src/debris.c

   1 /*
   2  * See Licensing and Copyright notice in naev.h
   3  */
   4
   5 /**
   6  * @file debris.c
   7  *
   8  * @brief Handles scattering debris around.
   9  */
  10
  11
  12 #include "debris.h"
  13
  14 #include "naev.h"
  15
  16 #include "log.h"
  17 #include "pilot.h"
  18 #include "spfx.h"
  19 #include "rng.h"
  20
  21
  22 static int *debris_spfx = NULL; /**< Debris special effects. */
  23 static int debris_nspfx = 0; /**< Number of debris special effects. */
  24
  25
  26 /**
  27  * @brief Cleans up after the debris.
  28  */
  29 void debris_cleanup (void)
  30 {
  31    free(debris_spfx);
  32    debris_spfx = NULL;
  33 }
  34
  35
  36 /**
  37  * @brief Loads the debris spfx into an array.
  38  */
  39 static int debris_load (void)
  40 {
  41    int i;
  42    char buf[32];
  43
  44    /* Calculate amount. */
  45    i = 0;
  46    do {
  47       snprintf( buf, 32, "Dbr%d", i );
  48       i++;
  49    } while (spfx_get(buf) != -1);
  50    debris_nspfx = i-1;
  51
  52    /* Check to make sure they exist. */
  53    if (debris_nspfx <= 0) {
  54       WARN("No debris special effects found.");
  55       return -1;
  56    }
  57
  58    /* Allocate. */
  59    debris_spfx = malloc( sizeof(int) * debris_nspfx );
  60
  61    /* Second pass to fill. */
  62    for (i=0; i<debris_nspfx; i++) {
  63       snprintf( buf, 32, "Dbr%d", i );
  64       debris_spfx[i] = spfx_get(buf);
  65    }
  66
  67    return 0;
  68 }
  69
  70
  71 /**
  72  * @brief Creates a cloud of debris.
  73  *
  74  *    @param mass Mass of the debris cloud.
  75  *    @param x X position to center cloud.
  76  *    @param y Y position to center cloud.
  77  */
  78 void debris_add( double mass, double r, double px, double py,
  79       double vx, double vy )
  80 {
  81    int i, n;
  82    double npx,npy, nvx,nvy;
  83    double a, d;
  84
  85    /* Lazy allocator. */
  86    if (debris_spfx == NULL)
  87       if (debris_load() < 0)
  88          return;
  89
  90    /* Get number of debris to render. */
  91    n = (int) ceil( sqrt(mass) / 1.5 );
  92
  93    /* Now add the spfx. */
  94    for (i=0; i<n; i++) {
  95       /* Get position. */
  96       d = r/2. * RNG_2SIGMA();
  97       a = RNGF()*2*M_PI;
  98       npx = px + d*cos(a);
  99       npy = py + d*sin(a);
 100
 101       /* Get velocity. */
 102       d = n * RNG_2SIGMA();
 103       a = RNGF()*2*M_PI;
 104       nvx = vx + d*cos(a);
 105       nvy = vy + d*sin(a);
 106
 107       /* Createsprite. */
 108       spfx_add( debris_spfx[ RNG( 0, debris_nspfx-1 ) ],
 109             npx, npy, nvx, nvy, RNG(0,1) );
 110    }
 111 }
 112