Demonstrates how to throw and object threw the air using projectile motion.

Documented code explaining the equations on throwing an object threw the air in 3D. Gravity and amount of initial force are factors in the object's movement. The character's (object thrower) angles also affect the arc and ultimately the distance of the object.

                                    ` This code was downloaded from The Game Creators
                                    ` It is reproduced here with full permission
                                    ` http://www.thegamecreators.com
                                    
                                    REM Coded by: Phaelax (Phaelax@hotmail.com)
REM Demonstrates how to throw and object threw the air
REM using projectile motion.

autocam off
sync on
sync rate 60
hide mouse

player_height# = 100.0 : rem height of the player's eyes
grav_str# = 1.0        : rem gravity strength
obj_size# = 10.0       : rem size of throwing object (in this case, the sphere's radius)

make matrix 1, 1000,1000,40,40

make object sphere 1, obj_size#*2

DO

   gosub player_controls
   gosub camera_status


   rem if left mouse button clicked, initialize the variables for
   rem throwing the object.
   rem tx#,ty#,tz# are the object's starting positon (character's current position).
   rem tYA# is the character's Y rotation.
   rem tPitch# is the characters X rotation or the angle at which the character
   rem is looking either up or down.
   rem T# is the time index. Since the object is just starting to be thrown,
   rem current time is 0 seconds.
   rem F# is the amount of force that's used to throw the object.
   rem tpx# is just a temp variable that needs to be reset.
   if mouseclick() and throw = 0
      throw=1
      tx# = x#
      tz# = z#
      ty# = get ground height(1,x#,z#)+player_height#
      tYA# = a#
      tPitch# = 360.0-camera angle x()
      T# = 0.0
      F# = 40.0
      tpx# = 0
   endif

   if throw = 1 then gosub throw_translocator

   sync
LOOP


REM control player's movement
PLAYER_CONTROLS:
  runspeed#=0.0
  if shiftkey()=1 then runspeed#=6.0
  if upkey()=1
    x#=newxvalue(x#,a#,6+runspeed#)
    z#=newzvalue(z#,a#,6+runspeed#)
  endif
  if downkey()=1
    x#=newxvalue(x#,a#,-6-runspeed#)
    z#=newzvalue(z#,a#,-6-runspeed#)
  endif
  if leftkey()=1
    x#=newxvalue(x#,wrapvalue(a#-90.0),5.0+runspeed#)
    z#=newzvalue(z#,wrapvalue(a#-90.0),5.0+runspeed#)
  endif
  if rightkey()=1
    x#=newxvalue(x#,wrapvalue(a#+90.0),5.0+runspeed#)
    z#=newzvalue(z#,wrapvalue(a#+90.0),5.0+runspeed#)
  endif

RETURN


REM control player's angle of site/rotation and position
CAMERA_STATUS:
  rem rotate camera according to mouse
  a#=wrapvalue(a#+(mousemovex()/3.0))
  rem position and rotate camera
  cxa#=cxa#+(mousemovey()/3.0)
  if cxa#<-90.0 then cxa#=-90.0
  if cxa#>90.0 then cxa#=90.0
  position camera x#,get ground height(1,x#,z#)+player_height#,z#
  rotate camera wrapvalue(cxa#),a#,0
RETURN


REM iterator sub to constantly update position of thrown object
throw_translocator:
   rem store old positions
   oldtpx#=tpx#
   oldtx#=tx#
   oldtz#=tz#
   rem TPX# is the distance the object has traveled from the origin
   TPX#=F#*COS(tPitch#)*T#
   rem TPY# is the height of the object's arc.
   TPY#=F#*SIN(tPitch#)*T#-(0.5*grav_str#)*(T#^2)
   rem dist# is the distance that the object has traveled during this iteration
   dis#=abs(oldtpx#-tpx#)
   rem tx# and tz# transforms that distance from 2D into a 3D distance based
   rem on the character's Y rotation.
   tx#=newxvalue(tx#,tYA#,dis#)
   tz#=newzvalue(tz#,tYA#,dis#)
   rem increment time index
   inc T#
   rem positions the object
   position object 1,tx#,ty#+TPY#,tz#
   rem stop movement if object hits ground
   if object position y(1)<=obj_size#
      throw=0
      rem make sure object's last position is above ground
      position object 1,oldtx#,obj_size#,oldtz#
   endif
RETURN