Nightly Build Transform Tool Considerations

--Issue Summary--

There are a few issues that have become present after using the tool:

[ ] [UX] Single Axis Constraint Request While transforming a selection in a single axis, pressing shift will constraint the transform diagonally (both axis) and not in the direction of the transform as to preserve the aspect ratio of the original selection. However sometimes you want to be very particular about which axis you are applying the transform to and you press the "constraint" key to limit the transformation axis.

Proposed Solutions(s): I suppose while using the constraint modifier (shift) the transformation could either infer the direction of the transform and not automatically transform it diagonally while pressing and holding shift by comparing it's width and height when invoking the key modifier and applying the constraint.

XOR

We could have additional anchor points that would only allow to transform to a specific axis or combination:

Pressing the constraint key (shift) should affect the transformation while:

[ ] Using diagonal anchors would keep X:Y aspect ratio
[ ] Using horizontal anchors would maintain the X:1 ratio
[ ] Using vertical anchors would maintain the 1:Y ratio

https://gyazo.com/0475727711c1513a4e84de66a5e1ecd5 Video courtesy of user tlcarus

[ ] Issue A: Very low reproduction rate: When I release the mouse button during the transformation (this happened specifically after mirror-transforming on a single axis) the marquee selection disappeared, but I pressed the ESC key and the transform was reset as expected of the current workflow.
- [ ] A1 It's possible that Issue A was actually a by-product of this: When you scale the selection from OUTside the marquee box, if you click outside to apply the transformation, you can still get the visual cues where the selection corners used to be even if the selection area has already disappeared.
[ ] Issue B: 100% Reproduction rate: When you try to create a selection area after a few times the selection tool will snap and make a tiny selection area after clicking and you can't undo it so you have to click again several times.
- reproduction steps:
  - Pick the SELECT tool, select an area
  - Pick the MOVE tool, press CTRL and rotate the selection
  - Press the ESC key to reset the transform (the marquee box disappears)
  - Pick the SELECT tool and try to create a new selection, then you'll get issue B
- [ ] B1 Once you get the problem if you press ESC and then try to create a new selection (just clicking will do), you can reproduce the bug indefinitely.
- [ ] B2 Visual Cues: Once you get the tiny selection form this bug, If instead of creating a new selection after it you take your cursor to a corner just to let the cursor change to the new and then press ESC the visual resize cue will bug out and the cursor will show like that until you create a new selection or change tools.
- [ ] B3 A similar problem to B, can occur if you click a single point just using the marquee tool without following the repro steps.
[ ] Issue C: It also happened that when i tried to select the drawing once the transform applied rotation out of the blue, but I pressed ESC to undo that (visible on the GIF)
- reproduction steps:
  - Pick the SELECT tool, select an area
  - Pick the MOVE tool, press CTRL and rotate the selection
  - Press the ESC key to reset the transform (the marquee box disappears)
  - Pick the SELECT tool and try to create a new selection, then you'll get issue B
  - Create a new selection by clicking and dragging a larger box beyond the original selection corner that gave the tiny selection.
  - Click outside of the selection and you'll notice that the drawing will have a slight rotation applied (probably a fraction of the original rotation transform made with the move tool)
[ ] Issue D Flip Selection Based on non-transformed image:
- Reproduction Steps
  - Select the drawing and transform it for the following cases (Note: use scale, it happens with rotation too but it's less noticeable):
    1. scale it UP to enlarge
    2. scale it DOWN to shrink
  - Go To Edit >Selection> Flip X/Y
  - There are two possible resulting scenarios: If you shrunk the image, using the Flip command will make it disappear. If you enlarged the image, the Flip command will work but it will apply itself to the original drawing and not the transformed drawing.
[ ] Issue E Creating a new File will keep any selection marquee active between documents. The marquee tool should be reset on both new file and file opening operations. Also on a second test I got a random crash after doing this and loading an animation file (can't reproduce the crash anymore tho).

--Video or Image Reference--

Issue A recording_transform_tool_2

UX Anchor Request + Issue B & C Approx. duration: 35 secs recording_transform_tool

--System Information--

Pencil2D Version: Version: 0.6.1.1 commit: c7803d0f761dabb71da6ecdb95f34b05a2b7a71a date: 2018-07-05_20:03:27 Development build Operating System: Windows 7 SP 1 (6.1) CPU Architecture: x86_64

pencil2d / pencil