UX: Polyline Gesture #119353

New Issue

Sean Kim · 2024-03-12T00:44:15+01:00

Sean Kim commented

2024-03-12 00:44:15 +01:00

Issue

Currently, there is no support for a generic polyline gesture that allows developers to take advantage of a common structure similar to the other WM_gesture types (e.g. WM_GESTURE_RECT, WM_GESTURE_CIRCLE, WM_GESTURE_LASSO, etc).

Revision History:

2024-03-13: Added minor updates to the User Interaction section.
2024-03-19: Minor addition to User Interaction.

Proposal

I propose adding a new WM_GESTURE_POLYLINE type and corresponding default operator callbacks so that existing actions that use other gesture types can also be modified to use this mode of selection (e.g. SCULPT_OT_face_set_lasso_gesture, MASK_OT_select_lasso, SCULPT_OT_trim_lasso_gesture, etc).

A prototype of this feature can be seen below:

User Interaction

Upon selecting the operator via either the toolbar or a menu, the first click inside the viewport will add a point. The specific modifier key or mouse button applied to this action will vary based on tool but will align with user expectations for similar lasso tools - the key difference being that it does not require a drag action. The user's cursor will track the next point and display both its current position and a line connecting it to the previous point selected. Any subsequent clicks will repeat this process, saving the current point to where the user's cursor was at the time of selection.

After two points are saved, a line will be drawn back to the initial point to indicate to the user what the resulting selected will look like. At this point, the user can press Enter to confirm the selected area and submit the data for the operator specific actions. A user can also click on the original starting point to submit the gesture instead of pressing Enter

At any point, a user can press Esc to cancel the operation.

Similar to the Lasso gesture, this gesture will also support holding Spacebar to move the selection area around before submitting it.

A status bar will be added to inform users of the modified controls.

Code

A new wmGesture::type will be added named WM_GESTURE_POLYLINE. The wmGesture customdata data will be similar to WM_GESTURE_LASSO - an array of shorts representing the selected mouse positions in screen space. This array will need fewer entries inside it as it will not be updated upon every mouse movement, only when clicked.

Much of the existing lasso code can be repurposed for this implementation since they share similar features for drawing and selection.

For users of these new default callbacks, they should be able to use existing code that works for WM_GESTURE_LASSO, as the process of selecting the bounding box of the points and creating a bitmap of the area will work similarly.

Open Questions

~~Does the user need to be able to click on the starting point to complete the loop and execute the gesture?~~

Yes, this should be possible.
~~Is there an upper limit to the number of gesture points that we should enforce?~~

There should be no issue with allowing the user to select as many points as they want, it is unlikely there will be any memory concerns in comparison to the lasso tool.
All other generic gesture operations appear to correspond to click + drag invocations. Is there an issue with adding this new type that follows a completely different input model?

## Issue Currently, there is no support for a generic polyline gesture that allows developers to take advantage of a common structure similar to the other `WM_gesture` types (e.g. `WM_GESTURE_RECT`, `WM_GESTURE_CIRCLE`, `WM_GESTURE_LASSO`, etc). ## Revision History: * 2024-03-13: Added minor updates to the **User Interaction** section. * 2024-03-19: Minor addition to **User Interaction**. ## Proposal I propose adding a new `WM_GESTURE_POLYLINE` type and corresponding default operator callbacks so that existing actions that use other gesture types can also be modified to use this mode of selection (e.g. `SCULPT_OT_face_set_lasso_gesture`, `MASK_OT_select_lasso`, `SCULPT_OT_trim_lasso_gesture`, etc). A prototype of this feature can be seen below: ![initial_polyline.gif](/attachments/2629afe6-96b1-464d-b668-80cc777937bb) ### User Interaction Upon selecting the operator via either the toolbar or a menu, the first click inside the viewport will add a point. The specific modifier key or mouse button applied to this action will vary based on tool but will align with user expectations for similar lasso tools - the key difference being that it does not require a drag action. The user's cursor will track the next point and display both its current position and a line connecting it to the previous point selected. Any subsequent clicks will repeat this process, saving the current point to where the user's cursor was at the time of selection. After two points are saved, a line will be drawn back to the initial point to indicate to the user what the resulting selected will look like. At this point, the user can press `Enter` to confirm the selected area and submit the data for the operator specific actions. A user can also click on the original starting point to submit the gesture instead of pressing `Enter` At any point, a user can press `Esc` to cancel the operation. Similar to the Lasso gesture, this gesture will also support holding `Spacebar` to move the selection area around before submitting it. A status bar will be added to inform users of the modified controls. ### Code A new `wmGesture::type` will be added named `WM_GESTURE_POLYLINE`. The `wmGesture` `customdata` data will be similar to `WM_GESTURE_LASSO` - an array of `short`s representing the selected mouse positions in screen space. This array will need fewer entries inside it as it will not be updated upon every mouse movement, only when clicked. Much of the existing lasso code can be repurposed for this implementation since they share similar features for drawing and selection. For users of these new default callbacks, they should be able to use existing code that works for `WM_GESTURE_LASSO`, as the process of selecting the bounding box of the points and creating a bitmap of the area will work similarly. ## Open Questions * ~~Does the user need to be able to click on the starting point to complete the loop and execute the gesture?~~ Yes, this should be possible. * ~~Is there an upper limit to the number of gesture points that we should enforce?~~ There should be no issue with allowing the user to select as many points as they want, it is unlikely there will be any memory concerns in comparison to the lasso tool. * All other generic gesture operations appear to correspond to click + drag invocations. Is there an issue with adding this new type that follows a completely different input model?

initial_polyline.gif

1.1 MiB

👍 5 ❤️ 3

Sean Kim added the

Type

Design

label 2024-03-12 00:44:15 +01:00

TheRedWaxPolice commented

2024-03-12 15:43:42 +01:00

Cool stuff... 👍

Does the user need to be able to click on the starting point to complete the loop and execute the gesture?

That's another common way of executing this type of tool, yes. So it would be nice to have that ability here too...

Is there an upper limit to the number of gesture points that we should enforce?

I never encountered a limit when using this kind of tool in other software... if there's a limit, the number must be fairly high... 🤔

All other generic gesture operations appear to correspond to click + drag invocations. Is there an issue with adding this new type that follows a completely different input model?

IMHO, that shouldn't be an issue... That's the nature of this tool and how it works.. no issue at all..

Cool stuff... 👍 > Does the user need to be able to click on the starting point to complete the loop and execute the gesture? That's another common way of executing this type of tool, yes. So it would be nice to have that ability here too... > Is there an upper limit to the number of gesture points that we should enforce? I never encountered a limit when using this kind of tool in other software... if there's a limit, the number must be fairly high... 🤔 > All other generic gesture operations appear to correspond to click + drag invocations. Is there an issue with adding this new type that follows a completely different input model? IMHO, that shouldn't be an issue... That's the nature of this tool and how it works.. no issue at all..

👍 1

Sean Kim commented

2024-03-13 18:57:23 +01:00

@TheRedWaxPolice - Appreciate the feedback. I've edited the main post

👍 2

Sean Kim referenced this issue

2024-03-14 19:18:31 +01:00

Sculpt: Add polyline hide operator #119483

Paul Kotelevets commented

2024-03-19 21:13:05 +01:00

Nice to see polygonal lasso concept. It is long awaited.
A couple of questions

Will it support object/edit mode?
How about the ability to start/draw polygonal lasso via Ctrl+RMB clicks, similar to regular lasso?

Nice to see polygonal lasso concept. It is long awaited. A couple of questions - Will it support object/edit mode? - How about the ability to start/draw polygonal lasso via Ctrl+RMB clicks, similar to regular lasso?

Sean Kim commented

2024-03-19 21:20:57 +01:00

@1D_Inc

Will it support object/edit mode?

I assume you mean as a Select Polyline tool, similar to Select Lasso - if so yes, this should be able to be used for that tool as well, though the first implementation that I'm working on is Polyline Hide.

How about the ability to start/draw polygonal lasso via Ctrl+RMB clicks, similar to regular lasso?

Assuming you're using Select Lasso as a reference point again, yes, that should be able to be added for an equivalent tool.

@1D_Inc > - Will it support object/edit mode? I assume you mean as a *Select Polyline* tool, similar to *Select Lasso* - if so yes, this should be able to be used for that tool as well, though the first implementation that I'm working on is *Polyline Hide*. > - How about the ability to start/draw polygonal lasso via Ctrl+RMB clicks, similar to regular lasso? Assuming you're using *Select Lasso* as a reference point again, yes, that should be able to be added for an equivalent tool.

👍 1

Paul Kotelevets commented

2024-03-20 01:47:30 +01:00

Sounds great!
Thank you.

Sounds great! Thank you.

Hans Goudey referenced this issue from a commit

2024-04-29 14:04:29 +02:00

Sculpt: Polyline hide operator

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UX: Polyline Gesture #119353

Issue

Revision History:

Proposal

User Interaction

Code

Open Questions