tree.lua

-local size = 50
+-- NUR DURCH 4 TEILBARE ZAHLEN > 20 VERWENDEN!!!
+local leds = {
+    64,
+    56,
+    48,
+    36,
+    20,
+}
+
+for i = 1, #leds do
+    if leds[i] % 4 ~= 0 then
+        error("[ledtree] led count per layer must be divisible by 4. Error location: 'leds' table, item "..i..": "..leds[i])
+    end
+    if leds[i] < 20 then
+        error("[ledtree] led count per layer must be greater than or qual to 20. Error location: 'leds' table, item "..i..": "..leds[i])
+    end
+end
+
 local height_increment = 3
 
-local function place_tree(pos)
-    local set = {}
-    local iled = 0
-    for iy = 0, size - 1 do
-        for ix = iy, size - 1 - iy do
-            for iz = iy, size - 1 - iy do
-                for h = 0, height_increment - 1 do
-                    table.insert(set, {x = pos.x + ix, y = pos.y + iy * height_increment + h, z = pos.z + iz})
-                    iled = iled + 1
+local function breite(n)
+    return n / 4
+end
 
+local function is_led(center, breite, pos)
+    if math.abs(center.x - pos.x) >= (breite - 1) / 2 and math.abs(center.z - pos.z) >= (breite - 1) / 2 then
+        return false
+    end
+    if math.abs(center.x - pos.x) == (breite - 1) / 2 then
+        return math.abs(center.z - pos.z) % 2 == 0
+    end
+    if math.abs(center.z - pos.z) == (breite - 1) / 2 then
+        return math.abs(center.x - pos.x) % 2 == 0
+    end
+end
+
+local function place_layer(center, breite)
+    breite = breite * 2 + 1
+    local needles = {}
+    local leds = {}
+    local max_offset = math.floor(breite / 2)
+    for y = math.ceil(-height_increment / 2), math.floor(height_increment / 2) do
+        for x = -max_offset, max_offset do
+            for z = -max_offset, max_offset do
+                local pos = vector.new({x = center.x + x, y = center.y + y, z = center.z + z})
+                table.insert(needles, pos)
+                if y == 0 and is_led(center, breite, pos) then
+                    table.insert(leds, pos)
                 end
             end
         end
     end
-    minetest.bulk_set_node(set, {name = "ledtree:pine_needles"})
+    core.bulk_set_node(needles, {name = "ledtree:pine_needles"})
+    return leds
+end
+
+local function place_leds(led_index, leds)
+    for i = 1, #leds do
+        core.set_node(leds[i], {name = "ledtree:led"..led_index.."_red"})
+        led_index = led_index + 1
+    end
+    return led_index
+end
+
+local function place_tree(pos)
+    local led_index = 0
+    for index = 1, #leds do
+        local l = leds[index]
+        local layer_center = vector.new(pos.x, pos.y + index * height_increment - height_increment / 2, pos.z)
+        local leds = place_layer(layer_center, breite(l))
+        led_index = place_leds(led_index, leds)
+    end
 end
 
 core.register_node("ledtree:ledtree", {