LineEdit cursor is sometimes invisible if 2D scaling is below the native resolution

[brianwinterpixel]

Godot version

3.4.2.stable

System information

Windows 10, GLES3

Issue description

All text editing controls use a cursor line width of 1 pixel in exported projects. This causes issues when using controls with different scales. This is a common use case when scaling down UI to fit smaller resolution screens.

Example:

This LineEdit has rect_scale=(0.9, 0.9)

At some cursor positions, it is visible:

However, in others, it is always invisible:

Steps to reproduce

See above

Minimal reproduction project

lineeditScaleBug.zip

[Calinou]

Related to #44253.

This can likely be fixed by dividing the caret width by the control's scale if it's lower than 1.0, but this requires querying all the parent Controls for their own scale (which can be slow in complex scene trees).

This causes issues when using controls with different scales. This is a common use case when scaling down UI to fit smaller resolution screens.

Control scaling should only be used for animation purposes, as it breaks down in many situations (input handling, containers, …). Do not rely on Control scaling for multiple resolutions. Use Godot's built-in support for handling multiple resolutions instead, which supports lower-than-native scale factors and specifying a custom scale factor since Godot 3.4.

[brianwinterpixel]

In our project we don't explicitly scale down nodes, but our base resolution is set higher than some platforms we deploy to, resulting in them being scaled down by the engine. So perhaps the issue title/description could be improved.

[Calinou]

To my knowledge, this automatic scaling can't be easily detected on the node's size, so I'm not sure what could be done (other than defaulting the caret width to 2).

[jasonwinterpixel]

Potential solution is allowing users to set the caret width in theme properties.

[Calinou]

Potential solution is allowing users to set the caret width in theme properties.

This is already done in master, but it wasn't backported to 3.x yet: #54956

Feel free to look into backporting this to 3.x 🙂

[Calinou]

• Duplicate of Thin lines are not rendered correctly if rendering at a scale factor lower than the default #24207 (same cause).