test/testpalette.c - third_party/sdl - Git at Google

 /*
  * testpalette.c
  *
  * A simple test of runtime palette modification for animation
  * (using the SDL_SetPalette() API).
  */

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>

 /* This isn't in the Windows headers */
 #ifndef M_PI
 #define M_PI	3.14159265358979323846
 #endif

 #include "SDL.h"

 /* screen size */
 #define SCRW 640
 #define SCRH 480

 #define NBOATS 5
 #define SPEED 2

 #ifndef MIN
 #define MIN(a, b) ((a) < (b) ? (a) : (b))
 #endif
 #ifndef MAX
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
 #endif

 /*
  * wave colours: Made by taking a narrow cross-section of a wave picture
  * in Gimp, saving in PPM ascii format and formatting with Emacs macros.
  */
 static SDL_Color wavemap[] = {
     {0,2,103}, {0,7,110}, {0,13,117}, {0,19,125},
     {0,25,133}, {0,31,141}, {0,37,150}, {0,43,158},
     {0,49,166}, {0,55,174}, {0,61,182}, {0,67,190},
     {0,73,198}, {0,79,206}, {0,86,214}, {0,96,220},
     {5,105,224}, {12,112,226}, {19,120,227}, {26,128,229},
     {33,135,230}, {40,143,232}, {47,150,234}, {54,158,236},
     {61,165,238}, {68,173,239}, {75,180,241}, {82,188,242},
     {89,195,244}, {96,203,246}, {103,210,248}, {112,218,250},
     {124,224,250}, {135,226,251}, {146,229,251}, {156,231,252},
     {167,233,252}, {178,236,252}, {189,238,252}, {200,240,252},
     {211,242,252}, {222,244,252}, {233,247,252}, {242,249,252},
     {237,250,252}, {209,251,252}, {174,251,252}, {138,252,252},
     {102,251,252}, {63,250,252}, {24,243,252}, {7,225,252},
     {4,203,252}, {3,181,252}, {2,158,252}, {1,136,251},
     {0,111,248}, {0,82,234}, {0,63,213}, {0,50,192},
     {0,39,172}, {0,28,152}, {0,17,132}, {0,7,114}
 };

 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void quit(int rc)
 {
 	SDL_Quit();
 	exit(rc);
 }

 static void sdlerr(char *when)
 {
     fprintf(stderr, "SDL error: %s: %s\n", when, SDL_GetError());
     quit(1);
 }

 /* create a background surface */
 static SDL_Surface *make_bg(SDL_Surface *screen, int startcol)
 {
     int i;
     SDL_Surface *bg = SDL_CreateRGBSurface(SDL_SWSURFACE, screen->w, screen->h,
 					   8, 0, 0, 0, 0);
     if(!bg)
 	sdlerr("creating background surface");

     /* set the palette to the logical screen palette so that blits
        won't be translated */
     SDL_SetColors(bg, screen->format->palette->colors, 0, 256);

     /* Make a wavy background pattern using colours 0-63 */
     if(SDL_LockSurface(bg) < 0)
 	sdlerr("locking background");
     for(i = 0; i < SCRH; i++) {
 	Uint8 *p = (Uint8 *)bg->pixels + i * bg->pitch;
 	int j, d;
 	d = 0;
 	for(j = 0; j < SCRW; j++) {
 	    int v = MAX(d, -2);
 	    v = MIN(v, 2);
 	    if(i > 0)
 		v += p[-bg->pitch] + 65 - startcol;
 	    p[j] = startcol + (v & 63);
 	    d += ((rand() >> 3) % 3) - 1;
 	}
     }
     SDL_UnlockSurface(bg);
     return(bg);
 }

 /*
  * Return a surface flipped horisontally. Only works for 8bpp;
  * extension to arbitrary bitness is left as an exercise for the reader.
  */
 static SDL_Surface *hflip(SDL_Surface *s)
 {
     int i;
     SDL_Surface *z = SDL_CreateRGBSurface(SDL_SWSURFACE, s->w, s->h, 8,
 					  0, 0, 0, 0);
     /* copy palette */
     SDL_SetColors(z, s->format->palette->colors,
 		  0, s->format->palette->ncolors);
     if(SDL_LockSurface(s) < 0 || SDL_LockSurface(z) < 0)
 	sdlerr("locking flip images");

     for(i = 0; i < s->h; i++) {
 	int j;
 	Uint8 *from = (Uint8 *)s->pixels + i * s->pitch;
 	Uint8 *to = (Uint8 *)z->pixels + i * z->pitch + s->w - 1;
 	for(j = 0; j < s->w; j++)
 	    to[-j] = from[j];
     }

     SDL_UnlockSurface(z);
     SDL_UnlockSurface(s);
     return z;
 }

 int main(int argc, char **argv)
 {
     SDL_Color cmap[256];
     SDL_Surface *screen;
     SDL_Surface *bg;
     SDL_Surface *boat[2];
     unsigned vidflags = 0;
     unsigned start;
     int fade_max = 400;
     int fade_level, fade_dir;
     int boatcols, frames, i, red;
     int boatx[NBOATS], boaty[NBOATS], boatdir[NBOATS];
     int gamma_fade = 0;
     int gamma_ramp = 0;

     if(SDL_Init(SDL_INIT_VIDEO) < 0)
 	sdlerr("initialising SDL");

     while(--argc) {
 	++argv;
 	if(strcmp(*argv, "-hw") == 0)
 	    vidflags |= SDL_HWSURFACE;
 	else if(strcmp(*argv, "-fullscreen") == 0)
 	    vidflags |= SDL_FULLSCREEN;
 	else if(strcmp(*argv, "-nofade") == 0)
 	    fade_max = 1;
 	else if(strcmp(*argv, "-gamma") == 0)
 	    gamma_fade = 1;
 	else if(strcmp(*argv, "-gammaramp") == 0)
 	    gamma_ramp = 1;
 	else {
 	    fprintf(stderr,
 		    "usage: testpalette "
 		    " [-hw] [-fullscreen] [-nofade] [-gamma] [-gammaramp]\n");
 	    quit(1);
 	}
     }

     /* Ask explicitly for 8bpp and a hardware palette */
     if((screen = SDL_SetVideoMode(SCRW, SCRH, 8, vidflags | SDL_HWPALETTE)) == NULL) {
 	fprintf(stderr, "error setting %dx%d 8bpp indexed mode: %s\n",
 		SCRW, SCRH, SDL_GetError());
 	quit(1);
     }

     if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor (SDL_FALSE);

     if((boat[0] = SDL_LoadBMP("sail.bmp")) == NULL)
 	sdlerr("loading sail.bmp");
     /* We've chosen magenta (#ff00ff) as colour key for the boat */
     SDL_SetColorKey(boat[0], SDL_SRCCOLORKEY | SDL_RLEACCEL,
 		    SDL_MapRGB(boat[0]->format, 0xff, 0x00, 0xff));
     boatcols = boat[0]->format->palette->ncolors;
     boat[1] = hflip(boat[0]);
     SDL_SetColorKey(boat[1], SDL_SRCCOLORKEY | SDL_RLEACCEL,
 		    SDL_MapRGB(boat[1]->format, 0xff, 0x00, 0xff));

     /*
      * First set the physical screen palette to black, so the user won't
      * see our initial drawing on the screen.
      */
     memset(cmap, 0, sizeof(cmap));
     SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, 256);

     /*
      * Proper palette management is important when playing games with the
      * colormap. We have divided the palette as follows:
      *
      * index 0..(boatcols-1):		used for the boat
      * index boatcols..(boatcols+63):	used for the waves
      */
     SDL_SetPalette(screen, SDL_LOGPAL,
 		   boat[0]->format->palette->colors, 0, boatcols);
     SDL_SetPalette(screen, SDL_LOGPAL, wavemap, boatcols, 64);

     /*
      * Now the logical screen palette is set, and will remain unchanged.
      * The boats already have the same palette so fast blits can be used.
      */
     memcpy(cmap, screen->format->palette->colors, 256 * sizeof(SDL_Color));

     /* save the index of the red colour for later */
     red = SDL_MapRGB(screen->format, 0xff, 0x00, 0x00);

     bg = make_bg(screen, boatcols); /* make a nice wavy background surface */

     /* initial screen contents */
     if(SDL_BlitSurface(bg, NULL, screen, NULL) < 0)
 	sdlerr("blitting background to screen");
     SDL_Flip(screen);		/* actually put the background on screen */

     /* determine initial boat placements */
     for(i = 0; i < NBOATS; i++) {
 	boatx[i] = (rand() % (SCRW + boat[0]->w)) - boat[0]->w;
 	boaty[i] = i * (SCRH - boat[0]->h) / (NBOATS - 1);
 	boatdir[i] = ((rand() >> 5) & 1) * 2 - 1;
     }

     start = SDL_GetTicks();
     frames = 0;
     fade_dir = 1;
     fade_level = 0;
     do {
 	SDL_Event e;
 	SDL_Rect updates[NBOATS];
 	SDL_Rect r;
 	int redphase;

 	/* A small event loop: just exit on any key or mouse button event */
 	while(SDL_PollEvent(&e)) {
 	    if(e.type == SDL_KEYDOWN || e.type == SDL_QUIT
 	       || e.type == SDL_MOUSEBUTTONDOWN) {
 		if(fade_dir < 0)
 		    fade_level = 0;
 		fade_dir = -1;
 	    }
 	}

 	/* move boats */
 	for(i = 0; i < NBOATS; i++) {
 	    int old_x = boatx[i];
 	    /* update boat position */
 	    boatx[i] += boatdir[i] * SPEED;
 	    if(boatx[i] <= -boat[0]->w || boatx[i] >= SCRW)
 		boatdir[i] = -boatdir[i];

 	    /* paint over the old boat position */
 	    r.x = old_x;
 	    r.y = boaty[i];
 	    r.w = boat[0]->w;
 	    r.h = boat[0]->h;
 	    if(SDL_BlitSurface(bg, &r, screen, &r) < 0)
 		sdlerr("blitting background");

 	    /* construct update rectangle (bounding box of old and new pos) */
 	    updates[i].x = MIN(old_x, boatx[i]);
 	    updates[i].y = boaty[i];
 	    updates[i].w = boat[0]->w + SPEED;
 	    updates[i].h = boat[0]->h;
 	    /* clip update rectangle to screen */
 	    if(updates[i].x < 0) {
 		updates[i].w += updates[i].x;
 		updates[i].x = 0;
 	    }
 	    if(updates[i].x + updates[i].w > SCRW)
 		updates[i].w = SCRW - updates[i].x;
 	}

 	for(i = 0; i < NBOATS; i++) {
 	    /* paint boat on new position */
 	    r.x = boatx[i];
 	    r.y = boaty[i];
 	    if(SDL_BlitSurface(boat[(boatdir[i] + 1) / 2], NULL,
 			       screen, &r) < 0)
 		sdlerr("blitting boat");
 	}

 	/* cycle wave palette */
 	for(i = 0; i < 64; i++)
 	    cmap[boatcols + ((i + frames) & 63)] = wavemap[i];

 	if(fade_dir) {
 	    /* Fade the entire palette in/out */
 	    fade_level += fade_dir;

 	    if(gamma_fade) {
 		/* Fade linearly in gamma level (lousy) */
 		float level = (float)fade_level / fade_max;
 		if(SDL_SetGamma(level, level, level) < 0)
 		    sdlerr("setting gamma");

 	    } else if(gamma_ramp) {
 		/* Fade using gamma ramp (better) */
 		Uint16 ramp[256];
 		for(i = 0; i < 256; i++)
 		    ramp[i] = (i * fade_level / fade_max) << 8;
 		if(SDL_SetGammaRamp(ramp, ramp, ramp) < 0)
 		    sdlerr("setting gamma ramp");

 	    } else {
 		/* Fade using direct palette manipulation (best) */
 		memcpy(cmap, screen->format->palette->colors,
 		       boatcols * sizeof(SDL_Color));
 		for(i = 0; i < boatcols + 64; i++) {
 		    cmap[i].r = cmap[i].r * fade_level / fade_max;
 		    cmap[i].g = cmap[i].g * fade_level / fade_max;
 		    cmap[i].b = cmap[i].b * fade_level / fade_max;
 		}
 	    }
 	    if(fade_level == fade_max)
 		fade_dir = 0;
 	}

 	/* pulse the red colour (done after the fade, for a night effect) */
 	redphase = frames % 64;
 	cmap[red].r = (int)(255 * sin(redphase * M_PI / 63));

 	SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, boatcols + 64);

 	/* update changed areas of the screen */
 	SDL_UpdateRects(screen, NBOATS, updates);
 	frames++;
     } while(fade_level > 0);

     printf("%d frames, %.2f fps\n",
 	   frames, 1000.0 * frames / (SDL_GetTicks() - start));

     if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor (SDL_TRUE);
     SDL_Quit();
     return 0;
 }
	/*
	* testpalette.c
	*
	* A simple test of runtime palette modification for animation
	* (using the SDL_SetPalette() API).
	*/

	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <math.h>

	/* This isn't in the Windows headers */
	#ifndef M_PI
	#define M_PI 3.14159265358979323846
	#endif

	#include "SDL.h"

	/* screen size */
	#define SCRW 640
	#define SCRH 480

	#define NBOATS 5
	#define SPEED 2

	#ifndef MIN
	#define MIN(a, b) ((a) < (b) ? (a) : (b))
	#endif
	#ifndef MAX
	#define MAX(a, b) ((a) > (b) ? (a) : (b))
	#endif

	/*
	* wave colours: Made by taking a narrow cross-section of a wave picture
	* in Gimp, saving in PPM ascii format and formatting with Emacs macros.
	*/
	static SDL_Color wavemap[] = {
	{0,2,103}, {0,7,110}, {0,13,117}, {0,19,125},
	{0,25,133}, {0,31,141}, {0,37,150}, {0,43,158},
	{0,49,166}, {0,55,174}, {0,61,182}, {0,67,190},
	{0,73,198}, {0,79,206}, {0,86,214}, {0,96,220},
	{5,105,224}, {12,112,226}, {19,120,227}, {26,128,229},
	{33,135,230}, {40,143,232}, {47,150,234}, {54,158,236},
	{61,165,238}, {68,173,239}, {75,180,241}, {82,188,242},
	{89,195,244}, {96,203,246}, {103,210,248}, {112,218,250},
	{124,224,250}, {135,226,251}, {146,229,251}, {156,231,252},
	{167,233,252}, {178,236,252}, {189,238,252}, {200,240,252},
	{211,242,252}, {222,244,252}, {233,247,252}, {242,249,252},
	{237,250,252}, {209,251,252}, {174,251,252}, {138,252,252},
	{102,251,252}, {63,250,252}, {24,243,252}, {7,225,252},
	{4,203,252}, {3,181,252}, {2,158,252}, {1,136,251},
	{0,111,248}, {0,82,234}, {0,63,213}, {0,50,192},
	{0,39,172}, {0,28,152}, {0,17,132}, {0,7,114}
	};

	/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
	static void quit(int rc)
	{
	SDL_Quit();
	exit(rc);
	}

	static void sdlerr(char *when)
	{
	fprintf(stderr, "SDL error: %s: %s\n", when, SDL_GetError());
	quit(1);
	}

	/* create a background surface */
	static SDL_Surface make_bg(SDL_Surface screen, int startcol)
	{
	int i;
	SDL_Surface *bg = SDL_CreateRGBSurface(SDL_SWSURFACE, screen->w, screen->h,
	8, 0, 0, 0, 0);
	if(!bg)
	sdlerr("creating background surface");

	/* set the palette to the logical screen palette so that blits
	won't be translated */
	SDL_SetColors(bg, screen->format->palette->colors, 0, 256);

	/* Make a wavy background pattern using colours 0-63 */
	if(SDL_LockSurface(bg) < 0)
	sdlerr("locking background");
	for(i = 0; i < SCRH; i++) {
	Uint8 p = (Uint8 )bg->pixels + i * bg->pitch;
	int j, d;
	d = 0;
	for(j = 0; j < SCRW; j++) {
	int v = MAX(d, -2);
	v = MIN(v, 2);
	if(i > 0)
	v += p[-bg->pitch] + 65 - startcol;
	p[j] = startcol + (v & 63);
	d += ((rand() >> 3) % 3) - 1;
	}
	}
	SDL_UnlockSurface(bg);
	return(bg);
	}

	/*
	* Return a surface flipped horisontally. Only works for 8bpp;
	* extension to arbitrary bitness is left as an exercise for the reader.
	*/
	static SDL_Surface hflip(SDL_Surface s)
	{
	int i;
	SDL_Surface *z = SDL_CreateRGBSurface(SDL_SWSURFACE, s->w, s->h, 8,
	0, 0, 0, 0);
	/* copy palette */
	SDL_SetColors(z, s->format->palette->colors,
	0, s->format->palette->ncolors);
	if(SDL_LockSurface(s) < 0 \|\| SDL_LockSurface(z) < 0)
	sdlerr("locking flip images");

	for(i = 0; i < s->h; i++) {
	int j;
	Uint8 from = (Uint8 )s->pixels + i * s->pitch;
	Uint8 to = (Uint8 )z->pixels + i * z->pitch + s->w - 1;
	for(j = 0; j < s->w; j++)
	to[-j] = from[j];
	}

	SDL_UnlockSurface(z);
	SDL_UnlockSurface(s);
	return z;
	}

	int main(int argc, char **argv)
	{
	SDL_Color cmap[256];
	SDL_Surface *screen;
	SDL_Surface *bg;
	SDL_Surface *boat[2];
	unsigned vidflags = 0;
	unsigned start;
	int fade_max = 400;
	int fade_level, fade_dir;
	int boatcols, frames, i, red;
	int boatx[NBOATS], boaty[NBOATS], boatdir[NBOATS];
	int gamma_fade = 0;
	int gamma_ramp = 0;

	if(SDL_Init(SDL_INIT_VIDEO) < 0)
	sdlerr("initialising SDL");

	while(--argc) {
	++argv;
	if(strcmp(*argv, "-hw") == 0)
	vidflags \|= SDL_HWSURFACE;
	else if(strcmp(*argv, "-fullscreen") == 0)
	vidflags \|= SDL_FULLSCREEN;
	else if(strcmp(*argv, "-nofade") == 0)
	fade_max = 1;
	else if(strcmp(*argv, "-gamma") == 0)
	gamma_fade = 1;
	else if(strcmp(*argv, "-gammaramp") == 0)
	gamma_ramp = 1;
	else {
	fprintf(stderr,
	"usage: testpalette "
	" [-hw] [-fullscreen] [-nofade] [-gamma] [-gammaramp]\n");
	quit(1);
	}
	}

	/* Ask explicitly for 8bpp and a hardware palette */
	if((screen = SDL_SetVideoMode(SCRW, SCRH, 8, vidflags \| SDL_HWPALETTE)) == NULL) {
	fprintf(stderr, "error setting %dx%d 8bpp indexed mode: %s\n",
	SCRW, SCRH, SDL_GetError());
	quit(1);
	}

	if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor (SDL_FALSE);

	if((boat[0] = SDL_LoadBMP("sail.bmp")) == NULL)
	sdlerr("loading sail.bmp");
	/* We've chosen magenta (#ff00ff) as colour key for the boat */
	SDL_SetColorKey(boat[0], SDL_SRCCOLORKEY \| SDL_RLEACCEL,
	SDL_MapRGB(boat[0]->format, 0xff, 0x00, 0xff));
	boatcols = boat[0]->format->palette->ncolors;
	boat[1] = hflip(boat[0]);
	SDL_SetColorKey(boat[1], SDL_SRCCOLORKEY \| SDL_RLEACCEL,
	SDL_MapRGB(boat[1]->format, 0xff, 0x00, 0xff));

	/*
	* First set the physical screen palette to black, so the user won't
	* see our initial drawing on the screen.
	*/
	memset(cmap, 0, sizeof(cmap));
	SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, 256);

	/*
	* Proper palette management is important when playing games with the
	* colormap. We have divided the palette as follows:
	*
	* index 0..(boatcols-1): used for the boat
	* index boatcols..(boatcols+63): used for the waves
	*/
	SDL_SetPalette(screen, SDL_LOGPAL,
	boat[0]->format->palette->colors, 0, boatcols);
	SDL_SetPalette(screen, SDL_LOGPAL, wavemap, boatcols, 64);

	/*
	* Now the logical screen palette is set, and will remain unchanged.
	* The boats already have the same palette so fast blits can be used.
	*/
	memcpy(cmap, screen->format->palette->colors, 256 * sizeof(SDL_Color));

	/* save the index of the red colour for later */
	red = SDL_MapRGB(screen->format, 0xff, 0x00, 0x00);

	bg = make_bg(screen, boatcols); /* make a nice wavy background surface */

	/* initial screen contents */
	if(SDL_BlitSurface(bg, NULL, screen, NULL) < 0)
	sdlerr("blitting background to screen");
	SDL_Flip(screen); /* actually put the background on screen */

	/* determine initial boat placements */
	for(i = 0; i < NBOATS; i++) {
	boatx[i] = (rand() % (SCRW + boat[0]->w)) - boat[0]->w;
	boaty[i] = i * (SCRH - boat[0]->h) / (NBOATS - 1);
	boatdir[i] = ((rand() >> 5) & 1) * 2 - 1;
	}

	start = SDL_GetTicks();
	frames = 0;
	fade_dir = 1;
	fade_level = 0;
	do {
	SDL_Event e;
	SDL_Rect updates[NBOATS];
	SDL_Rect r;
	int redphase;

	/* A small event loop: just exit on any key or mouse button event */
	while(SDL_PollEvent(&e)) {
	if(e.type == SDL_KEYDOWN \|\| e.type == SDL_QUIT
	\|\| e.type == SDL_MOUSEBUTTONDOWN) {
	if(fade_dir < 0)
	fade_level = 0;
	fade_dir = -1;
	}
	}

	/* move boats */
	for(i = 0; i < NBOATS; i++) {
	int old_x = boatx[i];
	/* update boat position */
	boatx[i] += boatdir[i] * SPEED;
	if(boatx[i] <= -boat[0]->w \|\| boatx[i] >= SCRW)
	boatdir[i] = -boatdir[i];

	/* paint over the old boat position */
	r.x = old_x;
	r.y = boaty[i];
	r.w = boat[0]->w;
	r.h = boat[0]->h;
	if(SDL_BlitSurface(bg, &r, screen, &r) < 0)
	sdlerr("blitting background");

	/* construct update rectangle (bounding box of old and new pos) */
	updates[i].x = MIN(old_x, boatx[i]);
	updates[i].y = boaty[i];
	updates[i].w = boat[0]->w + SPEED;
	updates[i].h = boat[0]->h;
	/* clip update rectangle to screen */
	if(updates[i].x < 0) {
	updates[i].w += updates[i].x;
	updates[i].x = 0;
	}
	if(updates[i].x + updates[i].w > SCRW)
	updates[i].w = SCRW - updates[i].x;
	}

	for(i = 0; i < NBOATS; i++) {
	/* paint boat on new position */
	r.x = boatx[i];
	r.y = boaty[i];
	if(SDL_BlitSurface(boat[(boatdir[i] + 1) / 2], NULL,
	screen, &r) < 0)
	sdlerr("blitting boat");
	}

	/* cycle wave palette */
	for(i = 0; i < 64; i++)
	cmap[boatcols + ((i + frames) & 63)] = wavemap[i];

	if(fade_dir) {
	/* Fade the entire palette in/out */
	fade_level += fade_dir;

	if(gamma_fade) {
	/* Fade linearly in gamma level (lousy) */
	float level = (float)fade_level / fade_max;
	if(SDL_SetGamma(level, level, level) < 0)
	sdlerr("setting gamma");

	} else if(gamma_ramp) {
	/* Fade using gamma ramp (better) */
	Uint16 ramp[256];
	for(i = 0; i < 256; i++)
	ramp[i] = (i * fade_level / fade_max) << 8;
	if(SDL_SetGammaRamp(ramp, ramp, ramp) < 0)
	sdlerr("setting gamma ramp");

	} else {
	/* Fade using direct palette manipulation (best) */
	memcpy(cmap, screen->format->palette->colors,
	boatcols * sizeof(SDL_Color));
	for(i = 0; i < boatcols + 64; i++) {
	cmap[i].r = cmap[i].r * fade_level / fade_max;
	cmap[i].g = cmap[i].g * fade_level / fade_max;
	cmap[i].b = cmap[i].b * fade_level / fade_max;
	}
	}
	if(fade_level == fade_max)
	fade_dir = 0;
	}

	/* pulse the red colour (done after the fade, for a night effect) */
	redphase = frames % 64;
	cmap[red].r = (int)(255 * sin(redphase * M_PI / 63));

	SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, boatcols + 64);

	/* update changed areas of the screen */
	SDL_UpdateRects(screen, NBOATS, updates);
	frames++;
	} while(fade_level > 0);

	printf("%d frames, %.2f fps\n",
	frames, 1000.0 * frames / (SDL_GetTicks() - start));

	if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor (SDL_TRUE);
	SDL_Quit();
	return 0;
	}