| 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(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("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 | } |