scale messing up my y translation

[jesper.landberg]

Hi,

 

I'm trying to make an image gallery where the big image is transformed based on the thumbnail getBoundingClientRect() values. But I'm having trouble with the y transform value, I get the correct difference value but the scaling makes it look out of place. 

 

Check my Pen and u will see what I mean.

See the Pen VXMxKr?editors=0010 by ReGGae (@ReGGae) on CodePen.

[OSUblake]

getBoundingClientRect includes transforms. Sometimes it's better to use offfsetLeft/Top/Width/Height. And if scale is involved, you should probably animate the x/y values from the center instead of the top/left corner. Basically, calculate the x/y values based on where the transform origin is. By default, it's at the center for HTML elements.

 

 

[Sahil]

You can either calculate the difference scale will cause or you can record values after applying scale. Check following demo where I calculate difference scale will cause, this will work only if your transformOrigin is center, otherwise you will need to do more calculations.

 

But what you are doing doesn't seem like right approach because if user scrolls, your element vanishes at wrong point. You will need to recalculate position in both direction to fix it.

 

See the Pen RMjNJJ?editors=1010 by Sahil89 (@Sahil89) on CodePen.