How to write this code in LUA?

[NÖÖB]

Hey guys, I'm wondering how I would go about converting this BASIC code to LUA.. What's getting me is the "field X[4] and "en:enemy = new enemy". I've been looking at code from the people on this forum, but couldn't find anything like this; I really should read Programming in Lua. But, if anyone could be bothered to have a go, please do

Code: Select all

type enemy
	field X[4]
	field Y[4]
end type

function createEnemy:enemy( ..parameters.. )
	local en:enemy = new enemy
	en.x[0] = 10
	en.x[1] = 20
	en.y[0] = 10
	en.y[1] = 20
	return en
end function

function drawEnemy(en.enemy, size, color)
	...
end function

[crow]

Hey guys, I'm wondering how I would go about converting this BASIC code to LUA.. What's getting me is the "field X[4] and "en:enemy = new enemy". I've been looking at code from the people on this forum, but couldn't find anything like this; I really should read Programming in Lua. But, if anyone could be bothered to have a go, please do

Code: Select all

type enemy
	field X[4]
	field Y[4]
end type

function createEnemy:enemy( ..parameters.. )
	local en:enemy = new enemy
	en.x[0] = 10
	en.x[1] = 20
	en.y[0] = 10
	en.y[1] = 20
	return en
end function

function drawEnemy(en.enemy, size, color)
	...
end function

Where did you get the code from ? that does not look like basic to me it looks like mixed up lua

Just from what I can see its missing some code from somewhere like I see it is stating tables but no table as been defined anywhere the en:enemy is enemy, as it is = to new enemy

from what I can see enemy should be soemthing like

Code: Select all

enemy = {y = {0=0, 1=0, 2= 0}, x = {0=0, 1=0, 2= 0},};

[NÖÖB]

It's BlitzBasic Max

[crow]

Maybe something like this then

Code: Select all

enemy = {y = {0=0, 1=0, 2= 0}, x = {0=0, 1=0, 2= 0},};

function createEnemy(n_x_f, n_x_s, n_y_f, n_y_s, )
          local en = enemy;
          en.x[n_x_f] = 10;
          en.x[n_x_s] = 20;
          en.y[n_y_f] = 10;
          en.y[n_y_s] = 20;
          return en;
end

[BlackBulletIV]

I don't know hardly anything about Basic, but it seems that Basic has a class (type) system. This isn't the case in Lua, you have to use the language's data structure "tables" to do it, along with metatables. However, there are a number of libraries that take care of this for you, like MiddleClass.

Maybe something like this then

Code: Select all

enemy = {y = {0=0, 1=0, 2= 0}, x = {0=0, 1=0, 2= 0},};

function createEnemy(n_x_f, n_x_s, n_y_f, n_y_s, )
          local en = enemy;
          en.x[n_x_f] = 10;
          en.x[n_x_s] = 20;
          en.y[n_y_f] = 10;
          en.y[n_y_s] = 20;
          return en;
end

No, that wouldn't work. You're not copying "enemy". This would be better:

Code: Select all

function createEnemy(n_x_f, n_x_s, n_y_f, n_y_s)
    local en = {
        y = {0=0, 1=0, 2= 0},
        x = {0=0, 1=0, 2= 0}
    }
    
    en.x[n_x_f] = 10
    en.x[n_x_s] = 20
    en.y[n_y_f] = 10
    en.y[n_y_s] = 20
    return en
end

Although that does seem a bit of a weird way of doing OOP.

[crow]

Or ok I was not far off tho hehe it was not bad for a shot in the dark hehe

Edit I was doing like that as if the table was used else where also i am not really big on OOP

[Robin]

I really should read Programming in Lua.

You really should.

[NÖÖB]

"Type enemy" is like a blueprint for an enemy-being, it would include parameters like X, Y, size, strenght, image, inventory..
"Function CreateEnemy:Enemy(100, 100, small, mediumstrong, lizard) creates an instance of a new enemy.. it could be used over and over again, spawning enemies of different appearance, strength etc.
I just used x[4] as an example to show that it's possible

[crow]

"Type enemy" is like a blueprint for an enemy-being, it would include parameters like X, Y, size, strenght, image, inventory..
"Function CreateEnemy:Enemy(100, 100, small, mediumstrong, lizard) creates an instance of a new enemy.. it could be used over and over again, spawning enemies of different appearance, strength etc.
I just used x[4] as an example to show that it's possible

you would have to build the whole function far as I know as love is a game framework not really a rebuild default engine and i think thats that Basic is

so you would need to set the love.newgraphics command i think that will set the x and y and you would need to tell it the image file and so on, sorry I
have not got really deep with love I will start in the next few months soon as I get my IDE stable

[miko]

Hey guys, I'm wondering how I would go about converting this BASIC code to LUA.. What's getting me is the "field X[4] and "en:enemy = new enemy". I've been looking at code from the people on this forum, but couldn't find anything like this; I really should read Programming in Lua. But, if anyone could be bothered to have a go, please do

Code: Select all

type enemy
	field X[4]
	field Y[4]
end type

function createEnemy:enemy( ..parameters.. )
	local en:enemy = new enemy
	en.x[0] = 10
	en.x[1] = 20
	en.y[0] = 10
	en.y[1] = 20
	return en
end function

function drawEnemy(en.enemy, size, color)
	...
end function

Forget about translating Basic code directly to lua. Your code will look better in Lua! Read about MiddleClass here: http://love2d.org/wiki/MiddleClass and do something like:

Code: Select all

require 'middleclass'
Enemy=class('Enemy')

function Enemy:initialize(x1,x2,y1,y2)
  self.X={x1,x2}
  self.Y={y1,y2}
end

function createEnemy(x1,x2,y1,y2)
  return Enemy:new(x1,x2,y1,y2)
end

local e1=createEnemy(10,20,10,20)

print(e1,e1.X[1], e1.Y[1])

Notes:
- you dont need/can not create "types" (records?) in Lua
- tables are 1-based