/*    showimage:  A test application for the SDL image loading library.    Copyright (C) 1997-2006 Sam Lantinga    This library is free software; you can redistribute it and/or    modify it under the terms of the GNU Lesser General Public    License as published by the Free Software Foundation; either    version 2.1 of the License, or (at your option) any later version.    This library 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    Lesser General Public License for more details.    You should have received a copy of the GNU Lesser General Public    License along with this library; if not, write to the Free Software    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA    Sam Lantinga    slouken@libsdl.org*/#include <stdlib.h>#include <stdio.h>#include <string.h>#include "SDL.h"#include "SDL_image.h"/* #define XPM_INCLUDED and supply picture.xpm to test the XPM inclusion   feature */#ifdef XPM_INCLUDED#include "picture.xpm"#endif/* Draw a Gimpish background pattern to show transparency in the image */void draw_background(SDL_Surface *screen){    Uint8 *dst = screen->pixels;    int x, y;    int bpp = screen->format->BytesPerPixel;    Uint32 col[2];    col[0] = SDL_MapRGB(screen->format, 0x66, 0x66, 0x66);    col[1] = SDL_MapRGB(screen->format, 0x99, 0x99, 0x99);    for(y = 0; y < screen->h; y++) {	for(x = 0; x < screen->w; x++) {	    /* use an 8x8 checkerboard pattern */	    Uint32 c = col[((x ^ y) >> 3) & 1];	    switch(bpp) {	    case 1:		dst[x] = (Uint8)c;		break;	    case 2:		((Uint16 *)dst)[x] = (Uint16)c;		break;	    case 3:#if SDL_BYTEORDER == SDL_LIL_ENDIAN		dst[x * 3]     = (Uint8)(c);		dst[x * 3 + 1] = (Uint8)(c >> 8);		dst[x * 3 + 2] = (Uint8)(c >> 16);#else		dst[x * 3]     = (Uint8)(c >> 16);		dst[x * 3 + 1] = (Uint8)(c >> 8);		dst[x * 3 + 2] = (Uint8)(c);#endif		break;	    case 4:		((Uint32 *)dst)[x] = c;		break;	    }	}	dst += screen->pitch;    }}int main(int argc, char *argv[]){	Uint32 flags;	SDL_Surface *screen, *image;	int i, depth, done;	SDL_Event event;	/* Check command line usage */	if ( ! argv[1] ) {		fprintf(stderr, "Usage: %s <image_file>\n", argv[0]);		return(1);	}	/* Initialize the SDL library */	if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {		fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());		return(255);	}	flags = SDL_SWSURFACE;	for ( i=1; argv[i]; ++i ) {		if ( strcmp(argv[i], "-fullscreen") == 0 ) {			SDL_ShowCursor(0);			flags |= SDL_FULLSCREEN;			continue;		}		/* Open the image file */#ifdef XPM_INCLUDED		image = IMG_ReadXPMFromArray(picture_xpm);#else		image = IMG_Load(argv[i]);#endif		if ( image == NULL ) {			fprintf(stderr, "Couldn't load %s: %s\n",			        argv[i], SDL_GetError());			continue;		}		SDL_WM_SetCaption(argv[i], "showimage");		/* Create a display for the image */		depth = SDL_VideoModeOK(image->w, image->h, 32, flags);		/* Use the deepest native mode, except that we emulate 32bpp		   for viewing non-indexed images on 8bpp screens */		if ( depth == 0 ) {			if ( image->format->BytesPerPixel > 1 ) {				depth = 32;			} else {				depth = 8;			}		} else		if ( (image->format->BytesPerPixel > 1) && (depth == 8) ) {	    		depth = 32;		}		if(depth == 8)			flags |= SDL_HWPALETTE;		screen = SDL_SetVideoMode(image->w, image->h, depth, flags);		if ( screen == NULL ) {			fprintf(stderr,"Couldn't set %dx%dx%d video mode: %s\n",				image->w, image->h, depth, SDL_GetError());			continue;		}		/* Set the palette, if one exists */		if ( image->format->palette ) {			SDL_SetColors(screen, image->format->palette->colors,			              0, image->format->palette->ncolors);		}		/* Draw a background pattern if the surface has transparency */		if(image->flags & (SDL_SRCALPHA | SDL_SRCCOLORKEY))	    		draw_background(screen);		/* Display the image */		SDL_BlitSurface(image, NULL, screen, NULL);		SDL_UpdateRect(screen, 0, 0, 0, 0);		done = 0;		while ( ! done ) {			if ( SDL_PollEvent(&event) ) {				switch (event.type) {				    case SDL_KEYUP:					switch (event.key.keysym.sym) {					    case SDLK_LEFT:						if ( i > 1 ) {							i -= 2;							done = 1;						}						break;					    case SDLK_RIGHT:						if ( argv[i+1] ) {							done = 1;						}						break;					    case SDLK_ESCAPE:					    case SDLK_q:						argv[i+1] = NULL;						/* Drop through to done */					    case SDLK_SPACE:					    case SDLK_TAB:						done = 1;						break;					    default:						break;					}					break;				    case SDL_MOUSEBUTTONDOWN:					done = 1;					break;                                    case SDL_QUIT:					argv[i+1] = NULL;					done = 1;					break;				    default:					break;				}			} else {				SDL_Delay(10);			}		}		SDL_FreeSurface(image);	}	/* We're done! */	SDL_Quit();	return(0);}