view test/testwin.c @ 968:4675910b0b7b

Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST) From: Hannu Savolainen Subject: Re: SDL uses obsolete OSS features I did some work on getting OSS to work better with SDL. There have been some problems with select which should be fixed now. I'm having some problems in understanding what is the purpose of the DSP_WaitAudio() routine. I added a return to the very beginning of this routine and commendted out the define for USE_BLOCKING_WRITES. At least lbreakout2 seems to work as well as earlier. The latencies are the same. An ordinary blocking write does exactly the same thing than DSP_WaitAudio does. So I would recommend using the USE_BLOCKING_WRITES approach and removing everything from the DSP_WaitAudio routine. Also enabling USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because you don't need to handle the partial writes (the do-while loop). Attached is a patch against SDL-1.2.7. After these changes SDL will use OSS as it's designed to be used (make it as simple as possible). This code should work with all OSS implementations because it uses only the very fundamental features that have been there since the jurassic times.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 12 Nov 2004 21:39:04 +0000
parents 153f221b7d48
children be9c9c8f6d53
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"

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;
	w = 640;
	h = 480;
	desired_bpp = 0;
	video_flags = 0;
	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");
				exit(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");
				exit(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");
				exit(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");
				exit(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;
	}

	if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
		fprintf(stderr,
			"Couldn't initialize SDL: %s\n", SDL_GetError());
		exit(1);
	}
	atexit(SDL_Quit);			/* Clean up on exit */

	/* 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());
		exit(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);
	return(0);
}