love2d-tank/bullet.lua

Bullet = Object:extend()
cos = math.cos
sin = math.sin --optimisation
pi = math.pi

function Bullet:new(x, y, p, speed, rotation)
	self.image = love.graphics.newImage("assets/bullet.png")
	self.x = x
	self.y = y
	self.p = p
	self.speed = speed
	self.rotation = rotation

	self.width = self.image:getWidth()
	self.height = self.image:getHeight()

	self.scaleX = 1
	self.scaleY = 1
	self.originX = self.width / 2
	self.originY = self.height / 2

	self.collider = World:newCircleCollider(x, y, 10)
	self.collider:setFixedRotation(true)
	self.collider:setPosition(self.x, self.y)

	if self.p == 1 then
		self.collider:setCollisionClass("Bullet1")
	elseif self.p == 2 then
		self.collider:setCollisionClass("Bullet2")
	end
end

function Bullet:update(dt)
	--If a bullet hits a wall, make it bounce off the wall and change its rotation
	if self.p == 1 then
		if self.collider:enter("Wall") then
			--calculate normal of the wall
			--calculate the angle of reflection
			local angle = (math.atan2(dx, dy))
			--get normal of the wall without using getNormal()

			----TODO: fix this

			--set the new angle
			self.rotation = angle
			self.collider:setAngle(self.rotation)
		end
		dx = cos(self.rotation) * self.speed * dt
		dy = sin(self.rotation) * self.speed * dt
		self.collider:setLinearVelocity(dx, dy)
	end

	if self.p == 2 then
		local dx = cos(self.rotation) * self.speed * dt
		local dy = sin(self.rotation) * self.speed * dt
		self.collider:setLinearVelocity(dx, dy)
	end

	self.x = self.collider:getX()
	self.y = self.collider:getY()
end

function Bullet:draw()
	for _, _ in ipairs(Bullets1) do
		love.graphics.draw(
			self.image,
			self.x,
			self.y,
			self.rotation,
			self.scaleX,
			self.scaleY,
			self.originX,
			self.originY
		)
	end

	for _, _ in ipairs(Bullets2) do
		love.graphics.draw(
			self.image,
			self.x,
			self.y,
			self.rotation,
			self.scaleX,
			self.scaleY,
			self.originX,
			self.originY
		)
	end
end