Round widgets to integer coordinates

crates/egui/src/containers/area.rs

@@ -66,21 +66,25 @@ impl AreaState {
             pivot_pos.x - self.pivot.x().to_factor() * size.x,
             pivot_pos.y - self.pivot.y().to_factor() * size.y,
         )
+        .round()
     }
 
     /// Move the left top positions of the area.
     pub fn set_left_top_pos(&mut self, pos: Pos2) {
         let size = self.size.unwrap_or_default();
-        self.pivot_pos = Some(pos2(
-            pos.x + self.pivot.x().to_factor() * size.x,
-            pos.y + self.pivot.y().to_factor() * size.y,
-        ));
+        self.pivot_pos = Some(
+            pos2(
+                pos.x + self.pivot.x().to_factor() * size.x,
+                pos.y + self.pivot.y().to_factor() * size.y,
+            )
+            .round(),
+        );
     }
 
     /// Where the area is on screen.
     pub fn rect(&self) -> Rect {
         let size = self.size.unwrap_or_default();
-        Rect::from_min_size(self.left_top_pos(), size)
+        Rect::from_min_size(self.left_top_pos(), size).round()
     }
 }
 
@@ -493,12 +497,11 @@ impl Area {
 
         if constrain {
             state.set_left_top_pos(
-                ctx.constrain_window_rect_to_area(state.rect(), constrain_rect)
-                    .min,
+                Context::constrain_window_rect_to_area(state.rect(), constrain_rect).min,
             );
         }
 
-        state.set_left_top_pos(ctx.round_pos_to_pixels(state.left_top_pos()));
+        state.set_left_top_pos(state.left_top_pos().round());
 
         // Update response with possibly moved/constrained rect:
         move_response.rect = state.rect();

crates/egui/src/containers/resize.rs

@@ -261,7 +261,8 @@ impl Resize {
         state.desired_size = state
             .desired_size
             .at_least(self.min_size)
-            .at_most(self.max_size);
+            .at_most(self.max_size)
+            .round();
 
         // ------------------------------
 

crates/egui/src/containers/window.rs

@@ -470,7 +470,7 @@ impl<'open> Window<'open> {
         let (title_bar_height, title_content_spacing) = if with_title_bar {
             let style = ctx.style();
             let spacing = window_margin.top + window_margin.bottom;
-            let height = ctx.fonts(|f| title.font_height(f, &style)) + spacing;
+            let height = ctx.fonts(|f| title.font_height(f, &style)).round() + spacing;
             window_frame.rounding.ne = window_frame.rounding.ne.clamp(0.0, height / 2.0);
             window_frame.rounding.nw = window_frame.rounding.nw.clamp(0.0, height / 2.0);
             (height, spacing)
@@ -771,13 +771,12 @@ fn resize_response(
     area: &mut area::Prepared,
     resize_id: Id,
 ) {
-    let Some(new_rect) = move_and_resize_window(ctx, &resize_interaction) else {
+    let Some(mut new_rect) = move_and_resize_window(ctx, &resize_interaction) else {
         return;
     };
-    let mut new_rect = ctx.round_rect_to_pixels(new_rect);
 
     if area.constrain() {
-        new_rect = ctx.constrain_window_rect_to_area(new_rect, area.constrain_rect());
+        new_rect = Context::constrain_window_rect_to_area(new_rect, area.constrain_rect());
     }
 
     // TODO(emilk): add this to a Window state instead as a command "move here next frame"
@@ -802,18 +801,18 @@ fn move_and_resize_window(ctx: &Context, interaction: &ResizeInteraction) -> Opt
     let mut rect = interaction.start_rect; // prevent drift
 
     if interaction.left.drag {
-        rect.min.x = ctx.round_to_pixel(pointer_pos.x);
+        rect.min.x = pointer_pos.x;
     } else if interaction.right.drag {
-        rect.max.x = ctx.round_to_pixel(pointer_pos.x);
+        rect.max.x = pointer_pos.x;
     }
 
     if interaction.top.drag {
-        rect.min.y = ctx.round_to_pixel(pointer_pos.y);
+        rect.min.y = pointer_pos.y;
     } else if interaction.bottom.drag {
-        rect.max.y = ctx.round_to_pixel(pointer_pos.y);
+        rect.max.y = pointer_pos.y;
     }
 
-    Some(rect)
+    Some(rect.round())
 }
 
 fn resize_interaction(
@@ -1047,13 +1046,14 @@ impl TitleBar {
         let inner_response = ui.horizontal(|ui| {
             let height = ui
                 .fonts(|fonts| title.font_height(fonts, ui.style()))
-                .max(ui.spacing().interact_size.y);
+                .max(ui.spacing().interact_size.y)
+                .round();
             ui.set_min_height(height);
 
             let item_spacing = ui.spacing().item_spacing;
             let button_size = Vec2::splat(ui.spacing().icon_width);
 
-            let pad = (height - button_size.y) / 2.0; // calculated so that the icon is on the diagonal (if window padding is symmetrical)
+            let pad = ((height - button_size.y) / 2.0).round(); // calculated so that the icon is on the diagonal (if window padding is symmetrical)
 
             if collapsible {
                 ui.add_space(pad);

crates/egui/src/context.rs

@@ -2065,7 +2065,7 @@ impl Context {
     // ---------------------------------------------------------------------
 
     /// Constrain the position of a window/area so it fits within the provided boundary.
-    pub(crate) fn constrain_window_rect_to_area(&self, window: Rect, area: Rect) -> Rect {
+    pub(crate) fn constrain_window_rect_to_area(window: Rect, area: Rect) -> Rect {
         let mut pos = window.min;
 
         // Constrain to screen, unless window is too large to fit:
@@ -2077,9 +2077,7 @@ impl Context {
         pos.y = pos.y.at_most(area.bottom() + margin_y - window.height()); // move right if needed
         pos.y = pos.y.at_least(area.top() - margin_y); // move down if needed
 
-        pos = self.round_pos_to_pixels(pos);
-
-        Rect::from_min_size(pos, window.size())
+        Rect::from_min_size(pos, window.size()).round()
     }
 }
 

crates/egui/src/grid.rs

@@ -179,13 +179,15 @@ impl GridLayout {
         let width = self.prev_state.col_width(self.col).unwrap_or(0.0);
         let height = self.prev_row_height(self.row);
         let size = child_size.max(vec2(width, height));
-        Rect::from_min_size(cursor.min, size)
+        Rect::from_min_size(cursor.min, size).round()
     }
 
     #[allow(clippy::unused_self)]
     pub(crate) fn align_size_within_rect(&self, size: Vec2, frame: Rect) -> Rect {
         // TODO(emilk): allow this alignment to be customized
-        Align2::LEFT_CENTER.align_size_within_rect(size, frame)
+        Align2::LEFT_CENTER
+            .align_size_within_rect(size, frame)
+            .round()
     }
 
     pub(crate) fn justify_and_align(&self, frame: Rect, size: Vec2) -> Rect {

crates/egui/src/layout.rs

@@ -394,7 +394,7 @@ impl Layout {
     pub fn align_size_within_rect(&self, size: Vec2, outer: Rect) -> Rect {
         debug_assert!(size.x >= 0.0 && size.y >= 0.0);
         debug_assert!(!outer.is_negative());
-        self.align2().align_size_within_rect(size, outer)
+        self.align2().align_size_within_rect(size, outer).round()
     }
 
     fn initial_cursor(&self, max_rect: Rect) -> Rect {
@@ -634,7 +634,7 @@ impl Layout {
         debug_assert!(!frame_rect.any_nan());
         debug_assert!(!frame_rect.is_negative());
 
-        frame_rect
+        frame_rect.round()
     }
 
     /// Apply justify (fill width/height) and/or alignment after calling `next_space`.

crates/egui/src/ui.rs

@@ -708,6 +708,7 @@ impl Ui {
     /// The height of text of this text style
     pub fn text_style_height(&self, style: &TextStyle) -> f32 {
         self.fonts(|f| f.row_height(&style.resolve(self.style())))
+            .round()
     }
 
     /// Screen-space rectangle for clipping what we paint in this ui.

crates/egui/src/widget_text.rs

@@ -269,7 +269,7 @@ impl RichText {
         if let Some(family) = &self.family {
             font_id.family = family.clone();
         }
-        fonts.row_height(&font_id)
+        fonts.row_height(&font_id).round()
     }
 
     /// Append to an existing [`LayoutJob`]

crates/egui/src/widgets/button.rs

@@ -204,7 +204,9 @@ impl Widget for Button<'_> {
         }
 
         let space_available_for_image = if let Some(text) = &text {
-            let font_height = ui.fonts(|fonts| text.font_height(fonts, ui.style()));
+            let font_height = ui
+                .fonts(|fonts| text.font_height(fonts, ui.style()))
+                .round();
             Vec2::splat(font_height) // Reasonable?
         } else {
             ui.available_size() - 2.0 * button_padding

crates/egui/src/widgets/label.rs

@@ -195,10 +195,10 @@ impl Label {
             assert!(!galley.rows.is_empty(), "Galleys are never empty");
             // collect a response from many rows:
             let rect = galley.rows[0].rect.translate(vec2(pos.x, pos.y));
-            let mut response = ui.allocate_rect(rect, sense);
+            let mut response = ui.allocate_rect(rect.round(), sense);
             for row in galley.rows.iter().skip(1) {
                 let rect = row.rect.translate(vec2(pos.x, pos.y));
-                response |= ui.allocate_rect(rect, sense);
+                response |= ui.allocate_rect(rect.round(), sense);
             }
             (pos, galley, response)
         } else {

crates/egui/src/widgets/text_edit/builder.rs

@@ -487,7 +487,7 @@ impl<'t> TextEdit<'t> {
         let prev_text = text.as_str().to_owned();
 
         let font_id = font_selection.resolve(ui.style());
-        let row_height = ui.fonts(|f| f.row_height(&font_id));
+        let row_height = ui.fonts(|f| f.row_height(&font_id)).round();
         const MIN_WIDTH: f32 = 24.0; // Never make a [`TextEdit`] more narrow than this.
         let available_width = (ui.available_width() - margin.sum().x).at_least(MIN_WIDTH);
         let desired_width = desired_width.unwrap_or_else(|| ui.spacing().text_edit_width);

crates/egui_demo_lib/src/demo/scrolling.rs

@@ -191,7 +191,7 @@ fn huge_content_painter(ui: &mut egui::Ui) {
     ui.add_space(4.0);
 
     let font_id = TextStyle::Body.resolve(ui.style());
-    let row_height = ui.fonts(|f| f.row_height(&font_id)) + ui.spacing().item_spacing.y;
+    let row_height = ui.fonts(|f| f.row_height(&font_id)).round() + ui.spacing().item_spacing.y;
     let num_rows = 10_000;
 
     ScrollArea::vertical()

crates/egui_demo_lib/src/easy_mark/easy_mark_viewer.rs

@@ -162,7 +162,7 @@ fn bullet_point(ui: &mut Ui, width: f32) -> Response {
 
 fn numbered_point(ui: &mut Ui, width: f32, number: &str) -> Response {
     let font_id = TextStyle::Body.resolve(ui.style());
-    let row_height = ui.fonts(|f| f.row_height(&font_id));
+    let row_height = ui.fonts(|f| f.row_height(&font_id)).round();
     let (rect, response) = ui.allocate_exact_size(vec2(width, row_height), Sense::hover());
     let text = format!("{number}.");
     let text_color = ui.visuals().strong_text_color();

crates/egui_extras/src/layout.rs

@@ -123,7 +123,7 @@ impl<'l> StripLayout<'l> {
 
         // Make sure we don't have a gap in the stripe/frame/selection background:
         let item_spacing = self.ui.spacing().item_spacing;
-        let gapless_rect = max_rect.expand2(0.5 * item_spacing);
+        let gapless_rect = max_rect.expand2(0.5 * item_spacing).round();
 
         if flags.striped {
             self.ui.painter().rect_filled(

crates/emath/src/rect.rs

@@ -245,6 +245,16 @@ impl Rect {
         )
     }
 
+    /// Round to integer
+    #[must_use]
+    #[inline]
+    pub fn round(self) -> Self {
+        Self {
+            min: self.min.round(),
+            max: self.max.round(),
+        }
+    }
+
     #[must_use]
     #[inline]
     pub fn intersects(self, other: Self) -> bool {