ) {
			for ( x=0; x<SDL_cursor->area.w; ++x ) {
				if ( (x%8) == 0 ) {
					maskb = *mask++;
					datab = *data++;
				}
				if ( (x >= minx) && (x < maxx) ) {
					if ( maskb & 0x80 ) {
						memset(dst, pixels[datab>>7], dstbpp);
					}
				}
				maskb <<= 1;
				datab <<= 1;
				dst += dstbpp;
			}
			dst += dstskip;
		}
	}
}

/* This handles the ugly work of converting the saved cursor background from
   the pixel format of the shadow surface to that of the video surface.
   This is only necessary when blitting from a shadow surface of a different
   pixel format than the video surface, and using a software rendered cursor.
*/
static void SDL_ConvertCursorSave(SDL_Surface *screen, int w, int h)
{
	SDL_BlitInfo info;
	SDL_loblit RunBlit;

	/* Make sure we can steal the blit mapping */
	if ( screen->map->dst != SDL_VideoSurface ) {
		return;
	}

	/* Set up the blit information */
	info.s_pixels = SDL_cursor->save[1];
	info.s_width = w;
	info.s_height = h;
	info.s_skip = 0;
	info.d_pixels = SDL_cursor->save[0];
	info.d_width = w;
	info.d_height = h;
	info.d_skip = 0;
	info.aux_data = screen->map->sw_data->aux_data;
	info.src = screen->format;
	info.table = screen->map->table;
	info.dst = SDL_VideoSurface->format;
	RunBlit = screen->map->sw_data->blit;

	/* Run the actual software blit */
	RunBlit(&info);
}

void SDL_DrawCursorNoLock(SDL_Surface *screen)
{
	SDL_Rect area;

	/* Get the mouse rectangle, clipped to the screen */
	SDL_MouseRect(&area);
	if ( (area.w == 0) || (area.h == 0) ) {
		return;
	}

	/* Copy mouse background */
	{ int w, h, screenbpp;
	  Uint8 *src, *dst;

	  /* Set up the copy pointers */
	  screenbpp = screen->format->BytesPerPixel;
	  if ( (screen == SDL_VideoSurface) ||
	          FORMAT_EQUAL(screen->format, SDL_VideoSurface->format) ) {
		dst = SDL_cursor->save[0];
	  } else {
		dst = SDL_cursor->save[1];
	  }
	  src = (Uint8 *)screen->pixels + area.y * screen->pitch +
                                          area.x * screenbpp;

	  /* Perform the copy */
	  w = area.w*screenbpp;
	  h = area.h;
	  while ( h-- ) {
		  memcpy(dst, src, w);
		  dst += w;
		  src += screen->pitch;
	  }
	}

	/* Draw the mouse cursor */
	area.x -= SDL_cursor->area.x;
	area.y -= SDL_cursor->area.y;
	if ( (area.x == 0) && (area.w == SDL_cursor->area.w) ) {
		SDL_DrawCursorFast(screen, &area);
	} else {
		SDL_DrawCursorSlow(screen, &area);
	}
}

void SDL_DrawCursor(SDL_Surface *screen)
{
	/* Lock the screen if necessary */
	if ( screen == NULL ) {
		return;
	}
	if ( SDL_MUSTLOCK(screen) ) {
		if ( SDL_LockSurface(screen) < 0 ) {
			return;
		}
	}

	SDL_DrawCursorNoLock(screen);

	/* Unlock the screen and update if necessary */
	if ( SDL_MUSTLOCK(screen) ) {
		SDL_UnlockSurface(screen);
	}
	if ( (screen == SDL_VideoSurface) &&
	     ((screen->flags & SDL_HWSURFACE) != SDL_HWSURFACE) ) {
		SDL_VideoDevice *video = current_video;
		SDL_VideoDevice *this  = current_video;
		SDL_Rect area;

		SDL_MouseRect(&area);

		/* This can be called before a video mode is set */
		if ( video->UpdateRects ) {
			video->UpdateRects(this, 1, &area);
		}
	}
}

void SDL_EraseCursorNoLock(SDL_Surface *screen)
{
	SDL_Rect area;

	/* Get the mouse rectangle, clipped to the screen */
	SDL_MouseRect(&area);
	if ( (area.w == 0) || (area.h == 0) ) {
		return;
	}

	/* Copy mouse background */
	{ int w, h, screenbpp;
	  Uint8 *src, *dst;

	  /* Set up the copy pointers */
	  screenbpp = screen->format->BytesPerPixel;
	  if ( (screen == SDL_VideoSurface) ||
	          FORMAT_EQUAL(screen->format, SDL_VideoSurface->format) ) {
		src = SDL_cursor->save[0];
	  } else {
		src = SDL_cursor->save[1];
	  }
	  dst = (Uint8 *)screen->pixels + area.y * screen->pitch +
                                          area.x * screenbpp;

	  /* Perform the copy */
	  w = area.w*screenbpp;
	  h = area.h;
	  while ( h-- ) {
		  memcpy(dst, src, w);
		  src += w;
		  dst += screen->pitch;
	  }

	  /* Perform pixel conversion on cursor background */
	  if ( src > SDL_cursor->save[1] ) {
		SDL_ConvertCursorSave(screen, area.w, area.h);
	  }
	}
}

void SDL_EraseCursor(SDL_Surface *screen)
{
	/* Lock the screen if necessary */
	if ( screen == NULL ) {
		return;
	}
	if ( SDL_MUSTLOCK(screen) ) {
		if ( SDL_LockSurface(screen) < 0 ) {
			return;
		}
	}

	SDL_EraseCursorNoLock(screen);

	/* Unlock the screen and update if necessary */
	if ( SDL_MUSTLOCK(screen) ) {
		SDL_UnlockSurface(screen);
	}
	if ( (screen == SDL_VideoSurface) &&
	     ((screen->flags & SDL_HWSURFACE) != SDL_HWSURFACE) ) {
		SDL_VideoDevice *video = current_video;
		SDL_VideoDevice *this  = current_video;
		SDL_Rect area;

		SDL_MouseRect(&area);
		if ( video->UpdateRects ) {
			video->UpdateRects(this, 1, &area);
		}
	}
}

/* Reset the cursor on video mode change
   FIXME:  Keep track of all cursors, and reset them all.
 */
void SDL_ResetCursor(void)
{
	int savelen;

	if ( SDL_cursor ) {
		savelen = SDL_cursor->area.w*4*SDL_cursor->area.h;
		SDL_cursor->area.x = 0;
		SDL_cursor->area.y = 0;
		memset(SDL_cursor->save[0], 0, savelen);
	}
}