grenades: Improve API (#615)

mods/pvp/grenades/api.md

@@ -1,9 +1,10 @@
 # Grenades API
 
-Still WIP. Please suggest new features here: https://forum.minetest.net/viewtopic.php?f=9&t=21466
+Please suggest new features here: https://forum.minetest.net/viewtopic.php?f=9&t=21466
 
 ## API
 
+```lua
 grenades.register_grenade("name", { -- Name of the grenade (Like 'smoke' or 'flashbang')
 	description = "", -- A short description of the grenade.
 	image = "", -- The name of the grenade's texture
@@ -12,7 +13,12 @@ Still WIP. Please suggest new features here: https://forum.minetest.net/viewtopi
 		-- <pos> the place the grenade 'exploded' at
 		-- <name> the name of the player that threw the grenade
 	end,
-		placeable = false, -- Optional, default is false
+	on_collide = function(obj, name)
+	-- This function is called when the grenade collides with a surface
+	-- <obj> the grenade object
+	-- <name> the name of the player that threw the grenade
+	-- return true to cause grenade explosion
+	end,
 	clock = 3, -- Optional, controls how long until grenade detonates. Default is 3
 	particle = { -- Adds particles in the grenade's trail
 		image = "grenades_smoke.png", -- The particle's image
@@ -22,3 +28,4 @@ Still WIP. Please suggest new features here: https://forum.minetest.net/viewtopi
 		interval = 5, -- How long it takes before a particle can be added
 	}
 })
+```

mods/pvp/grenades/grenades.lua

@@ -194,6 +194,6 @@ grenades.register_grenade("grenades:smoke", {
 		life = 1,
 		size = 4,
 		glow = 0,
-		interval = 5,
+		interval = 0.3,
 	}
 })

mods/pvp/grenades/init.lua

@@ -2,16 +2,17 @@ grenades = {
 	grenade_deaccel = 9
 }
 
-local function throw_grenade(name, player)
+function grenades.throw_grenade(name, startspeed, player)
 	local dir = player:get_look_dir()
 	local pos = player:get_pos()
 	local obj = minetest.add_entity({x = pos.x + dir.x, y = pos.y + 1.5 + dir.y, z = pos.z + dir.z}, name)
 
-	local m = 20
+	obj:set_velocity(vector.multiply(dir, startspeed))
-	obj:set_velocity({x = dir.x * m, y = dir.y * m, z = dir.z * m})
 	obj:set_acceleration({x = 0, y = -9.8, z = 0})
 
-	return(obj:get_luaentity())
+	obj:get_luaentity().thrower_name = player:get_player_name()
+
+	return obj:get_luaentity()
 end
 
 function grenades.register_grenade(name, def)
@@ -20,8 +21,8 @@ function grenades.register_grenade(name, def)
 	end
 
 	local grenade_entity = {
+		initial_properties = {
 			physical = true,
-		sliding = 1,
 			collide_with_objects = false,
 			visual = "sprite",
 			visual_size = {x = 0.5, y = 0.5, z = 0.5},
@@ -29,6 +30,8 @@ function grenades.register_grenade(name, def)
 			collisionbox = {-0.2, -0.2, -0.2, 0.2, 0.15, 0.2},
 			pointable = false,
 			static_save = false,
+		},
+		sliding = 1,
 		particle = 0,
 		timer = 0,
 		on_step = function(self, dtime)
@@ -46,6 +49,16 @@ function grenades.register_grenade(name, def)
 			-- Check for a collision on the x/y/z axis
 
 			if not vector.equals(self.last_vel, vel) and vector.distance(self.last_vel, vel) > 4 then
+				if def.on_collide and def.on_collide(obj, self.thrower_name) then
+					if self.thrower_name then
+						minetest.log("action", "[Grenades] A grenade thrown by " .. self.thrower_name ..
+						" explodes at " .. minetest.pos_to_string(vector.round(pos)))
+						def.on_explode(pos, self.thrower_name)
+					end
+
+					obj:remove()
+				end
+
 				if math.abs(self.last_vel.x - vel.x) > 5 then -- Check for a large reduction in velocity
 					vel.x = self.last_vel.x * -0.3 -- Invert velocity and reduce it a bit
 				end
@@ -87,13 +100,13 @@ function grenades.register_grenade(name, def)
 
 			-- Grenade Particles
 
-			if def.particle and self.particle >= 4 then
+			if def.particle and self.particle >= def.particle.interval then
 				self.particle = 0
 
 				minetest.add_particle({
 					pos = obj:get_pos(),
 					velocity = vector.divide(vel, 2),
-					acceleration = vector.divide(obj:get_acceleration(), -5),
+					acceleration = vector.divide(obj:get_acceleration() or vector.new(1, 1, 1), -5),
 					expirationtime = def.particle.life,
 					size = def.particle.size,
 					collisiondetection = false,
@@ -103,14 +116,14 @@ function grenades.register_grenade(name, def)
 					glow = def.particle.glow
 				})
 			elseif def.particle and self.particle < def.particle.interval then
-				self.particle = self.particle + 1
+				self.particle = self.particle + dtime
 			end
 
 			-- Explode when clock is up
 
 			if self.timer > def.clock or not self.thrower_name then
 				if self.thrower_name then
-					minetest.log("[Grenades] A grenade thrown by " .. self.thrower_name ..
+					minetest.log("action", "[Grenades] A grenade thrown by " .. self.thrower_name ..
 					" explodes at " .. minetest.pos_to_string(vector.round(pos)))
 					def.on_explode(pos, self.thrower_name)
 				end
@@ -129,14 +142,11 @@ function grenades.register_grenade(name, def)
 	newdef.range = 0
 	newdef.inventory_image = def.image
 	newdef.on_use = function(itemstack, user, pointed_thing)
-		local player_name = user:get_player_name()
-
 		if pointed_thing.type ~= "node" then
-			local grenade = throw_grenade(name, user)
+			grenades.throw_grenade(name, 20, user)
-			grenade.thrower_name = player_name
 
 			if not minetest.settings:get_bool("creative_mode") then
-				itemstack = ""
+				itemstack:take_item(1)
 			end
 		end