Const dt=.1 'timsslice, smaller = more accurate,but slower
Const v_int = 700 'muzzle velocity.  Rifle = 600m/s Tank = 1500
Const angle= 37 'launch angle in degrees
Const theta = angle*PI/180 ' convert degrees to radians
Const A_m = 0.00004 ' expeimental drag factor from Bennett
Const nmax = 10000 ' number of iterations
Const A_m2 = 0.004 ' surface area of projectile
Const wind =-35 'wind speed. 40 = hurricane -ve means headwind
Const rho = 1.2 ' density of air
Const wind_force = (0.5*A_m2*rho*wind^2*dt)

max_x = 25000
max_y = 9000

mode 1,8
cls

Function round(num,dp)  ' provids proper rounding

 exp= 10^dp
 n = num* exp
 If n >= 0 then
   n = sgn(n) * (abs(int(n+0.5)))
 ElSE
   n= sgn(n) * (abs(int(n-0.5)))
 End if

 round = n / exp
End function

Dim x(nmax), y(nmax) ' arrays to stor x and y positon

Sub calculate

 x(1) = 0
 y(1) = 0
 vx = v_int * cos(theta)
 vy = v_int * sin(theta)

 for i = 2 to nmax
   x(i) = x(i-1)+(vx*dt)  'calculate new x based on previous
   y(i) = y(i-1)+(vy*dt)

   f=A_m*sqr(vx^2+vy^2)

   vy = vy - (9.8*dt)-(f*vy*dt)
   vx = vx - (f*vx*dt)+(wind_force*sgn(wind))

   if y(i) <=0 then
      index=i
      exit for
   end if

   if y(i) > max_height then max_height = y(i)

 next i

xrange = (x(i)+x(i-1))/2


print "Range = " round(xrange,0) "m"
print "Max Height = " round(max_height,0) "m"
print "Index = " index
end sub

calculate()
axes()
draw()


sub axes()
line 0,0,0,600,3
line 0,550,650,550,3

end sub


sub draw()
for i = 1 to index
 pixel((x(i)/25000)*650)+3,(550-((y(i)/max_height)*550))

next i
End sub

Text 700,100,"Range "+ str$(round(xrange,0))

Const dt=.5 'timsslice, smaller = more accurate,but slower
Const v_int= 700 'muzzle velocity.  Rifle = 600m/s Tank = 1500
Const angle= 45 'launch angle in degrees
Const theta = angle*PI/180 ' convert degrees to radians
Const A_m = 0.00004 ' expeimental drag factor from Bennett
Const nmax = 10000 ' number of iterations
Const A_m2 = 0.004 ' surface area of projectile
Const wind =-35 'wind speed. 40 = hurricane -ve means headwind
Const rho = 1.2 ' density of air
Const wind_force = (0.5*A_m2*rho*wind^2*dt)

max_x = 25000
max_y = 9000

mode 1,8
cls

page write 2
load png "cball.png"  'load sprite from file

image resize 0,0,110,111,0,0,20,20,2  'make it smaller -- should resize the file
sprite read 1,0,0,20,20,2  'read into sprite 1



page write 0

'sprite show 1,0,0,1

Function round(num,dp)  ' provids proper rounding
 exp= 10^dp
 n = num* exp
 If n >= 0 then
   n = sgn(n) * (abs(int(n+0.5)))
 ElSE
   n= sgn(n) * (abs(int(n-0.5)))
 End if

 round = n / exp
End function

Dim x(nmax), y(nmax) ' arrays to stor x and y positon

Sub calculate

 x(1) = 0
 y(1) = 0
 vx = v_int * cos(theta)
 vy = v_int * sin(theta)

 for i = 2 to nmax
   x(i) = x(i-1)+(vx*dt)  'calculate new x based on previous
   y(i) = y(i-1)+(vy*dt)

   f=A_m*sqr(vx^2+vy^2)

   vy = vy - (9.8*dt)-(f*vy*dt)
   vx = vx - (f*vx*dt)+(wind_force*sgn(wind))

   if y(i) <=0 then
      index=i
      exit for
   end if

   if y(i) > max_height then max_height = y(i)

 next i

xrange = (x(i)+x(i-1))/2


print "Range = " round(xrange,0) "m"
print "Max Height = " round(max_height,0) "m"
print "Index = " index
end sub

calculate()
axes()
draw()


sub axes()
line 0,0,0,600,3
line 0,550,650,550,3


end sub

sub draw()
sprite show 1,0,599,1  'put sprite onto screen

for i = 1 to index
 sprite next 1,((x(i)/25000)*650)-10,(550-((y(i)/max_height)*550)-10)
 pause 5  
 sprite move
next i

End sub


Text 700,100,"Range "+ str$(round(xrange,0))