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   if(pphysic->state != -1)
  56     return YES;
  57   else
  58     return NO;
  59 }
  60
  61 float physic_get_velocity(physic_type* pphysic)
  62 {
  63   if(pphysic->state == PH_VT)
  64     return - (pphysic->start_vy - gravity* ((float)(st_get_ticks() - pphysic->start_time))/1000.);
  65   else if(pphysic->state == PH_HA)
  66     return - (pphysic->start_vx - pphysic->acceleration * ((float)(st_get_ticks() - pphysic->start_time))/1000.);
  67   else
  68     return 0;
  69 }
  70
  71 float physic_get_max_distance(physic_type* pphysic)
  72 {
  73   return (pphysic->start_vy * pphysic->start_vy / 2.*gravity);
  74 }
  75
  76 unsigned int physic_get_max_time(physic_type* pphysic)
  77 {
  78   return (unsigned int)((pphysic->start_vy / gravity) * 1000);
  79 }
  80
  81 unsigned int physic_get_time_gone(physic_type* pphysic)
  82 {
  83   return st_get_ticks() - pphysic->start_time;
  84 }
  85
  86