test/testsprite.c
author Ryan C. Gordon <icculus@icculus.org>
Fri, 13 Jan 2006 02:32:07 +0000
changeset 1246 ca51a76a7328
parent 1214 31103dbf1c26
child 1516 4d241ea8a1cd
permissions -rw-r--r--
Make error message meaningful if dlopen() fails on libX11.
     1 /* Simple program:  Move N sprites around on the screen as fast as possible */
     2 
     3 #include <stdio.h>
     4 #include <stdlib.h>
     5 #include <string.h>
     6 #include <ctype.h>
     7 #include <math.h>
     8 #include <time.h>
     9 
    10 #include "SDL.h"
    11 
    12 #define NUM_SPRITES	100
    13 #define MAX_SPEED 	1
    14 
    15 SDL_Surface *sprite;
    16 int numsprites;
    17 SDL_Rect *sprite_rects;
    18 SDL_Rect *positions;
    19 SDL_Rect *velocities;
    20 int sprites_visible;
    21 int debug_flip;
    22 Uint16 sprite_w, sprite_h;
    23 
    24 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
    25 static void quit(int rc)
    26 {
    27 	SDL_Quit();
    28 	exit(rc);
    29 }
    30 
    31 int LoadSprite(SDL_Surface *screen, char *file)
    32 {
    33 	SDL_Surface *temp;
    34 
    35 	/* Load the sprite image */
    36 	sprite = SDL_LoadBMP(file);
    37 	if ( sprite == NULL ) {
    38 		fprintf(stderr, "Couldn't load %s: %s", file, SDL_GetError());
    39 		return(-1);
    40 	}
    41 
    42 	/* Set transparent pixel as the pixel at (0,0) */
    43 	if ( sprite->format->palette ) {
    44 		SDL_SetColorKey(sprite, (SDL_SRCCOLORKEY|SDL_RLEACCEL),
    45 						*(Uint8 *)sprite->pixels);
    46 	}
    47 
    48 	/* Convert sprite to video format */
    49 	temp = SDL_DisplayFormat(sprite);
    50 	SDL_FreeSurface(sprite);
    51 	if ( temp == NULL ) {
    52 		fprintf(stderr, "Couldn't convert background: %s\n",
    53 							SDL_GetError());
    54 		return(-1);
    55 	}
    56 	sprite = temp;
    57 
    58 	/* We're ready to roll. :) */
    59 	return(0);
    60 }
    61 
    62 void MoveSprites(SDL_Surface *screen, Uint32 background)
    63 {
    64 	int i, nupdates;
    65 	SDL_Rect area, *position, *velocity;
    66 
    67 	nupdates = 0;
    68 	/* Erase all the sprites if necessary */
    69 	if ( sprites_visible ) {
    70 		SDL_FillRect(screen, NULL, background);
    71 	}
    72 
    73 	/* Move the sprite, bounce at the wall, and draw */
    74 	for ( i=0; i<numsprites; ++i ) {
    75 		position = &positions[i];
    76 		velocity = &velocities[i];
    77 		position->x += velocity->x;
    78 		if ( (position->x < 0) || (position->x >= (screen->w - sprite_w)) ) {
    79 			velocity->x = -velocity->x;
    80 			position->x += velocity->x;
    81 		}
    82 		position->y += velocity->y;
    83 		if ( (position->y < 0) || (position->y >= (screen->h - sprite_w)) ) {
    84 			velocity->y = -velocity->y;
    85 			position->y += velocity->y;
    86 		}
    87 
    88 		/* Blit the sprite onto the screen */
    89 		area = *position;
    90 		SDL_BlitSurface(sprite, NULL, screen, &area);
    91 		sprite_rects[nupdates++] = area;
    92 	}
    93 
    94 	if (debug_flip) {
    95 		if ( (screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF ) {
    96 			static int t = 0;
    97 
    98 			Uint32 color = SDL_MapRGB (screen->format, 255, 0, 0);
    99 			SDL_Rect r;
   100 			r.x = (sin((float)t * 2 * 3.1459) + 1.0) / 2.0 * (screen->w-20);
   101 			r.y = 0;
   102 			r.w = 20;
   103 			r.h = screen->h;
   104 
   105 			SDL_FillRect (screen, &r, color);
   106 			t+=2;
   107 		}
   108 	}
   109 
   110 	/* Update the screen! */
   111 	if ( (screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF ) {
   112 		SDL_Flip(screen);
   113 	} else {
   114 		SDL_UpdateRects(screen, nupdates, sprite_rects);
   115 	}
   116 	sprites_visible = 1;
   117 }
   118 
   119 /* This is a way of telling whether or not to use hardware surfaces */
   120 Uint32 FastestFlags(Uint32 flags, int width, int height, int bpp)
   121 {
   122 	const SDL_VideoInfo *info;
   123 
   124 	/* Hardware acceleration is only used in fullscreen mode */
   125 	flags |= SDL_FULLSCREEN;
   126 
   127 	/* Check for various video capabilities */
   128 	info = SDL_GetVideoInfo();
   129 	if ( info->blit_hw_CC && info->blit_fill ) {
   130 		/* We use accelerated colorkeying and color filling */
   131 		flags |= SDL_HWSURFACE;
   132 	}
   133 	/* If we have enough video memory, and will use accelerated
   134 	   blits directly to it, then use page flipping.
   135 	 */
   136 	if ( (flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
   137 		/* Direct hardware blitting without double-buffering
   138 		   causes really bad flickering.
   139 		 */
   140 		if ( info->video_mem*1024 > (height*width*bpp/8) ) {
   141 			flags |= SDL_DOUBLEBUF;
   142 		} else {
   143 			flags &= ~SDL_HWSURFACE;
   144 		}
   145 	}
   146 
   147 	/* Return the flags */
   148 	return(flags);
   149 }
   150 
   151 int main(int argc, char *argv[])
   152 {
   153 	SDL_Surface *screen;
   154 	Uint8 *mem;
   155 	int width, height;
   156 	Uint8  video_bpp;
   157 	Uint32 videoflags;
   158 	Uint32 background;
   159 	int    i, done;
   160 	SDL_Event event;
   161 	Uint32 then, now, frames;
   162 
   163 	/* Initialize SDL */
   164 	if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
   165 		fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
   166 		return(1);
   167 	}
   168 
   169 	numsprites = NUM_SPRITES;
   170 	videoflags = SDL_SWSURFACE|SDL_ANYFORMAT;
   171 	width = 640;
   172 	height = 480;
   173 	video_bpp = 8;
   174 	debug_flip = 0;
   175 	while ( argc > 1 ) {
   176 		--argc;
   177 		if ( strcmp(argv[argc-1], "-width") == 0 ) {
   178 			width = atoi(argv[argc]);
   179 			--argc;
   180 		} else
   181 		if ( strcmp(argv[argc-1], "-height") == 0 ) {
   182 			height = atoi(argv[argc]);
   183 			--argc;
   184 		} else
   185 		if ( strcmp(argv[argc-1], "-bpp") == 0 ) {
   186 			video_bpp = atoi(argv[argc]);
   187 			videoflags &= ~SDL_ANYFORMAT;
   188 			--argc;
   189 		} else
   190 		if ( strcmp(argv[argc], "-fast") == 0 ) {
   191 			videoflags = FastestFlags(videoflags, width, height, video_bpp);
   192 		} else
   193 		if ( strcmp(argv[argc], "-hw") == 0 ) {
   194 			videoflags ^= SDL_HWSURFACE;
   195 		} else
   196 		if ( strcmp(argv[argc], "-flip") == 0 ) {
   197 			videoflags ^= SDL_DOUBLEBUF;
   198 		} else
   199 		if ( strcmp(argv[argc], "-debugflip") == 0 ) {
   200 			debug_flip ^= 1;
   201 		} else
   202 		if ( strcmp(argv[argc], "-fullscreen") == 0 ) {
   203 			videoflags ^= SDL_FULLSCREEN;
   204 		} else
   205 		if ( isdigit(argv[argc][0]) ) {
   206 			numsprites = atoi(argv[argc]);
   207 		} else {
   208 			fprintf(stderr, 
   209 	"Usage: %s [-bpp N] [-hw] [-flip] [-fast] [-fullscreen] [numsprites]\n",
   210 								argv[0]);
   211 			quit(1);
   212 		}
   213 	}
   214 
   215 	/* Set video mode */
   216 	screen = SDL_SetVideoMode(width, height, video_bpp, videoflags);
   217 	if ( ! screen ) {
   218 		fprintf(stderr, "Couldn't set %dx%d video mode: %s\n",
   219 					width, height, SDL_GetError());
   220 		quit(2);
   221 	}
   222 
   223 	/* Load the sprite */
   224 	if ( LoadSprite(screen, "icon.bmp") < 0 ) {
   225 		quit(1);
   226 	}
   227 
   228 	/* Allocate memory for the sprite info */
   229 	mem = (Uint8 *)malloc(4*sizeof(SDL_Rect)*numsprites);
   230 	if ( mem == NULL ) {
   231 		SDL_FreeSurface(sprite);
   232 		fprintf(stderr, "Out of memory!\n");
   233 		quit(2);
   234 	}
   235 	sprite_rects = (SDL_Rect *)mem;
   236 	positions = sprite_rects;
   237 	sprite_rects += numsprites;
   238 	velocities = sprite_rects;
   239 	sprite_rects += numsprites;
   240 	sprite_w = sprite->w;
   241 	sprite_h = sprite->h;
   242 	srand(time(NULL));
   243 	for ( i=0; i<numsprites; ++i ) {
   244 		positions[i].x = rand()%(screen->w - sprite_w);
   245 		positions[i].y = rand()%(screen->h - sprite_h);
   246 		positions[i].w = sprite->w;
   247 		positions[i].h = sprite->h;
   248 		velocities[i].x = 0;
   249 		velocities[i].y = 0;
   250 		while ( ! velocities[i].x && ! velocities[i].y ) {
   251 			velocities[i].x = (rand()%(MAX_SPEED*2+1))-MAX_SPEED;
   252 			velocities[i].y = (rand()%(MAX_SPEED*2+1))-MAX_SPEED;
   253 		}
   254 	}
   255 	background = SDL_MapRGB(screen->format, 0x00, 0x00, 0x00);
   256 
   257 	/* Print out information about our surfaces */
   258 	printf("Screen is at %d bits per pixel\n",screen->format->BitsPerPixel);
   259 	if ( (screen->flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
   260 		printf("Screen is in video memory\n");
   261 	} else {
   262 		printf("Screen is in system memory\n");
   263 	}
   264 	if ( (screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF ) {
   265 		printf("Screen has double-buffering enabled\n");
   266 	}
   267 	if ( (sprite->flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
   268 		printf("Sprite is in video memory\n");
   269 	} else {
   270 		printf("Sprite is in system memory\n");
   271 	}
   272 	/* Run a sample blit to trigger blit acceleration */
   273 	{ SDL_Rect dst;
   274 		dst.x = 0;
   275 		dst.y = 0;
   276 		dst.w = sprite->w;
   277 		dst.h = sprite->h;
   278 		SDL_BlitSurface(sprite, NULL, screen, &dst);
   279 		SDL_FillRect(screen, &dst, background);
   280 	}
   281 	if ( (sprite->flags & SDL_HWACCEL) == SDL_HWACCEL ) {
   282 		printf("Sprite blit uses hardware acceleration\n");
   283 	}
   284 	if ( (sprite->flags & SDL_RLEACCEL) == SDL_RLEACCEL ) {
   285 		printf("Sprite blit uses RLE acceleration\n");
   286 	}
   287 
   288 	/* Loop, blitting sprites and waiting for a keystroke */
   289 	frames = 0;
   290 	then = SDL_GetTicks();
   291 	done = 0;
   292 	sprites_visible = 0;
   293 	while ( !done ) {
   294 		/* Check for events */
   295 		++frames;
   296 		while ( SDL_PollEvent(&event) ) {
   297 			switch (event.type) {
   298 				case SDL_MOUSEBUTTONDOWN:
   299 					SDL_WarpMouse(screen->w/2, screen->h/2);
   300 					break;
   301 				case SDL_KEYDOWN:
   302 					/* Any keypress quits the app... */
   303 				case SDL_QUIT:
   304 					done = 1;
   305 					break;
   306 				default:
   307 					break;
   308 			}
   309 		}
   310 		MoveSprites(screen, background);
   311 	}
   312 	SDL_FreeSurface(sprite);
   313 	free(mem);
   314 
   315 	/* Print out some timing information */
   316 	now = SDL_GetTicks();
   317 	if ( now > then ) {
   318 		printf("%2.2f frames per second\n",
   319 					((double)frames*1000)/(now-then));
   320 	}
   321 	SDL_Quit();
   322 	return(0);
   323 }