Mount Gen: convert HeightMap as class. Relates to #1906

mods/lord/World/mountgen/src/algorithms/cone.lua

@@ -1,25 +1,15 @@
 local math_min, math_max, math_floor, math_ceil, math_sqrt, math_tan, math_rad
     = math.min, math.max, math.floor, math.ceil, math.sqrt, math.tan, math.rad
 
+local HeightMap = require('generator.HeightMap')
 
-local MIN_CONE_FOOT_DIAMETER = 3
-
---- @param diameter number
---- @return number[][]
-local function fill_with_zeroes(diameter)
-	local map = {}
-	for i = 1, diameter do
-		map[i] = {}
-		for j = 1, diameter do  map[i][j] = 0  end
-	end
 
-	return map
-end
+local MIN_CONE_FOOT_DIAMETER = 3
 
 --- Generate mountain as cone
 --- @param top_pos Position
 --- @param config  table
---- @return table, number, number "height map, map size, center_coordinate"
+--- @return mountgen.generator.HeightMap, number, number "height map, map size, center_coordinate"
 mountgen.cone = function(top_pos, config)
 	local H = top_pos.y - config.Y0                        -- height of truncated cone
 	local W = 2 * (config.TOP_RADIUS + math_ceil(          -- width (diameter) of cone foot
@@ -32,7 +22,7 @@ mountgen.cone = function(top_pos, config)
 
 	local height_map_size   = math_min(W, 2 * config.MAX_RADIUS)
 	local height_map_radius = math_floor(height_map_size / 2)
-	local height_map        = fill_with_zeroes(height_map_size)
+	local height_map        = HeightMap:new(height_map_size)
 
 	local l0 = math_sqrt(radius^2 + radius^2)
 
@@ -44,7 +34,7 @@ mountgen.cone = function(top_pos, config)
 			local l  = math_sqrt(px^2 + pz^2)
 			if l <= height_map_radius then
 				local h  = height * (1 - 2 * l / l0)
-				mountgen.set_value(height_map, z, x, math_min(h, H))
+				height_map:set_value(z, x, math_min(h, H))
 			end
 		end
 	end

mods/lord/World/mountgen/src/algorithms/diamond_square.lua

@@ -1,6 +1,8 @@
 local math_max, math_ceil, math_log, math_random
 	= math.max, math.ceil, math.log, math.random
 
+local HeightMap = require('generator.HeightMap')
+
 
 local smooth_filter = {
 	{ 0, 1, 1, 1, 0 },
@@ -11,15 +13,15 @@ local smooth_filter = {
 }
 
 ---smooth map at (x,z)
----@param map table height map
+---@param map mountgen.generator.HeightMap height map
 ---@param z number z coordinate
 ---@param x number x coordinate
 local function smooth(map, z, x)
 	local sum = 0
 	local cnt = 0
 	for i = 1, 5 do
 		for j = 1, 5 do
-			local val = mountgen.get_value(map, z - 3 + i, x - 3 + j)
+			local val = map:get_value(z - 3 + i, x - 3 + j)
 			if val ~= nil then
 				cnt = cnt + smooth_filter[i][j]
 				sum = sum + val * smooth_filter[i][j]
@@ -29,7 +31,7 @@ local function smooth(map, z, x)
 	if cnt == 0 then
 		return
 	end
-	mountgen.set_value(map, z, x, sum / cnt)
+	map:set_value(z, x, sum / cnt)
 end
 
 ---Random value from -max_value to max_value
@@ -84,20 +86,14 @@ mountgen.diamond_square = function(map_w, mountain_h, rk_thr, rk_small, rk_big)
 	n = math_max(n, 1)
 	local r = 2 ^ (n - 1)
 	local w = 2 * r + 1
-	local map = {}
-	for i = 1, w do
-		map[i] = {}
-		for j = 1, w do
-			map[i][j] = "nan"
-		end
-	end
+	local height_map = HeightMap:new(w)
 
 	-- set central peak and corners
-	mountgen.set_value(map, r, r, H)
-	mountgen.set_value(map, 0, 0, -H / 2)
-	mountgen.set_value(map, 0, w - 1, -H / 2)
-	mountgen.set_value(map, w - 1, 0, -H / 2)
-	mountgen.set_value(map, w - 1, w - 1, -H / 2)
+	height_map:set_value(r, r, H)
+	height_map:set_value(0, 0, -H / 2)
+	height_map:set_value(0, w - 1, -H / 2)
+	height_map:set_value(w - 1, 0, -H / 2)
+	height_map:set_value(w - 1, w - 1, -H / 2)
 
 	-- run diamond square
 	local i = n
@@ -120,13 +116,13 @@ mountgen.diamond_square = function(map_w, mountain_h, rk_thr, rk_small, rk_big)
 			for _ = 1, num do
 				local x = 0
 				for _ = 1, num do
-					local val1 = mountgen.get_value(map, z, x)
-					local val2 = mountgen.get_value(map, z + step, x)
-					local val3 = mountgen.get_value(map, z, x + step)
-					local val4 = mountgen.get_value(map, z + step, x + step)
+					local val1 = height_map:get_value(z, x)
+					local val2 = height_map:get_value(z + step, x)
+					local val3 = height_map:get_value(z, x + step)
+					local val4 = height_map:get_value(z + step, x + step)
 					local rand = adjust_random(step2 / rk)
 					local val = average(val1, val2, val3, val4) + rand
-					mountgen.set_value(map, z + step2, x + step2, val)
+					height_map:set_value(z + step2, x + step2, val)
 					x = x + step
 				end
 				z = z + step
@@ -142,20 +138,20 @@ mountgen.diamond_square = function(map_w, mountain_h, rk_thr, rk_small, rk_big)
 				local rand
 
 				rand = adjust_random(step2 / rk)
-				val1 = mountgen.get_value(map, z - step2, x + step2)
-				val2 = mountgen.get_value(map, z + step2, x + step2)
-				val3 = mountgen.get_value(map, z, x)
-				val4 = mountgen.get_value(map, z, x + step)
+				val1 = height_map:get_value(z - step2, x + step2)
+				val2 = height_map:get_value(z + step2, x + step2)
+				val3 = height_map:get_value(z, x)
+				val4 = height_map:get_value(z, x + step)
 				val = average(val1, val2, val3, val4) + rand
-				mountgen.set_value(map, z, x + step2, val)
+				height_map:set_value(z, x + step2, val)
 
 				rand = adjust_random(step2 / rk)
-				val1 = mountgen.get_value(map, z + step2, x - step2)
-				val2 = mountgen.get_value(map, z + step2, x + step2)
-				val3 = mountgen.get_value(map, z, x)
-				val4 = mountgen.get_value(map, z + step, x)
+				val1 = height_map:get_value(z + step2, x - step2)
+				val2 = height_map:get_value(z + step2, x + step2)
+				val3 = height_map:get_value(z, x)
+				val4 = height_map:get_value(z + step, x)
 				val = average(val1, val2, val3, val4) + rand
-				mountgen.set_value(map, z + step2, x, val)
+				height_map:set_value(z + step2, x, val)
 
 				x = x + step
 			end
@@ -164,6 +160,7 @@ mountgen.diamond_square = function(map_w, mountain_h, rk_thr, rk_small, rk_big)
 
 		i = i - 1
 	end
-	smooth(map, r, r)
-	return map, w, r + 1
+	smooth(height_map, r, r)
+
+	return height_map, w, r + 1
 end

mods/lord/World/mountgen/src/generator.lua

@@ -60,6 +60,7 @@ mountgen.mountgen = function(top, config)
 		return
 	end
 
+	--- @type mountgen.generator.HeightMap
 	local height_map, width, center
 	if method_name == "cone" then
 
@@ -117,7 +118,7 @@ mountgen.mountgen = function(top, config)
 				if global_z >= 1 and global_z <= width and
 					global_x >= 1 and global_x <= width and
 					global_y >= 1 then
-					local height = math_floor(height_map[global_z][global_x] + 0.5)
+					local height = math_floor(height_map.map[global_z][global_x] + 0.5)
 					if height > 0 then
 						if global_y < height then
 							data[i] = stone_id

mods/lord/World/mountgen/src/generator/HeightMap.lua

@@ -0,0 +1,56 @@
+
+--- @param size number
+--- @return number[][]
+local function fill_with_zeroes(size)
+	local map = {}
+	for i = 1, size do
+		map[i] = {}
+		for j = 1, size do  map[i][j] = 0  end
+	end
+
+	return map
+end
+
+
+--- @class mountgen.generator.HeightMap
+local HeightMap = {
+	--- @type number
+	size = nil,
+	--- @type number[][]
+	map  = nil,
+}
+
+function HeightMap:new(size)
+	local class = self
+	self = {}
+
+	self.size = size
+	self.map  = fill_with_zeroes(size)
+
+	return setmetatable(self, { __index = class })
+end
+
+function HeightMap:get_value(z, x)
+	local h = self.size
+	local w = self.size
+
+	if x < 0 or z < 0 or x > w-1 or z > h-1 then
+		return nil
+	end
+
+	return self.map[z+1][x+1]
+end
+
+function HeightMap:set_value(z, x, val)
+	local h = self.size
+	local w = self.size
+
+	if x < 0 or z < 0 or x > w-1 or z > h-1 then
+		return
+	end
+
+	self.map[z+1][x+1] = val
+end
+
+
+return HeightMap

mods/lord/World/mountgen/src/mountgen.lua

@@ -4,7 +4,6 @@ mountgen = {}
 require('algorithms.cone')
 require('algorithms.diamond_square')
 require('generator')
-require('generator.height_map')
 require('map')
 require('ui')