extends MeshInstance

var latMin = 0
var latMax = 1
var lonMin = 0
var lonMax = 1
var resolution = 512
var radius = 1737.4 
var rng = RandomNumberGenerator.new()

var datafile = "user://sldem2015_512_00n_30n_000_045_float.img"
var samplesPerLine = 23040
var lines = 15360
var offset = 1737.4
var scaleFact = 1

func init(startLat, startLon):
	
	self.latMin = startLat
	self.latMax = startLat + 1
	self.lonMin = startLon
	self.lonMax = startLon + 1
		
# Called when the node enters the scene tree for the first time.
func _ready():
	
	if ResourceLoader.exists("user://tile_"+str(latMin)+"-"+str(lonMin)+".tres"):
		print("loading tile from file: ", "user://tile_"+str(latMin)+"-"+str(lonMin)+".tres")
		mesh = ResourceLoader.load("user://tile_"+str(latMin)+"-"+str(lonMin)+".tres")
	else:
		self.genMesh()
	
	var texture = ImageTexture.new()
	var image = Image.new()
	#image.load("res://m-"+str(latMin+90)+"-"+str(lonMin+180)+".png")
	image.load("user://colorTiles/m-" + str(latMin+90)+"-"+str(lonMin+180)+".png")
	texture.create_from_image(image)
	var material=SpatialMaterial.new()
	material.albedo_texture = texture
	.set_material_override(material)
	#print("creating collition...")
	#.create_trimesh_collision()
		
func genMesh():
	var file = File.new()
	file.open(datafile, File.READ)
	#for lala in range(10):
	#	file.seek(lala*samplesPerLine*4)
	#	var blubb = ""
	#	for bla in range(10):
	#		blubb += " " + str(file.get_float())
	#	print(blubb)
	rng.randomize()
	var arr = []
	arr.resize(Mesh.ARRAY_MAX)
	#OS.delay_msec(2000)
	# PoolVectorXXArrays for mesh construction.
	var verts = PoolVector3Array()
	verts.resize((lonMax-lonMin) *resolution*(lonMax-lonMin) *resolution)
	var uvs = PoolVector2Array()
	uvs.resize((lonMax-lonMin) *resolution*(lonMax-lonMin) *resolution)
	var normals = PoolVector3Array()
	normals.resize((lonMax-lonMin) *resolution*resolution * (lonMax-lonMin))
	var indices = PoolIntArray()
	indices.resize(6* (lonMax-lonMin)*resolution*(lonMax-lonMin) * resolution*6)
	var i_idx = 0
	

	# Vertex indices.
	var thisrow = 0
	var prevrow = 0
	var point = 0

	print(
		"calculating segment "+str(latMin)+"-"+str(lonMin)+":\n",
		"lat:\n",
		"  min: ", latMin*resolution, "\n",
		"  max:", latMax*resolution, "\n",
		"  count: ", (latMax-latMin) * resolution, "\n",
		"lon:\n",
		"  min: ", lonMin*resolution, "\n",
		"  max:", lonMax*resolution, "\n",
		"  count: ", (lonMax-lonMin) * resolution, "\n"
	)
	
	#OS.delay_msec(2000)

	var vert = Vector3()
	# Loop over rings.
	for latPos in range(float(latMin)*resolution, float(latMax)*resolution):
		var latCur = float(latPos)/float(resolution)
		#jump to    last line in file   -   current local lat    -      local startLat     +  local startLon
		file.seek(lines*samplesPerLine*4-latPos*samplesPerLine*4 - latMin*samplesPerLine*4 + lonMin*resolution*4)
		#file.seek(latPos*samplesPerLine*4 + latMin*samplesPerLine*4 + lonMin*resolution*4)
		#file.seek(latPos*samplesPerLine*4 + lonMin*resolution*4) 
		#file.seek(((latMax*resolution-1-latPos)*samplesPerLine + lonMin*resolution)*4)
		#var v = float(latPos-latMin*resolution) / ((latMax-latMin) * resolution)
		var v = float(latPos-latMin*resolution) / ((latMax-latMin) * resolution)
		#var lat = float(latPos)*PI/(resolution*180)
		#var w = cos(lat)
		#var y = sin(lat)
		#print(v*100, "%")

		# Loop over segments in ring.
		for lonPos in range(float(lonMin)*resolution, float(lonMax)*resolution):
			var lonCur = float(lonPos)/float(resolution)
			var u = float(lonPos-lonMin*resolution) / ((lonMax - lonMin) * resolution)
			#var lon = float(lonPos)*PI/(resolution*180)
			#var x = sin(lon)
			#var z = cos(lon)
			#print("Lon: ", lon)
			#var height = file.get_float()/offset*radius+radius
			var height = file.get_float()+radius
			vert = Common.latLonToGlobal(latCur, lonCur, height)
			#vert = Vector3(scaleFact * x * height * w, scaleFact * y*height, scaleFact * z * height * w)
			verts[point] = vert
			normals[point] = vert.normalized()
			uvs[point] = Vector2(u, 1-v)
			point += 1

			# Create triangles in ring using indices.
			if latPos > lonMin*resolution and lonPos > lonMin*resolution:
				indices[i_idx] = (prevrow + (lonPos-lonMin*resolution) - 1)
				i_idx+=1
				indices[i_idx] = (thisrow + (lonPos-lonMin*resolution) - 1)
				i_idx+=1
				indices[i_idx] = (prevrow + (lonPos-lonMin*resolution))
				i_idx+=1

				indices[i_idx] = (prevrow + (lonPos-lonMin*resolution))
				i_idx+=1
				indices[i_idx] = (thisrow + (lonPos-lonMin*resolution) - 1)
				i_idx+=1
				indices[i_idx] = (thisrow + (lonPos-lonMin*resolution))
				i_idx+=1
				

		#if latPos > latMin*resolution:
		#	indices[i_idx] = (prevrow + ((latMax - latMin) * resolution) - 1)
		#	i_idx+=1
		#	indices[i_idx] = (prevrow)
		#	i_idx+=1
		#	indices[i_idx] = (thisrow + ((latMax - latMin) * resolution) - 1)
		#	i_idx+=1

		#	indices[i_idx] = (prevrow)
		#	i_idx+=1
		#	indices[i_idx] = (prevrow + ((latMax - latMin) * resolution))
		#	i_idx+=1
		#	indices[i_idx] = (thisrow + ((latMax - latMin) * resolution) - 1)
		#	i_idx+=1
		#print(vert)

		prevrow = thisrow
		thisrow = point

	file.close()
	print(vert)
	# Assign arrays to mesh array.
	arr[Mesh.ARRAY_VERTEX] = verts
	arr[Mesh.ARRAY_TEX_UV] = uvs
	arr[Mesh.ARRAY_NORMAL] = normals
	arr[Mesh.ARRAY_INDEX] = indices

	mesh = Mesh.new()
	# Create mesh surface from mesh array.
	mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, arr)
	print(mesh)
	ResourceSaver.save("user://tile_"+str(latMin)+"-"+str(lonMin)+".tres", mesh, 32)
	print("saved tile_"+str(latMin)+"-"+str(lonMin))
	

# Called every frame. 'delta' is the elapsed time since the previous frame.
#func _process(delta):
#	pass