`RTS Mouse control demo by Van-B (DBPro)
`Note - would work in DBClassic with some minor modifications (mainly using an array for the globals)

`This system uses 0 as the lowest level - I like to use 0 as the water height, so when you click water,
`you click the surface of the water instead of underneath.

sync on : sync rate 0 : autocam off

`Globalised variables for MUS function
global musx#
global musy#
global musz#


`Make a test texture
cls rgb(0,255,0)
ink rgb(0,32,0),rgb(0,32,0)
box 1,1,31,31
get image 1,0,0,32,32

ink rgb(255,255,0),0

`Simple matrix
make matrix 1,6400,6400,64,64
prepare matrix texture 1,1,1,1
randomize matrix 1,100
update matrix 1

yang=0

`Object 2 is the fake mouse pointer, but it can be reused for other calculations too
make object cube 2,50 : hide object 2
`Object 3 is moved with the left mouse button
make object sphere 3,50

hide mouse

`Default camera start location
camy#=500
camx#=3200
camz#=3200



`Main loop

do


   mx=mousex()
   my=mousey()
   mc=mouseclick()

   if leftkey()=1 then yang=wrapvalue(yang-1)
   if rightkey()=1 then yang=wrapvalue(yang+1)
   if upkey()=1 then inc camy#,10
   if downkey()=1 then dec camy#,10

   gosub calc_camera

   gosub calc_mouse

   `Scale the ball, just to show the accuracy better
   scale=abs(sin(timer()/6.0)*100)
   scale object 3,scale,scale,scale

sync
loop









calc_mouse:
   `Calculate the MMZ# and MMX# as 0.0-1.0 floating point variables
   mmz#=(((my*1.0)/(screen height()*1.0))-1.05)*(camy#*2.10)
   mmx#=(((mx*1.0)/(screen width()*1.0))-0.500)*(camy#*2.0)*(1.10-(((my*1.15)/(screen height()*1.15))-0.575))

   mx#=newxvalue(camx#,camera angle y(),0-mmz#)
   mz#=newzvalue(camz#,camera angle y(),0-mmz#)
   mx#=newxvalue(mx#,wrapvalue(camera angle y()-90),0-mmx#)
   mz#=newzvalue(mz#,wrapvalue(camera angle y()-90),0-mmx#)

   position object 2,mx#,0,mz#

   osx=object screen x(2) : osy=object screen y(2)

   `Stand-in cursor
   line osx-10,osy,osx+10,osy
   line osx,osy-10,osx,osy+10

   `Click the mouse to position the box
   `NOTE: Everytime you click on the matrice MUSX# etc are set, so you'd do all your mouseclick chores here
   if mc=1
      mus(mx#,mz#)
      position object 3,musx#,musy#,musz#
   endif
return


calc_camera:
   `Very important, you can't change this without changing the forumulaes - live with it if you can
   rotate camera 55,yang,0
   mmx=0
   mmz=0
   msx=mx : if msx<0 then msx=0
   msy=my : if msy<0 then msy=0
   mox=screen width()-mx : if mox<0 then mox=0
   moy=screen height()-my : if moy<0 then moy=0

   `Check the edges of the screen and set the values for push scrolling
   if msx<50 then mmx=(-50.0+msx)/1.5
   if msy<50 then mmz=(-50.0+msy)/1.5
   if mox<50 then mmx=(50.0-mox)/1.5
   if moy<50 then mmz=(50.0-moy)/1.5

   `Calculate the new camera position based on the push scrolling values
   camx#=newxvalue(camx#,camera angle y(),0-mmz)
   camz#=newzvalue(camz#,camera angle y(),0-mmz)
   camx#=newxvalue(camx#,wrapvalue(camera angle y()-90),0-mmx)
   camz#=newzvalue(camz#,wrapvalue(camera angle y()-90),0-mmx)
   camh#=get ground height(1,camx#,camz#)
   if camy#<camh#+50.0 then camy#=camh#+50
   position camera camx#,camy#,camz#
return


`This function will return the 3D cursor location based on X, Z, and a height of 0
`It stores the results in MUSX#,MUSY#,MUSZ#
function mus(mx#,mz#)
musx#=mx#
musy#=0
musz#=mz#
position object 2,mx#,0,mz#
point object 2,camera position x(),camera position y(),camera position z()

while object position y(2)<camera position y()

   `NOTE - the 25 is for the accuracy, this needs to be as big as you can for speed sakes
   `about 1/4 of a tiles width is reasonable, however it can be much less without killing the speed
   move object 2,25

   mh#=get ground height(1,object position x(2),object position z(2))
   if object position y(2)<mh#
      musx#=object position x(2)
      musy#=object position y(2)
      musz#=object position z(2)
   endif
endwhile
musy#=get ground height(1,musx#,musz#)
endfunction

   mmz#=(((my*1.0)/(screen height()*1.0))-1.05)*(camy#*2.10)
   mmx#=(((mx*1.0)/(screen width()*1.0))-0.500)*(camy#*2.0)*(1.10-(((my*1.15)/(screen height()*1.15))-0.575))

mmz#=(((my*1.0)/(screen height()*1.0))-1.05)*(camy#*2.10)
   mmx#=(((mx*1.0)/(screen width()*1.0))-0.500)*(camy#*2.0)*(1.10-(((my*1.15)/(screen height()*1.15))-0.575))