That 3d thing

[1micha.elok]

I had a really busy weekend. Jazz concert (my son) on Saturday and gymnastics competion (daughter) on Sunday. ....

You are so lucky to have an awesome family time. Great !!!
By the way, you may reply my question when you are free,  it's not urgent 

   
click the image to zoom-in

I'm trying to make a kind of first-person-shooter game, but I believe I do it in a wrong way .... lol
a. Could you please advice me the right-way, where should I put the code of draw image weapon ?
b. And how to put the weapon at the middle of the bottom screen ?
    I can not put it as draw image weapon, width(primary)/2, height(primary) as it will draw out of screen.  

Code:

'---------------
' INITILIZATION
'---------------
include "myassets/enginea.n7"

set window "stargate",320,240,false,2
set redraw off

visible weapon = loadimage("myassets/shooter.png")

EA_SetView(primary, rad(65), 0.1,6)
EA_SetFog(EA_NORMAL, 255,255,255)

flags = EA_LoadMap("myassets/map.json")
player = unset
foreach f in flags
    if f.flag = "player"
        player = EA_FpsPlayer()
        player.SetPos(f.x,f.floorY, f.z)
    endif
next


'------
' MAIN
'------   
EA_AddObject(player)
EA_SetCamera(player)
player.SetMouseSens(0.3)

EA_SetUpdateAction(Update)

EA_Run()


'-----------
' FUNCTIONS
'-----------
function Update(dt)
    draw image weapon, 100,130
    redraw
    fwait 30

    if keydown(KEY_ESCAPE,true) then
        EA_Stop()
    endif
endfunc