On Wed, Apr 9, 2014 at 7:50 AM, Alejandro Tejada <[hidden email]>wrote:
> Hi All,
> Please, review this new bug report:
> http://quality.runrev.com/show_bug.cgi?id=12148 > Add your comments and demonstration stacks to
> this report.
> Created attachment 4113 [details]
> Infinite Zoom 2014.livecode
> (Stack with images that zoom in or zoom out on mousedown)
> 1. Download the zipped sample stack
> 2. Open the stack in LiveCode 6.6
> 3. The stack opens in full screen. Using the keys alt-tab bring to front
> LiveCode menu
> 4. Check the card script, before running.
> 5. To run the infinite zoom effect, click and hold down the mouse pointer
> near the left side of the card (zoom in) or
> near the right side of the card (zoom out)
> 6. Notice how the effect of resizing the images is slow and moves
> step by step.
> 7. Notice the faint line in the border of every image, barely visible.
> This border effectively breaks the illusion of a single continuous
> and infinite image.
> 8. Follow the previous steps using LiveCode 6.5.2
> The stack runs perfectly. There is no trace of these
> faint lines in image borders.
> 9. These marked differences in image processing speed was noticed
> by Kenji Kojima in this message:
> http://lists.runrev.com/pipermail/use-livecode/2014-March/199672.html >
> Have a nice day!
> use-livecode mailing list
> [hidden email] > Please visit this url to subscribe, unsubscribe and manage your
> subscription preferences:
> http://lists.runrev.com/mailman/listinfo/use-livecode >
I can confirm the slow-down - this is due to the changes to image filtering we
made in 6.6. We need to revise that slightly I think as 'normal' now does some
filtering on all platforms where as before it was a box filter on Mac and a
nearest filter on other platforms. (The 'normal' filter now appears to be a
fair bit slower).
I suspect the faint lines (I noticed some black ones in 6.5.2) are related to
the cases where the space for the nested scaled image is not quite the right
size - you can only set image objects to pixel boundaries, and it could be some
of the black holes in the images when scaled to certain sizes are no longer
aligned on pixel boundaries.
[ i.e. If hole is 30 x 30, and you scale 25%, the whole will be 7.5x7.5 - so if
your original nested image is 30x30 and you scale down by 25% it will end up
being 7x7 and so leave a slight border ].
It is likely that the filtering in 6.6 is exacerbating this problem though.