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Add ability to specify color and font of axis tick labels for each axis #155

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Add ability to specify color and font of axis tick labels for each axis #155

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7b09ce3
Add ability to change tick label color and size for each axis
Nov 18, 2025
c290139
change AxisHints::tick_label_color to take an into<Color32> rather th…
Nov 19, 2025
7d0ff18
import Color32 and FontId directly, clean up method docs
Nov 24, 2025
79eb72d
Merge branch 'main' into feat/tick-label-decoration
TommiKabelitz Nov 24, 2025
dd6f178
Merge branch 'main' into feat/tick-label-decoration
TommiKabelitz Dec 19, 2025
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40 changes: 38 additions & 2 deletions egui_plot/src/axis.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -107,6 +107,8 @@ pub struct AxisHints<'a> {
pub(super) min_thickness: f32,
pub(super) placement: Placement,
pub(super) label_spacing: Rangef,
pub(super) tick_label_color: Option<egui::Color32>,
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@bircni bircni Nov 20, 2025

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import egui::Color32 directly

pub(super) tick_label_font: Option<egui::FontId>,
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@bircni bircni Nov 20, 2025

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import egui::FontId directly

}

impl<'a> AxisHints<'a> {
Expand Down Expand Up @@ -134,6 +136,8 @@ impl<'a> AxisHints<'a> {
Axis::X => Rangef::new(60.0, 80.0), // labels can get pretty wide
Axis::Y => Rangef::new(20.0, 30.0), // text isn't very high
},
tick_label_color: None,
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@bircni bircni Nov 20, 2025

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whats the default?
maybe set it to a default which we already use

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@bircni bircni Nov 20, 2025

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else use Default::default()

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@TommiKabelitz TommiKabelitz Nov 24, 2025 •
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Currently the default is whatever is in ui.visuals().text_color() when the plot is actually rendered because this function

/// Determine a color from a 0-1 strength value.
pub fn color_from_strength(ui: &Ui, strength: f32) -> Color32 {
    let base_color = ui.visuals().text_color();
    base_color.gamma_multiply(strength.sqrt())
}

is called to determine the color when the plot is shown.

I am still just calling this function when color is None so the behavior is not changing. I could potentially move the default to the instantiation of AxisHints, but that would change the behavior in cases where ui.visuals().text_color() is changed between creation of the axes and showing the plot.

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@bircni bircni Dec 12, 2025

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works for me

tick_label_font: None,
}
}

Expand Down Expand Up @@ -200,6 +204,27 @@ impl<'a> AxisHints<'a> {
self.label_spacing = range.into();
self
}

/// Set the color of the axis tick labels.
///
/// As labels get close, they will fade in color until they become invisible. See
/// [`Self::label_spacing`].
///
/// To change the font of the tick labels see [`Self::tick_label_font`].
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@bircni bircni Nov 20, 2025

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this comment is not necessary for this func

#[inline]
pub fn tick_label_color(mut self, color: impl Into<egui::Color32>) -> Self {
self.tick_label_color = Some(color.into());
self
}

/// Set the font of the axis tick labels.
///
/// To change the color of the tick labels see [`Self::tick_label_color`].
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@bircni bircni Nov 20, 2025

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this comment is not necessary for this func

#[inline]
pub fn tick_label_font(mut self, font: egui::FontId) -> Self {
self.tick_label_font = Some(font);
self
}
}

#[derive(Clone)]
Expand Down Expand Up @@ -319,8 +344,19 @@ impl<'a> AxisWidget<'a> {
// Fade in labels as they get further apart:
let strength = remap_clamp(spacing_in_points, label_spacing, 0.0..=1.0);

let text_color = super::color_from_strength(ui, strength);
let galley = painter.layout_no_wrap(text, font_id.clone(), text_color);
let text_color = if let Some(color) = self.hints.tick_label_color {
color.gamma_multiply(strength.sqrt())
} else {
super::color_from_strength(ui, strength)
};

let label_font_id = self
.hints
.tick_label_font
.clone()
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@bircni bircni Nov 20, 2025

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2x clones?
Is there something else possible?

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@TommiKabelitz TommiKabelitz Nov 24, 2025 •
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I could be mistaken, but I don't think so. Cloning FontId is pretty cheap as it is just an f32 and the FontFamily enum which is an Arc.

I think you need to clone in both cases as layout_no_wrap expects an owned FontId. When the font has not been specified we use the global one so you need to clone. When it is specified, you have to clone as we only have a reference to self and so cannot move it out of the shared reference.

The implications of changing layout_no_wrap to accept an owned value look to be significant at a glance.

.unwrap_or(font_id.clone());

let galley = painter.layout_no_wrap(text, label_font_id, text_color);
let galley_size = match axis {
Axis::X => galley.size(),
Axis::Y => galley.size() + 2.0 * SIDE_MARGIN * Vec2::X,
Expand Down