ストワで始めるLua 第九回 アクティブソナー

activve sonar

--Initialize
pi=math.pi
pi2=pi*2
dt=1/60
waterSoundSpeed=1480*dt
range=property.getNumber('range')

behindAngle=math.rad(3) --Backward angle not visible.

activeData={}
pingTick=0
isPing=false

function onTick()

	isPingPush=input.getBool(19)
	
	if isPingPush and isPing==false then
		isPing=true
		activeData={}
		pingTick=0
	end

	if isPing then
		--Sonar data input
		for i=0,15 do
			if input.getBool(i+1) then
				local x,y
				x=input.getNumber(i*2+1)*pi2
				y=input.getNumber(i*2+2)*pi2
				if pi-behindAngle >= x and -pi+behindAngle <= x then
					table.insert(activeData,{distance=(pingTick*waterSoundSpeed)/2,bearing=x,elevation=y})
				end
			end
		end
		
		pingTick=pingTick+1
	end

	if (pingTick*waterSoundSpeed)/2 >range then
		isPing=false
	end
	output.setBool(1,isPing)
end

function onDraw()
	local w,h,cw,ch,radius
	--resolution
	w=screen.getWidth()
	h=screen.getHeight()
	--center
	cw=w/2
	ch=h/2
	--display sonars circle radius
	radius=h/2-3
	
	--drawing echo
	screen.setColor(0,255,0,128)
	for i=1,#activeData do
		local echoX,echoY
		echoX=cw+(activeData[i].distance/range)*radius*math.sin(activeData[i].bearing)
		echoY=ch-(activeData[i].distance/range)*radius*math.cos(activeData[i].bearing)
		screen.drawCircleF(echoX,echoY,2)
	end
	
	--drawing circle
	screen.setColor(0,255,0)
	screen.drawCircle(cw,ch,radius)
	screen.drawText(0,0,string.format("%.0f",range))
end