Rotate grouped images

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zugende
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Joined: Sun Feb 21, 2016 5:47 pm

Rotate grouped images

Post by zugende »

Hi everyone,

does a function exist, which groups some images to one group so that I then can easily rotate all images together with the same origin?

At the moment I'm manipulating the offset parameter for each image.. but this is really time consuming.
Any idea how to speed up this process?

Thanks a lot! :)

Here a screenshot from a rocket (consisting of multiple images) I am trying to rotate:
Attachments
rocket.png
rocket.png (4.9 KiB) Viewed 2420 times
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Sheepolution
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Re: Rotate grouped images

Post by Sheepolution »

You can use a canvas for this

Code: Select all

function love.load()
	x = 300
	y = 100
	angle = 0
	canvas = love.graphics.newCanvas(140, 200)
end

function love.update(dt)
	if love.keyboard.isDown("up") then
		y = y - 400 * dt
	elseif love.keyboard.isDown("down") then
		y = y + 400 * dt
	end
	angle = angle + dt
end


function love.draw()
	love.graphics.setCanvas(canvas)
		love.graphics.clear()
		love.graphics.rectangle("fill", 0, 0, 20, 200)
		love.graphics.rectangle("fill", 120, 0, 20, 200)
	love.graphics.setCanvas()

	love.graphics.draw(canvas, x, y, angle, 1, 1, canvas:getWidth()/2, canvas:getHeight()/2)
end
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Ulydev
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Re: Rotate grouped images

Post by Ulydev »

zugende wrote:same origin

Code: Select all

love.graphics.translate(origin.x, origin.y)
love.graphics.rotate(rotation)
love.graphics.translate(-origin.x, -origin.y)
drawImages()
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zugende
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Joined: Sun Feb 21, 2016 5:47 pm

Re: Rotate grouped images

Post by zugende »

Ahh nice! Thank you both. Canvas is the one I was looking for.
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s-ol
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Location: Cologne, Germany
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Re: Rotate grouped images

Post by s-ol »

zugende wrote:Ahh nice! Thank you both. Canvas is the one I was looking for.
I would still urge you to learn the transforms API, it is a very essential part of graphics programming and useful for a lot of different things.

s-ol.nu /blog  -  p.s-ol.be /st8.lua  -  g.s-ol.be /gtglg /curcur

Code: Select all

print( type(love) )
if false then
  baby:hurt(me)
end
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zugende
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Joined: Sun Feb 21, 2016 5:47 pm

Re: Rotate grouped images

Post by zugende »

s-ol wrote: I would still urge you to learn the transforms API, it is a very essential part of graphics programming and useful for a lot of different things.
Lets take the attached love file as example. Eventually I want the rocket to rotate together with the "fire" - would you suggest doing this with canvas or the transform API?

Press A or D for acceleration. :)

Thanks a lot!
zugende
Attachments
rocket_test.love
(8.39 KiB) Downloaded 86 times
rocket.png
rocket.png (14.48 KiB) Viewed 2342 times
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s-ol
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Re: Rotate grouped images

Post by s-ol »

zugende wrote:
s-ol wrote: I would still urge you to learn the transforms API, it is a very essential part of graphics programming and useful for a lot of different things.
Lets take the attached love file as example. Eventually I want the rocket to rotate together with the "fire" - would you suggest doing this with canvas or the transform API?

Press A or D for acceleration. :)

Thanks a lot!
zugende
Theres no reason to use the canvas when you are going to clear and redraw it every frame (except for some very rare cases in which a Canvas has another advantage, but that won't be the case here).

s-ol.nu /blog  -  p.s-ol.be /st8.lua  -  g.s-ol.be /gtglg /curcur

Code: Select all

print( type(love) )
if false then
  baby:hurt(me)
end
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