--First stop time
celestia:settimescale(0)

--Then get variables containing Mars, the observer and the Celestia co-ord->km conversion factors
mars = celestia:find("Mars")
obs = celestia:getobserver()
km_per_mly=9466411.842
mly_per_km=1.0 / km_per_mly

--Clear render flags & labels
celestia:hide("orbits", "constellations", "boundaries", "markers", "grid")
celestia:hidelabel("planets", "moons", "spacecraft", "asteroids", "comets", "constellations", "stars", "galaxies", "locations")

--Preload Mars textures
mars:preloadtexture()

--Create arrays with the TASC generated MEX locations for each image
names = {
          "09-302_14.36.31_VMC_Img_No_1.png",
          "09-302_14.37.27_VMC_Img_No_2.png",
          "09-302_14.38.19_VMC_Img_No_3.png",
          "09-302_14.39.13_VMC_Img_No_4.png",
          "09-302_14.40.07_VMC_Img_No_5.png",
          "09-302_14.40.59_VMC_Img_No_6.png",
          "09-302_14.41.53_VMC_Img_No_7.png",
          "09-302_14.42.47_VMC_Img_No_8.png",
          "09-302_14.43.39_VMC_Img_No_9.png",
          "09-302_14.44.33_VMC_Img_No_10.png",
          "09-302_14.45.27_VMC_Img_No_11.png",
          "09-302_14.46.19_VMC_Img_No_12.png",
          "09-302_14.47.13_VMC_Img_No_13.png",
          "09-302_14.48.07_VMC_Img_No_14.png",
          "09-302_14.48.59_VMC_Img_No_15.png",
          "09-302_14.49.53_VMC_Img_No_16.png",
          "09-302_14.50.47_VMC_Img_No_17.png",
          "09-302_14.51.39_VMC_Img_No_18.png",
          "09-302_14.52.33_VMC_Img_No_19.png",
          "09-302_14.53.27_VMC_Img_No_20.png",
          "09-302_14.54.19_VMC_Img_No_21.png",
          "09-302_14.55.13_VMC_Img_No_22.png",
          "09-302_14.56.07_VMC_Img_No_23.png",
          "09-302_14.56.59_VMC_Img_No_24.png",
          "09-302_14.57.53_VMC_Img_No_25.png",
          "09-302_14.58.47_VMC_Img_No_26.png",
          "09-302_14.59.39_VMC_Img_No_27.png",
          "09-302_15.00.33_VMC_Img_No_28.png",
          "09-302_15.01.27_VMC_Img_No_29.png",
          "09-302_15.02.19_VMC_Img_No_30.png",
          "09-302_15.03.13_VMC_Img_No_31.png",
          "09-302_15.04.07_VMC_Img_No_32.png",
          "09-302_15.04.59_VMC_Img_No_33.png",
          "09-302_15.05.51_VMC_Img_No_34.png",
        }

dates = {
          celestia:utctotdb(2009, 10, 29, 14, 36, 31),
          celestia:utctotdb(2009, 10, 29, 14, 37, 27),
          celestia:utctotdb(2009, 10, 29, 14, 38, 19),
          celestia:utctotdb(2009, 10, 29, 14, 39, 13),
          celestia:utctotdb(2009, 10, 29, 14, 40, 07),
          celestia:utctotdb(2009, 10, 29, 14, 40, 59),
          celestia:utctotdb(2009, 10, 29, 14, 41, 53),
          celestia:utctotdb(2009, 10, 29, 14, 42, 47),
          celestia:utctotdb(2009, 10, 29, 14, 43, 39),
          celestia:utctotdb(2009, 10, 29, 14, 44, 33),
          celestia:utctotdb(2009, 10, 29, 14, 45, 27),
          celestia:utctotdb(2009, 10, 29, 14, 46, 19),
          celestia:utctotdb(2009, 10, 29, 14, 47, 13),
          celestia:utctotdb(2009, 10, 29, 14, 48, 07),
          celestia:utctotdb(2009, 10, 29, 14, 48, 59),
          celestia:utctotdb(2009, 10, 29, 14, 49, 53),
          celestia:utctotdb(2009, 10, 29, 14, 50, 47),
          celestia:utctotdb(2009, 10, 29, 14, 51, 39),
          celestia:utctotdb(2009, 10, 29, 14, 52, 33),
          celestia:utctotdb(2009, 10, 29, 14, 53, 27),
          celestia:utctotdb(2009, 10, 29, 14, 54, 19),
          celestia:utctotdb(2009, 10, 29, 14, 55, 13),
          celestia:utctotdb(2009, 10, 29, 14, 56, 07),
          celestia:utctotdb(2009, 10, 29, 14, 56, 59),
          celestia:utctotdb(2009, 10, 29, 14, 57, 53),
          celestia:utctotdb(2009, 10, 29, 14, 58, 47),
          celestia:utctotdb(2009, 10, 29, 14, 59, 39),
          celestia:utctotdb(2009, 10, 29, 15, 00, 33),
          celestia:utctotdb(2009, 10, 29, 15, 01, 27),
          celestia:utctotdb(2009, 10, 29, 15, 02, 19),
          celestia:utctotdb(2009, 10, 29, 15, 03, 13),
          celestia:utctotdb(2009, 10, 29, 15, 04, 07),
          celestia:utctotdb(2009, 10, 29, 15, 04, 59),
          celestia:utctotdb(2009, 10, 29, 15, 05, 51),
        }

 xarr = {
          -7400.942,
          -7387.908,
          -7375.425,
          -7362.070,
          -7348.318,
          -7334.698,
          -7320.161,
          -7305.224,
          -7290.459,
          -7274.731,
          -7258.599,
          -7242.682,
          -7225.753,
          -7208.418,
          -7191.338,
          -7173.200,
          -7154.651,
          -7136.400,
          -7117.042,
          -7097.270,
          -7077.837,
          -7057.249,
          -7036.242,
          -7015.618,
          -6993.787,
          -6971.535,
          -6949.708,
          -6926.624,
          -6903.115,
          -6880.072,
          -6855.723,
          -6830.944,
          -6806.675,
          -6782.005,
        }

 zarr = {
          -9531.896,
          -9553.93,
          -9573.897,
          -9594.126,
          -9613.835,
          -9632.322,
          -9651.003,
          -9669.156,
          -9686.134,
          -9703.24,
          -9719.806,
          -9735.247,
          -9750.745,
          -9765.694,
          -9779.567,
          -9793.426,
          -9806.726,
          -9818.999,
          -9831.187,
          -9842.803,
          -9853.445,
          -9863.927,
          -9873.825,
          -9882.8,
          -9891.54,
          -9899.684,
          -9906.959,
          -9913.919,
          -9920.271,
          -9925.807,
          -9930.95,
          -9935.47,
          -9939.229,
          -9942.403,
        }

 yarr = {
          -5520.470,
          -5455.952,
          -5395.761,
          -5332.969,
          -5269.888,
          -5208.873,
          -5145.233,
          -5081.310,
          -5019.491,
          -4955.021,
          -4890.276,
          -4827.671,
          -4762.392,
          -4696.845,
          -4633.474,
          -4567.407,
          -4501.078,
          -4436.960,
          -4370.125,
          -4303.035,
          -4238.192,
          -4170.610,
          -4102.782,
          -4037.234,
          -3968.928,
          -3900.382,
          -3834.151,
          -3765.143,
          -3695.904,
          -3629.013,
          -3559.327,
          -3489.418,
          -3421.890,
          -3354.159,
        }

obsno = 34
obstring = "29 October 2009"

--Set the initial time
celestia:settime(dates[1]);

--Go to Mars then write title
obs:track(mars)
celestia:flash("European Space Agency\nMars Express Visual Monitoring Camera\nObservation "..obstring, 15)
obs:goto(mars,5)
obs:goto((mars:getposition() + celestia:newvector(xarr[1], yarr[1], zarr[1]) * (mly_per_km)),5)
wait(10)
celestia:flash("Press 'M' for next image, 'N' for previous image.\nUse left and right arrow keys to rotate the\nplanet to the same orientation as the image.", 10)
wait(10)
celestia:showlabel("locations", "moons", "spacecraft")

--Create a function that goes to a given image number
gotoimage = function(imgno)
	
	celestia:settime(dates[imgno])
		
	obs:setposition(mars:getposition() + celestia:newvector(xarr[imgno], yarr[imgno], zarr[imgno]) * (mly_per_km))
		
	celestia:select(mars)
	
	obs:track(mars)
	
	celestia:flash(names[imgno], 60)	

end

--Create a function that will go to the next image in the series
next = function(goto)

	if (count + 1)>obsno then
		count = 1
	else
		count = count + 1
	end
	
	gotoimage(count)
end

--Create a function that will go to the previous image in the series
last = function()
	
	if (count - 1)<1 then
		count = obsno
	else
		count = count - 1
	end
  
    gotoimage(count)
end

--Create a counter holding the position of the current image
count = 1

--Set the position to the first image
gotoimage(count)

--Add the necessary keyboard callback code
keymap = { n = last, m = next }

celestia_keyboard_callback = function(key) 
     f = keymap[key]
     if f then 
        f() 
        return true
     end
        return false
end

celestia:requestkeyboard(true)
repeat
     wait(10)
until false