Merge branch 'emilk:master' into patch8

crates/egui/src/containers/area.rs

@@ -2,6 +2,8 @@
 //! It has no frame or own size. It is potentially movable.
 //! It is the foundation for windows and popups.
 
+use emath::GuiRounding as _;
+
 use crate::{
     emath, pos2, Align2, Context, Id, InnerResponse, LayerId, NumExt, Order, Pos2, Rect, Response,
     Sense, Ui, UiBuilder, UiKind, UiStackInfo, Vec2, WidgetRect, WidgetWithState,
@@ -66,6 +68,7 @@ impl AreaState {
             pivot_pos.x - self.pivot.x().to_factor() * size.x,
             pivot_pos.y - self.pivot.y().to_factor() * size.y,
         )
+        .round_ui()
     }
 
     /// Move the left top positions of the area.
@@ -80,7 +83,7 @@ impl AreaState {
     /// 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_ui()
     }
 }
 
@@ -493,12 +496,11 @@ 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());
 
         // Update response with possibly moved/constrained rect:
         move_response.rect = state.rect();

crates/egui/src/containers/panel.rs

@@ -15,6 +15,8 @@
 //!
 //! Add your [`crate::Window`]:s after any top-level panels.
 
+use emath::GuiRounding as _;
+
 use crate::{
     lerp, vec2, Align, Context, CursorIcon, Frame, Id, InnerResponse, LayerId, Layout, NumExt,
     Rangef, Rect, Sense, Stroke, Ui, UiBuilder, UiKind, UiStackInfo, Vec2,
@@ -76,6 +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.
@@ -264,6 +273,8 @@ impl SidePanel {
             }
         }
 
+        panel_rect = panel_rect.round_ui();
+
         let mut panel_ui = ui.new_child(
             UiBuilder::new()
                 .id_salt(id)
@@ -345,12 +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);
         }
 
@@ -558,6 +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.
@@ -756,6 +770,8 @@ impl TopBottomPanel {
             }
         }
 
+        panel_rect = panel_rect.round_ui();
+
         let mut panel_ui = ui.new_child(
             UiBuilder::new()
                 .id_salt(id)
@@ -837,12 +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);
         }
 
@@ -1130,15 +1142,14 @@ impl CentralPanel {
         ctx: &Context,
         add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
-        let available_rect = ctx.available_rect();
         let id = Id::new((ctx.viewport_id(), "central_panel"));
 
         let mut panel_ui = Ui::new(
             ctx.clone(),
             id,
             UiBuilder::new()
                 .layer_id(LayerId::background())
-                .max_rect(available_rect),
+                .max_rect(ctx.available_rect().round_ui()),
         );
         panel_ui.set_clip_rect(ctx.screen_rect());
 

crates/egui/src/containers/resize.rs

@@ -221,7 +221,8 @@ impl Resize {
                 .at_most(self.max_size)
                 .at_most(
                     ui.ctx().screen_rect().size() - ui.spacing().window_margin.sum(), // hack for windows
-                );
+                )
+                .round_ui();
 
             State {
                 desired_size: default_size,
@@ -233,7 +234,8 @@ impl Resize {
         state.desired_size = state
             .desired_size
             .at_least(self.min_size)
-            .at_most(self.max_size);
+            .at_most(self.max_size)
+            .round_ui();
 
         let mut user_requested_size = state.requested_size.take();
 
@@ -383,6 +385,7 @@ impl Resize {
     }
 }
 
+use emath::GuiRounding as _;
 use epaint::Stroke;
 
 pub fn paint_resize_corner(ui: &Ui, response: &Response) {
@@ -397,7 +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

crates/egui/src/containers/window.rs

@@ -7,6 +7,7 @@ use crate::{
     Align, Align2, Context, CursorIcon, Id, InnerResponse, LayerId, NumExt, Order, Response, Sense,
     TextStyle, Ui, UiKind, Vec2b, WidgetInfo, WidgetRect, WidgetText, WidgetType,
 };
+use emath::GuiRounding as _;
 use epaint::{emath, pos2, vec2, Galley, Pos2, Rect, RectShape, Rounding, Shape, Stroke, Vec2};
 
 use super::scroll_area::ScrollBarVisibility;
@@ -596,7 +597,7 @@ impl<'open> Window<'open> {
                     )
                     .shrink(frame_stroke.width);
 
-                    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;
@@ -789,13 +790,12 @@ 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"
@@ -820,18 +820,18 @@ 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_ui())
 }
 
 fn resize_interaction(
@@ -1071,7 +1071,7 @@ impl TitleBar {
             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_ui(); // 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

@@ -3,10 +3,10 @@
 use std::{borrow::Cow, cell::RefCell, panic::Location, sync::Arc, time::Duration};
 
 use containers::area::AreaState;
+use emath::GuiRounding as _;
 use epaint::{
     emath::{self, TSTransform},
     mutex::RwLock,
-    pos2,
     stats::PaintStats,
     tessellator,
     text::{FontInsert, FontPriority, Fonts},
@@ -1989,50 +1989,6 @@ 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.
@@ -2107,7 +2063,7 @@ 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:
@@ -2119,9 +2075,7 @@ 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_ui()
     }
 }
 
@@ -2554,15 +2508,15 @@ impl Context {
 
     /// Position and size of the egui area.
     pub fn screen_rect(&self) -> Rect {
-        self.input(|i| i.screen_rect())
+        self.input(|i| i.screen_rect()).round_ui()
     }
 
     /// How much space is still available after panels has been added.
     ///
     /// This is the "background" area, what egui doesn't cover with panels (but may cover with windows).
     /// This is also the area to which windows are constrained.
     pub fn available_rect(&self) -> Rect {
-        self.pass_state(|s| s.available_rect())
+        self.pass_state(|s| s.available_rect()).round_ui()
     }
 
     /// How much space is used by panels and windows.
@@ -2572,15 +2526,15 @@ impl Context {
             for (_id, window) in ctx.memory.areas().visible_windows() {
                 used = used.union(window.rect());
             }
-            used
+            used.round_ui()
         })
     }
 
     /// How much space is used by panels and windows.
     ///
     /// You can shrink your egui area to this size and still fit all egui components.
     pub fn used_size(&self) -> Vec2 {
-        self.used_rect().max - Pos2::ZERO
+        (self.used_rect().max - Pos2::ZERO).round_ui()
     }
 
     // ---------------------------------------------------------------------

crates/egui/src/grid.rs

@@ -1,3 +1,5 @@
+use emath::GuiRounding as _;
+
 use crate::{
     vec2, Align2, Color32, Context, Id, InnerResponse, NumExt, Painter, Rect, Region, Style, Ui,
     UiBuilder, Vec2,
@@ -179,13 +181,15 @@ 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_ui()
     }
 
     #[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_ui()
     }
 
     pub(crate) fn justify_and_align(&self, frame: Rect, size: Vec2) -> Rect {