-- Check the end of the script for some explanations!

if (sim_call_type==sim_childscriptcall_initialization) then 
	modelBase=simGetObjectAssociatedWithScript(sim_handle_self)
	ref=simGetObjectHandle('GPS_reference')
	ui=simGetUIHandle('GPS_UI')
	simSetUIButtonLabel(ui,0,simGetObjectName(modelBase))
	gpsCommunicationTube=simTubeOpen(0,'gpsData'..simGetNameSuffix(nil),1)

	xShiftAmplitude=0
	yShiftAmplitude=0
	zShiftAmplitude=0
	xShift=0
	yShift=0
	zShift=0

--  By FOsorio
    fGPSsensors = io.open("GPS.log", "w")

end 

if (sim_call_type==sim_childscriptcall_cleanup) then 
    fGPSsensors:close()
end 

if (sim_call_type==sim_childscriptcall_sensing) then 
	xNoiseAmplitude=simGetScriptSimulationParameter(sim_handle_self,'xNoiseAmplitude')
	if not xNoiseAmplitude then xNoiseAmplitude=0 end
	if xNoiseAmplitude<0 then xNoiseAmplitude=0 end
	if xNoiseAmplitude>100 then xNoiseAmplitude=100 end
	
	yNoiseAmplitude=simGetScriptSimulationParameter(sim_handle_self,'yNoiseAmplitude')
	if not yNoiseAmplitude then yNoiseAmplitude=0 end
	if yNoiseAmplitude<0 then yNoiseAmplitude=0 end
	if yNoiseAmplitude>100 then yNoiseAmplitude=100 end
	
	zNoiseAmplitude=simGetScriptSimulationParameter(sim_handle_self,'zNoiseAmplitude')
	if not zNoiseAmplitude then zNoiseAmplitude=0 end
	if zNoiseAmplitude<0 then zNoiseAmplitude=0 end
	if zNoiseAmplitude>100 then zNoiseAmplitude=100 end
	
	xShiftAmplitudeN=simGetScriptSimulationParameter(sim_handle_self,'xShiftAmplitude')
	if not xShiftAmplitudeN then xShiftAmplitudeN=0 end
	if xShiftAmplitudeN<0 then xShiftAmplitudeN=0 end
	if xShiftAmplitudeN>100 then xShiftAmplitudeN=100 end
	if (xShiftAmplitudeN~=xShiftAmplitude) then
		xShiftAmplitude=xShiftAmplitudeN
		xShift=2*(math.random()-0.5)*xShiftAmplitude
	end
	
	yShiftAmplitudeN=simGetScriptSimulationParameter(sim_handle_self,'yShiftAmplitude')
	if not yShiftAmplitudeN then yShiftAmplitudeN=0 end
	if yShiftAmplitudeN<0 then yShiftAmplitudeN=0 end
	if yShiftAmplitudeN>100 then yShiftAmplitudeN=100 end
	if (yShiftAmplitudeN~=yShiftAmplitude) then
		yShiftAmplitude=yShiftAmplitudeN
		yShift=2*(math.random()-0.5)*yShiftAmplitude
	end
	
	zShiftAmplitudeN=simGetScriptSimulationParameter(sim_handle_self,'zShiftAmplitude')
	if not zShiftAmplitudeN then zShiftAmplitudeN=0 end
	if zShiftAmplitudeN<0 then zShiftAmplitudeN=0 end
	if zShiftAmplitudeN>100 then zShiftAmplitudeN=100 end
	if (zShiftAmplitudeN~=zShiftAmplitude) then
		zShiftAmplitude=zShiftAmplitudeN
		zShift=2*(math.random()-0.5)*zShiftAmplitude
	end
	
	objectAbsolutePosition=simGetObjectPosition(ref,-1)
	
	-- Now add some noise to make it more realistic:
	objectAbsolutePosition[1]=objectAbsolutePosition[1]+2*(math.random()-0.5)*xNoiseAmplitude+xShift
	objectAbsolutePosition[2]=objectAbsolutePosition[2]+2*(math.random()-0.5)*yNoiseAmplitude+yShift
	objectAbsolutePosition[3]=objectAbsolutePosition[3]+2*(math.random()-0.5)*zNoiseAmplitude+zShift
	
	simTubeWrite(gpsCommunicationTube,simPackFloats(objectAbsolutePosition))
	simSetUIButtonLabel(ui,3,string.format("X-pos: %.4f",objectAbsolutePosition[1]))
	simSetUIButtonLabel(ui,4,string.format("Y-pos: %.4f",objectAbsolutePosition[2]))
	simSetUIButtonLabel(ui,5,string.format("Z-pos: %.4f",objectAbsolutePosition[3]))

    fGPSsensors:write(string.format("%.4f ", objectAbsolutePosition[1]))
    fGPSsensors:write(string.format("%.4f\n",objectAbsolutePosition[2]))
	
	-- To read data from this GPS in another script, use following code:
	--
	-- gpsCommunicationTube=simTubeOpen(0,'gpsData'..simGetNameSuffix(nil),1) -- put this in the initialization phase
	-- data=simTubeRead(gpsCommunicationTube)
	-- if (data) then
	--     gpsPosition=simUnpackFloats(data)
	-- end
	--
	-- If the script in which you read the gps has a different suffix than the GPS suffix,
	-- then you will have to slightly adjust the code, e.g.:
	-- gpsCommunicationTube=simTubeOpen(0,'gpsData#') -- if the GPS script has no suffix
	-- or
	-- gpsCommunicationTube=simTubeOpen(0,'gpsData#0') -- if the GPS script has a suffix 0
	-- or
	-- gpsCommunicationTube=simTubeOpen(0,'gpsData#1') -- if the GPS script has a suffix 1
	-- etc.
	--
	--
	-- You can of course also use global variables (not elegant and not scalable), e.g.:
	-- In the GPS script:
	-- simSetFloatSignal('gpsX',objectAbsolutePosition[1])
	-- simSetFloatSignal('gpsY',objectAbsolutePosition[2])
	-- simSetFloatSignal('gpsZ',objectAbsolutePosition[3])
	--
	-- And in the script that needs the data:
	-- positionX=simGetFloatSignal('gpsX')
	-- positionY=simGetFloatSignal('gpsY')
	-- positionZ=simGetFloatSignal('gpsZ')
	--
	-- In addition to that, there are many other ways to have 2 scripts exchange data. Check the documentation for more details
end