projectile.lua

love = require("love")
vector = require("libs.vector.vector")


function CreateProjectile(start_pos, end_pos, weapon_type, shooter)

    local start_end_vector = end_pos - start_pos
    start_end_vector:norm()
    local projectile = {}
    projectile.position = start_pos -- The current position of the projectile
    projectile.origin = start_pos -- The starting position of the projectile
    projectile.unit_vector = start_end_vector -- The vector between the start and end of the projectile
    projectile.hit_list = {} -- List of things already hit, to prevent something being hit every frame
    projectile.shooter_id = shooter.id -- The id of the shooter, to prevent the shooter from being hit when the projectile is fired
    projectile.time_created = love.timer.getTime()
    local current_speed_vector = shooter.state.speed
    local current_speed = current_speed_vector:getmag()

    if weapon_type == nil then
        -- Default/testing weapon type
        projectile.range = 5000
        projectile.damage = 1
        projectile.speed = 3000
        projectile.speed_penalty = 1000
        local stability = math.min(current_speed/0.5,1)
        projectile.spread = (math.random()-0.5) * 0.3 * stability
        --print(projectile.spread)

        if projectile.spread ~= 0 then
            local heading = projectile.unit_vector:heading()
            heading = heading + projectile.spread
            projectile.unit_vector = vector.fromAngle(heading)
        end

        projectile.pierce = weapon_type.pierce
        projectile.size = 0.15


    else
        -- Taking the equipped weapon type's projectiles
        projectile.range = weapon_type.range
        projectile.damage = weapon_type.damage
        projectile.lifetime = weapon_type.lifetime
        if shooter.state.isStill() then
            projectile.damage = projectile.damage * weapon_type.head_shot_multiplier --Normal damage if the player is standing still, headshot damage otherwise
        end

        projectile.speed = weapon_type.bullet_speed
        projectile.speed_penalty = weapon_type.bullet_speed_penalty
        local stability = math.min(current_speed/weapon_type.stability,1)
        projectile.spread = (math.random()-0.5) * weapon_type.spread * stability

        if projectile.spread ~= 0 then
            local heading = projectile.unit_vector:heading()
            heading = heading + projectile.spread
            projectile.unit_vector = vector.fromAngle(heading)
        end

        projectile.pierce = weapon_type.pierce
        projectile.size = weapon_type.size

    end


    projectile.dead = function () return ((love.timer.getTime() - projectile.time_created) > projectile.lifetime) or projectile.pierce < 0 end

    projectile.Progress = function (dt)
        projectile.position = projectile.position + ((projectile.unit_vector*dt)*projectile.speed)
        projectile.speed = projectile.speed - (projectile.speed_penalty * dt)
    end

    projectile.Render = function ()
        local pos = GAME.functions.getScreenPosition(projectile.position)
        love.graphics.circle("fill",pos.x,pos.y, projectile.size*ZOOM_MULT)
    end

    projectile.idInHitList = function (id)
        for i, value in pairs(projectile.hit_list) do
            if id == value then
                return true
            end
        end
        return false
    end

    
    return projectile
end