LÖVE

Posted: **Wed Aug 21, 2013 5:40 pm**

I've once again searched through tutorials and forums alike for an answer and my search has turned up blank. I'm trying to make this plane appear to rotate when a key is pressed, but not using orientation, as that doesn't give the desired effect.
I'm sure the answer lies with quads, I just don't know where.
Any help is appreciated.

Posted: **Wed Aug 21, 2013 6:14 pm**

Well first off your whole thing doesn't run. For so many reasons. First one is that you attempt to assign a table to a number constant, which is impossible operation. Read the Programming in Lua book for that (available online). Second, you apply arguments in wrong order. First two are X and Y, and rotation (R) would be third. Oh and drawq would accept a quad as a second argument (shifting all other arguments by one to the right). Refer to the LÖVE manual available at the wiki section.

Also, whereas you change X and Y by values amplified by DT, you don't do so for rotation. And, given that rotation angles are in radians rather than in degrees (1 rad ≈ 57.2°) your rotation will go really fast.

Code: Select all

local a1 = love.graphics.newQuad(0, 0, 32, 32, 160, 64)
local a2 = love.graphics.newQuad(32, 0, 32, 32, 160, 64)
local a3 = love.graphics.newQuad(64, 0, 32, 32, 160, 64)
local r, x, y, speed, Plane = 0, 0, 0, 0, 0

function love.load()
   x = 50
   y = 50
   speed = 200
   Plane = love.graphics.newImage("Plane.png")
end

function love.update(dt)
   if love.keyboard.isDown("right") then
      x = x + (speed * dt)
   end
   if love.keyboard.isDown("left") then
      x = x - (speed * dt)
   end

   if love.keyboard.isDown("down") then
      y = y + (speed * dt)
   end
   if love.keyboard.isDown("up") then
      y = y - (speed * dt)
   end
   if love.keyboard.isDown("r") then
      r = r + dt
   end
end

function love.draw()
   love.graphics.drawq(Plane, a1, x, y, r)
end

Posted: **Wed Aug 21, 2013 6:17 pm**

Tried to fix your code. If something is wrong with my variant of code, feel free to tell =)

Code: Select all

a = { }
a[1] = love.graphics.newQuad(0, 0, 32, 32, 160, 64)
a[2] = love.graphics.newQuad(32, 0, 32, 32, 160, 64)
a[3] = love.graphics.newQuad(64, 0, 32, 32, 160, 64)
r = 1

function love.load()
   x = 50
   y = 50
   speed = 200
   Plane = love.graphics.newImage("Plane.png")
end

function love.update(dt)
   if love.keyboard.isDown("right") then
      x = x + (speed * dt)
   end
   if love.keyboard.isDown("left") then
      x = x - (speed * dt)
   end

   if love.keyboard.isDown("down") then
      y = y + (speed * dt)
   end
   if love.keyboard.isDown("up") then
      y = y - (speed * dt)
   end
   if love.keyboard.isDown("r") then
      r = r + 1
	  if r > 3 then
		r = 1
	  end
   end
end

function love.draw()
   love.graphics.drawq(Plane, a[r], x, y)
end

Posted: **Wed Aug 21, 2013 6:23 pm**

I wouldn't use three different quads for this, you can just use one and then use Quad:setViewport to change the sprite. In addition, use some timer variable, so the quad doesn't change every frame, which just makes the plane go crazy.

Posted: **Wed Aug 21, 2013 6:33 pm**

Many thanks for all the help, however crazy the plane appears to be.

After I add a timer variable, it should be fine, I'll just have to find the magic number first.

Posted: **Wed Aug 21, 2013 9:31 pm**

Aren't quads gonna be romoved from löve ?

Posted: **Wed Aug 21, 2013 10:04 pm**

Yes, but they'll be replaced by Geometry. Also love.graphics.newQuad will still exist, it'll just return a Geometry.

Posted: **Thu Aug 22, 2013 12:11 am**

Good to know that newQuad'll still work, that way people won't need to change their whole code

Posted: **Thu Aug 22, 2013 1:16 am**

Does anyone have an idea of when we're expecting 0.9.0?

Posted: **Thu Aug 22, 2013 1:57 pm**

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