Recalculating path's array after modification - fabricjs
After moving, rescaling or rotating a path in fabricjs, I would like to recalculate the path's array coordinates in order to use them later to draw the exact same path on a plain HTML5 canvas.
I have gotten around rotation by storing the angle and then performing a transformation of the whole html canvas. For translation I tried recalculating the points like so:
point[1] = (point[1] + modifiedObject.left - oldState.left);
point[2] = (point[2] + modifiedObject.top - oldState.top);
but this messes up with rescaling on fabric.
I also tried using the transformation matrix on the points, but this didn't work either and I think it's because I am missing some steps in between.
Any help would be appreciated.
Here's a simple demo of what I'm trying to do in essence: https://jsfiddle.net/1b68eLdr/86688/
fabricjs
asked Nov 26 '18 at 16:16
CybrookeCybrooke
65
add a comment |
After moving, rescaling or rotating a path in fabricjs, I would like to recalculate the path's array coordinates in order to use them later to draw the exact same path on a plain HTML5 canvas.
I have gotten around rotation by storing the angle and then performing a transformation of the whole html canvas. For translation I tried recalculating the points like so:
point[1] = (point[1] + modifiedObject.left - oldState.left);
point[2] = (point[2] + modifiedObject.top - oldState.top);
but this messes up with rescaling on fabric.
I also tried using the transformation matrix on the points, but this didn't work either and I think it's because I am missing some steps in between.
Any help would be appreciated.
Here's a simple demo of what I'm trying to do in essence: https://jsfiddle.net/1b68eLdr/86688/
fabricjs
asked Nov 26 '18 at 16:16
CybrookeCybrooke
65
Could you provide a more complete example to demonstrate the issue? Something runnable, if possible?
– shkaper
Nov 27 '18 at 1:23
@shkaper Hey, I added a simple fiddle to it.
– Cybrooke
Nov 27 '18 at 10:50
add a comment |
After moving, rescaling or rotating a path in fabricjs, I would like to recalculate the path's array coordinates in order to use them later to draw the exact same path on a plain HTML5 canvas.
I have gotten around rotation by storing the angle and then performing a transformation of the whole html canvas. For translation I tried recalculating the points like so:
point[1] = (point[1] + modifiedObject.left - oldState.left);
point[2] = (point[2] + modifiedObject.top - oldState.top);
but this messes up with rescaling on fabric.
I also tried using the transformation matrix on the points, but this didn't work either and I think it's because I am missing some steps in between.
Any help would be appreciated.
Here's a simple demo of what I'm trying to do in essence: https://jsfiddle.net/1b68eLdr/86688/
fabricjs
asked Nov 26 '18 at 16:16
CybrookeCybrooke
65
After moving, rescaling or rotating a path in fabricjs, I would like to recalculate the path's array coordinates in order to use them later to draw the exact same path on a plain HTML5 canvas.
I have gotten around rotation by storing the angle and then performing a transformation of the whole html canvas. For translation I tried recalculating the points like so:
point[1] = (point[1] + modifiedObject.left - oldState.left);
point[2] = (point[2] + modifiedObject.top - oldState.top);
but this messes up with rescaling on fabric.
I also tried using the transformation matrix on the points, but this didn't work either and I think it's because I am missing some steps in between.
Any help would be appreciated.
Here's a simple demo of what I'm trying to do in essence: https://jsfiddle.net/1b68eLdr/86688/
fabricjs
fabricjs
asked Nov 26 '18 at 16:16
CybrookeCybrooke
65
asked Nov 26 '18 at 16:16
CybrookeCybrooke
65
edited Nov 27 '18 at 10:49
Cybrooke
asked Nov 26 '18 at 16:16
CybrookeCybrooke
65
asked Nov 26 '18 at 16:16
CybrookeCybrooke
65
asked Nov 26 '18 at 16:16
CybrookeCybrooke
65
65
Could you provide a more complete example to demonstrate the issue? Something runnable, if possible?
– shkaper
Nov 27 '18 at 1:23
@shkaper Hey, I added a simple fiddle to it.
– Cybrooke
Nov 27 '18 at 10:50
add a comment |
Could you provide a more complete example to demonstrate the issue? Something runnable, if possible?
– shkaper
Nov 27 '18 at 1:23
@shkaper Hey, I added a simple fiddle to it.
– Cybrooke
Nov 27 '18 at 10:50
Could you provide a more complete example to demonstrate the issue? Something runnable, if possible?
– shkaper
Nov 27 '18 at 1:23
Could you provide a more complete example to demonstrate the issue? Something runnable, if possible?
– shkaper
Nov 27 '18 at 1:23
@shkaper Hey, I added a simple fiddle to it.
– Cybrooke
Nov 27 '18 at 10:50
@shkaper Hey, I added a simple fiddle to it.
– Cybrooke
Nov 27 '18 at 10:50
add a comment |
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Could you provide a more complete example to demonstrate the issue? Something runnable, if possible?
– shkaper
Nov 27 '18 at 1:23
@shkaper Hey, I added a simple fiddle to it.
– Cybrooke
Nov 27 '18 at 10:50