/* Simple program:  Test bitmap blits */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "SDL.h"

#include "picture.xbm"

/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */

static void quit(int rc)

{

	SDL_Quit();

	exit(rc);

}

SDL_Surface *LoadXBM(SDL_Surface *screen, int w, int h, Uint8 *bits)

{

	SDL_Surface *bitmap;

	Uint8 *line;

	/* Allocate the bitmap */

	bitmap = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 1, 0, 0, 0, 0);

	if ( bitmap == NULL ) {

		fprintf(stderr, "Couldn't allocate bitmap: %s\n",

						SDL_GetError());

		return(NULL);

	}

	/* Copy the pixels */

	line = (Uint8 *)bitmap->pixels;

	w = (w+7)/8;

	while ( h-- ) {

		memcpy(line, bits, w);

		/* X11 Bitmap images have the bits reversed */

		{ int i, j; Uint8 *buf, byte;

			for ( buf=line, i=0; i<w; ++i, ++buf ) {

				byte = *buf;

				*buf = 0;

				for ( j=7; j>=0; --j ) {

					*buf |= (byte&0x01)<<j;

					byte >>= 1;

				}

			}

		}

		line += bitmap->pitch;

		bits += w;

	}

	return(bitmap);

}

int main(int argc, char *argv[])

{

	SDL_Surface *screen;

	SDL_Surface *bitmap;

	Uint8  video_bpp;

	Uint32 videoflags;

	Uint8 *buffer;

	int i, k, done;

	SDL_Event event;

	Uint16 *buffer16;

        Uint16 color;

        Uint8  gradient;

	SDL_Color palette[256];

	/* Initialize SDL */

	if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {

		fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());

		return(1);

	}

	video_bpp = 0;

	videoflags = SDL_SWSURFACE;

	while ( argc > 1 ) {

		--argc;

		if ( strcmp(argv[argc-1], "-bpp") == 0 ) {

			video_bpp = atoi(argv[argc]);

			--argc;

		} else

		if ( strcmp(argv[argc], "-warp") == 0 ) {

			videoflags |= SDL_HWPALETTE;

		} else

		if ( strcmp(argv[argc], "-hw") == 0 ) {

			videoflags |= SDL_HWSURFACE;

		} else

		if ( strcmp(argv[argc], "-fullscreen") == 0 ) {

			videoflags |= SDL_FULLSCREEN;

		} else {

			fprintf(stderr,

			"Usage: %s [-bpp N] [-warp] [-hw] [-fullscreen]\n",

								argv[0]);

			quit(1);

		}

	}

	/* Set 640x480 video mode */

	if ( (screen=SDL_SetVideoMode(640,480,video_bpp,videoflags)) == NULL ) {

		fprintf(stderr, "Couldn't set 640x480x%d video mode: %s\n",

						video_bpp, SDL_GetError());

		quit(2);

	}

	if (video_bpp==8) {

		/* Set a gray colormap, reverse order from white to black */

		for ( i=0; i<256; ++i ) {

			palette[i].r = 255-i;

			palette[i].g = 255-i;

			palette[i].b = 255-i;

		}

		SDL_SetColors(screen, palette, 0, 256);

	}

	/* Set the surface pixels and refresh! */

	if ( SDL_LockSurface(screen) < 0 ) {

		fprintf(stderr, "Couldn't lock the display surface: %s\n",

							SDL_GetError());

		quit(2);

	}

	buffer=(Uint8 *)screen->pixels;

	if (screen->format->BytesPerPixel!=2) {

        	for ( i=0; i<screen->h; ++i ) {

        		memset(buffer,(i*255)/screen->h, screen->pitch);

        		buffer += screen->pitch;

        	}

        }

        else

        {

		for ( i=0; i<screen->h; ++i ) {

			gradient=((i*255)/screen->h);

                        color = SDL_MapRGB(screen->format, gradient, gradient, gradient);

                        buffer16=(Uint16*)buffer;

                        for (k=0; k<screen->w; k++)

                        {

                            *(buffer16+k)=color;

                        }

			buffer += screen->pitch;

		}

        }

	SDL_UnlockSurface(screen);

	SDL_UpdateRect(screen, 0, 0, 0, 0);

	/* Load the bitmap */

	bitmap = LoadXBM(screen, picture_width, picture_height,

					(Uint8 *)picture_bits);

	if ( bitmap == NULL ) {

		quit(1);

	}

	/* Wait for a keystroke */

	done = 0;

	while ( !done ) {

		/* Check for events */

		while ( SDL_PollEvent(&event) ) {

			switch (event.type) {

				case SDL_MOUSEBUTTONDOWN: {

					SDL_Rect dst;

					dst.x = event.button.x - bitmap->w/2;

					dst.y = event.button.y - bitmap->h/2;

					dst.w = bitmap->w;

					dst.h = bitmap->h;

					SDL_BlitSurface(bitmap, NULL,

								screen, &dst);

					SDL_UpdateRects(screen,1,&dst);

					}

					break;

				case SDL_KEYDOWN:

					/* Any key press quits the app... */

					done = 1;

					break;

				case SDL_QUIT:

					done = 1;

					break;

				default:

					break;

			}

		}

	}

	SDL_FreeSurface(bitmap);

	SDL_Quit();

	return(0);

}