Drawing a Grid

[Sekaru]

So I'm trying to draw a 32x32 grid. Before I was using the .line function to draw it but I couldn't really find any way of colouring the line so I went with using quads.

I've been messing around with this for a while and I keep getting a "world.lua.26: attempt to index global 'columngrid' (a nil value)" and I'm not really sure how to fix it.

I've attached the world.lua I'm doing this in. Thanks in advance!

world.lua

(802 Bytes) Downloaded 148 times

[Przemator]

I'm not sure, but if you want to make a grid, should it not be a two-dimensional array? ( grid[x][y] )

But I think you can achieve what you want in a MUCH simpler way. Just use this function:

Code: Select all

grid = love.graphics.newImage('/misc/grid.png')
grid:setWrap("repeat", "repeat")
quad = love.graphics.newQuad(0, 0, 16000, 16000, grid:getWidth(), grid:getHeight())
love.graphics.drawq(grid, quad, 0, 0)

Then create ONE quad that is much bigger than the image.

[Sekaru]

I'm not sure, but if you want to make a grid, should it not be a two-dimensional array? ( grid[x][y] )

But I think you can achieve what you want in a MUCH simpler way. Just use this function:

Code: Select all

grid = love.graphics.newImage('/misc/grid.png')
grid:setWrap("repeat", "repeat")
quad = love.graphics.newQuad(0, 0, 16000, 16000)
love.graphics.drawq(grid, quad, 0, 0)

Then create ONE quad that is much bigger than the image.

I gave that a go and split the drawq off into my rendering function and the rest into a loading function. I'm getting a "Incorrect parameter type: expected userdata" on the drawq line.

[Przemator]

I made a small mistake when creating the quad, missed the reference width and height arguments.

Just tested this and it works like a charm:

Code: Select all

function love.load()
	grid = love.graphics.newImage("grid.png")
	grid:setWrap("repeat", "repeat")
	quad = love.graphics.newQuad(0, 0, 16000, 16000, grid:getWidth(), grid:getHeight())
end

function love.draw()
	love.graphics.drawq(grid, quad, 0, 0)
end

[Sekaru]

I made a small mistake when creating the quad, missed the reference width and height arguments.

Just tested this and it works like a charm:

Code: Select all

function love.load()
	grid = love.graphics.newImage("grid.png")
	grid:setWrap("repeat", "repeat")
	quad = love.graphics.newQuad(0, 0, 16000, 16000, grid:getWidth(), grid:getHeight())
end

function love.draw()
	love.graphics.drawq(grid, quad, 0, 0)
end

Didn't work for me. I ended up rewriting it and it worked this time:

Code: Select all

world = {
	width   = 16000,
	height  = 16000,
	rows    = 500,
	columns = 500
	}
	
function initWorld()
	grid = love.graphics.newImage('/misc/grid.png')

	columngrid = {}
	columnWidth = world.width/world.columns
	
	for i = 1, world.columns do
		columngrid[i] = love.graphics.newQuad(i*columnWidth, 0, 1, world.height, grid:getWidth(), grid:getHeight())
	end
	
	rowgrid = {}
	rowHeight = world.height/world.rows
	
	for i = 1, world.rows do
		rowgrid[i] = love.graphics.newQuad(0, i*rowHeight, world.width, 1, grid:getWidth(), grid:getHeight())
	end
end

function drawWorld()
	
    for i = 1, world.columns do
		love.graphics.drawq(grid, columngrid[i], i*columnWidth, 0)
	end

	for i = 1, world.rows do
		love.graphics.drawq(grid, rowgrid[i], 0, i*rowHeight)
	end
end

Thanks for your help anyway.

[Przemator]

Here, find attached the exact code that I pasted, it works.

What you're doing is really not optimal IMO.

[Kadoba]

Another approach is to use love.graphics.rectangle("line").

grid.love

(255 Bytes) Downloaded 461 times

[Sekaru]

Here, find attached the exact code that I pasted, it works.

What you're doing is really not optimal IMO.

I'm pretty new to LUA so I'm not really sure how to optimise yet. What you're doing is essentially tiling an image, what I'm doing is drawing lines to create a grid.

Another approach is to use love.graphics.rectangle("line").

Yeah I was using that before but because I couldn't change the image or colour of the lines I went with using Quads.

[Kadoba]

Yeah I was using that before but because I couldn't change the image or colour of the lines I went with using Quads.

Whoops. Didn't see that part. You can change the color of all love.graphics functions by using love.graphics.setColor. Just be sure to set the draw color back to white (255,255,255,255) when you're done.

[Sekaru]

Yeah I was using that before but because I couldn't change the image or colour of the lines I went with using Quads.

Whoops. Didn't see that part. You can change the color of all love.graphics functions by using love.graphics.setColor. Just be sure to set the draw color back to white (255,255,255,255) when you're done.

Well damn. That would've made it a lot easier. Thanks a lot xD!