From d20f93e9bf1e2fe52c1b11aff8cf741d10b2cb85 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Thu, 26 Dec 2024 21:02:27 +0100
Subject: [PATCH] Make all lines and rectangles crisp (#5518)

* Merge this first: https://github.com/emilk/egui/pull/5517

This aligns all rectangles and (horizontal or vertical) line segments to
the physical pixel grid in the `epaint::Tessellator`, making these
shapes appear crisp everywhere.

* Closes https://github.com/emilk/egui/issues/5164
* Closes https://github.com/emilk/egui/issues/3667

This undoes a lot of the explicit, egui-side aligning added in:
* https://github.com/emilk/egui/pull/4943

The new approach has several benefits over the old one:

* It is done automatically by epaint, so it is applied to everything (no
longer opt-in)
* It is applied after any layer transforms (so it always works)
* It makes line segments crisper on high-DPI screens
* All filled rectangles now has sides that end on pixel boundaries
---
 crates/egui/src/containers/panel.rs           |  30 ++--
 crates/egui/src/containers/resize.rs          |   4 +-
 crates/egui/src/containers/window.rs          |   2 +-
 crates/egui/src/context.rs                    |  45 -----
 crates/egui/src/introspection.rs              |  15 +-
 crates/egui/src/painter.rs                    |  83 ++++++----
 crates/egui/src/style.rs                      |   8 +-
 crates/egui/src/text_selection/visuals.rs     |  15 +-
 crates/egui/src/ui.rs                         |   8 +-
 crates/egui/src/widgets/separator.rs          |   4 +-
 crates/egui_demo_lib/src/rendering_test.rs    |   7 +-
 .../snapshots/demos/B\303\251zier Curve.png"  |   4 +-
 .../tests/snapshots/demos/Code Editor.png     |   4 +-
 .../tests/snapshots/demos/Code Example.png    |   4 +-
 .../tests/snapshots/demos/Context Menus.png   |   4 +-
 .../tests/snapshots/demos/Dancing Strings.png |   4 +-
 .../tests/snapshots/demos/Drag and Drop.png   |   4 +-
 .../tests/snapshots/demos/Extra Viewport.png  |   4 +-
 .../tests/snapshots/demos/Font Book.png       |   4 +-
 .../tests/snapshots/demos/Frame.png           |   4 +-
 .../tests/snapshots/demos/Highlighting.png    |   4 +-
 .../snapshots/demos/Interactive Container.png |   4 +-
 .../tests/snapshots/demos/Misc Demos.png      |   4 +-
 .../tests/snapshots/demos/Modals.png          |   4 +-
 .../tests/snapshots/demos/Multi Touch.png     |   4 +-
 .../tests/snapshots/demos/Painting.png        |   4 +-
 .../tests/snapshots/demos/Pan Zoom.png        |   4 +-
 .../tests/snapshots/demos/Panels.png          |   4 +-
 .../tests/snapshots/demos/Screenshot.png      |   4 +-
 .../tests/snapshots/demos/Scrolling.png       |   4 +-
 .../tests/snapshots/demos/Sliders.png         |   4 +-
 .../tests/snapshots/demos/Strip.png           |   4 +-
 .../tests/snapshots/demos/Table.png           |   4 +-
 .../tests/snapshots/demos/Text Layout.png     |   4 +-
 .../tests/snapshots/demos/TextEdit.png        |   4 +-
 .../tests/snapshots/demos/Tooltips.png        |   4 +-
 .../tests/snapshots/demos/Undo Redo.png       |   4 +-
 .../tests/snapshots/demos/Window Options.png  |   4 +-
 .../tests/snapshots/modals_1.png              |   4 +-
 .../tests/snapshots/modals_2.png              |   4 +-
 .../tests/snapshots/modals_3.png              |   4 +-
 ...rop_should_prevent_focusing_lower_area.png |   4 +-
 .../snapshots/rendering_test/dpi_1.00.png     |   4 +-
 .../snapshots/rendering_test/dpi_1.25.png     |   4 +-
 .../snapshots/rendering_test/dpi_1.50.png     |   4 +-
 .../snapshots/rendering_test/dpi_1.67.png     |   4 +-
 .../snapshots/rendering_test/dpi_1.75.png     |   4 +-
 .../snapshots/rendering_test/dpi_2.00.png     |   4 +-
 .../tests/snapshots/widget_gallery.png        |   4 +-
 crates/emath/src/gui_rounding.rs              |   1 +
 crates/epaint/src/lib.rs                      |   2 +-
 crates/epaint/src/shape.rs                    |  23 ++-
 crates/epaint/src/shape_transform.rs          |   2 +-
 crates/epaint/src/tessellator.rs              | 155 ++++++++++++++----
 examples/hello_android/Cargo.toml             |   9 +-
 55 files changed, 314 insertions(+), 251 deletions(-)

diff --git a/crates/egui/src/containers/panel.rs b/crates/egui/src/containers/panel.rs
index f659a8c4efa..6fd19e18688 100644
--- a/crates/egui/src/containers/panel.rs
+++ b/crates/egui/src/containers/panel.rs
@@ -78,6 +78,13 @@ impl Side {
             Self::Right => rect.right(),
         }
     }
+
+    fn sign(self) -> f32 {
+        match self {
+            Self::Left => -1.0,
+            Self::Right => 1.0,
+        }
+    }
 }
 
 /// A panel that covers the entire left or right side of a [`Ui`] or screen.
@@ -349,12 +356,8 @@ impl SidePanel {
             // TODO(emilk): draw line on top of all panels in this ui when https://github.com/emilk/egui/issues/1516 is done
             let resize_x = side.opposite().side_x(rect);
 
-            // This makes it pixel-perfect for odd-sized strokes (width=1.0, width=3.0, etc)
-            let resize_x = ui.painter().round_to_pixel_center(resize_x);
-
-            // We want the line exactly on the last pixel but rust rounds away from zero so we bring it back a bit for
-            // left-side panels
-            let resize_x = resize_x - if side == Side::Left { 1.0 } else { 0.0 };
+            // Make sure the line is on the inside of the panel:
+            let resize_x = resize_x + 0.5 * side.sign() * stroke.width;
             ui.painter().vline(resize_x, panel_rect.y_range(), stroke);
         }
 
@@ -562,6 +565,13 @@ impl TopBottomSide {
             Self::Bottom => rect.bottom(),
         }
     }
+
+    fn sign(self) -> f32 {
+        match self {
+            Self::Top => -1.0,
+            Self::Bottom => 1.0,
+        }
+    }
 }
 
 /// A panel that covers the entire top or bottom of a [`Ui`] or screen.
@@ -843,12 +853,8 @@ impl TopBottomPanel {
             // TODO(emilk): draw line on top of all panels in this ui when https://github.com/emilk/egui/issues/1516 is done
             let resize_y = side.opposite().side_y(rect);
 
-            // This makes it pixel-perfect for odd-sized strokes (width=1.0, width=3.0, etc)
-            let resize_y = ui.painter().round_to_pixel_center(resize_y);
-
-            // We want the line exactly on the last pixel but rust rounds away from zero so we bring it back a bit for
-            // top-side panels
-            let resize_y = resize_y - if side == TopBottomSide::Top { 1.0 } else { 0.0 };
+            // Make sure the line is on the inside of the panel:
+            let resize_y = resize_y + 0.5 * side.sign() * stroke.width;
             ui.painter().hline(panel_rect.x_range(), resize_y, stroke);
         }
 
diff --git a/crates/egui/src/containers/resize.rs b/crates/egui/src/containers/resize.rs
index 0165eba996a..bbb86dfbf36 100644
--- a/crates/egui/src/containers/resize.rs
+++ b/crates/egui/src/containers/resize.rs
@@ -400,7 +400,9 @@ pub fn paint_resize_corner_with_style(
     corner: Align2,
 ) {
     let painter = ui.painter();
-    let cp = painter.round_pos_to_pixels(corner.pos_in_rect(rect));
+    let cp = corner
+        .pos_in_rect(rect)
+        .round_to_pixels(ui.pixels_per_point());
     let mut w = 2.0;
     let stroke = Stroke {
         width: 1.0, // Set width to 1.0 to prevent overlapping
diff --git a/crates/egui/src/containers/window.rs b/crates/egui/src/containers/window.rs
index 44c3dda58c1..414c58cfae7 100644
--- a/crates/egui/src/containers/window.rs
+++ b/crates/egui/src/containers/window.rs
@@ -596,7 +596,7 @@ impl<'open> Window<'open> {
                         },
                     );
 
-                    title_rect = area_content_ui.painter().round_rect_to_pixels(title_rect);
+                    title_rect = title_rect.round_to_pixels(area_content_ui.pixels_per_point());
 
                     if on_top && area_content_ui.visuals().window_highlight_topmost {
                         let mut round = window_frame.rounding;
diff --git a/crates/egui/src/context.rs b/crates/egui/src/context.rs
index eaca8d36f52..118cddb31fa 100644
--- a/crates/egui/src/context.rs
+++ b/crates/egui/src/context.rs
@@ -7,7 +7,6 @@ use emath::GuiRounding as _;
 use epaint::{
     emath::{self, TSTransform},
     mutex::RwLock,
-    pos2,
     stats::PaintStats,
     tessellator,
     text::{FontInsert, FontPriority, Fonts},
@@ -2004,50 +2003,6 @@ impl Context {
         });
     }
 
-    /// Useful for pixel-perfect rendering of lines that are one pixel wide (or any odd number of pixels).
-    #[inline]
-    pub(crate) fn round_to_pixel_center(&self, point: f32) -> f32 {
-        let pixels_per_point = self.pixels_per_point();
-        ((point * pixels_per_point - 0.5).round() + 0.5) / pixels_per_point
-    }
-
-    /// Useful for pixel-perfect rendering of lines that are one pixel wide (or any odd number of pixels).
-    #[inline]
-    pub(crate) fn round_pos_to_pixel_center(&self, point: Pos2) -> Pos2 {
-        pos2(
-            self.round_to_pixel_center(point.x),
-            self.round_to_pixel_center(point.y),
-        )
-    }
-
-    /// Useful for pixel-perfect rendering of filled shapes
-    #[inline]
-    pub(crate) fn round_to_pixel(&self, point: f32) -> f32 {
-        let pixels_per_point = self.pixels_per_point();
-        (point * pixels_per_point).round() / pixels_per_point
-    }
-
-    /// Useful for pixel-perfect rendering of filled shapes
-    #[inline]
-    pub(crate) fn round_pos_to_pixels(&self, pos: Pos2) -> Pos2 {
-        pos2(self.round_to_pixel(pos.x), self.round_to_pixel(pos.y))
-    }
-
-    /// Useful for pixel-perfect rendering of filled shapes
-    #[inline]
-    pub(crate) fn round_vec_to_pixels(&self, vec: Vec2) -> Vec2 {
-        vec2(self.round_to_pixel(vec.x), self.round_to_pixel(vec.y))
-    }
-
-    /// Useful for pixel-perfect rendering of filled shapes
-    #[inline]
-    pub(crate) fn round_rect_to_pixels(&self, rect: Rect) -> Rect {
-        Rect {
-            min: self.round_pos_to_pixels(rect.min),
-            max: self.round_pos_to_pixels(rect.max),
-        }
-    }
-
     /// Allocate a texture.
     ///
     /// This is for advanced users.
diff --git a/crates/egui/src/introspection.rs b/crates/egui/src/introspection.rs
index 7f0ced6ba93..85e1ee6c62f 100644
--- a/crates/egui/src/introspection.rs
+++ b/crates/egui/src/introspection.rs
@@ -144,6 +144,8 @@ impl Widget for &mut epaint::TessellationOptions {
                 coarse_tessellation_culling,
                 prerasterized_discs,
                 round_text_to_pixels,
+                round_line_segments_to_pixels,
+                round_rects_to_pixels,
                 debug_paint_clip_rects,
                 debug_paint_text_rects,
                 debug_ignore_clip_rects,
@@ -179,13 +181,22 @@ impl Widget for &mut epaint::TessellationOptions {
 
             ui.checkbox(validate_meshes, "Validate meshes").on_hover_text("Check that incoming meshes are valid, i.e. that all indices are in range, etc.");
 
+            ui.collapsing("Align to pixel grid", |ui| {
+                ui.checkbox(round_text_to_pixels, "Text")
+                    .on_hover_text("Most text already is, so don't expect to see a large change.");
+
+                ui.checkbox(round_line_segments_to_pixels, "Line segments")
+                    .on_hover_text("Makes line segments appear crisp on any display.");
+
+                ui.checkbox(round_rects_to_pixels, "Rectangles")
+                    .on_hover_text("Makes line segments appear crisp on any display.");
+            });
+
             ui.collapsing("Debug", |ui| {
                 ui.checkbox(
                     coarse_tessellation_culling,
                     "Do coarse culling in the tessellator",
                 );
-                ui.checkbox(round_text_to_pixels, "Align text positions to pixel grid")
-                    .on_hover_text("Most text already is, so don't expect to see a large change.");
 
                 ui.checkbox(debug_ignore_clip_rects, "Ignore clip rectangles");
                 ui.checkbox(debug_paint_clip_rects, "Paint clip rectangles");
diff --git a/crates/egui/src/painter.rs b/crates/egui/src/painter.rs
index 232450e3862..e30a148d979 100644
--- a/crates/egui/src/painter.rs
+++ b/crates/egui/src/painter.rs
@@ -1,23 +1,30 @@
 use std::sync::Arc;
 
+use emath::GuiRounding as _;
+use epaint::{
+    text::{Fonts, Galley, LayoutJob},
+    CircleShape, ClippedShape, PathStroke, RectShape, Rounding, Shape, Stroke,
+};
+
 use crate::{
     emath::{Align2, Pos2, Rangef, Rect, Vec2},
     layers::{LayerId, PaintList, ShapeIdx},
     Color32, Context, FontId,
 };
-use epaint::{
-    text::{Fonts, Galley, LayoutJob},
-    CircleShape, ClippedShape, PathStroke, RectShape, Rounding, Shape, Stroke,
-};
 
 /// Helper to paint shapes and text to a specific region on a specific layer.
 ///
 /// All coordinates are screen coordinates in the unit points (one point can consist of many physical pixels).
+///
+/// A [`Painter`] never outlive a single frame/pass.
 #[derive(Clone)]
 pub struct Painter {
     /// Source of fonts and destination of shapes
     ctx: Context,
 
+    /// For quick access, without having to go via [`Context`].
+    pixels_per_point: f32,
+
     /// Where we paint
     layer_id: LayerId,
 
@@ -38,8 +45,10 @@ pub struct Painter {
 impl Painter {
     /// Create a painter to a specific layer within a certain clip rectangle.
     pub fn new(ctx: Context, layer_id: LayerId, clip_rect: Rect) -> Self {
+        let pixels_per_point = ctx.pixels_per_point();
         Self {
             ctx,
+            pixels_per_point,
             layer_id,
             clip_rect,
             fade_to_color: None,
@@ -49,14 +58,10 @@ impl Painter {
 
     /// Redirect where you are painting.
     #[must_use]
-    pub fn with_layer_id(self, layer_id: LayerId) -> Self {
-        Self {
-            ctx: self.ctx,
-            layer_id,
-            clip_rect: self.clip_rect,
-            fade_to_color: None,
-            opacity_factor: 1.0,
-        }
+    #[inline]
+    pub fn with_layer_id(mut self, layer_id: LayerId) -> Self {
+        self.layer_id = layer_id;
+        self
     }
 
     /// Create a painter for a sub-region of this [`Painter`].
@@ -64,13 +69,9 @@ impl Painter {
     /// The clip-rect of the returned [`Painter`] will be the intersection
     /// of the given rectangle and the `clip_rect()` of the parent [`Painter`].
     pub fn with_clip_rect(&self, rect: Rect) -> Self {
-        Self {
-            ctx: self.ctx.clone(),
-            layer_id: self.layer_id,
-            clip_rect: rect.intersect(self.clip_rect),
-            fade_to_color: self.fade_to_color,
-            opacity_factor: self.opacity_factor,
-        }
+        let mut new_self = self.clone();
+        new_self.clip_rect = rect.intersect(self.clip_rect);
+        new_self
     }
 
     /// Redirect where you are painting.
@@ -82,7 +83,7 @@ impl Painter {
     }
 
     /// If set, colors will be modified to look like this
-    pub(crate) fn set_fade_to_color(&mut self, fade_to_color: Option<Color32>) {
+    pub fn set_fade_to_color(&mut self, fade_to_color: Option<Color32>) {
         self.fade_to_color = fade_to_color;
     }
 
@@ -118,24 +119,27 @@ impl Painter {
     /// If `false`, nothing you paint will show up.
     ///
     /// Also checks [`Context::will_discard`].
-    pub(crate) fn is_visible(&self) -> bool {
+    pub fn is_visible(&self) -> bool {
         self.fade_to_color != Some(Color32::TRANSPARENT) && !self.ctx.will_discard()
     }
 
     /// If `false`, nothing added to the painter will be visible
-    pub(crate) fn set_invisible(&mut self) {
+    pub fn set_invisible(&mut self) {
         self.fade_to_color = Some(Color32::TRANSPARENT);
     }
-}
 
-/// ## Accessors etc
-impl Painter {
     /// Get a reference to the parent [`Context`].
     #[inline]
     pub fn ctx(&self) -> &Context {
         &self.ctx
     }
 
+    /// Number of physical pixels for each logical UI point.
+    #[inline]
+    pub fn pixels_per_point(&self) -> f32 {
+        self.pixels_per_point
+    }
+
     /// Read-only access to the shared [`Fonts`].
     ///
     /// See [`Context`] documentation for how locks work.
@@ -180,37 +184,42 @@ impl Painter {
     /// Useful for pixel-perfect rendering of lines that are one pixel wide (or any odd number of pixels).
     #[inline]
     pub fn round_to_pixel_center(&self, point: f32) -> f32 {
-        self.ctx().round_to_pixel_center(point)
+        point.round_to_pixel_center(self.pixels_per_point())
     }
 
     /// Useful for pixel-perfect rendering of lines that are one pixel wide (or any odd number of pixels).
+    #[deprecated = "Use `emath::GuiRounding` with `painter.pixels_per_point()` instead"]
     #[inline]
     pub fn round_pos_to_pixel_center(&self, pos: Pos2) -> Pos2 {
-        self.ctx().round_pos_to_pixel_center(pos)
+        pos.round_to_pixel_center(self.pixels_per_point())
     }
 
     /// Useful for pixel-perfect rendering of filled shapes.
+    #[deprecated = "Use `emath::GuiRounding` with `painter.pixels_per_point()` instead"]
     #[inline]
     pub fn round_to_pixel(&self, point: f32) -> f32 {
-        self.ctx().round_to_pixel(point)
+        point.round_to_pixels(self.pixels_per_point())
     }
 
     /// Useful for pixel-perfect rendering.
+    #[deprecated = "Use `emath::GuiRounding` with `painter.pixels_per_point()` instead"]
     #[inline]
     pub fn round_vec_to_pixels(&self, vec: Vec2) -> Vec2 {
-        self.ctx().round_vec_to_pixels(vec)
+        vec.round_to_pixels(self.pixels_per_point())
     }
 
     /// Useful for pixel-perfect rendering.
+    #[deprecated = "Use `emath::GuiRounding` with `painter.pixels_per_point()` instead"]
     #[inline]
     pub fn round_pos_to_pixels(&self, pos: Pos2) -> Pos2 {
-        self.ctx().round_pos_to_pixels(pos)
+        pos.round_to_pixels(self.pixels_per_point())
     }
 
     /// Useful for pixel-perfect rendering.
+    #[deprecated = "Use `emath::GuiRounding` with `painter.pixels_per_point()` instead"]
     #[inline]
     pub fn round_rect_to_pixels(&self, rect: Rect) -> Rect {
-        self.ctx().round_rect_to_pixels(rect)
+        rect.round_to_pixels(self.pixels_per_point())
     }
 }
 
@@ -337,7 +346,7 @@ impl Painter {
 /// # Paint different primitives
 impl Painter {
     /// Paints a line from the first point to the second.
-    pub fn line_segment(&self, points: [Pos2; 2], stroke: impl Into<PathStroke>) -> ShapeIdx {
+    pub fn line_segment(&self, points: [Pos2; 2], stroke: impl Into<Stroke>) -> ShapeIdx {
         self.add(Shape::LineSegment {
             points,
             stroke: stroke.into(),
@@ -351,13 +360,13 @@ impl Painter {
     }
 
     /// Paints a horizontal line.
-    pub fn hline(&self, x: impl Into<Rangef>, y: f32, stroke: impl Into<PathStroke>) -> ShapeIdx {
-        self.add(Shape::hline(x, y, stroke.into()))
+    pub fn hline(&self, x: impl Into<Rangef>, y: f32, stroke: impl Into<Stroke>) -> ShapeIdx {
+        self.add(Shape::hline(x, y, stroke))
     }
 
     /// Paints a vertical line.
-    pub fn vline(&self, x: f32, y: impl Into<Rangef>, stroke: impl Into<PathStroke>) -> ShapeIdx {
-        self.add(Shape::vline(x, y, stroke.into()))
+    pub fn vline(&self, x: f32, y: impl Into<Rangef>, stroke: impl Into<Stroke>) -> ShapeIdx {
+        self.add(Shape::vline(x, y, stroke))
     }
 
     pub fn circle(
@@ -398,6 +407,7 @@ impl Painter {
         })
     }
 
+    /// The stroke extends _outside_ the [`Rect`].
     pub fn rect(
         &self,
         rect: Rect,
@@ -417,6 +427,7 @@ impl Painter {
         self.add(RectShape::filled(rect, rounding, fill_color))
     }
 
+    /// The stroke extends _outside_ the [`Rect`].
     pub fn rect_stroke(
         &self,
         rect: Rect,
diff --git a/crates/egui/src/style.rs b/crates/egui/src/style.rs
index 91c0e09dbfa..33ab21a6837 100644
--- a/crates/egui/src/style.rs
+++ b/crates/egui/src/style.rs
@@ -2485,12 +2485,8 @@ impl Widget for &mut Stroke {
 
             // stroke preview:
             let (_id, stroke_rect) = ui.allocate_space(ui.spacing().interact_size);
-            let left = ui
-                .painter()
-                .round_pos_to_pixel_center(stroke_rect.left_center());
-            let right = ui
-                .painter()
-                .round_pos_to_pixel_center(stroke_rect.right_center());
+            let left = stroke_rect.left_center();
+            let right = stroke_rect.right_center();
             ui.painter().line_segment([left, right], (*width, *color));
         })
         .response
diff --git a/crates/egui/src/text_selection/visuals.rs b/crates/egui/src/text_selection/visuals.rs
index 2a31d1e1270..dd7c867a222 100644
--- a/crates/egui/src/text_selection/visuals.rs
+++ b/crates/egui/src/text_selection/visuals.rs
@@ -96,19 +96,8 @@ pub fn paint_text_selection(
 pub fn paint_cursor_end(painter: &Painter, visuals: &Visuals, cursor_rect: Rect) {
     let stroke = visuals.text_cursor.stroke;
 
-    // Ensure the cursor is aligned to the pixel grid for whole number widths.
-    // See https://github.com/emilk/egui/issues/5164
-    let (top, bottom) = if (stroke.width as usize) % 2 == 0 {
-        (
-            painter.round_pos_to_pixels(cursor_rect.center_top()),
-            painter.round_pos_to_pixels(cursor_rect.center_bottom()),
-        )
-    } else {
-        (
-            painter.round_pos_to_pixel_center(cursor_rect.center_top()),
-            painter.round_pos_to_pixel_center(cursor_rect.center_bottom()),
-        )
-    };
+    let top = cursor_rect.center_top();
+    let bottom = cursor_rect.center_bottom();
 
     painter.line_segment([top, bottom], (stroke.width, stroke.color));
 
diff --git a/crates/egui/src/ui.rs b/crates/egui/src/ui.rs
index 9cf2d4b5427..19fda5d0fee 100644
--- a/crates/egui/src/ui.rs
+++ b/crates/egui/src/ui.rs
@@ -483,6 +483,12 @@ impl Ui {
         &self.painter
     }
 
+    /// Number of physical pixels for each logical UI point.
+    #[inline]
+    pub fn pixels_per_point(&self) -> f32 {
+        self.painter.pixels_per_point()
+    }
+
     /// If `false`, the [`Ui`] does not allow any interaction and
     /// the widgets in it will draw with a gray look.
     #[inline]
@@ -2385,9 +2391,7 @@ impl Ui {
 
             let stroke = self.visuals().widgets.noninteractive.bg_stroke;
             let left_top = child_rect.min - 0.5 * indent * Vec2::X;
-            let left_top = self.painter().round_pos_to_pixel_center(left_top);
             let left_bottom = pos2(left_top.x, child_ui.min_rect().bottom() - 2.0);
-            let left_bottom = self.painter().round_pos_to_pixel_center(left_bottom);
 
             if left_vline {
                 // draw a faint line on the left to mark the indented section
diff --git a/crates/egui/src/widgets/separator.rs b/crates/egui/src/widgets/separator.rs
index 2cc3a857ce6..d018cfa4d0d 100644
--- a/crates/egui/src/widgets/separator.rs
+++ b/crates/egui/src/widgets/separator.rs
@@ -116,12 +116,12 @@ impl Widget for Separator {
             if is_horizontal_line {
                 painter.hline(
                     (rect.left() - grow)..=(rect.right() + grow),
-                    painter.round_to_pixel_center(rect.center().y),
+                    rect.center().y,
                     stroke,
                 );
             } else {
                 painter.vline(
-                    painter.round_to_pixel_center(rect.center().x),
+                    rect.center().x,
                     (rect.top() - grow)..=(rect.bottom() + grow),
                     stroke,
                 );
diff --git a/crates/egui_demo_lib/src/rendering_test.rs b/crates/egui_demo_lib/src/rendering_test.rs
index df3add3776e..bd454267e7a 100644
--- a/crates/egui_demo_lib/src/rendering_test.rs
+++ b/crates/egui_demo_lib/src/rendering_test.rs
@@ -1,9 +1,9 @@
 use std::collections::HashMap;
 
 use egui::{
-    epaint, lerp, pos2, vec2, widgets::color_picker::show_color, Align2, Color32, FontId, Image,
-    Mesh, Pos2, Rect, Response, Rgba, RichText, Sense, Shape, Stroke, TextureHandle,
-    TextureOptions, Ui, Vec2,
+    emath::GuiRounding, epaint, lerp, pos2, vec2, widgets::color_picker::show_color, Align2,
+    Color32, FontId, Image, Mesh, Pos2, Rect, Response, Rgba, RichText, Sense, Shape, Stroke,
+    TextureHandle, TextureOptions, Ui, Vec2,
 };
 
 const GRADIENT_SIZE: Vec2 = vec2(256.0, 18.0);
@@ -270,6 +270,7 @@ impl ColorTest {
 
 fn vertex_gradient(ui: &mut Ui, bg_fill: Color32, gradient: &Gradient) -> Response {
     let (rect, response) = ui.allocate_at_least(GRADIENT_SIZE, Sense::hover());
+    let rect = rect.round_to_pixels(ui.pixels_per_point());
     if bg_fill != Default::default() {
         let mut mesh = Mesh::default();
         mesh.add_colored_rect(rect, bg_fill);
diff --git "a/crates/egui_demo_lib/tests/snapshots/demos/B\303\251zier Curve.png" "b/crates/egui_demo_lib/tests/snapshots/demos/B\303\251zier Curve.png"
index ad7d9becfaa..c4cd0bd1099 100644
--- "a/crates/egui_demo_lib/tests/snapshots/demos/B\303\251zier Curve.png"	
+++ "b/crates/egui_demo_lib/tests/snapshots/demos/B\303\251zier Curve.png"	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:4a725aa81433f301fda4ff8a28be869366332964995d1ae4ed996591596eb7e2
-size 31461
+oid sha256:cf83bead834ec8f88d74b32ae6331715e8c6df183e007e2a16004c019534a30f
+size 31810
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Code Editor.png b/crates/egui_demo_lib/tests/snapshots/demos/Code Editor.png
index 252c7c8f205..77ebb00947f 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Code Editor.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Code Editor.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:36028d85f49ee77562250214237def2b676ecc9ed413d2fd8afc473d61289ca1
-size 32761
+oid sha256:b8ca5a27491c0589a97e43a70bc10dc52778d25ca3f7e7c895dbbbb784adfcfa
+size 33245
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Code Example.png b/crates/egui_demo_lib/tests/snapshots/demos/Code Example.png
index 33121fe85fa..04fa9ba3c55 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Code Example.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Code Example.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:f93cbf4968e69e2b51256631ab8703d1af2274147924f8d802d9da0f9767aa1b
-size 81162
+oid sha256:e640606207265b4f040f793b0ffb989504b6a98b89e95e77a9a9d3e3abc9327a
+size 80933
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Context Menus.png b/crates/egui_demo_lib/tests/snapshots/demos/Context Menus.png
index 9191ade8504..caa3c3a5d96 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Context Menus.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Context Menus.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:b7157cc3a1c87b63a1af41e9c3493beb426f9a2c7e3ce1adf228a8d1aee23818
-size 11549
+oid sha256:332c2af36873d8ccccb36c08fd2e475dc1f18454a3090a851c0889395d4f364f
+size 11518
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Dancing Strings.png b/crates/egui_demo_lib/tests/snapshots/demos/Dancing Strings.png
index ac28a61122d..e86d10772ef 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Dancing Strings.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Dancing Strings.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
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-size 20645
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+size 20626
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Drag and Drop.png b/crates/egui_demo_lib/tests/snapshots/demos/Drag and Drop.png
index c25087b71fe..38199566d27 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Drag and Drop.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Drag and Drop.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
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-size 20883
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+size 20831
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Extra Viewport.png b/crates/egui_demo_lib/tests/snapshots/demos/Extra Viewport.png
index aa6372175d0..96adb69423d 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Extra Viewport.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Extra Viewport.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
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-size 10711
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+size 10703
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Font Book.png b/crates/egui_demo_lib/tests/snapshots/demos/Font Book.png
index f8c028fb0cc..10f5d0b40a0 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Font Book.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Font Book.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:cce41bc2887462a0a3aebc4148faf769d3666ff4a0e4c7db6ffbddb174be0ed3
-size 135734
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+size 135712
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Frame.png b/crates/egui_demo_lib/tests/snapshots/demos/Frame.png
index 28a855fa38c..e896f366e31 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Frame.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Frame.png
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
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-size 24701
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+size 24413
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Highlighting.png b/crates/egui_demo_lib/tests/snapshots/demos/Highlighting.png
index edc26309f9f..ea317322420 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Highlighting.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Highlighting.png
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
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-size 17806
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+size 17785
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Interactive Container.png b/crates/egui_demo_lib/tests/snapshots/demos/Interactive Container.png
index 2bfbf20f91e..68d03d9fd07 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Interactive Container.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Interactive Container.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:d9c8395e6b4287b92d85a52ca2d47750f67abeb0ad88c6b42264bfe2e62fd09d
-size 22283
+oid sha256:d6328c86b70f3e24aaf87db200d13dfd0baa787dd8431e47621457937f8f5021
+size 22552
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Misc Demos.png b/crates/egui_demo_lib/tests/snapshots/demos/Misc Demos.png
index 9eea2ac7b92..dcd12b097f2 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Misc Demos.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Misc Demos.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:17901f3e235cfbac03fb2334f36f614ed152a25b3a212e78beba9fb342039844
-size 65339
+oid sha256:afb57dc0bb8ff839138e36b8780136e0c8da55ff380832538fae0394143807c0
+size 65321
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Modals.png b/crates/egui_demo_lib/tests/snapshots/demos/Modals.png
index 274b4b57686..3341eebff84 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Modals.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Modals.png
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:026723cb5d89b32386a849328c34420ee9e3ae1f97cbf6fa3c4543141123549e
-size 32890
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+size 32879
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Multi Touch.png b/crates/egui_demo_lib/tests/snapshots/demos/Multi Touch.png
index af91ac8e61f..882279e03b7 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Multi Touch.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Multi Touch.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:950c825c8f6eadc682c57fe8843ded2ceb6981b6d4086d427dcf0d27740df8ef
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+size 36780
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Painting.png b/crates/egui_demo_lib/tests/snapshots/demos/Painting.png
index 8ad735d6c6f..40cb73fe06a 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Painting.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Painting.png
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:e68f145f57812a1f6a81e1a8ab41bcb134320dcaaee3f462d1aa00d6c331752a
-size 17579
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+size 17531
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Pan Zoom.png b/crates/egui_demo_lib/tests/snapshots/demos/Pan Zoom.png
index 6a1b79e3d78..cecfb843283 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Pan Zoom.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Pan Zoom.png	
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:6aec5a6291ad2796457d1c4fc44228c75bf075262aa672749a3cceb4baef1e08
-size 25271
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+size 25330
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Panels.png b/crates/egui_demo_lib/tests/snapshots/demos/Panels.png
index 585c126360c..6576f9ad5dd 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Panels.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Panels.png
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
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-size 261946
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+size 262141
diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Screenshot.png b/crates/egui_demo_lib/tests/snapshots/demos/Screenshot.png
index 56978de2001..4c97bde2061 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Screenshot.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Screenshot.png
@@ -1,3 +1,3 @@
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diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Scrolling.png b/crates/egui_demo_lib/tests/snapshots/demos/Scrolling.png
index eef59e1b79c..98b10f30d6f 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Scrolling.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Scrolling.png
@@ -1,3 +1,3 @@
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diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Sliders.png b/crates/egui_demo_lib/tests/snapshots/demos/Sliders.png
index e3a213176e9..19b7cf0ff35 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Sliders.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Sliders.png
@@ -1,3 +1,3 @@
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diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Strip.png b/crates/egui_demo_lib/tests/snapshots/demos/Strip.png
index 24e613b1c91..16a54ae0fa8 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Strip.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Strip.png
@@ -1,3 +1,3 @@
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index fd796f69561..232a5ec327c 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Table.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Table.png
@@ -1,3 +1,3 @@
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diff --git a/crates/egui_demo_lib/tests/snapshots/demos/Text Layout.png b/crates/egui_demo_lib/tests/snapshots/demos/Text Layout.png
index dfef3f17542..cc2da3a5563 100644
--- a/crates/egui_demo_lib/tests/snapshots/demos/Text Layout.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Text Layout.png	
@@ -1,3 +1,3 @@
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--- a/crates/egui_demo_lib/tests/snapshots/demos/TextEdit.png
+++ b/crates/egui_demo_lib/tests/snapshots/demos/TextEdit.png
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--- a/crates/egui_demo_lib/tests/snapshots/demos/Undo Redo.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Undo Redo.png	
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--- a/crates/egui_demo_lib/tests/snapshots/demos/Window Options.png	
+++ b/crates/egui_demo_lib/tests/snapshots/demos/Window Options.png	
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+++ b/crates/egui_demo_lib/tests/snapshots/modals_1.png
@@ -1,3 +1,3 @@
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-oid sha256:bd53d25bcecc4f22cb9226237d69557696e8aa08b969157c0cdb015cfacf206d
-size 48244
+oid sha256:17217e600d8a85ec00ecb11f0e5fe69496b30bbf715cc86785cec6e18b8c2fa1
+size 48158
diff --git a/crates/egui_demo_lib/tests/snapshots/modals_2.png b/crates/egui_demo_lib/tests/snapshots/modals_2.png
index bfac37e75a9..8c496d81dd1 100644
--- a/crates/egui_demo_lib/tests/snapshots/modals_2.png
+++ b/crates/egui_demo_lib/tests/snapshots/modals_2.png
@@ -1,3 +1,3 @@
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-oid sha256:d9d9226996b0eecf516b9b89f09c57e5f7ad43cc154a2c8937779421a6580113
-size 48157
+oid sha256:fac50d2327a9e5e99989dd81d5644db86031b91b9c5c68fc17b5ef53ae655048
+size 47970
diff --git a/crates/egui_demo_lib/tests/snapshots/modals_3.png b/crates/egui_demo_lib/tests/snapshots/modals_3.png
index ab2e1f12553..1cc989ddce5 100644
--- a/crates/egui_demo_lib/tests/snapshots/modals_3.png
+++ b/crates/egui_demo_lib/tests/snapshots/modals_3.png
@@ -1,3 +1,3 @@
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-oid sha256:49401fcd6e348c75d81ad7419e1fa1a77500ca3d2360b418e8304ad5843e5b3a
-size 44080
+oid sha256:e5e829257b742194742429be0efd326be17ff7f5b9b16f9df58df21e899320bd
+size 43963
diff --git a/crates/egui_demo_lib/tests/snapshots/modals_backdrop_should_prevent_focusing_lower_area.png b/crates/egui_demo_lib/tests/snapshots/modals_backdrop_should_prevent_focusing_lower_area.png
index 8042b02babb..0246090d4a6 100644
--- a/crates/egui_demo_lib/tests/snapshots/modals_backdrop_should_prevent_focusing_lower_area.png
+++ b/crates/egui_demo_lib/tests/snapshots/modals_backdrop_should_prevent_focusing_lower_area.png
@@ -1,3 +1,3 @@
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-size 44044
+oid sha256:5da064332c669a860a92a34b101f23e28026d4f07948f7c3e9a40e611f5e284f
+size 43986
diff --git a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.00.png b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.00.png
index b4c96d8397d..4bb0582ae12 100644
--- a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.00.png
+++ b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.00.png
@@ -1,3 +1,3 @@
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-oid sha256:dc83a67ac7ff574f981dae02c05ecfba934df4fb181bba12fd7607ef9cba5aa6
-size 523650
+oid sha256:ed2a356452d792e32bea57f044da9d86da27fd8504826dd6b87618a53519ea6a
+size 522556
diff --git a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.25.png b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.25.png
index 82426652255..1abf12ef16a 100644
--- a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.25.png
+++ b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.25.png
@@ -1,3 +1,3 @@
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-size 737802
+oid sha256:0d04a5854528c6141f7def6f9229c51c6d2d4c87e2f656be4d149e7b2b852976
+size 729056
diff --git a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.50.png b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.50.png
index 29514c4e7ff..c3bd68ac263 100644
--- a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.50.png
+++ b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.50.png
@@ -1,3 +1,3 @@
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-size 887154
+oid sha256:e6e5c1a745e357faa7b98f7a2cd1ca139c4a14be154b9d21feb8030933acfdb7
+size 867552
diff --git a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.67.png b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.67.png
index 3d412b56667..4564e587106 100644
--- a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.67.png
+++ b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.67.png
@@ -1,3 +1,3 @@
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-size 1002104
+oid sha256:7d9f4a37541fd1a0754c1cb1f3a2d4a76f03d67ca4e5596c8e6982d691d29dea
+size 980286
diff --git a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.75.png b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.75.png
index f10d189a56e..93931ef3889 100644
--- a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.75.png
+++ b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_1.75.png
@@ -1,3 +1,3 @@
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-size 1080661
+oid sha256:4d1c99867202e16500146b7146a32fd83d70d60f5ac94aae4ca405a6377e4625
+size 1066559
diff --git a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_2.00.png b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_2.00.png
index 6890b9d4611..4d76639461c 100644
--- a/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_2.00.png
+++ b/crates/egui_demo_lib/tests/snapshots/rendering_test/dpi_2.00.png
@@ -1,3 +1,3 @@
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+oid sha256:08fc1c89fd2d04aa12c75a1829dacfff090e322c65ad969648799833e1b072eb
+size 1235574
diff --git a/crates/egui_demo_lib/tests/snapshots/widget_gallery.png b/crates/egui_demo_lib/tests/snapshots/widget_gallery.png
index a2adca3db43..51596247499 100644
--- a/crates/egui_demo_lib/tests/snapshots/widget_gallery.png
+++ b/crates/egui_demo_lib/tests/snapshots/widget_gallery.png
@@ -1,3 +1,3 @@
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-oid sha256:9da93a7c27e17d370a3df73930d71694d436c300656b054722646ea57db45810
-size 160803
+oid sha256:d122b1a995e691b5049c57d65c9f222a5f1639b1e4f6f96f91823444339693cc
+size 160540
diff --git a/crates/emath/src/gui_rounding.rs b/crates/emath/src/gui_rounding.rs
index 3c2cf92411b..ac624792a27 100644
--- a/crates/emath/src/gui_rounding.rs
+++ b/crates/emath/src/gui_rounding.rs
@@ -116,6 +116,7 @@ impl GuiRounding for crate::Vec2 {
         )
     }
 
+    // This doesn't really make sense for a Vec2, but 🤷‍♂️
     #[inline]
     fn round_to_pixel_center(self, pixels_per_point: f32) -> Self {
         Self::new(
diff --git a/crates/epaint/src/lib.rs b/crates/epaint/src/lib.rs
index 89664cdb844..b769275cc2d 100644
--- a/crates/epaint/src/lib.rs
+++ b/crates/epaint/src/lib.rs
@@ -53,7 +53,7 @@ pub use self::{
         Rounding, Shape, TextShape,
     },
     stats::PaintStats,
-    stroke::{PathStroke, Stroke},
+    stroke::{PathStroke, Stroke, StrokeKind},
     tessellator::{TessellationOptions, Tessellator},
     text::{FontFamily, FontId, Fonts, Galley},
     texture_atlas::TextureAtlas,
diff --git a/crates/epaint/src/shape.rs b/crates/epaint/src/shape.rs
index 6f67a2bc6a6..56af703b669 100644
--- a/crates/epaint/src/shape.rs
+++ b/crates/epaint/src/shape.rs
@@ -35,10 +35,7 @@ pub enum Shape {
     Ellipse(EllipseShape),
 
     /// A line between two points.
-    LineSegment {
-        points: [Pos2; 2],
-        stroke: PathStroke,
-    },
+    LineSegment { points: [Pos2; 2], stroke: Stroke },
 
     /// A series of lines between points.
     /// The path can have a stroke and/or fill (if closed).
@@ -92,7 +89,7 @@ impl Shape {
     /// A line between two points.
     /// More efficient than calling [`Self::line`].
     #[inline]
-    pub fn line_segment(points: [Pos2; 2], stroke: impl Into<PathStroke>) -> Self {
+    pub fn line_segment(points: [Pos2; 2], stroke: impl Into<Stroke>) -> Self {
         Self::LineSegment {
             points,
             stroke: stroke.into(),
@@ -100,7 +97,7 @@ impl Shape {
     }
 
     /// A horizontal line.
-    pub fn hline(x: impl Into<Rangef>, y: f32, stroke: impl Into<PathStroke>) -> Self {
+    pub fn hline(x: impl Into<Rangef>, y: f32, stroke: impl Into<Stroke>) -> Self {
         let x = x.into();
         Self::LineSegment {
             points: [pos2(x.min, y), pos2(x.max, y)],
@@ -109,7 +106,7 @@ impl Shape {
     }
 
     /// A vertical line.
-    pub fn vline(x: f32, y: impl Into<Rangef>, stroke: impl Into<PathStroke>) -> Self {
+    pub fn vline(x: f32, y: impl Into<Rangef>, stroke: impl Into<Stroke>) -> Self {
         let y = y.into();
         Self::LineSegment {
             points: [pos2(x, y.min), pos2(x, y.max)],
@@ -262,6 +259,7 @@ impl Shape {
         Self::Rect(RectShape::filled(rect, rounding, fill_color))
     }
 
+    /// The stroke extends _outside_ the [`Rect`].
     #[inline]
     pub fn rect_stroke(
         rect: Rect,
@@ -670,6 +668,11 @@ pub struct RectShape {
     pub fill: Color32,
 
     /// The thickness and color of the outline.
+    ///
+    /// The stroke extends _outside_ the edge of [`Self::rect`],
+    /// i.e. using [`crate::StrokeKind::Outside`].
+    ///
+    /// This means the [`Self::visual_bounding_rect`] is `rect.size() + 2.0 * stroke.width`.
     pub stroke: Stroke,
 
     /// If larger than zero, the edges of the rectangle
@@ -695,6 +698,7 @@ pub struct RectShape {
 }
 
 impl RectShape {
+    /// The stroke extends _outside_ the [`Rect`].
     #[inline]
     pub fn new(
         rect: Rect,
@@ -730,6 +734,7 @@ impl RectShape {
         }
     }
 
+    /// The stroke extends _outside_ the [`Rect`].
     #[inline]
     pub fn stroke(rect: Rect, rounding: impl Into<Rounding>, stroke: impl Into<Stroke>) -> Self {
         Self {
@@ -761,8 +766,8 @@ impl RectShape {
         if self.fill == Color32::TRANSPARENT && self.stroke.is_empty() {
             Rect::NOTHING
         } else {
-            self.rect
-                .expand((self.stroke.width + self.blur_width) / 2.0)
+            let Stroke { width, .. } = self.stroke; // Make sure we remember to update this if we change `stroke` to `PathStroke`
+            self.rect.expand(width + self.blur_width / 2.0)
         }
     }
 }
diff --git a/crates/epaint/src/shape_transform.rs b/crates/epaint/src/shape_transform.rs
index f072393f557..263f9cf07a6 100644
--- a/crates/epaint/src/shape_transform.rs
+++ b/crates/epaint/src/shape_transform.rs
@@ -21,7 +21,7 @@ pub fn adjust_colors(
         }
 
         Shape::LineSegment { stroke, points: _ } => {
-            adjust_color_mode(&mut stroke.color, adjust_color);
+            adjust_color(&mut stroke.color);
         }
 
         Shape::Path(PathShape {
diff --git a/crates/epaint/src/tessellator.rs b/crates/epaint/src/tessellator.rs
index ebd22f55303..e04eb03bee8 100644
--- a/crates/epaint/src/tessellator.rs
+++ b/crates/epaint/src/tessellator.rs
@@ -11,7 +11,7 @@ use crate::{
     EllipseShape, Mesh, PathShape, Primitive, QuadraticBezierShape, RectShape, Rounding, Shape,
     Stroke, TextShape, TextureId, Vertex, WHITE_UV,
 };
-use emath::{pos2, remap, vec2, NumExt, Pos2, Rect, Rot2, Vec2};
+use emath::{pos2, remap, vec2, GuiRounding as _, NumExt, Pos2, Rect, Rot2, Vec2};
 
 use self::color::ColorMode;
 use self::stroke::PathStroke;
@@ -671,10 +671,21 @@ pub struct TessellationOptions {
     /// from the font atlas.
     pub prerasterized_discs: bool,
 
-    /// If `true` (default) align text to mesh grid.
+    /// If `true` (default) align text to the physical pixel grid.
     /// This makes the text sharper on most platforms.
     pub round_text_to_pixels: bool,
 
+    /// If `true` (default), align right-angled line segments to the physical pixel grid.
+    ///
+    /// This makes the line segments appear crisp on any display.
+    pub round_line_segments_to_pixels: bool,
+
+    /// If `true` (default), align rectangles to the physical pixel grid.
+    ///
+    /// This makes the rectangle strokes more crisp,
+    /// and makes filled rectangles tile perfectly (without feathering).
+    pub round_rects_to_pixels: bool,
+
     /// Output the clip rectangles to be painted.
     pub debug_paint_clip_rects: bool,
 
@@ -708,6 +719,8 @@ impl Default for TessellationOptions {
             coarse_tessellation_culling: true,
             prerasterized_discs: true,
             round_text_to_pixels: true,
+            round_line_segments_to_pixels: true,
+            round_rects_to_pixels: true,
             debug_paint_text_rects: false,
             debug_paint_clip_rects: false,
             debug_ignore_clip_rects: false,
@@ -754,8 +767,11 @@ fn fill_closed_path(
 
     // TODO(juancampa): This bounding box is computed twice per shape: once here and another when tessellating the
     // stroke, consider hoisting that logic to the tessellator/scratchpad.
-    let bbox = Rect::from_points(&path.iter().map(|p| p.pos).collect::<Vec<Pos2>>())
-        .expand((stroke.width / 2.0) + feathering);
+    let bbox = if matches!(stroke.color, ColorMode::UV(_)) {
+        Rect::from_points(&path.iter().map(|p| p.pos).collect::<Vec<Pos2>>()).expand(feathering)
+    } else {
+        Rect::NAN
+    };
 
     let stroke_color = &stroke.color;
     let get_stroke_color: Box<dyn Fn(Pos2) -> Color32> = match stroke_color {
@@ -900,7 +916,7 @@ fn fill_closed_path_with_uv(
 #[inline(always)]
 fn translate_stroke_point(p: &mut PathPoint, stroke: &PathStroke) {
     match stroke.kind {
-        stroke::StrokeKind::Middle => { /* Nothingn to do */ }
+        stroke::StrokeKind::Middle => { /* Nothing to do */ }
         stroke::StrokeKind::Outside => {
             p.pos += p.normal * stroke.width * 0.5;
         }
@@ -932,9 +948,13 @@ fn stroke_path(
             .for_each(|p| translate_stroke_point(p, stroke));
     }
 
-    // expand the bounding box to include the thickness of the path
-    let bbox = Rect::from_points(&path.iter().map(|p| p.pos).collect::<Vec<Pos2>>())
-        .expand((stroke.width / 2.0) + feathering);
+    // Expand the bounding box to include the thickness of the path
+    let bbox = if matches!(stroke.color, ColorMode::UV(_)) {
+        Rect::from_points(&path.iter().map(|p| p.pos).collect::<Vec<Pos2>>())
+            .expand((stroke.width / 2.0) + feathering)
+    } else {
+        Rect::NAN
+    };
 
     let get_color = |col: &ColorMode, pos: Pos2| match col {
         ColorMode::Solid(col) => *col,
@@ -1386,7 +1406,9 @@ impl Tessellator {
 
                 out.append(mesh);
             }
-            Shape::LineSegment { points, stroke } => self.tessellate_line(points, stroke, out),
+            Shape::LineSegment { points, stroke } => {
+                self.tessellate_line_segment(points, stroke, out);
+            }
             Shape::Path(path_shape) => {
                 self.tessellate_path(&path_shape, out);
             }
@@ -1563,10 +1585,10 @@ impl Tessellator {
     ///
     /// * `shape`: the mesh to tessellate.
     /// * `out`: triangles are appended to this.
-    pub fn tessellate_line(
+    pub fn tessellate_line_segment(
         &mut self,
-        points: [Pos2; 2],
-        stroke: impl Into<PathStroke>,
+        mut points: [Pos2; 2],
+        stroke: impl Into<Stroke>,
         out: &mut Mesh,
     ) {
         let stroke = stroke.into();
@@ -1582,10 +1604,38 @@ impl Tessellator {
             return;
         }
 
+        if self.options.round_line_segments_to_pixels {
+            let [a, b] = &mut points;
+            if a.x == b.x {
+                // Vertical line
+                let mut x = a.x;
+                round_line_segment(&mut x, &stroke, self.pixels_per_point);
+                a.x = x;
+                b.x = x;
+            }
+            if a.y == b.y {
+                // Horizontal line
+                let mut y = a.y;
+                round_line_segment(&mut y, &stroke, self.pixels_per_point);
+                a.y = y;
+                b.y = y;
+            }
+        }
+
         self.scratchpad_path.clear();
         self.scratchpad_path.add_line_segment(points);
         self.scratchpad_path
-            .stroke_open(self.feathering, &stroke, out);
+            .stroke_open(self.feathering, &stroke.into(), out);
+    }
+
+    #[deprecated = "Use `tessellate_line_segment` instead"]
+    pub fn tessellate_line(
+        &mut self,
+        points: [Pos2; 2],
+        stroke: impl Into<Stroke>,
+        out: &mut Mesh,
+    ) {
+        self.tessellate_line_segment(points, stroke, out);
     }
 
     /// Tessellate a single [`PathShape`] into a [`Mesh`].
@@ -1660,6 +1710,14 @@ impl Tessellator {
             return;
         }
 
+        if self.options.round_rects_to_pixels {
+            // Since the stroke extends outside of the rectangle,
+            // we can round the rectangle sides to the physical pixel edges,
+            // and the filled rect will appear crisp, as will the inside of the stroke.
+            let Stroke { .. } = stroke; // Make sure we remember to update this if we change `stroke` to `PathStroke`
+            rect = rect.round_to_pixels(self.pixels_per_point);
+        }
+
         // It is common to (sometimes accidentally) create an infinitely sized rectangle.
         // Make sure we can handle that:
         rect.min = rect.min.at_least(pos2(-1e7, -1e7));
@@ -1688,46 +1746,33 @@ impl Tessellator {
             self.feathering = self.feathering.max(blur_width);
         }
 
-        if rect.width() < self.feathering {
+        if rect.width() < 0.5 * self.feathering {
             // Very thin - approximate by a vertical line-segment:
             let line = [rect.center_top(), rect.center_bottom()];
             if fill != Color32::TRANSPARENT {
-                self.tessellate_line(line, Stroke::new(rect.width(), fill), out);
+                self.tessellate_line_segment(line, Stroke::new(rect.width(), fill), out);
             }
             if !stroke.is_empty() {
-                self.tessellate_line(line, stroke, out); // back…
-                self.tessellate_line(line, stroke, out); // …and forth
+                self.tessellate_line_segment(line, stroke, out); // back…
+                self.tessellate_line_segment(line, stroke, out); // …and forth
             }
-        } else if rect.height() < self.feathering {
+        } else if rect.height() < 0.5 * self.feathering {
             // Very thin - approximate by a horizontal line-segment:
             let line = [rect.left_center(), rect.right_center()];
             if fill != Color32::TRANSPARENT {
-                self.tessellate_line(line, Stroke::new(rect.height(), fill), out);
+                self.tessellate_line_segment(line, Stroke::new(rect.height(), fill), out);
             }
             if !stroke.is_empty() {
-                self.tessellate_line(line, stroke, out); // back…
-                self.tessellate_line(line, stroke, out); // …and forth
+                self.tessellate_line_segment(line, stroke, out); // back…
+                self.tessellate_line_segment(line, stroke, out); // …and forth
             }
         } else {
-            let rect = if !stroke.is_empty() && stroke.width < self.feathering {
-                // Very thin rectangle strokes create extreme aliasing when they move around.
-                // We can fix that by rounding the rectangle corners to pixel centers.
-                // TODO(#5164): maybe do this for all shapes and stroke sizes
-                // TODO(emilk): since we use StrokeKind::Outside, we should probably round the
-                // corners after offsetting them with half the stroke width (see `translate_stroke_point`).
-                Rect {
-                    min: self.round_pos_to_pixel_center(rect.min),
-                    max: self.round_pos_to_pixel_center(rect.max),
-                }
-            } else {
-                rect
-            };
-
             let path = &mut self.scratchpad_path;
             path.clear();
             path::rounded_rectangle(&mut self.scratchpad_points, rect, rounding);
             path.add_line_loop(&self.scratchpad_points);
             let path_stroke = PathStroke::from(stroke).outside();
+
             if uv.is_positive() {
                 // Textured
                 let uv_from_pos = |p: Pos2| {
@@ -1741,6 +1786,7 @@ impl Tessellator {
                 // Untextured
                 path.fill(self.feathering, fill, &path_stroke, out);
             }
+
             path.stroke_closed(self.feathering, &path_stroke, out);
         }
 
@@ -1968,6 +2014,45 @@ impl Tessellator {
     }
 }
 
+fn round_line_segment(coord: &mut f32, stroke: &Stroke, pixels_per_point: f32) {
+    // If the stroke is an odd number of pixels wide,
+    // we want to round the center of it to the center of a pixel.
+    //
+    // If however it is an even number of pixels wide,
+    // we want to round the center to be between two pixels.
+    //
+    // We also want to treat strokes that are _almost_ odd as it it was odd,
+    // to make it symmetric. Same for strokes that are _almost_ even.
+    //
+    // For strokes less than a pixel wide we also round to the center,
+    // because it will rendered as a single row of pixels by the tessellator.
+
+    let pixel_size = 1.0 / pixels_per_point;
+
+    if stroke.width <= pixel_size || is_nearest_integer_odd(pixels_per_point * stroke.width) {
+        *coord = coord.round_to_pixel_center(pixels_per_point);
+    } else {
+        *coord = coord.round_to_pixels(pixels_per_point);
+    }
+}
+
+fn is_nearest_integer_odd(width: f32) -> bool {
+    (width * 0.5 + 0.25).fract() > 0.5
+}
+
+#[test]
+fn test_is_nearest_integer_odd() {
+    assert!(is_nearest_integer_odd(0.6));
+    assert!(is_nearest_integer_odd(1.0));
+    assert!(is_nearest_integer_odd(1.4));
+    assert!(!is_nearest_integer_odd(1.6));
+    assert!(!is_nearest_integer_odd(2.0));
+    assert!(!is_nearest_integer_odd(2.4));
+    assert!(is_nearest_integer_odd(2.6));
+    assert!(is_nearest_integer_odd(3.0));
+    assert!(is_nearest_integer_odd(3.4));
+}
+
 #[deprecated = "Use `Tessellator::new(…).tessellate_shapes(…)` instead"]
 pub fn tessellate_shapes(
     pixels_per_point: f32,
diff --git a/examples/hello_android/Cargo.toml b/examples/hello_android/Cargo.toml
index dcb0a5a5c01..a7d27277359 100644
--- a/examples/hello_android/Cargo.toml
+++ b/examples/hello_android/Cargo.toml
@@ -4,7 +4,7 @@ version = "0.1.0"
 authors = ["Emil Ernerfeldt <emil.ernerfeldt@gmail.com>"]
 license = "MIT OR Apache-2.0"
 edition = "2021"
-rust-version = "1.76"
+rust-version = "1.80"
 publish = false
 
 # `unsafe_code` is required for `#[no_mangle]`, disable workspace lints to workaround lint error.
@@ -16,10 +16,7 @@ crate-type = ["cdylib"]
 
 
 [dependencies]
-eframe = { workspace = true, features = [
-    "default",
-    "android-native-activity",
-] }
+eframe = { workspace = true, features = ["default", "android-native-activity"] }
 
 # For image support:
 egui_extras = { workspace = true, features = ["default", "image"] }
@@ -29,4 +26,4 @@ winit = { workspace = true }
 android_logger = "0.14"
 
 [package.metadata.android]
-build_targets = [ "armv7-linux-androideabi", "aarch64-linux-android" ]
+build_targets = ["armv7-linux-androideabi", "aarch64-linux-android"]