Reclaim field highlight widget from ZK now in BAR. Makes it easier and faster to see reclaim fields and their sizes on the map map.

reclaim_field_highlight.lua

function widget:GetInfo()
	return {
		name      = "Reclaim Field Highlight",
		desc      = "Highlights clusters of reclaimable material",
		author    = "ivand, refactored by esainane, edited for BAR by Lexon",
		date      = "2022",
		license   = "public",
		layer     = 1000,
		enabled   = true  --  loaded by default?
	}
end

VFS.Include("LuaRules/Configs/customcmds.h.lua")


--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- Options

--[[----------------------------------------------------------------------------
	When to show reclaim highlight?
	In addition to options below you can bind "reclaim_highlight" action to a key
	and show reclaim when that key is pressed
------------------------------------------------------------------------------]]

--Always show reclaim highlight
local showHighlight_Always = false

	--Show reclaim when f4 resource view is active
	local showHighlight_Ecoview = true

	--Show reclaim when any unit that can reclaim is selected
	local showHighlight_AnyReclaimerSelected = true

		--Show reclaim when a ressurection bot is selected
		local showHighlight_ResBotSelected = true

		--Show reclaim when reclaim order is selected
		local showHighlight_ReclaimOrder = true


--------------------------------------------------------------------------------

--If true energy reclaim will be converted into metal (1 / 70) and added to the reclaim field value
local includeEnergy = false

--Metal value font
local numberColor = {1, 1, 1, 0.8}
local fontSizeMin = 30
local fontSizeMax = 250
local fontScaling = 0.6

--Field color
local reclaimColor = {0, 0, 0, 0.2}
local reclaimEdgeColor = {1, 1, 1, 0.22}

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- Priority Queue
local min = math.min
local max = math.max
local mathHuge = math.huge
local sqrt = math.sqrt

local insert = table.insert
local remove = table.remove

local PriorityQueue = {}

function PriorityQueue.new(cmp, initial)
	local pq = setmetatable({}, {
		__index = {
			cmp = cmp or function(a,b) return a < b end,
			push = function(self, v)
				insert(self, v)
				local next = #self
				local prev = (next-next%2)/2
				while next > 1 and cmp(self[next], self[prev]) do
					self[next], self[prev] = self[prev], self[next]
					next = prev
					prev = (next-next%2)/2
				end
			end,
			pop = function(self)
				if #self < 2 then
					return remove(self)
				end
				local root = 1
				local r = self[root]
				self[root] = remove(self)
				local size = #self
				if size > 1 then
					local child = 2*root
					while child <= size do
						local aBool =   cmp(self[root],self[child]);
						local bBool =   true;
						local cBool =   true;
						if child+1 <= size then
							bBool =   cmp( self[root],self[child+1]);
							cBool =   cmp(self[child], self[child+1]);
						end
						if aBool and bBool then
							break;
						elseif cBool then
							self[root], self[child] = self[child], self[root]
							root = child
						else
							self[root], self[child+1] = self[child+1], self[root]
							root = child+1
						end
						child = 2*root
					end
				end
				return r
			end,
			peek = function(self)
				return self[1]
			end,
		}
	})

	for _,el in ipairs(initial or {}) do
		pq:push(el)
	end

	return pq
end

-------
-------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- Optics

local function DistSq(p1, p2)
	return (p1.x - p2.x)^2 + (p1.z - p2.z)^2
end

local TableEcho = Spring.Utilities.TableEcho

local Optics = {}
function Optics.new(incPoints, incNeighborMatrix, incMinPoints)
	local object = setmetatable({}, {
		__index = {
			points = incPoints or {},
			neighborMatrix  = incNeighborMatrix or {},
			minPoints = incMinPoints,

			pointByfID = {},

			unprocessed = {},
			ordered = {},

			-- get ready for a clustering run
			_Setup = function(self)
				local points, unprocessed = self.points, self.unprocessed
				--Spring.Echo("epsSq", self.epsSq, "minPoints", self.minPoints)

				for pIdx, point in pairs(points) do
					point.rd = nil
					point.cd = nil
					point.processed = nil
					unprocessed[point] = true
					self.pointByfID[point.fID] = point
				end
			end,

			-- distance from a point to its nth neighbor (n = minPoints - 1)
			_CoreDistance = function(self, point, neighbors)
				if point.cd then
					return point.cd
				end

				if #neighbors >= self.minPoints - 1 then --(minPoints - 1) because point is also part of minPoints
					local distTable = {}
					for i = 1, #neighbors do
						local neighbor = neighbors[i]
						distTable[#distTable + 1] = DistSq(point, neighbor)
					end
					table.sort(distTable)
					--TableEcho({point=point, neighbors=neighbors, distTable=distTable}, "_CoreDistance (#neighbors >= self.minPoints - 1)")

					point.cd = distTable[self.minPoints - 1] --return (minPoints - 1) farthest distance as CoreDistance
					return point.cd
				end
				return nil
			end,

			-- neighbors for a point within eps
			_Neighbors = function(self, pIdx)
				local neighbors = {}

				for pIdx2, _ in pairs(self.neighborMatrix[pIdx]) do
					neighbors[#neighbors + 1] = self.pointByfID[pIdx2]
				end
				--Spring.Echo("#neighbors", #neighbors)

				return neighbors
			end,

			-- mark a point as processed
			_Processed = function(self, point)
				--Spring.Echo("_Processed")
				point.processed = true
				self.unprocessed[point] = nil

				local ordered = self.ordered
				ordered[#ordered + 1] = point
			end,

			-- update seeds if a smaller reachability distance is found
			_Update = function(self, neighbors, point, seedsPQ)
				for ni = 1, #neighbors do
					local n = neighbors[ni]
					if not n.processed then
						--Spring.Echo("newRD")
						local newRd = max(point.cd, DistSq(point, n))
						if n.rd == nil then
							n.rd = newRd
							--this is a bug!!!!
							seedsPQ:push({newRd, n})
						elseif newRd < n.rd then
							--this is a bug!!!!
							n.rd = newRd
						end
					end
				end
				--return seedsPQ
			end,

			-- run the OPTICS algorithm
			Run = function(self)
				self:_Setup()

				local unprocessed = self.unprocessed
				--TableEcho(unprocessed, "unprocessed")
				while next(unprocessed) do
					--TableEcho({item=next(unprocessed)}, "next(unprocessed)")
					local point = next(unprocessed)

					-- mark p as processed
					self:_Processed(point)

					-- find p's neighbors
					local neighbors = self:_Neighbors(point.fID)
					--TableEcho({point=point, neighbors=neighbors}, "self:_Neighbors(point)")
					--TableEcho({point=point, neighborsNum=#neighbors}, "self:_Neighbors(point)")

					-- if p has a core_distance, i.e has min_cluster_size - 1 neighbors
					if self:_CoreDistance(point, neighbors) then
						--Spring.Echo("if self:_CoreDistance(point, neighbors) then")
						local seedsPQ = PriorityQueue.new( function(a,b) return a[1] < b[1] end )
						--seedsPQ = self:_Update(neighbors, point, seedsPQ)
						self:_Update(neighbors, point, seedsPQ)
						while seedsPQ:peek() do
							-- seeds.sort(key=lambda n: n.rd)
							local n = seedsPQ:pop()[2] --because we don't need priority
							--TableEcho({n=n}, "seedsPQ:pop()")

							-- mark n as processed
							self:_Processed(n)

							-- find n's neighbors
							local nNeighbors = self:_Neighbors(n.fID)
							--TableEcho({n=n, nNeighbors=nNeighbors}, "seedsPQ:peek()")

							-- if p has a core_distance...
							if self:_CoreDistance(n, nNeighbors) then
								--seedsPQ = self:_Update(nNeighbors, n, seedsPQ)
								self:_Update(nNeighbors, n, seedsPQ)
							end
						end
					end
				end

				-- when all points have been processed
				-- return the ordered list
				--Spring.Echo("#ordered", #self.ordered)
				--TableEcho({ordered = self.ordered}, "ordered")
				return self.ordered
			end,

			-- ???
			Clusterize = function(self, clusterThreshold)
				local clusters = {}
				local separators = {}

				local clusterThresholdSq = clusterThreshold^2

				local ordered = self.ordered

				for i = 1, #ordered do
					local thisP = ordered[i]
					local thisRD = thisP.rd or mathHuge

					-- use an upper limit to separate the clusters

					if thisRD > clusterThresholdSq then
						separators[#separators + 1] = i
					end
				end
				separators[#separators + 1] = #ordered + 1
				--TableEcho(separators,"separators")

				for j = 1, #separators - 1 do
					local sepStart = separators[j]
					local sepEnd = separators[j + 1]
					print(sepEnd, sepStart, sepEnd - sepStart, self.minPoints)
					if sepEnd - sepStart >= self.minPoints then
						--Spring.Echo("sepEnd - sepStart >= self.minPoints")
						--self.ordered[start:end]
						local clPoints = {}
						for si = sepStart, sepEnd - 1 do
							clPoints[#clPoints + 1] = ordered[si].fID
						end
					--	TableEcho({clPoints=clPoints}, "clPoints")

						clusters[#clusters + 1] = {}
						clusters[#clusters].members = clPoints
						--Spring.Echo("#clPoints", #clPoints)
					end
				end
				--TableEcho({ordered=ordered}, "clusters")
				return clusters
			end,
		}
	})
	return object
end


--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- Convex Hull

local function cross(p, q, r)
	return (q.z - p.z) * (r.x - q.x)
		 - (q.x - p.x) * (r.z - q.z)
end

--- JARVIS MARCH

--- MONOTONE CHAIN
-- https://gist.githubusercontent.com/sixFingers/ee5c1dce72206edc5a42b3246a52ce2e/raw/b2d51e5236668e5408d24b982eec9c339dc94065/Lua%2520Convex%2520Hull

-- Andrew's monotone chain convex hull algorithm
-- https://en.wikibooks.org/wiki/Algorithm_Implementation/Geometry/Convex_hull/Monotone_chain
-- Direct port from Javascript version

local function MonotoneChain(points)
	local numPoints = #points
	if numPoints < 3 then return end

	table.sort(points,
		function(a, b)
			return a.x == b.x and a.z > b.z or a.x > b.x
		end
	)

	local lower = {}
	for i = 1, numPoints do
		while (#lower >= 2 and cross(lower[#lower - 1], lower[#lower], points[i]) <= 0) do
			table.remove(lower, #lower)
		end

		table.insert(lower, points[i])
	end

	local upper = {}
	for i = numPoints, 1, -1 do
		while (#upper >= 2 and cross(upper[#upper - 1], upper[#upper], points[i]) <= 0) do
			table.remove(upper, #upper)
		end

		table.insert(upper, points[i])
	end

	table.remove(upper, #upper)
	table.remove(lower, #lower)
	for _, point in ipairs(lower) do
		table.insert(upper, point)
	end
	return upper
end


--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- Speedups

local glBeginEnd = gl.BeginEnd
local glBlending = gl.Blending
local glCallList = gl.CallList
local glColor = gl.Color
local glCreateList = gl.CreateList
local glDeleteList = gl.DeleteList
local glDepthTest = gl.DepthTest
local glLineWidth = gl.LineWidth
local glPolygonMode = gl.PolygonMode
local glPopMatrix = gl.PopMatrix
local glPushMatrix = gl.PushMatrix
local glRotate = gl.Rotate
local glText = gl.Text
local glTranslate = gl.Translate
local glVertex = gl.Vertex
local spGetAllFeatures = Spring.GetAllFeatures
local spGetCameraPosition = Spring.GetCameraPosition
local spGetFeatureHeight = Spring.GetFeatureHeight
local spGetFeaturePosition = Spring.GetFeaturePosition
local spGetFeatureResources = Spring.GetFeatureResources
local spGetFeatureTeam = Spring.GetFeatureTeam
local spGetGaiaTeamID = Spring.GetGaiaTeamID
local spGetGameFrame = Spring.GetGameFrame
local spGetGroundHeight = Spring.GetGroundHeight
local spIsGUIHidden = Spring.IsGUIHidden
local spTraceScreenRay = Spring.TraceScreenRay
local spValidFeatureID = Spring.ValidFeatureID
local spGetActiveCommand = Spring.GetActiveCommand
local spGetActiveCmdDesc = Spring.GetActiveCmdDesc
local spGetMapDrawMode = Spring.GetMapDrawMode
local spGetUnitDefID = Spring.GetUnitDefID
local spGetCameraVectors = Spring.GetCameraVectors

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- Data

local screenx, screeny

local gaiaTeamId = spGetGaiaTeamID()

local scanInterval = 1 * Game.gameSpeed
local scanForRemovalInterval = 2 * Game.gameSpeed --2 sec

local minDistance = 300
local minSqDistance = minDistance^2
local minPoints = 2
local minFeatureMetal = 9 --flea

local drawEnabled = true
local actionActive = false
local textParametersChanged = false
local knownFeatures = {}

local reclaimerSelected = false
local resBotSelected = false


local canReclaim = {}
local canResurrect = {}
for unitDefID, unitDef in pairs(UnitDefs) do
	if unitDef.canResurrect then
		canResurrect[unitDefID] = true
	end
	if unitDef.isBuilder and not unitDef.isBuilding then
		canReclaim[unitDefID] = true
	end
end

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- State update

local function enableHighlight()
	actionActive = true
end

local function disableHighlight()
	actionActive = false
end

local function UpdateDrawEnabled()
	if actionActive then return true end
	local ecoview = (spGetMapDrawMode() == 'metal')
	if showHighlight_Always or
		(showHighlight_Ecoview and ecoview) or
		(showHighlight_AnyReclaimerSelected and reclaimerSelected) or
		(showHighlight_ResBotSelected and resBotSelected) then
		return true
	end
	if showHighlight_ReclaimOrder then
		local currentCmd = spGetActiveCommand()
		if currentCmd then
			local activeCmdDesc = spGetActiveCmdDesc(currentCmd)
			return (activeCmdDesc and (activeCmdDesc.name == "Reclaim"))
		end
	end
	return false
end

function widget:SelectionChanged(units)
	local udefID
	reclaimerSelected = false
	resBotSelected = false
	for _, v in pairs(units) do
		udefID = spGetUnitDefID(v)
		if canResurrect[udefID] then
			resBotSelected = true
			reclaimerSelected = true
			return
		elseif canReclaim[udefID] then
			reclaimerSelected = true
			return
		end
	end
end

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- Feature Tracking

local featureNeighborsMatrix = {}
local function UpdateFeatureNeighborsMatrix(fID, added, posChanged, removed)
	local fInfo = knownFeatures[fID]

	if added then
		featureNeighborsMatrix[fID] = {}
		for fID2, fInfo2 in pairs(knownFeatures) do
			if fID2 ~= fID then --don't include self into featureNeighborsMatrix[][]
				local sqDist = (fInfo.x - fInfo2.x)^2 + (fInfo.z - fInfo2.z)^2
				if sqDist <= minSqDistance then
					featureNeighborsMatrix[fID][fID2] = true
					featureNeighborsMatrix[fID2][fID] = true
				end
			end
		end
	end

	if removed then
		for fID2, _ in pairs(featureNeighborsMatrix[fID]) do
			featureNeighborsMatrix[fID2][fID] = nil
			featureNeighborsMatrix[fID][fID2] = nil
		end
	end

	if posChanged then
		UpdateFeatureNeighborsMatrix(fID, false, false, true) --remove
		UpdateFeatureNeighborsMatrix(fID, true, false, false) --add again
	end
end

local featureClusters = {}

local E2M = 1 / 70 --solar ratio

local featuresUpdated = false
local clusterMetalUpdated = false

local function UpdateFeatures(gf)
	featuresUpdated = false
	clusterMetalUpdated = false

	for _, fID in ipairs(spGetAllFeatures()) do
		local metal, _, energy = spGetFeatureResources(fID)

		if includeEnergy then metal = metal + energy * E2M end

		if (not knownFeatures[fID]) and (metal >= minFeatureMetal) then --first time seen
			local f = {}
			f.lastScanned = gf

			local fx, _, fz = spGetFeaturePosition(fID)
			local fy = spGetGroundHeight(fx, fz)
			f.x = fx
			f.y = fy
			f.z = fz

			f.isGaia = (spGetFeatureTeam(fID) == gaiaTeamId)
			f.height = spGetFeatureHeight(fID)
			f.drawAlt = ((fy > 0 and fy) or 0) --+ f.height

			f.metal = metal

			knownFeatures[fID] = f

			UpdateFeatureNeighborsMatrix(fID, true, false, false)
			featuresUpdated = true
		end

		if knownFeatures[fID] and gf - knownFeatures[fID].lastScanned >= scanInterval then
			knownFeatures[fID].lastScanned = gf

			local fx, _, fz = spGetFeaturePosition(fID)
			local fy = spGetGroundHeight(fx, fz)

			if knownFeatures[fID].x ~= fx or knownFeatures[fID].y ~= fy or knownFeatures[fID].z ~= fz then
				knownFeatures[fID].x = fx
				knownFeatures[fID].y = fy
				knownFeatures[fID].z = fz

				knownFeatures[fID].drawAlt = ((fy > 0 and fy) or 0) --+ knownFeatures[fID].height

				UpdateFeatureNeighborsMatrix(fID, false, true, false)
			featuresUpdated = true
			end

			if knownFeatures[fID].metal ~= metal then
				--spEcho("knownFeatures[fID].metal ~= metal", metal)
				if knownFeatures[fID].clID then
					--spEcho("knownFeatures[fID].clID")
					local thisCluster = featureClusters[ knownFeatures[fID].clID ]
					thisCluster.metal = thisCluster.metal - knownFeatures[fID].metal
					if metal >= minFeatureMetal then
						thisCluster.metal = thisCluster.metal + metal
						knownFeatures[fID].metal = metal
						--spEcho("clusterMetalUpdated = true", thisCluster.metal)
						clusterMetalUpdated = true
					else
						UpdateFeatureNeighborsMatrix(fID, false, false, true)
						knownFeatures[fID] = nil
						featuresUpdated = true
					end
				end
			end
		end
	end

	for fID, fInfo in pairs(knownFeatures) do

		if fInfo.isGaia and spValidFeatureID(fID) == false then
			--spEcho("fInfo.isGaia and spValidFeatureID(fID) == false")

			UpdateFeatureNeighborsMatrix(fID, false, false, true)
			fInfo = nil
			knownFeatures[fID] = nil
			featuresUpdated = true
		end

		if fInfo and gf - fInfo.lastScanned >= scanForRemovalInterval then --long time unseen features, maybe they were relcaimed or destroyed?
			UpdateFeatureNeighborsMatrix(fID, false, false, true)
			fInfo = nil
			knownFeatures[fID] = nil
			featuresUpdated = true
		end

		if fInfo and featuresUpdated then
			knownFeatures[fID].clID = nil
		end
	end
	
end


local function ClusterizeFeatures()
	local pointsTable = {}

	local unclusteredPoints  = {}

	--spEcho("#knownFeatures", #knownFeatures)

	for fID, fInfo in pairs(knownFeatures) do
		pointsTable[#pointsTable + 1] = {
			x = fInfo.x,
			z = fInfo.z,
			fID = fID,
		}
		unclusteredPoints[fID] = true
	end

	--TableEcho(featureNeighborsMatrix, "featureNeighborsMatrix")

	local opticsObject = Optics.new(pointsTable, featureNeighborsMatrix, minPoints)
	opticsObject:Run()

	featureClusters = opticsObject:Clusterize(minDistance)

	for i = 1, #featureClusters do
		local thisCluster = featureClusters[i]

		thisCluster.xmin = mathHuge
		thisCluster.xmax = -mathHuge
		thisCluster.zmin = mathHuge
		thisCluster.zmax = -mathHuge


		local metal = 0
		for j = 1, #thisCluster.members do
			local fID = thisCluster.members[j]
			local fInfo = knownFeatures[fID]

			thisCluster.xmin = min(thisCluster.xmin, fInfo.x)
			thisCluster.xmax = max(thisCluster.xmax, fInfo.x)
			thisCluster.zmin = min(thisCluster.zmin, fInfo.z)
			thisCluster.zmax = max(thisCluster.zmax, fInfo.z)

			metal = metal + fInfo.metal
			knownFeatures[fID].clID = i
			unclusteredPoints[fID] = nil
		end

		thisCluster.metal = metal
	end

	for fID, _ in pairs(unclusteredPoints) do --add Singlepoint featureClusters
		local fInfo = knownFeatures[fID]
		local thisCluster = {}

		thisCluster.members = {fID}
		thisCluster.metal = fInfo.metal

		thisCluster.xmin = fInfo.x
		thisCluster.xmax = fInfo.x
		thisCluster.zmin = fInfo.z
		thisCluster.zmax = fInfo.z

		featureClusters[#featureClusters + 1] = thisCluster
		knownFeatures[fID].clID = #featureClusters
	end

end

local function lineCheck(points)
	if points[1] == nil then return true end
	local totalArea = 0
	local pt1 = points[1]
	for i = 2, #points - 1 do
		local pt2 = points[i]
		local pt3 = points[i + 1]
		--Heron formula to get triangle area
		local a = sqrt((pt2.x - pt1.x)^2 + (pt2.z - pt1.z)^2)
		local b = sqrt((pt3.x - pt2.x)^2 + (pt3.z - pt2.z)^2)
		local c = sqrt((pt3.x - pt1.x)^2 + (pt3.z - pt1.z)^2)
		local p = (a + b + c)/2 --half perimeter

		local triangleArea = sqrt(p * (p - a) * (p - b) * (p - c))
		totalArea = totalArea + triangleArea
	end
	if totalArea < 3000 then return false end
	return true
end


local minDim = 100

local featureConvexHulls = {}
local function ClustersToConvexHull()

	featureConvexHulls = {}
	--spEcho("#featureClusters", #featureClusters)
	for fc = 1, #featureClusters do
		local clusterPoints = {}

		for fcm = 1, #featureClusters[fc].members do
			local fID = featureClusters[fc].members[fcm]
			clusterPoints[#clusterPoints + 1] = {
				x = knownFeatures[fID].x,
				y = knownFeatures[fID].drawAlt,
				z = knownFeatures[fID].z
			}
			--Spring.MarkerAddPoint(knownFeatures[fID].x, 0, knownFeatures[fID].z, string.format("%i(%i)", fc, fcm))
		end
		
		--- TODO perform pruning as described in the article below, if convex hull algo will start to choke out
		-- http://mindthenerd.blogspot.ru/2012/05/fastest-convex-hull-algorithm-ever.html
		
		local convexHull
		if #clusterPoints >= 3 and lineCheck(clusterPoints) then
			--spEcho("#clusterPoints >= 3")
			--convexHull = ConvexHull.JarvisMarch(clusterPoints)
			convexHull = MonotoneChain(clusterPoints) --twice faster
		else 
			--spEcho("not #clusterPoints >= 3")
			local thisCluster = featureClusters[fc]

			local xmin, xmax, zmin, zmax = thisCluster.xmin, thisCluster.xmax, thisCluster.zmin, thisCluster.zmax

			local dx, dz = xmax - xmin, zmax - zmin

			if dx < minDim then
				xmin = xmin - (minDim - dx) / 2
				xmax = xmax + (minDim - dx) / 2
			end

			if dz < minDim then
				zmin = zmin - (minDim - dz) / 2
				zmax = zmax + (minDim - dz) / 2
			end

			local height = clusterPoints[1].y
			if #clusterPoints == 2 then
				height = max(height, clusterPoints[2].y)
			end

			convexHull = {
				{x = xmin, y = height, z = zmin},
				{x = xmax, y = height, z = zmin},
				{x = xmax, y = height, z = zmax},
				{x = xmin, y = height, z = zmax},
			}
		end

		local cx, cz, cy = 0, 0, 0
		for i = 1, #convexHull do
			local convexHullPoint = convexHull[i]
			cx = cx + convexHullPoint.x
			cz = cz + convexHullPoint.z
			cy = max(cy, convexHullPoint.y)
		end
		
		local totalArea = 0
		local pt1 = convexHull[1]
		for i = 2, #convexHull - 1 do
			local pt2 = convexHull[i]
			local pt3 = convexHull[i + 1]
			--Heron formula to get triangle area
			local a = sqrt((pt2.x - pt1.x)^2 + (pt2.z - pt1.z)^2)
			local b = sqrt((pt3.x - pt2.x)^2 + (pt3.z - pt2.z)^2)
			local c = sqrt((pt3.x - pt1.x)^2 + (pt3.z - pt1.z)^2)
			local p = (a + b + c)/2 --half perimeter

			local triangleArea = sqrt(p * (p - a) * (p - b) * (p - c))
			totalArea = totalArea + triangleArea
		end
		
		convexHull.area = totalArea
		convexHull.center = {x = cx/#convexHull, z = cz/#convexHull, y = cy + 1}

		featureConvexHulls[fc] = convexHull

--[[
		for i = 1, #convexHull do
			Sppring.MarkerAddPoint(convexHull[i].x, convexHull[i].y, convexHull[i].z, string.format("C%i(%i)", fc, i))
		end
]]--
	end
end

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

function widget:Initialize()
	screenx, screeny = widgetHandler:GetViewSizes()
	
	widgetHandler:AddAction("reclaim_highlight", enableHighlight, nil, "p")
	widgetHandler:AddAction("reclaim_highlight", disableHighlight, nil, "r")
end

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- Drawing

local camUpVector
local cameraScale

local function DrawHullVertices(hull)
	for j = 1, #hull do
		glVertex(hull[j].x, hull[j].y, hull[j].z)
	end
end

local drawFeatureConvexHullSolidList
local function DrawFeatureConvexHullSolid()
	glPolygonMode(GL.FRONT_AND_BACK, GL.FILL)
	for i = 1, #featureConvexHulls do
		glBeginEnd(GL.TRIANGLE_FAN, DrawHullVertices, featureConvexHulls[i])
	end
end

local drawFeatureConvexHullEdgeList
local function DrawFeatureConvexHullEdge()
	glPolygonMode(GL.FRONT_AND_BACK, GL.LINE)
	for i = 1, #featureConvexHulls do
		glBeginEnd(GL.LINE_LOOP, DrawHullVertices, featureConvexHulls[i])
	end
	glPolygonMode(GL.FRONT_AND_BACK, GL.FILL)
end

local drawFeatureClusterTextList
local function DrawFeatureClusterText()
	for i = 1, #featureConvexHulls do
		glPushMatrix()

		local center = featureConvexHulls[i].center

		glTranslate(center.x, center.y, center.z)
		glRotate(-90, 1, 0, 0)

		-- Rotate text based on camera rotation
		if camUpVector[1] and camUpVector[3] then
			local rotationAngle = math.atan2(-camUpVector[1], -camUpVector[3]) * (180 / math.pi)
			glRotate(rotationAngle, 0, 0, 1)
		end


		local fontSize = fontSizeMin * fontScaling
		local area = featureConvexHulls[i].area
		fontSize = sqrt(area) * fontSize / minDim
		fontSize = max(fontSize, fontSizeMin)
		fontSize = min(fontSize, fontSizeMax)

		local metal = featureClusters[i].metal
		local metalText
		--Spring.Debug.TableEcho(Spring.GetCameraState())
		if metal < 1000 then
			metalText = string.format("%.0f", metal) --exact number
		elseif metal < 10000 then
			metalText = string.format("%.1fK", math.floor(metal / 100) / 10) --4.5K
		else
			metalText = string.format("%.0fK", math.floor(metal / 1000)) --40K
		end

		glColor(numberColor)

		glText(metalText, 0, 0, fontSize, "cv")--cvo for outline

		glPopMatrix()
	end
end

local checkFrequency = 30

local cumDt = 0
function widget:Update(dt)
	cumDt = cumDt + dt
	local cx, cy, cz = spGetCameraPosition()

	local desc, w = spTraceScreenRay(screenx / 2, screeny / 2, true)
	if desc then
		local cameraDist = min( 8000, sqrt( (cx-w[1])^2 + (cy-w[2])^2 + (cz-w[3])^2 ) )
		cameraScale = sqrt((cameraDist / 600)) --number is an "optimal" view distance
	else
		cameraScale = 1.0
	end

	drawEnabled = UpdateDrawEnabled()
end

function widget:GameFrame(frame)
	local frameMod = frame % checkFrequency
	if frameMod ~= 0 then
		return
	end

	UpdateFeatures(frame)

	if featuresUpdated then
		ClusterizeFeatures()
		ClustersToConvexHull()
	end

	if featuresUpdated or drawFeatureConvexHullSolidList == nil then
		if drawFeatureConvexHullSolidList then
			glDeleteList(drawFeatureConvexHullSolidList)
			drawFeatureConvexHullSolidList = nil
		end

		if drawFeatureConvexHullEdgeList then
			glDeleteList(drawFeatureConvexHullEdgeList)
			drawFeatureConvexHullEdgeList = nil
		end

		drawFeatureConvexHullSolidList = glCreateList(DrawFeatureConvexHullSolid)
		drawFeatureConvexHullEdgeList = glCreateList(DrawFeatureConvexHullEdge)
	end


	local camUpVectorCurrent = spGetCameraVectors().up
	if textParametersChanged or featuresUpdated or clusterMetalUpdated or drawFeatureClusterTextList == nil or camUpVectorCurrent ~= camUpVector then
		camUpVector = camUpVectorCurrent
		if drawFeatureClusterTextList then
			glDeleteList(drawFeatureClusterTextList)
			drawFeatureClusterTextList = nil
		end
		drawFeatureClusterTextList = glCreateList(DrawFeatureClusterText)
		textParametersChanged = false
	end
end

function widget:ViewResize(viewSizeX, viewSizeY)
	screenx, screeny = widgetHandler:GetViewSizes()
end

function widget:DrawWorld()
	if spIsGUIHidden() or not drawEnabled then
		return
	end

	glDepthTest(false)

	glBlending(GL.SRC_ALPHA, GL.ONE_MINUS_SRC_ALPHA)

	if drawFeatureClusterTextList then
		glCallList(drawFeatureClusterTextList)
		--DrawFeatureClusterText()
	end

	glDepthTest(true)
end

function widget:DrawWorldPreUnit()
	if spIsGUIHidden() or not drawEnabled then
		return
	end

	glDepthTest(false)

	glBlending(GL.SRC_ALPHA, GL.ONE_MINUS_SRC_ALPHA)
	if drawFeatureConvexHullSolidList then
		glColor(reclaimColor)
		glCallList(drawFeatureConvexHullSolidList)
		--DrawFeatureConvexHullSolid()
	end

	if drawFeatureConvexHullEdgeList then
		glLineWidth(6.0 / cameraScale)
		glColor(reclaimEdgeColor)
		glCallList(drawFeatureConvexHullEdgeList)
		--DrawFeatureConvexHullEdge()
		glLineWidth(1.0)
	end

	glDepthTest(true)
end

function widget:Shutdown()
	if drawFeatureConvexHullSolidList then
		glDeleteList(drawFeatureConvexHullSolidList)
	end
	if drawFeatureConvexHullEdgeList then
		glDeleteList(drawFeatureConvexHullEdgeList)
	end
	if drawFeatureClusterTextList then
		glDeleteList(drawFeatureClusterTextList)
	end
end