I forgot how to use translate/rotate

Programmer1500

Hey, so yeah I can’t remember how to use these lol. I’m trying to animate my player sprite by rotating it but when I rotate it at a 45 degree angle, it rotates from whatever center point i don’t want. I can’t remember how I use translation I believe to correct this so it rotates around the center of the sprite.

Thanks guys!

Simeon

Here's an example where a sprite rotates under your finger wherever you touch the screen

Basically translate to the position, rotate, translate back

-- RotationAroundPoint

function setup()
end

function draw()
    background(40, 40, 50)

    local pos = CurrentTouch.pos

    rotateAround(pos, ElapsedTime * 100)
    sprite("Tyrian Remastered:Boss D", pos.x, pos.y)

end

function rotateAround(pos, angle)
    translate(pos.x, pos.y)
    rotate(angle)
    translate(-pos.x, -pos.y)
end

Bri_G

@Programmer1500 - also remember rotate is additive, so multiple rotates in a draw function add up. Your not starting from the zero poi t with each rotation - its from the last angle you used.

dave1707

@Programmer1500 Here's an example using tween.

displayMode(FULLSCREEN)

function setup()
    tw={x=0,y=HEIGHT/2,rot=0}
    tween(5,tw,{x=WIDTH,y=HEIGHT/2,rot=720},
                {easing=tween.easing.linear,loop=tween.loop.pingpong})
end

function draw()
    background(40, 40, 50)
    translate(tw.x,tw.y)
    rotate(tw.rot)
    sprite("Cargo Bot:Clear Button")
end