LÖVE

1. Using the metatable feature:
   1. Make a table that will be your template, giving it keys for all the functions that you want other tables to "inherit".
   2. Store that template table in the __index key of a table that will be used as the metatable that all inheriting tables will use.
   3. To create new table following that template (an "instance"), set the metatable of the new table to the one that has that __index key pointing to the template table. You can use the template table itself as the metatable, if you add the __index key to it with the value as itself, like...
      TemplateTable.__index = TemplateTable
      setmetatable(myInstance, TemplateTable)
2. Manually storing functions into the new table that must follow the template, like going...
   t = {}
   t.function1 = function1
   t.function2 = function2
   (Preferably using a function, like a factory function, where it takes in a preexisting table or creates a new table, then stores all the needed functions into that table and returns it. So to get a new instance you call that function).

Here is an example implementation of a clickable object library in Lua using metatables and methods:

Code: Select all

-- define a clickable object metatable
local ClickableObject = {}
ClickableObject.__index = ClickableObject

-- constructor
function ClickableObject:new(x, y, width, height, callback)
    local obj = {
        x = x,
        y = y,
        width = width,
        height = height,
        callback = callback
    }
    setmetatable(obj, ClickableObject)
    return obj
end

-- check if a point is inside the clickable object
function ClickableObject:contains(x, y)
    return x >= self.x and x <= self.x + self.width and y >= self.y and y <= self.y + self.height
end

-- handle click events on the clickable object
function ClickableObject:onClick(x, y)
    if self:contains(x, y) and self.callback then
        self.callback()
    end
end

-- create a new clickable object and add it to the objects table
function clickable(x, y, width, height, callback)
    local obj = ClickableObject:new(x, y, width, height, callback)
    table.insert(objects, obj)
    return obj
end

-- handle mouse click events by checking if any of the clickable objects were clicked
function love.mousepressed(x, y, button)
    if button == 1 then -- left mouse button
        for _, obj in ipairs(objects) do
            obj:onClick(x, y)
        end
    end
end

To use this library, you can create a new clickable object by calling the clickable function, passing in the x and y position, width and height, and a callback function that will be executed when the object is clicked. For example:

Code: Select all

function love.load()
    objects = {}

    -- create a new clickable object
    clickable(100, 100, 50, 50, function()
        -- code to execute when the object is clicked
        print("Object clicked!")
    end)
end

In this example, a new clickable object is created at position (100, 100) with a width and height of 50 pixels, and a callback function that prints a message to the console when the object is clicked.

When the left mouse button is clicked, the love.mousepressed function is called, which in turn calls the onClick method on each of the clickable objects in the objects table. If the mouse click is inside the bounds of a clickable object, the callback function for that object will be executed.

darkfrei wrote: ↑Wed Feb 22, 2023 1:35 pm From chatGPT(not tested):

RNavega wrote: ↑Wed Feb 22, 2023 12:03 am B. Manually storing functions into the new table that must follow the template

• https://developer.mozilla.org/en-US/doc ... rogramming
• https://www.freecodecamp.org/news/objec ... beginners/