src/physic.cpp

   1 //
   2 // C Implementation: physic
   3 //
   4 // Description:
   5 //
   6 //
   7 // Author: Tobias Glaesser <tobi.web@gmx.de>, (C) 2004
   8 //
   9 // Copyright: See COPYING file that comes with this distribution
  10 //
  11 //
  12
  13 #include <stdio.h>
  14 #include "defines.h"
  15 #include "physic.h"
  16
  17 float gravity;
  18
  19 void physic_init(physic_type* pphysic)
  20 {
  21   pphysic->state = -1;
  22   pphysic->start_time = 0;
  23   pphysic->start_vy = 0;
  24 }
  25
  26 int physic_get_state(physic_type* pphysic)
  27 {
  28   return pphysic->state;
  29 }
  30
  31 void physic_set_state(physic_type* pphysic, int nstate)
  32 {
  33   pphysic->state = nstate;
  34   pphysic->start_time = st_get_ticks();
  35 }
  36
  37 void physic_set_start_vy(physic_type* pphysic, float start_vy)
  38 {
  39   pphysic->start_vy = start_vy;
  40 }
  41
  42 void physic_set_start_vx(physic_type* pphysic, float start_vx)
  43 {
  44   pphysic->start_vx = start_vx;
  45 }
  46
  47 void physic_set_acceleration(physic_type* pphysic, float acceleration)
  48 {
  49   pphysic->acceleration = acceleration;
  50 }
  51
  52
  53 int physic_is_set(physic_type* pphysic)
  54 {
  55   return (pphysic->state != -1);
  56 }
  57
  58 float physic_get_velocity(physic_type* pphysic)
  59 {
  60   if(pphysic->state == PH_VT)
  61     return - (pphysic->start_vy - gravity* ((float)(st_get_ticks() - pphysic->start_time))/1000.);
  62   else if(pphysic->state == PH_HA)
  63     return - (pphysic->start_vx - pphysic->acceleration * ((float)(st_get_ticks() - pphysic->start_time))/1000.);
  64   else
  65     return 0;
  66 }
  67
  68 float physic_get_max_distance(physic_type* pphysic)
  69 {
  70   return (pphysic->start_vy * pphysic->start_vy / 2.*gravity);
  71 }
  72
  73 unsigned int physic_get_max_time(physic_type* pphysic)
  74 {
  75   return (unsigned int)((pphysic->start_vy / gravity) * 1000);
  76 }
  77
  78 unsigned int physic_get_time_gone(physic_type* pphysic)
  79 {
  80   return st_get_ticks() - pphysic->start_time;
  81 }
  82
  83