lovexp/asteroids/actors.lua

local love = require("love")
local phys = require("phys")
local inspect = require("inspect")

local actors = {}

function actors.buildActors(game)
    local asteroids = {}
    local asteroids_mt = { __index = asteroids }

    function asteroids.new(asteroid)
        local stageIndex = asteroid.stage or #game.asteroids.stages
        local stage = game.asteroids.stages[stageIndex]
        local instance = {
            angle = math.random() * phys.tau,
            speed = stage.speed,
            facing = math.random() * phys.tau,
            spin = (math.random() - 0.5),
            radius = stage.radius,
            sprite = stage.sprite,
        }
        for k, v in pairs(asteroid) do
            instance[k] = v
        end
        instance.stage = stageIndex
        setmetatable(instance, asteroids_mt)
        return instance
    end

    function asteroids:draw()
        local width = self.sprite:getWidth()
        local height = self.sprite:getHeight()
        love.graphics.push()
        love.graphics.setColor(1, 1, 1)
        local scale = 2 * self.radius / math.max(width, height)
        love.graphics.draw(self.sprite,
            self.x,
            self.y,
            self.facing,
            scale,
            scale,
            width / 2,
            height / 2
        )
        love.graphics.pop()
    end

    local bullets = {}
    local bullets_mt = { __index = bullets }

    function bullets.new(bullet)
        local instance = {
            spin = 0,
        }
        for k, v in pairs(game.ship.bullet) do
            instance[k] = v
        end
        for k, v in pairs(bullet) do
            instance[k] = v
        end
        instance.sound = love.audio.newSource(game.ship.bullet.sound)
        instance.timeLeft = instance.time
        setmetatable(instance, bullets_mt)
        return instance
    end

    function bullets:draw()
        love.graphics.push()
        love.graphics.setColor(0, 1, 0)
        love.graphics.circle('fill', self.x, self.y, self.radius)
        love.graphics.pop()
    end

    local ships = {}
    local ships_mt = { __index = ships }

    function ships.new(ship)
        local instance = {
            x = game.width / 2,
            y = game.height / 2,
            angle = 0,
            speed = 0,
            spin = 0,
            facing = phys.tau * 3 / 4,
            radius = game.ship.radius,
        }
        for k, v in pairs(game.ship) do
            instance[k] = v
        end
        for k, v in pairs(ship) do
            instance[k] = v
        end
        setmetatable(instance, ships_mt)
        return instance
    end

    function ships:draw()
        love.graphics.push()
        love.graphics.translate(self.x, self.y)
        love.graphics.setColor(1, 1, 1)
        local width = self.sprite:getWidth()
        local height = self.sprite:getHeight()

        local scale = 2 * game.ship.radius / math.max(width, height)
        love.graphics.draw(game.ship.sprite,
            0,
            0,
            (self.facing + phys.tau / 4) % phys.tau,
            scale,
            scale,
            width / 2,
            height / 2
        )
        -- TODO rocket exhaust
        love.graphics.pop()
    end

    return {
        asteroids = asteroids,
        bullets = bullets,
        ships = ships,
    }
end

return actors