Add variable fonts and system fonts to BiDi and Font Features demo

[Calinou]

Note that some of the code could be simplified once https://github.com/godotengine/godot/pull/79166 is merged, but I don't know if that PR will be cherry-picked for 4.1.x.

Preview

[Calinou]

I've tried replacing the workarounds with setting dictionary keys directly like this:

diff --git a/gui/bidi_and_font_features/bidi.gd b/gui/bidi_and_font_features/bidi.gd
index ea2f64d4..6bba4a61 100644
--- a/gui/bidi_and_font_features/bidi.gd
+++ b/gui/bidi_and_font_features/bidi.gd
@@ -44,42 +44,27 @@ func _on_variable_size_value_changed(value: float) -> void:

 func _on_variable_weight_value_changed(value: float) -> void:
    $"TabContainer/Variable fonts/Variables/Weight/Value".text = str(value)
-   # Workaround to make the variable font axis value effective. This requires duplicating the dictionary.
-   var dict = variable_font_variation.variation_opentype.duplicate()
-   dict["weight"] = value
-   variable_font_variation.variation_opentype = dict
+   variable_font_variation.variation_opentype["weight"] = value

 func _on_variable_slant_value_changed(value: float) -> void:
    $"TabContainer/Variable fonts/Variables/Slant/Value".text = str(value)
-   # Workaround to make the variable font axis value effective. This requires duplicating the dictionary.
-   var dict = variable_font_variation.variation_opentype.duplicate()
-   dict["slant"] = value
-   variable_font_variation.variation_opentype = dict
+   variable_font_variation.variation_opentype["slant"] = value

 func _on_variable_cursive_toggled(button_pressed: bool) -> void:
    $"TabContainer/Variable fonts/Variables/Cursive".button_pressed = button_pressed
-   # Workaround to make the variable font axis value effective. This requires duplicating the dictionary.
-   var dict = variable_font_variation.variation_opentype.duplicate()
-   dict["custom_CRSV"] = int(button_pressed)
-   variable_font_variation.variation_opentype = dict
+   variable_font_variation.variation_opentype["custom_CRSV"] = int(button_pressed)

 func _on_variable_casual_toggled(button_pressed: bool) -> void:
    $"TabContainer/Variable fonts/Variables/Casual".button_pressed = button_pressed
-   # Workaround to make the variable font axis value effective. This requires duplicating the dictionary.
-   var dict = variable_font_variation.variation_opentype.duplicate()
-   dict["custom_CASL"] = int(button_pressed)
-   variable_font_variation.variation_opentype = dict
+   variable_font_variation.variation_opentype["custom_CASL"] = int(button_pressed)

 func _on_variable_monospace_toggled(button_pressed: bool) -> void:
    $"TabContainer/Variable fonts/Variables/Monospace".button_pressed = button_pressed
-   # Workaround to make the variable font axis value effective. This requires duplicating the dictionary.
-   var dict = variable_font_variation.variation_opentype.duplicate()
-   dict["custom_MONO"] = int(button_pressed)
-   variable_font_variation.variation_opentype = dict
+   variable_font_variation.variation_opentype["custom_MONO"] = int(button_pressed)

 func _on_system_font_value_text_changed(new_text: String) -> void:

However, this has no effect in 4.2.beta1. @bruvzg Any ideas?

[bruvzg]

However, this has no effect in 4.2.beta1. @bruvzg Any ideas?

That's not gonna work, and I do not think there's any way to make it work. The only thing that can be removed for the old version is .duplicate().

[Calinou]

That's not gonna work, and I do not think there's any way to make it work. The only thing that can be removed for the old version is .duplicate().

I've tried removing .duplicate() and it didn't seem to work either. That said, I don't think this is critical for this demo to be mergeable.

[akien-mga]

Thanks!