--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 = {
          "10-238_21.53.43_VMC_Img_No_1.png",
          "10-238_21.54.31_VMC_Img_No_2.png",
          "10-238_21.55.13_VMC_Img_No_3.png",
          "10-238_21.55.56_VMC_Img_No_4.png",
          "10-238_21.56.39_VMC_Img_No_5.png",
          "10-238_21.57.22_VMC_Img_No_6.png",
          "10-238_21.58.05_VMC_Img_No_7.png",
          "10-238_21.58.48_VMC_Img_No_8.png",
          "10-238_21.59.31_VMC_Img_No_9.png",
          "10-238_22.00.13_VMC_Img_No_10.png",
          "10-238_22.00.57_VMC_Img_No_11.png",
          "10-238_22.01.40_VMC_Img_No_12.png",
          "10-238_22.02.23_VMC_Img_No_13.png",
          "10-238_22.03.06_VMC_Img_No_14.png",
          "10-238_22.03.49_VMC_Img_No_15.png",
          "10-238_22.04.32_VMC_Img_No_16.png",
          "10-238_22.05.15_VMC_Img_No_17.png",
          "10-238_22.05.58_VMC_Img_No_18.png",
          "10-238_22.06.41_VMC_Img_No_19.png",
          "10-238_22.07.24_VMC_Img_No_20.png",
          "10-238_22.08.07_VMC_Img_No_21.png",
          "10-238_22.08.50_VMC_Img_No_22.png",
          "10-238_22.09.33_VMC_Img_No_23.png",
          "10-238_22.10.16_VMC_Img_No_24.png",
          "10-238_22.10.59_VMC_Img_No_25.png",
          "10-238_22.11.41_VMC_Img_No_26.png",
          "10-238_22.12.25_VMC_Img_No_27.png",
          "10-238_22.13.08_VMC_Img_No_28.png",
          "10-238_22.13.51_VMC_Img_No_29.png",
          "10-238_22.14.34_VMC_Img_No_30.png",
          "10-238_22.15.17_VMC_Img_No_31.png",
          "10-238_22.16.00_VMC_Img_No_32.png",
          "10-238_22.16.43_VMC_Img_No_33.png",
          "10-238_22.17.26_VMC_Img_No_34.png",
          "10-238_22.18.09_VMC_Img_No_35.png",
          "10-238_22.18.52_VMC_Img_No_36.png",
          "10-238_22.19.35_VMC_Img_No_37.png",
          "10-238_22.20.18_VMC_Img_No_38.png",
        }

dates = {
          celestia:utctotdb(2010, 08, 26, 21, 53, 43),
          celestia:utctotdb(2010, 08, 26, 21, 54, 31),
          celestia:utctotdb(2010, 08, 26, 21, 55, 13),
          celestia:utctotdb(2010, 08, 26, 21, 55, 56),
          celestia:utctotdb(2010, 08, 26, 21, 56, 39),
          celestia:utctotdb(2010, 08, 26, 21, 57, 22),
          celestia:utctotdb(2010, 08, 26, 21, 58, 05),
          celestia:utctotdb(2010, 08, 26, 21, 58, 48),
          celestia:utctotdb(2010, 08, 26, 21, 59, 31),
          celestia:utctotdb(2010, 08, 26, 22, 00, 13),
          celestia:utctotdb(2010, 08, 26, 22, 00, 57),
          celestia:utctotdb(2010, 08, 26, 22, 01, 40),
          celestia:utctotdb(2010, 08, 26, 22, 02, 23),
          celestia:utctotdb(2010, 08, 26, 22, 03, 06),
          celestia:utctotdb(2010, 08, 26, 22, 03, 49),
          celestia:utctotdb(2010, 08, 26, 22, 04, 32),
          celestia:utctotdb(2010, 08, 26, 22, 05, 15),
          celestia:utctotdb(2010, 08, 26, 22, 05, 58),
          celestia:utctotdb(2010, 08, 26, 22, 06, 41),
          celestia:utctotdb(2010, 08, 26, 22, 07, 24),
          celestia:utctotdb(2010, 08, 26, 22, 08, 07),
          celestia:utctotdb(2010, 08, 26, 22, 08, 50),
          celestia:utctotdb(2010, 08, 26, 22, 09, 33),
          celestia:utctotdb(2010, 08, 26, 22, 10, 16),
          celestia:utctotdb(2010, 08, 26, 22, 10, 59),
          celestia:utctotdb(2010, 08, 26, 22, 11, 41),
          celestia:utctotdb(2010, 08, 26, 22, 12, 25),
          celestia:utctotdb(2010, 08, 26, 22, 13, 08),
          celestia:utctotdb(2010, 08, 26, 22, 13, 51),
          celestia:utctotdb(2010, 08, 26, 22, 14, 34),
          celestia:utctotdb(2010, 08, 26, 22, 15, 17),
          celestia:utctotdb(2010, 08, 26, 22, 16, 00),
          celestia:utctotdb(2010, 08, 26, 22, 16, 43),
          celestia:utctotdb(2010, 08, 26, 22, 17, 26),
          celestia:utctotdb(2010, 08, 26, 22, 18, 09),
          celestia:utctotdb(2010, 08, 26, 22, 18, 52),
          celestia:utctotdb(2010, 08, 26, 22, 19, 35),
          celestia:utctotdb(2010, 08, 26, 22, 20, 18),
        }

 xarr = {
          4333.619,
          4314.007,
          4296.703,
          4278.849,
          4260.855,
          4242.721,
          4224.447,
          4206.033,
          4187.480,
          4169.223,
          4149.954,
          4130.982,
          4111.871,
          4092.621,
          4073.231,
          4053.702,
          4034.034,
          4014.227,
          3994.281,
          3974.197,
          3953.973,
          3933.611,
          3913.111,
          3892.472,
          3871.694,
          3851.266,
          3829.724,
          3808.531,
          3787.200,
          3765.731,
          3744.124,
          3722.380,
          3700.497,
          3678.476,
          3656.318,
          3634.022,
          3611.588,
          3589.017,
        }

 zarr = {
          10908.443,
          10926.861,
          10942.614,
          10958.39,
          10973.807,
          10988.863,
          11003.558,
          11017.889,
          11031.853,
          11045.139,
          11058.678,
          11071.535,
          11084.017,
          11096.125,
          11107.855,
          11119.206,
          11130.176,
          11140.762,
          11150.963,
          11160.777,
          11170.201,
          11179.233,
          11187.872,
          11196.115,
          11203.959,
          11211.235,
          11218.445,
          11225.081,
          11231.311,
          11237.131,
          11242.539,
          11247.533,
          11252.111,
          11256.269,
          11260.006,
          11263.319,
          11266.206,
          11268.664,
        }

 yarr = {
          6616.641,
          6564.179,
          6518.056,
          6470.625,
          6422.982,
          6375.128,
          6327.064,
          6278.791,
          6230.309,
          6182.754,
          6132.722,
          6083.620,
          6034.312,
          5984.800,
          5935.084,
          5885.165,
          5835.044,
          5784.723,
          5734.201,
          5683.480,
          5632.560,
          5581.443,
          5530.129,
          5478.620,
          5426.915,
          5376.226,
          5322.925,
          5270.641,
          5218.166,
          5165.500,
          5112.645,
          5059.602,
          5006.371,
          4952.954,
          4899.351,
          4845.564,
          4791.593,
          4737.439,
        }

obsno = 38
obstring = "26 August 2010"

--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