-- sanity checks
v = vessel.get_interface('GL1')
if v == nil then
    term.out ('Could not find 1. Aborting')
    return
elseif v:get_classname() ~= 'DeltaGlider' then
    term.out ('Wrong vessel class. Aborting')
    return
end

-- set the types of notes position size and color on screen
note = oapi.create_annotation()
note:set_pos (0.002,0.23,0.5,0.5)
note:set_colour ({r=1,g=1,b=0})
note:set_size (0.8)

gnote = oapi.create_annotation()
gnote:set_pos (0.815,0.23,0.998,0.5)
gnote:set_colour ({r=1,g=1,b=0})
gnote:set_size (0.8)


-- wait for goals to be completed (I'm using this code for challenges, so I'm keeping this format)
contact = false
vessel_inside=0
goal2=0
goals=vessel_inside+goal2

while goals < 5 do --arbitrary number larger than the number of goals so the script doesn't close. In my challenge I set this to the number of goals
    gnote:set_text (string.format ("                GOALS\n---------------------------------\n• Check If the DeltaGlider is\n  on the ground or in the air\n• Return Ground or Airborn\n• If Ground Contact is true \n  check if inside cyan area\n• Return Inside or Outside"));
    
vessel_inside=0

    --my vessel's coordinates. I need to have them in the same units as the coordinates of the shapes
    hobj = v:get_surfaceref()
    equ = oapi.global_to_equ (hobj, v:get_globalpos())
    x0 = equ.lng*180/PI
    y0 = equ.lat*180/PI

    -- coordinates of the triangle points. important to move counter-clockwise to get to the next point
    xa1 = 27.997948
    xa2 = 28.003588
    xa3 = 27.996508
    ya1 = 35.998773
    ya2 = 35.997393
    ya3 = 36.002883

    -- areas of the triangles defined by each side of the shape above and my coordinates
    a_1 = 0.5*((xa1*ya2)-(ya1*xa2)-(x0*ya2)+(y0*xa2)+(x0*ya1)-(y0*xa1))
    a_2 = 0.5*((xa2*ya3)-(ya2*xa3)-(x0*ya3)+(y0*xa3)+(x0*ya2)-(y0*xa2))
    a_3 = 0.5*((xa3*ya1)-(ya3*xa1)-(x0*ya1)+(y0*xa1)+(x0*ya3)-(y0*xa3))

    -- check if all areas are positive
    if a_1>0 and a_2>0 and a_3>0 then 
       vessel_inside=1
    end

     -- coordinates of the irregular rectangle points. Important to move counter-clockwise to get to the next point
    xb1 = 28.010138
    xb2 = 28.012718
    xb3 = 28.010758
    xb4 = 28.005328
    yb1 = 35.997543
    yb2 = 35.997983
    yb3 = 36.000623
    yb4 = 36.000973

    -- areas of the triangles defined by each side of the shape above and my coordinates
    b_1 = 0.5*((xb1*yb2)-(yb1*xb2)-(x0*yb2)+(y0*xb2)+(x0*yb1)-(y0*xb1))
    b_2 = 0.5*((xb2*yb3)-(yb2*xb3)-(x0*yb3)+(y0*xb3)+(x0*yb2)-(y0*xb2))
    b_3 = 0.5*((xb3*yb4)-(yb3*xb4)-(x0*yb4)+(y0*xb4)+(x0*yb3)-(y0*xb3))
    b_4 = 0.5*((xb4*yb1)-(yb4*xb1)-(x0*yb1)+(y0*xb1)+(x0*yb4)-(y0*xb4))
    
    -- check if all areas are positive
    if b_1>0 and b_2>0 and b_3>0 and b_4>0 then 
       vessel_inside=1
    end

    -- coordinates of the irregular pentagon points. important to move counter-clockwise to get to the next point
    xc1 = 28.016268
    xc2 = 28.020388
    xc3 = 28.021108
    xc4 = 28.018698
    xc5 = 28.014218
    yc1 = 35.997183
    yc2 = 35.998113
    yc3 = 36.000933
    yc4 = 36.002633
    yc5 = 36.001333

    -- areas of the triangles defined by each side of the shape above and my coordinates
    c_1 = 0.5*((xc1*yc2)-(yc1*xc2)-(x0*yc2)+(y0*xc2)+(x0*yc1)-(y0*xc1))
    c_2 = 0.5*((xc2*yc3)-(yc2*xc3)-(x0*yc3)+(y0*xc3)+(x0*yc2)-(y0*xc2))
    c_3 = 0.5*((xc3*yc4)-(yc3*xc4)-(x0*yc4)+(y0*xc4)+(x0*yc3)-(y0*xc3))
    c_4 = 0.5*((xc4*yc5)-(yc4*xc5)-(x0*yc5)+(y0*xc5)+(x0*yc4)-(y0*xc4))
    c_5 = 0.5*((xc5*yc1)-(yc5*xc1)-(x0*yc1)+(y0*xc1)+(x0*yc5)-(y0*xc5))

    -- check if all areas are positive
    if c_1>0 and c_2>0 and c_3>0 and c_4>0 and c_5>0 then 
       vessel_inside=1
    end

    --msgs and info on screen
    msg = string.format("-------------------\n        Info\n-------------------\n• X: %.6f \n• Y: %.6f\n-------------------\n    Messages\n------------------- ",x0, y0)
    note:set_text (msg)
    alt = v:get_altitude()
    contact = false
    if contact == false then
        contact = v:get_groundcontact()
        if contact == true then
           msg = msg.."\n• Ground"
        end
        note:set_text (msg)
        if alt >= 3 then
          contact = false
          msg = msg.."\n• Airborn"
        end
     end
    if vessel_inside<1 and contact == true then
        msg = msg.."\n• Outside"
    end
    if vessel_inside>0 and contact == true then
        msg = msg.."\n• Inside"
    end 
    note:set_text (msg)
    	
    proc.skip()
	
    -- for challenges. check if goals have been met and close the script
    hobj = v:get_surfaceref()
       planet = v:is_landed() 
       if oapi.get_objname(planet) ~= 'Earth' then 
         planet = nil 
       end
         goal2=0
         if planet ~= nil then goal2=1
         end
         goals=vessel_inside+goal2
         if goals > 4 then -- same as at the beginning minus one. I use it for challenges, but here I don't want to close the script
         end
end
 
oapi.del_annotation (gnote)