view test/testwin.c @ 1257:448a9a64537b

[PATCH] SDL_GetVideoMode() does not find best mode, part 2 Following commit 1.51, I come accross a problem when SDL must choose between several video modes that could suit the one asked. If I ask 320x240 with this list: 768x480 768x240 640x400 640x200 384x480 384x240 320x400 320x200 The smallest selectables modes are 384x240 and 320x400. And SDL choose the later in this list, but 384x240 is more suitable. So I added a check to compare the pixel count (surface) of modes, and select the one which has the smallest pixel count. In my example, 384x240 has 92160 pixels, and 320x400 has 128000 pixels. So now SDL will choose 384x240 for the asked 320x240 mode.
author Patrice Mandin <patmandin@gmail.com>
date Thu, 19 Jan 2006 21:28:52 +0000
parents 51a8702d8ecd
children 14717b52abc0
line wrap: on
line source


/* Bring up a window and play with it */

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

#define BENCHMARK_SDL

#define NOTICE(X)	printf("%s", X);

#include "SDL.h"

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

void DrawPict(SDL_Surface *screen, char *bmpfile,
					int speedy, int flip, int nofade)
{
	SDL_Surface *picture;
	SDL_Rect dest, update;
	int i, centered;
	int ncolors;
	SDL_Color *colors, *cmap;

	/* Load the image into a surface */
	if ( bmpfile == NULL ) {
		bmpfile = "sample.bmp";		/* Sample image */
	}
fprintf(stderr, "Loading picture: %s\n", bmpfile);
	picture = SDL_LoadBMP(bmpfile);
	if ( picture == NULL ) {
		fprintf(stderr, "Couldn't load %s: %s\n", bmpfile,
							SDL_GetError());
		return;
	}

	/* Set the display colors -- on a hicolor display this is a no-op */
	if ( picture->format->palette ) {
		ncolors = picture->format->palette->ncolors;
		colors  = (SDL_Color *)malloc(ncolors*sizeof(SDL_Color));
		cmap    = (SDL_Color *)malloc(ncolors*sizeof(SDL_Color));
		memcpy(colors, picture->format->palette->colors,
						ncolors*sizeof(SDL_Color));
	} else {
		int       r, g, b;

		/* Allocate 256 color palette */
		ncolors = 256;
		colors  = (SDL_Color *)malloc(ncolors*sizeof(SDL_Color));
		cmap    = (SDL_Color *)malloc(ncolors*sizeof(SDL_Color));

		/* Set a 3,3,2 color cube */
		for ( r=0; r<8; ++r ) {
			for ( g=0; g<8; ++g ) {
				for ( b=0; b<4; ++b ) {
					i = ((r<<5)|(g<<2)|b);
					colors[i].r = r<<5;
					colors[i].g = g<<5;
					colors[i].b = b<<6;
				}
			}
		}
	}
NOTICE("testwin: setting colors\n");
	if ( ! SDL_SetColors(screen, colors, 0, ncolors) &&
				(screen->format->palette != NULL) ) {
		fprintf(stderr,
"Warning: Couldn't set all of the colors, but SDL will map the image\n"
"         (colormap fading will suffer - try the -warp option)\n"
		);
	}

	/* Set the screen to black (not really necessary) */
	if ( SDL_LockSurface(screen) == 0 ) {
		Uint32 black;
		Uint8 *pixels;

		black = SDL_MapRGB(screen->format, 0, 0, 0);
		pixels = (Uint8 *)screen->pixels;
		for ( i=0; i<screen->h; ++i ) {
			memset(pixels, black,
				screen->w*screen->format->BytesPerPixel);
			pixels += screen->pitch;
		}
		SDL_UnlockSurface(screen);
		SDL_UpdateRect(screen, 0, 0, 0, 0);
	}
	
	/* Display the picture */
	if ( speedy ) {
		SDL_Surface *displayfmt;

fprintf(stderr, "Converting picture\n");
		displayfmt = SDL_DisplayFormat(picture);
		if ( displayfmt == NULL ) {
			fprintf(stderr,
				"Couldn't convert image: %s\n", SDL_GetError());
			goto done;
		}
		SDL_FreeSurface(picture);
		picture = displayfmt;
	}
	printf("(image surface located in %s memory)\n", 
			(picture->flags&SDL_HWSURFACE) ? "video" : "system");
	centered = (screen->w - picture->w)/2;
	if ( centered < 0 ) {
		centered = 0;
	}
	dest.y = (screen->h - picture->h)/2;
	dest.w = picture->w;
	dest.h = picture->h;
NOTICE("testwin: moving image\n");
	for ( i=0; i<=centered; ++i ) {
		dest.x = i;
		update = dest;
		if ( SDL_BlitSurface(picture, NULL, screen, &update) < 0 ) {
			fprintf(stderr, "Blit failed: %s\n", SDL_GetError());
			break;
		}
		if ( flip ) {
			SDL_Flip(screen);
		} else {
			SDL_UpdateRects(screen, 1, &update);
		}
	}

#ifdef SCREENSHOT
	if ( SDL_SaveBMP(screen, "screen.bmp") < 0 )
		printf("Couldn't save screen: %s\n", SDL_GetError());
#endif

#ifndef BENCHMARK_SDL
	/* Let it sit there for a while */
	SDL_Delay(5*1000);
#endif
	/* Fade the colormap */
	if ( ! nofade ) {
		int maxstep;
		SDL_Color final;
		SDL_Color palcolors[256];
		struct {
			Sint16 r, g, b;
		} cdist[256];

NOTICE("testwin: fading out...\n");
		memcpy(cmap, colors, ncolors*sizeof(SDL_Color));
		maxstep = 32-1;
		final.r = 0xFF;
		final.g = 0x00;
		final.b = 0x00;
		memcpy(palcolors, colors, ncolors*sizeof(SDL_Color));
		for ( i=0; i<ncolors; ++i ) {
			cdist[i].r = final.r-palcolors[i].r;
			cdist[i].g = final.g-palcolors[i].g;
			cdist[i].b = final.b-palcolors[i].b;
		}
		for ( i=0; i<=maxstep/2; ++i ) {	/* halfway fade */
			int c;
			for ( c=0; c<ncolors; ++c ) {
				colors[c].r =
					palcolors[c].r+((cdist[c].r*i))/maxstep;
				colors[c].g =
					palcolors[c].g+((cdist[c].g*i))/maxstep;
				colors[c].b =
					palcolors[c].b+((cdist[c].b*i))/maxstep;
			}
			SDL_SetColors(screen, colors, 0, ncolors);
			SDL_Delay(1);
		}
		final.r = 0x00;
		final.g = 0x00;
		final.b = 0x00;
		memcpy(palcolors, colors, ncolors*sizeof(SDL_Color));
		for ( i=0; i<ncolors; ++i ) {
			cdist[i].r = final.r-palcolors[i].r;
			cdist[i].g = final.g-palcolors[i].g;
			cdist[i].b = final.b-palcolors[i].b;
		}
		maxstep /= 2;
		for ( i=0; i<=maxstep; ++i ) {		/* finish fade out */
			int c;
			for ( c=0; c<ncolors; ++c ) {
				colors[c].r =
					palcolors[c].r+((cdist[c].r*i))/maxstep;
				colors[c].g =
					palcolors[c].g+((cdist[c].g*i))/maxstep;
				colors[c].b =
					palcolors[c].b+((cdist[c].b*i))/maxstep;
			}
			SDL_SetColors(screen, colors, 0, ncolors);
			SDL_Delay(1);
		}
		for ( i=0; i<ncolors; ++i ) {
			colors[i].r = final.r;
			colors[i].g = final.g;
			colors[i].b = final.b;
		}
		SDL_SetColors(screen, colors, 0, ncolors);
NOTICE("testwin: fading in...\n");
		memcpy(palcolors, colors, ncolors*sizeof(SDL_Color));
		for ( i=0; i<ncolors; ++i ) {
			cdist[i].r = cmap[i].r-palcolors[i].r;
			cdist[i].g = cmap[i].g-palcolors[i].g;
			cdist[i].b = cmap[i].b-palcolors[i].b;
		}
		for ( i=0; i<=maxstep; ++i ) {	/* 32 step fade in */
			int c;
			for ( c=0; c<ncolors; ++c ) {
				colors[c].r =
					palcolors[c].r+((cdist[c].r*i))/maxstep;
				colors[c].g =
					palcolors[c].g+((cdist[c].g*i))/maxstep;
				colors[c].b =
					palcolors[c].b+((cdist[c].b*i))/maxstep;
			}
			SDL_SetColors(screen, colors, 0, ncolors);
			SDL_Delay(1);
		}
NOTICE("testwin: fading over\n");
	}
	
done:
	/* Free the picture and return */
	SDL_FreeSurface(picture);
	free(colors); free(cmap);
	return;
}

int main(int argc, char *argv[])
{
	SDL_Surface *screen;
	/* Options */
	int speedy, flip, nofade;
	int delay;
	int w, h;
	int desired_bpp;
	Uint32 video_flags;
#ifdef BENCHMARK_SDL
	Uint32 then, now;
#endif
	/* Set default options and check command-line */
	speedy = 0;
	flip = 0;
	nofade = 0;
	delay = 1;

#ifdef _WIN32_WCE
	w = 640;
	h = 320;
	desired_bpp = 0;
	video_flags = SDL_FULLSCREEN;
#else
	w = 640;
	h = 480;
	desired_bpp = 0;
	video_flags = 0;
#endif
	if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
		fprintf(stderr,
			"Couldn't initialize SDL: %s\n", SDL_GetError());
		return(1);
	}

	while ( argc > 1 ) {
		if ( strcmp(argv[1], "-speedy") == 0 ) {
			speedy = 1;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-nofade") == 0 ) {
			nofade = 1;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-delay") == 0 ) {
			if ( argv[2] ) {
				delay = atoi(argv[2]);
				argv += 2;
				argc -= 2;
			} else {
				fprintf(stderr,
				"The -delay option requires an argument\n");
				quit(1);
			}
		} else
		if ( strcmp(argv[1], "-width") == 0 ) {
			if ( argv[2] && ((w = atoi(argv[2])) > 0) ) {
				argv += 2;
				argc -= 2;
			} else {
				fprintf(stderr,
				"The -width option requires an argument\n");
				quit(1);
			}
		} else
		if ( strcmp(argv[1], "-height") == 0 ) {
			if ( argv[2] && ((h = atoi(argv[2])) > 0) ) {
				argv += 2;
				argc -= 2;
			} else {
				fprintf(stderr,
				"The -height option requires an argument\n");
				quit(1);
			}
		} else
		if ( strcmp(argv[1], "-bpp") == 0 ) {
			if ( argv[2] ) {
				desired_bpp = atoi(argv[2]);
				argv += 2;
				argc -= 2;
			} else {
				fprintf(stderr,
				"The -bpp option requires an argument\n");
				quit(1);
			}
		} else
		if ( strcmp(argv[1], "-warp") == 0 ) {
			video_flags |= SDL_HWPALETTE;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-hw") == 0 ) {
			video_flags |= SDL_HWSURFACE;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-flip") == 0 ) {
			video_flags |= SDL_DOUBLEBUF;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-fullscreen") == 0 ) {
			video_flags |= SDL_FULLSCREEN;
			argv += 1;
			argc -= 1;
		} else
			break;
	}

	/* Initialize the display */
	screen = SDL_SetVideoMode(w, h, desired_bpp, video_flags);
	if ( screen == NULL ) {
		fprintf(stderr, "Couldn't set %dx%dx%d video mode: %s\n",
					w, h, desired_bpp, SDL_GetError());
		quit(1);
	}
	printf("Set%s %dx%dx%d mode\n",
			screen->flags & SDL_FULLSCREEN ? " fullscreen" : "",
			screen->w, screen->h, screen->format->BitsPerPixel);
	printf("(video surface located in %s memory)\n",
			(screen->flags&SDL_HWSURFACE) ? "video" : "system");
	if ( screen->flags & SDL_DOUBLEBUF ) {
		printf("Double-buffering enabled\n");
		flip = 1;
	}

	/* Set the window manager title bar */
	SDL_WM_SetCaption("SDL test window", "testwin");

	/* Do all the drawing work */
#ifdef BENCHMARK_SDL
	then = SDL_GetTicks();
	DrawPict(screen, argv[1], speedy, flip, nofade);
	now = SDL_GetTicks();
	printf("Time: %d milliseconds\n", now-then);
#else
	DrawPict(screen, argv[1], speedy, flip, nofade);
#endif
	SDL_Delay(delay*1000);
	SDL_Quit();
	return(0);
}