royale.zerezo.com Git - zeRace/blob - sdl.c

   1 #include "sdl.h"
   2
   3 SDL_Surface *font=NULL;
   4
   5 void print(SDL_Surface *dst,int x,int y,unsigned char *text)
   6 {
   7   SDL_Rect srcpos,dstpos;
   8   if (!font) if ((font=IMG_Load("sprites/font.png"))==NULL)
   9   {
  10                 fprintf(stderr,"could not load font file\n",SDL_GetError());
  11   }
  12   while (*text!='\0')
  13   {
  14     if (*text>=' ' && *text<' '+16*10)
  15     srcpos.x=(*text-' ')%16*10;
  16     srcpos.y=(*text-' ')/16*19;
  17     srcpos.w=10;
  18     srcpos.h=19;
  19     dstpos.x=x;
  20     dstpos.y=y;
  21     SDL_BlitSurface(font,&srcpos,dst,&dstpos);
  22     x+=10;
  23     text++;
  24   }
  25 }
  26
  27 /*
  28  * Return the pixel value at (x, y)
  29  * NOTE: The surface must be locked before calling this!
  30  */
  31 Uint32 getpixel(SDL_Surface *surface, int x, int y)
  32 {
  33     int bpp = surface->format->BytesPerPixel;
  34     /* Here p is the address to the pixel we want to retrieve */
  35     Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;
  36
  37     switch(bpp) {
  38     case 1:
  39         return *p;
  40
  41     case 2:
  42         return *(Uint16 *)p;
  43
  44     case 3:
  45         if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
  46             return p[0] << 16 | p[1] << 8 | p[2];
  47         else
  48             return p[0] | p[1] << 8 | p[2] << 16;
  49
  50     case 4:
  51         return *(Uint32 *)p;
  52
  53     default:
  54         return 0;       /* shouldn't happen, but avoids warnings */
  55     }
  56 }
  57
  58 /*
  59  * Set the pixel at (x, y) to the given value
  60  * NOTE: The surface must be locked before calling this!
  61  */
  62 void putpixel(SDL_Surface *surface, int x, int y, Uint32 pixel)
  63 {
  64     int bpp = surface->format->BytesPerPixel;
  65     /* Here p is the address to the pixel we want to set */
  66     Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;
  67
  68     switch(bpp) {
  69     case 1:
  70         *p = pixel;
  71         break;
  72
  73     case 2:
  74         *(Uint16 *)p = pixel;
  75         break;
  76
  77     case 3:
  78         if(SDL_BYTEORDER == SDL_BIG_ENDIAN) {
  79             p[0] = (pixel >> 16) & 0xff;
  80             p[1] = (pixel >> 8) & 0xff;
  81             p[2] = pixel & 0xff;
  82         } else {
  83             p[0] = pixel & 0xff;
  84             p[1] = (pixel >> 8) & 0xff;
  85             p[2] = (pixel >> 16) & 0xff;
  86         }
  87         break;
  88
  89     case 4:
  90         *(Uint32 *)p = pixel;
  91         break;
  92     }
  93 }
  94
  95 /* Set pixel function */
  96 void setpixel(SDL_Surface *screen, int x, int y, Uint8 r, Uint8 g, Uint8 b)
  97 {
  98         Uint8 *ubuff8;
  99         Uint16 *ubuff16;
 100         Uint32 *ubuff32;
 101         Uint32 color;
 102
 103         /* Lock the screen, if needed */
 104         if(SDL_MUSTLOCK(screen)) {
 105                 if(SDL_LockSurface(screen) < 0)
 106                         return;
 107         }
 108
 109         /* Get the color */
 110         color = SDL_MapRGB( screen->format, r, g, b );
 111
 112         /* How we draw the pixel depends on the bitdepth */
 113         switch(screen->format->BytesPerPixel) {
 114                 case 1:
 115                         ubuff8 = (Uint8*) screen->pixels;
 116                         ubuff8 += (y * screen->pitch) + x;
 117                         *ubuff8 = (Uint8) color;
 118                         break;
 119                 case 2:
 120                         ubuff16 = (Uint16*) screen->pixels;
 121                         ubuff16 += ((y * screen->pitch)>>2) + x;
 122                         *ubuff16 = (Uint16) color;
 123                         break;
 124                 case 3:
 125                         ubuff8 = (Uint8*) screen->pixels;
 126                         ubuff8 += (y * screen->pitch) + x;
 127
 128                         r = (color>>screen->format->Rshift)&0xFF;
 129                         g = (color>>screen->format->Gshift)&0xFF;
 130                         b = (color>>screen->format->Bshift)&0xFF;
 131
 132                         ubuff8[0] = r;
 133                         ubuff8[1] = g;
 134                         ubuff8[2] = b;
 135                         break;
 136
 137                 case 4:
 138                         ubuff32 = (Uint32*) screen->pixels;
 139                         ubuff32 += ((y*screen->pitch)>>2) + x;
 140                         *ubuff32 = color;
 141                         break;
 142
 143                 default:
 144                         fprintf(stderr, "Error: Unknown bitdepth!\n");
 145         }
 146
 147         /* Unlock the screen if needed */
 148         if(SDL_MUSTLOCK(screen)) {
 149                 SDL_UnlockSurface(screen);
 150         }
 151 }