src/client/raycast.c

   1 #include <math.h>
   2 #include "client/client_node.h"
   3 #include "client/client_terrain.h"
   4 #include "client/raycast.h"
   5
   6 bool raycast(v3f64 pos, v3f64 dir, f64 len, v3s32 *node_pos, NodeType *node)
   7 {
   8         f64 dir_len = sqrt(dir.x * dir.x + dir.y * dir.y + dir.z * dir.z);
   9
  10         while (len > 0) {
  11                 *node = terrain_get_node(client_terrain,
  12                         *node_pos = (v3s32) {floor(pos.x + 0.5), floor(pos.y + 0.5), floor(pos.z + 0.5)}).type;
  13
  14                 if (*node == NODE_UNLOADED)
  15                         return false;
  16
  17                 if (client_node_defs[*node].pointable)
  18                         return true;
  19
  20                 f64 vpos[3] = {pos.x, pos.y, pos.z};
  21                 f64 vdir[3] = {dir.x, dir.y, dir.z};
  22                 f64 min_mul = 1.0;
  23
  24                 for (int i = 0; i < 3; i++) {
  25                         if (!vdir[i])
  26                                 continue;
  27
  28                         f64 p = vpos[i] + 0.5;
  29                         f64 d = vdir[i] / fabs(vdir[i]);
  30
  31                         f64 f = floor(p) - p;
  32                         if (d > 0.0)
  33                                 f += 1.0;
  34                         f += 0.001 * d;
  35
  36                         f64 mul = f / vdir[i];
  37                         if (min_mul > mul && mul)
  38                                 min_mul = mul;
  39                 }
  40
  41                 pos = v3f64_add(pos, v3f64_scale(dir, min_mul));
  42                 len -= dir_len * min_mul;
  43         }
  44
  45         return false;
  46 }