First Entity

In this section, we will create the first entity of the game, the player, and we will make it move around the screen.

Creating the player entity

To create the player entity, we need to create a new file called player.lua in the project folder, import the classic, and we will define the player entity in this file.

local Object = require("classic")

local Player = Object:extend()

function Player:new(x, y)
    self.x = x
    self.y = y
        self.width = 64 -- width of the player
        self.height = 64 -- height of the player
        self.speed = 300 -- speed of the player
end

-- This is a function that will be called by the engine every frame, and we can use it to draw the player on the screen
function Player:draw()
    sucata.graphic.draw_rect({
        x = self.x, -- The x position of the player, in pixels
        y = self.y, -- The y position of the player, in pixels
        width = self.width, -- The width of the player sprite, in pixels
        height = self.height, -- The height of the player sprite, in pixels
        origin = 0.5, -- The origin of the player sprite, 0.5 means that the sprite will be drawn from the center, 0 means that the sprite will be drawn from the top left corner
    })
end

return Player

Then we will call the player entity in the main.lua file, and spawn it in the scene.

local Player = require("player")

sucata.scene.spawn(Player(480, 500)) -- Spawn the player in the center of the screen

The game should show like this:

Now we will make the player move around the screen using the arrow keys.

to get the input from the player we will use the sucata.input, and we need to get the delta, that is the time passed between frames.

function Player:update() -- This a callback from sucata that be called all frame
    local delta = sucata.time.get_delta() -- The time between frames
    if sucata.input.is_held("a", "left") then -- Check if the keys "a" or "left arrow" are pressed
        self.x = self.x - self.speed * delta -- Add a value to x 
    end
    if sucata.input.is_held("d", "right") then
        self.x = self.x + self.speed * delta
    end
end