From d1e5ec27dc3b0a32f71d6d72ff2bf93c1b719d17 Mon Sep 17 00:00:00 2001
From: Alexsandro Percy <alexsandro.percy@gmail.com>
Date: Sun, 1 May 2022 11:19:14 -0300
Subject: [PATCH] added light support

---
 init.lua                    |  82 ++++++++++++++++++++++++++++++++++++
 textures/airutils_light.png | Bin 0 -> 246 bytes
 2 files changed, 82 insertions(+)
 create mode 100644 textures/airutils_light.png

diff --git a/init.lua b/init.lua
index c6c24cc..71536e9 100644
--- a/init.lua
+++ b/init.lua
@@ -317,3 +317,85 @@ function airutils.paint(self, colstr, texture_name)
     end
 end
 
+function airutils.get_xz_from_hipotenuse(orig_x, orig_z, yaw, distance)
+    --cara, o minetest é bizarro, ele considera o eixo no sentido ANTI-HORÁRIO... Então pra equação funcionar, subtrair o angulo de 360 antes
+    yaw = math.rad(360) - yaw
+    local z = (math.cos(yaw)*distance) + orig_z
+    local x = (math.sin(yaw)*distance) + orig_x
+    return x, z
+end
+
+minetest.register_node("airutils:light", {
+	drawtype = "glasslike",
+	tile_images = {"airutils_light.png"},
+	inventory_image = minetest.inventorycube("airutils_light.png"),
+	paramtype = "light",
+	walkable = false,
+	is_ground_content = true,
+	light_propagates = true,
+	sunlight_propagates = true,
+	light_source = 14,
+	selection_box = {
+		type = "fixed",
+		fixed = {0, 0, 0, 0, 0, 0},
+	},
+})
+
+function airutils.remove_light(self)
+    if self._light_old_pos then
+        --force the remotion of the last light
+        minetest.add_node(self._light_old_pos, {name="air"})
+        self._light_old_pos = nil
+    end
+end
+
+function airutils.swap_node(self, pos)
+    local target_pos = pos
+    local have_air = false
+    local node = nil
+    local count = 0
+    while have_air == false and count <= 3 do
+        node = minetest.get_node(target_pos)
+        if node.name == "air" then
+            have_air = true
+            break
+        end
+        count = count + 1
+        target_pos.y = target_pos.y + 1
+    end
+    
+    if have_air then
+        minetest.set_node(target_pos, {name='airutils:light'})
+        airutils.remove_light(self)
+        self._light_old_pos = target_pos
+        return true
+    end
+    return false
+end
+
+function airutils.put_light(self)
+    local pos = self.object:get_pos()
+    pos.y = pos.y + 1
+    local yaw = self.object:get_yaw()
+    local lx, lz = airutils.get_xz_from_hipotenuse(pos.x, pos.z, yaw, 10)
+    local light_pos = {x=lx, y=pos.y, z=lz}
+
+	local cast = minetest.raycast(pos, light_pos, false, false)
+	local thing = cast:next()
+    local was_set = false
+	while thing do
+		if thing.type == "node" then
+            local ipos = thing.intersection_point
+            if ipos then
+                was_set = airutils.swap_node(self, ipos)
+            end
+        end
+        thing = cast:next()
+    end
+    if was_set == false then
+        local n = minetest.get_node_or_nil(light_pos)
+        if n and n.name == 'air' then
+            airutils.swap_node(self, light_pos)
+        end
+    end
+end
diff --git a/textures/airutils_light.png b/textures/airutils_light.png
new file mode 100644
index 0000000000000000000000000000000000000000..334cb078a9a03b0d90342ac9418482494231ae71
GIT binary patch
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literal 0
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