dodge-bolt/src/systems/player.lua

local Player = {}
local data   = require("data")
local Vec    = require("lib.brinevector")

local controls = data.controls

local AIMED_BOLT_DISTANCE = 15

local BOLT_AMOUNT = 1

local function getDirection(up_key, down_key, left_key, right_key)
	local dx = (love.keyboard.isDown(right_key) and 1 or 0)
							- (love.keyboard.isDown(left_key) and 1 or 0)
	local dy = (love.keyboard.isDown(down_key) and 1 or 0)
							- (love.keyboard.isDown(up_key) and 1 or 0)
	return Vec(dx, dy).normalized
end

Player.required_groups = {"player", "controllable_player", "bolt"}

function Player:getMoveDirection()
	return getDirection(
		controls.move_up,
		controls.move_down,
		controls.move_left,
		controls.move_right
	)
end

function Player:getAimDirection(player)
	if self.use_mouse_aim then
		local ScreenScaler = self.pool:getSystem(require("systems.screen-scaler"))
		local dir = Vec(ScreenScaler:getMousePosition()) - player.pos

		return dir.normalized
		-- local MAX_DIRECTIONS = 8
		-- local angle_segment = math.pi*2/MAX_DIRECTIONS
		-- local new_angle = math.floor(dir.angle/angle_segment+0.5)*angle_segment
		-- return Vec(math.cos(new_angle), math.sin(new_angle))
	else
		return getDirection(
			controls.aim_up,
			controls.aim_down,
			controls.aim_left,
			controls.aim_right
		)
	end
end

function Player:addToGroup(group, e)
	if group == "player" then
		e.bolt_cooldown_timer = e.bolt_cooldown_timer or 0
		e.aim_dir = e.aim_dir or Vec()
		e.move_dir = e.move_dir or Vec()
	end
end

function Player:update(dt)
	if love.keyboard.isDown(controls.aim_up, controls.aim_down, controls.aim_left, controls.aim_right) then
		self.use_mouse_aim = false
	end

	-- Update controls for "my" players
	local move_direction = self:getMoveDirection()
	for _, e in ipairs(self.pool.groups.controllable_player.entities) do
		-- Update where they are aiming/looking
		local aim_direction = self:getAimDirection(e)
		if e.aim_dir ~= aim_direction then
			e.aim_dir = aim_direction
			self.pool:emit("playerAimed", e)
		end

		-- Update acceleration to make the player move
		if e.move_dir ~= move_direction then
			e.move_dir = move_direction
			self.pool:emit("playerMoved", e)
		end

		-- Check if the player tried to shoot a bolt
		if love.keyboard.isDown(controls.shoot) then
			if self:tryShootingBolt(e) then
				self.pool:emit("playerShot", e)
			end
		end
	end

	-- Update each player
	for _, e in ipairs(self.pool.groups.player.entities) do
		e.acc = e.move_dir * e.speed

		-- Decrease bolt cooldown timer
		if e.bolt_cooldown_timer > 0 then
			e.bolt_cooldown_timer = math.max(0, e.bolt_cooldown_timer - dt)
		end

		-- If the player is nearby a non-moving bolt, pick it up
		for _, bolt in ipairs(self.pool.groups.bolt.entities) do
			if (e.pos-bolt.pos).length < 20 and bolt.vel.length < 3 then
				self.pool:emit("storeBolt", e, bolt)
			end
		end

		if e.acc.x ~= 0 or e.acc.y ~= 0 then
			e.sprite.variant = "walk"
			e.sprite.wobble = true
		else
			e.sprite.variant = "idle"
			e.sprite.wobble = false
		end

		if e.acc.x < 0 then
			e.sprite.flip = true
		elseif e.acc.x > 0 then
			e.sprite.flip = false
		end

		if #e.bolts > 0 then
			local bolt = e.bolts[1]
			if e.aim_dir.x ~= 0 or e.aim_dir.y ~= 0 then
				bolt.hidden = nil
				bolt.pos = e.pos + e.aim_dir * AIMED_BOLT_DISTANCE
			else
				bolt.hidden = true
			end
		end
	end
end

function Player:mousemoved()
	self.use_mouse_aim = true
end

function Player:tryShootingBolt(player)
	if (player.aim_dir.x ~= 0 or player.aim_dir.y ~= 0) and
		  player.bolt_cooldown_timer == 0 and
			#player.bolts > 0
	   then
		player.bolt_cooldown_timer = player.bolt_cooldown
		self.pool:emit("shootBolt", player)
		return true
	end
end

function Player:shootBolt(player)
	local bolt = table.remove(player.bolts, 1)
	if not bolt then return end

	bolt.pos = player.pos + player.aim_dir * AIMED_BOLT_DISTANCE
	bolt.vel = player.aim_dir * player.bolt_speed
	bolt.owner = player
	self.pool:emit("boltShot", player, bolt)
end

function Player:storeBolt(player, bolt)
	bolt.owner = nil
	table.insert(player.bolts, bolt)
end

function Player:hitPlayer(player, bolt)
	self:resetMap()
end

local function createBolt()
	return {
		pos = Vec(),
		vel = Vec(),
		acc = Vec(),
		sprite = {
			name = "bolt",
			variant = "idle",
		},
		friction = 0.98,
		max_speed = 400,
	}
end

function Player:resetMap()
	local map = self.pool:getSystem(require("systems.map"))
	local spawnpoints = map:listSpawnpoints()

	for _, bolt in ipairs(self.pool.groups.bolt.entities) do
		self.pool:removeEntity(bolt)
	end

	for i, player in ipairs(self.pool.groups.player.entities) do
		for _, bolt in ipairs(player.bolts) do
			self.pool:removeEntity(bolt)
		end

		local spawnpoint = spawnpoints[(i - 1) % #spawnpoints + 1]
		player.pos = spawnpoint
		player.bolts = {}
		for _=1, BOLT_AMOUNT do
			local bolt = self.pool:queue(createBolt())
			self.pool:emit("storeBolt", player, bolt)
		end
	end
end

function Player:spawnPlayer(pos)
	if not pos then
		local map = self.pool:getSystem(require("systems.map"))
		local spawnpoints = map:listSpawnpoints()
		local players = self.pool.groups.player.entities
		pos = spawnpoints[#players % #spawnpoints + 1]
	end

	local player = self.pool:queue{
		pos = pos,
		vel = Vec(0, 0),
		acc = Vec(),

		sprite = {
			name = "player",
			variant = "walk"
		},
		friction = 0.998,
		speed = 800,
		bolt_speed = 2000,
		bolts = {},
		bolt_cooldown = 0.1,
		collider = {-5, -5, 4, 8}
	}

	for _=1, BOLT_AMOUNT do
		local bolt = self.pool:queue(createBolt())
		self.pool:emit("storeBolt", player, bolt)
	end

	return player
end

function Player:draw()
	for _, e in ipairs(self.pool.groups.controllable_player.entities) do
		if (e.aim_dir.x ~= 0 or e.aim_dir.y ~= 0) and #e.bolts > 0 then
			local boltSystem = self.pool:getSystem(require("systems.bolt"))
			local pos = e.pos + e.aim_dir * AIMED_BOLT_DISTANCE*0
			local vel = (e.aim_dir * e.bolt_speed).normalized * AIMED_BOLT_DISTANCE*1

			local point_amount = 8
			local points = boltSystem:projectTrajectory(pos, vel, point_amount+3)
			for i=3, point_amount+3-1 do
				local ghost = data.sprites["bolt-ghost"]
				local point = points[i]
				local frame = ghost.variants.default[1]
				love.graphics.setColor(1, 1, 1, (point_amount-(i-3))/point_amount)
				love.graphics.draw(
					frame.image,
					point.x,
					point.y,
					nil,
					nil,
					nil,
					ghost.width/2, ghost.height/2
				)
			end
		end
	end
end

return Player