ship.lua

local Gamestate = require "lib.gamestate"
local Bullet = require "weapon"
local entity = require "entity"

local _M   = {} -- Module
local _MT  = {__index = _M } -- Metatable
local _MMT = {__index = entity} -- Module Metatable
local ship = setmetatable(_M, _MMT)

-- sound effects, all one of them
local SFX_Explosion = love.audio.newSource("sfx/Explosion.wav", "static")

-- creates a new entity
function ship.new(t)
	t = t or {}
	local e = entity.new(t)
	
	e.kind      = 'ship'
	e.name      = t.name or string.format('ship#%d', e.id)

 	e.speed     = t.speed     or 100

	e.npc        = (t.npc == nil and true) or t.npc
	e.dir_timer  = t.dir_timer or 0
	e.entities   = {}
	for k, v in pairs(t.entities or {}) do
		e.entities[k] = v.new(v)
	end
	e.hit        = false   -- was hit by player?

	e.shooting   = false
	e.shot_rate  = t.shot_rate or 0.2 -- time between shots in seconds.
	e.shot_timer = 0

	return setmetatable(e, _MT)
end

-- draws the entity
function ship:draw()
	assert(self, "We have no self, so I really don't know how you expect this to work.")
	for i, e in next, self.entities do
		assert(e, "Entity doesn't seem to actually exist")
		assert(e._TYPE == 'entity', string.format("'Entity' is actually an '%s'", e._TYPE or type(e)))
		e:draw()
		--love.graphics.draw(e.texture, e.pos_x, e.pos_y)
	end

	entity.draw(self)
end

function ship:think(dt)
	if self.npc then
		self.facing = math.atan2(self.dir_y, self.dir_x)
		self.dir_timer = self.dir_timer + dt
		-- turn change directions
		if self.dir_timer > 1 then
			self.dir_timer = 0
			self.dir_x = (math.random()*2) - 1
			self.dir_y = (math.random()*2) - 1
		end
	end
end

-- updates the entity according the to time passed (in seconds)
function ship:update(dt, level)
	local dv = self.speed * dt
	self.pos_x = self.pos_x + (self.dir_x * dv)
	self.pos_y = self.pos_y + (self.dir_y * dv)

	self:docollision(level, dt)

	self:think(dt)

	-- Shoot lazers
	self.shot_timer = self.shot_timer + dt
	if self.shooting and self.shot_timer >= self.shot_rate then
		self.shot_timer = 0
		self:shoot()
	end
	-- Update entities
	for i, entity in next, self.entities do
		entity:update(dt)
		if entity.kind == "bullet" then
			-- Hit things
			for _, ship in next, Gamestate.space.enemies do
				if entity:testcollision(ship) then
					entity:collidewith(ship)
					entity.state = 'remove'
					self.entities[i] = nil

					ship.hit = true
				end
			end

			if entity.state == 'dead' or entity.state == 'remove' then
				self.entities[i] = nil
			end

		end
	end
end

-- handles keyboard button-down events
function ship:keypressed(key)
	if self.state == 'alive' then
		self.dir_x = self.dir_x + (key == "right" and 1 or 0) - (key == "left" and 1 or 0)
		self.dir_y = self.dir_y + (key ==  "down" and 1 or 0) - (key ==   "up" and 1 or 0)
		self.shooting = key == " " or self.shooting
	end
end

-- handles keyboard button-up events
function ship:keyreleased(key)
	if self.state == 'alive' then
		self.dir_x = self.dir_x + (key == "right" and -1 or 0) - (key == "left" and -1 or 0)
		self.dir_y = self.dir_y + (key ==  "down" and -1 or 0) - (key ==   "up" and -1 or 0)
		self.shooting = key ~= " " and self.shooting
	end
end

-- rounds a number to the nearest whole number, or to decimal
local function round(val, decimal)
	if (decimal) then
		return math.floor( (val * 10^decimal) + 0.5) / (10^decimal)
	else
		return math.floor(val+0.5)
	end
end

-- handles various collision related events.
-- mostly simply handles self Vs. Level terrain collision atm.
function ship:docollision(level, dt) -- this is new
	-- Keep ship inside play area
	local posy = self.pos_y
	posy = posy <= 32 and 32 or posy
	posy = posy + self.height >= level.height*32 and
	level.height*32 - self.height or posy
	self.pos_y = posy

	local posx = self.pos_x
	posx = posx <= 0 and 0 or posx
	posx = posx + self.width >= 800 and 800 - self.width or posx
	self.pos_x = posx

	local CurrentTileX = round(posx / 32 + level.x / 32, 0)
	if CurrentTileX > 0 and CurrentTileX < level.width then
		-- testtile1 has a magic value of 1, see Issue #22
		local testtile1 = 1 + math.max(	level.data[CurrentTileX] + level.offset[CurrentTileX], 
										level.data[CurrentTileX+1] + level.offset[CurrentTileX + 1])
		local testtile2 = math.max(	level.data[CurrentTileX] - level.offset[CurrentTileX], 
									level.data[CurrentTileX+1] - level.offset[CurrentTileX + 1])
		if posy - self.height < (testtile1) * 32 then
			self:dohit(dt*10)
			self.pos_y = ((testtile1) * 32) + self.height
		elseif posy + self.height > (level.height - testtile2) * 32 then
			self:dohit(dt*10)
			self.pos_y = ((level.height - testtile2) * 32) - self.height
		end

	end
end

-- handles the death of the entity.
function ship:die()
	entity.die(self)

	if self.npc then
		if self.hit then    -- Was the NPC hit by the player?
			Gamestate.space.player.score = Gamestate.space.player.score + 25
		end
	end
end

function ship:addentity(e)
	assert(e and e._TYPE == 'entity', string.format("Expected 'entity', got '%s' instead.", e and e.type or type(e)))
	if e then
		self.entities[#self.entities+1] = e
	end
end

function ship:shoot()
	self:addentity(Bullet.new(self))
end

function ship:collidewith(e, dt)
	assert(e and e._TYPE == 'entity', string.format("Expected 'entity', got '%s' instead.", e and e.type or type(e)))
	if e.kind == 'ship' then
		self:dohit(e.damage*dt)
	end
end

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return ship