Add large craters.

abms.lua

@@ -750,7 +750,7 @@ local last_meteor_strike = 0
 minetest.register_abm({
 	nodenames = {"default:dirt_with_grass", "default:dirt_with_dry_grass", 'default:dirt_with_snow'},
 	neighbors = {"air", 'default:snow'},
-	interval = 15 * time_factor,
+	interval = 25 * time_factor,
 	catch_up = false,
 	chance = 32767,
 	action = function(pos, node)

cavegen.lua

@@ -43,14 +43,19 @@ fun_caves.cavegen = function(minp, maxp, data, area, node, heightmap, underzone)
 	local write = false
 
 	local index = 0
-	local index3d = 0
+	local crater
-	local cave_width = fun_caves.cave_width
+	if not underzone and math.random(10) == 1 then
-	local styx_sea_level = fun_caves.underzones['Styx'].sealevel
+		crater = {
+			x = minp.x + math.random(math.floor(csize.x / 2)) + math.floor(csize.x / 4),
+			y = 15,
+			z = minp.z + math.random(math.floor(csize.z / 2)) + math.floor(csize.z / 4),
+		}
+	end
+
+	local crater_min = 33000
 	for z = minp.z, maxp.z do
 		for x = minp.x, maxp.x do
 			index = index + 1
-			index3d = (z - minp.z) * (csize.y + 2) * csize.x + (x - minp.x) + 1
-			local ivm = area:index(x, minp.y-1, z)
 
 			local height = heightmap[index]
 			if height and height < maxp.y - 1 and height > minp.y then
@@ -68,6 +73,30 @@ fun_caves.cavegen = function(minp, maxp, data, area, node, heightmap, underzone)
 				heightmap[index] = height
 			end
 
+			if crater then
+				local dist = crater.y - math.sqrt((x - crater.x) ^ 2 + (z - crater.z) ^ 2)
+				if dist > 0 and (height > maxp.y or height < minp.y + crater.y) then
+					crater = nil
+				end
+				if crater and dist > 0 and dist <= 1 and crater_min > height then
+					crater_min = height
+				end
+			end
+		end
+	end
+
+	index = 0
+	local index3d = 0
+	local cave_width = fun_caves.cave_width
+	local styx_sea_level = fun_caves.underzones['Styx'].sealevel
+	for z = minp.z, maxp.z do
+		for x = minp.x, maxp.x do
+			index = index + 1
+			index3d = (z - minp.z) * (csize.y + 2) * csize.x + (x - minp.x) + 1
+			local ivm = area:index(x, minp.y-1, z)
+
+			local height = heightmap[index]
+
 			local column = 0
 			if underzone then
 				if cave_3[index] < 30 then
@@ -77,7 +106,21 @@ fun_caves.cavegen = function(minp, maxp, data, area, node, heightmap, underzone)
 				end
 			end
 
+			local dist
+			if crater then
+				dist = crater.y - math.sqrt((x - crater.x) ^ 2 + (z - crater.z) ^ 2)
+			end
+
 			for y = minp.y-1, maxp.y+1 do
+				if crater and dist and dist > 0 then
+					if y > crater_min - 1.5 * dist and y < maxp.y - 1.5 * dist then
+						data[ivm] = data[ivm + (math.floor((height - crater_min) * dist / crater.y) + math.ceil(dist / 2)) * area.ystride]
+					end
+					if y > crater_min - dist and ground_nodes[data[ivm]] and math.random(300) == 1 then
+						data[ivm] = node['fun_caves:stone_with_meteoritic_iron']
+					end
+				end
+
 				if underzone and underzone.regular_columns and (x - minp.x) < 8 and (z - minp.z) < 8 then
 					data[ivm] = node[underzone.column_node]
 					write = true

nodes.lua

@@ -110,6 +110,11 @@ newnode.drop = "fun_caves:meteorite"
 newnode.groups.soil = 0
 minetest.register_node("fun_caves:meteorite_crater", newnode)
 
+local newnode = fun_caves.clone_node("default:stone_with_iron")
+newnode.description = "Stone With Meteoritic Iron"
+newnode.drop = "fun_caves:meteorite"
+minetest.register_node("fun_caves:stone_with_meteoritic_iron", newnode)
+
 
 newnode = fun_caves.clone_node("default:stone")
 newnode.tiles = {'dna.png'}