Games/Quake/chase.c

   1 /*
   2 Copyright (C) 1996-1997 Id Software, Inc.
   3
   4 This program is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU General Public License
   6 as published by the Free Software Foundation; either version 2
   7 of the License, or (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  12
  13 See the GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18
  19 */
  20 // chase.c -- chase camera code
  21
  22 #include "quakedef.h"
  23 qboolean SV_RecursiveHullCheck (hull_t *hull, int num, float p1f, float p2f, vec3_t p1, vec3_t p2, trace_t *trace);
  24
  25 cvar_t  chase_back = {"chase_back", "100"};
  26 cvar_t  chase_up = {"chase_up", "16"};
  27 cvar_t  chase_right = {"chase_right", "0"};
  28 cvar_t  chase_active = {"chase_active", "0"};
  29
  30 vec3_t  chase_pos;
  31 vec3_t  chase_angles;
  32
  33 vec3_t  chase_dest;
  34 vec3_t  chase_dest_angles;
  35
  36
  37 void Chase_Init (void)
  38 {
  39         Cvar_RegisterVariable (&chase_back);
  40         Cvar_RegisterVariable (&chase_up);
  41         Cvar_RegisterVariable (&chase_right);
  42         Cvar_RegisterVariable (&chase_active);
  43 }
  44
  45 void Chase_Reset (void)
  46 {
  47         // for respawning and teleporting
  48 //      start position 12 units behind head
  49 }
  50
  51 void TraceLine (vec3_t start, vec3_t end, vec3_t impact)
  52 {
  53         trace_t trace;
  54
  55         memset (&trace, 0, sizeof(trace));
  56         SV_RecursiveHullCheck (cl.worldmodel->hulls, 0, 0, 1, start, end, &trace);
  57
  58         VectorCopy (trace.endpos, impact);
  59 }
  60
  61 void Chase_Update (void)
  62 {
  63         int             i;
  64         float   dist;
  65         vec3_t  forward, up, right;
  66         vec3_t  dest, stop;
  67
  68
  69         // if can't see player, reset
  70         AngleVectors (cl.viewangles, forward, right, up);
  71
  72         // calc exact destination
  73         for (i=0 ; i<3 ; i++)
  74                 chase_dest[i] = r_refdef.vieworg[i]
  75                 - forward[i]*chase_back.value
  76                 - right[i]*chase_right.value;
  77         chase_dest[2] = r_refdef.vieworg[2] + chase_up.value;
  78
  79         // find the spot the player is looking at
  80         VectorMA (r_refdef.vieworg, 4096, forward, dest);
  81         TraceLine (r_refdef.vieworg, dest, stop);
  82
  83         // calculate pitch to look at the same spot from camera
  84         VectorSubtract (stop, r_refdef.vieworg, stop);
  85         dist = DotProduct (stop, forward);
  86         if (dist < 1)
  87                 dist = 1;
  88         r_refdef.viewangles[PITCH] = -atan(stop[2] / dist) / M_PI * 180;
  89
  90         // move towards destination
  91         VectorCopy (chase_dest, r_refdef.vieworg);
  92 }
  93