Move egui/math into new crate emath

CHANGELOG.md

@@ -17,6 +17,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 * Center window titles.
 * Tweak size and alignment of some emojis to match other text.
+* Rename feature "serde" to "persistence".
 
 ### Fixed 🐛
 

Cargo.lock

@@ -642,6 +642,7 @@ version = "0.7.0"
 dependencies = [
  "ahash",
  "atomic_refcell",
+ "emath",
  "parking_lot",
  "rusttype",
  "serde",
@@ -703,6 +704,13 @@ version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
 
+[[package]]
+name = "emath"
+version = "0.7.0"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "epi"
 version = "0.7.0"

Cargo.toml

@@ -5,6 +5,7 @@ members = [
     "egui_glium",
     "egui_web",
     "egui",
+    "emath",
     "epi",
 ]
 

egui/Cargo.toml

@@ -19,6 +19,8 @@ include = [
 [lib]
 
 [dependencies]
+emath = { path = "../emath" }
+
 ahash = { version = "0.6", features = ["std"], default-features = false }
 atomic_refcell = { version = "0.1", optional = true } # Used instead of parking_lot when you are always using Egui in a single thread. About as fast as parking_lot. Panics on multi-threaded use of egui::Context.
 parking_lot = { version = "0.11", optional = true } # Using parking_lot over std::sync::Mutex gives 50% speedups in some real-world scenarios
@@ -27,6 +29,7 @@ serde = { version = "1", features = ["derive", "rc"], optional = true }
 
 [features]
 default = ["atomic_refcell", "default_fonts"]
+persistence = ["serde", "emath/serde"]
 
 # If set, egui will use `include_bytes!` to bundle some fonts.
 # If you plan on specifying your own fonts you may disable this feature.

egui/src/containers/area.rs

@@ -8,7 +8,7 @@ use crate::*;
 
 /// State that is persisted between frames
 #[derive(Clone, Copy, Debug)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub(crate) struct State {
     /// Last known pos
     pub pos: Pos2,

egui/src/containers/collapsing_header.rs

@@ -7,8 +7,8 @@ use crate::{
 };
 
 #[derive(Clone, Copy, Debug)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub(crate) struct State {
     open: bool,
 
@@ -114,7 +114,7 @@ pub(crate) fn paint_icon(ui: &mut Ui, openness: f32, response: &Response) {
     let rect = Rect::from_center_size(rect.center(), vec2(rect.width(), rect.height()) * 0.75);
     let mut points = vec![rect.left_top(), rect.right_top(), rect.center_bottom()];
     use std::f32::consts::TAU;
-    let rotation = Rot2::from_angle(remap(openness, 0.0..=1.0, -TAU / 4.0..=0.0));
+    let rotation = math::Rot2::from_angle(remap(openness, 0.0..=1.0, -TAU / 4.0..=0.0));
     for p in &mut points {
         *p = rect.center() + rotation * (*p - rect.center());
     }

egui/src/containers/resize.rs

@@ -1,7 +1,7 @@
 use crate::*;
 
 #[derive(Clone, Copy, Debug)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub(crate) struct State {
     /// This is the size that the user has picked by dragging the resize handles.
     /// This may be smaller and/or larger than the actual size.

egui/src/containers/scroll_area.rs

@@ -1,8 +1,8 @@
 use crate::*;
 
 #[derive(Clone, Copy, Debug)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub(crate) struct State {
     /// Positive offset means scrolling down/right
     offset: Vec2,
@@ -10,7 +10,7 @@ pub(crate) struct State {
     show_scroll: bool,
 
     /// Momentum, used for kinetic scrolling
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     pub vel: Vec2,
     /// Mouse offset relative to the top of the handle when started moving the handle.
     scroll_start_offset_from_top: Option<f32>,
@@ -177,7 +177,7 @@ impl Prepared {
         // We take the scroll target so only this ScrollArea will use it.
         let scroll_target = content_ui.ctx().frame_state().scroll_target.take();
         if let Some((scroll_y, align)) = scroll_target {
-            let center_factor = align.scroll_center_factor();
+            let center_factor = align.to_factor();
 
             let top = content_ui.min_rect().top();
             let visible_range = top..=top + content_ui.clip_rect().height();

egui/src/containers/window.rs

@@ -720,7 +720,7 @@ impl TitleBar {
         self.title_label = self.title_label.text_color(style.fg_stroke.color);
 
         let full_top_rect = Rect::from_x_y_ranges(self.rect.x_range(), self.min_rect.y_range());
-        let text_pos = align::center_size_in_rect(self.title_galley.size, full_top_rect);
+        let text_pos = math::align::center_size_in_rect(self.title_galley.size, full_top_rect);
         let text_pos = text_pos.left_top() - 2.0 * Vec2::Y; // HACK: center on x-height of text (looks better)
         self.title_label
             .paint_galley(ui, text_pos, self.title_galley);

egui/src/id.rs

@@ -28,7 +28,7 @@ use std::hash::Hash;
 /// Then there are widgets that need no identifiers at all, like labels,
 /// because they have no state nor are interacted with.
 #[derive(Clone, Copy, Hash, Eq, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct Id(u64);
 
 impl Id {

egui/src/introspection.rs

@@ -1,6 +1,5 @@
 //! uis for egui types.
 use crate::{
-    math::*,
     paint::{self, PaintCmd, Texture, Triangles},
     *,
 };

egui/src/layers.rs

@@ -4,7 +4,7 @@ use crate::{math::Rect, paint::PaintCmd, Id, *};
 
 /// Different layer categories
 #[derive(Clone, Copy, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub enum Order {
     /// Painted behind all floating windows
     Background,
@@ -40,7 +40,7 @@ impl Order {
 /// An identifier for a paint layer.
 /// Also acts as an identifier for [`Area`]:s.
 #[derive(Clone, Copy, Debug, Hash, Eq, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct LayerId {
     pub order: Order,
     pub id: Id,

egui/src/layout.rs

@@ -66,8 +66,8 @@ impl Region {
 
 /// Layout direction, one of `LeftToRight`, `RightToLeft`, `TopDown`, `BottomUp`.
 #[derive(Clone, Copy, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(rename_all = "snake_case"))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(rename_all = "snake_case"))]
 pub enum Direction {
     LeftToRight,
     RightToLeft,
@@ -95,7 +95,7 @@ impl Direction {
 
 /// The layout of a [`Ui`][`crate::Ui`], e.g. "vertical & centered".
 #[derive(Clone, Copy, Debug, PartialEq)]
-// #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+// #[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct Layout {
     /// Main axis direction
     main_dir: Direction,

egui/src/lib.rs

@@ -86,7 +86,6 @@ mod input;
 mod introspection;
 mod layers;
 mod layout;
-pub mod math;
 mod memory;
 pub mod menu;
 pub mod paint;
@@ -97,6 +96,8 @@ mod ui;
 pub mod util;
 pub mod widgets;
 
+pub use emath as math;
+
 pub use {
     containers::*,
     context::{Context, CtxRef},
@@ -104,7 +105,7 @@ pub use {
     input::*,
     layers::*,
     layout::*,
-    math::*,
+    math::{clamp, lerp, pos2, remap, remap_clamp, vec2, Align, Align2, NumExt, Pos2, Rect, Vec2},
     memory::Memory,
     paint::{
         color, Color32, FontDefinitions, FontFamily, PaintCmd, PaintJobs, Rgba, Stroke, TextStyle,

egui/src/memory.rs

@@ -18,50 +18,50 @@ use crate::{
 ///
 /// If you want this to persist when closing your app you should serialize `Memory` and store it.
 #[derive(Clone, Debug, Default)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct Memory {
     pub(crate) options: Options,
 
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     pub(crate) interaction: Interaction,
 
     // states of various types of widgets
     pub(crate) collapsing_headers: HashMap<Id, collapsing_header::State>,
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     pub(crate) menu_bar: HashMap<Id, menu::BarState>,
     pub(crate) resize: HashMap<Id, resize::State>,
     pub(crate) scroll_areas: HashMap<Id, scroll_area::State>,
     pub(crate) text_edit: HashMap<Id, text_edit::State>,
 
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     pub(crate) window_interaction: Option<window::WindowInteraction>,
 
     /// For temporary edit of e.g. a slider value.
     /// Couples with [`Interaction::kb_focus_id`].
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     pub(crate) temp_edit_string: Option<String>,
 
     pub(crate) areas: Areas,
 
     /// Used by color picker
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     pub(crate) color_cache: Cache<Color32, Hsva>,
 
     /// Which popup-window is open (if any)?
     /// Could be a combo box, color picker, menu etc.
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     popup: Option<Id>,
 
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     everything_is_visible: bool,
 }
 
 // ----------------------------------------------------------------------------
 
 #[derive(Clone, Debug, Default)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub(crate) struct Options {
     /// The default style for new `Ui`:s.
     pub(crate) style: std::sync::Arc<Style>,
@@ -304,8 +304,8 @@ impl Memory {
 /// Keeps track of `Area`s, which are free-floating `Ui`s.
 /// These `Area`s can be in any `Order`.
 #[derive(Clone, Debug, Default)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct Areas {
     areas: HashMap<Id, area::State>,
     /// Top is last

egui/src/paint/color.rs

@@ -8,7 +8,7 @@ use crate::math::clamp;
 /// Internally this uses 0-255 gamma space `sRGBA` color with premultiplied alpha.
 /// Alpha channel is in linear space.
 #[derive(Clone, Copy, Debug, Default, Eq, Hash, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct Color32(pub(crate) [u8; 4]);
 
 impl std::ops::Index<usize> for Color32 {
@@ -130,7 +130,7 @@ impl Color32 {
 
 /// 0-1 linear space `RGBA` color with premultiplied alpha.
 #[derive(Clone, Copy, Debug, Default, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct Rgba(pub(crate) [f32; 4]);
 
 impl std::ops::Index<usize> for Rgba {

egui/src/paint/command.rs

@@ -192,7 +192,7 @@ impl PaintCmd {
 
 /// Describes the width and color of a line.
 #[derive(Clone, Copy, Debug, Default, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct Stroke {
     pub width: f32,
     pub color: Color32,

egui/src/paint/fonts.rs

@@ -14,8 +14,8 @@ use super::{
 // TODO: rename
 /// One of a few categories of styles of text, e.g. body, button or heading.
 #[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(rename_all = "snake_case"))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(rename_all = "snake_case"))]
 pub enum TextStyle {
     /// Used when small text is needed.
     Small,
@@ -45,8 +45,8 @@ impl TextStyle {
 
 /// Which style of font: [`Monospace`][`FontFamily::Monospace`] or [`Proportional`][`FontFamily::Proportional`].
 #[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(rename_all = "snake_case"))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(rename_all = "snake_case"))]
 pub enum FontFamily {
     /// A font where each character is the same width (`w` is the same width as `i`).
     Monospace,
@@ -81,15 +81,15 @@ fn rusttype_font_from_font_data(name: &str, data: &FontData) -> rusttype::Font<'
 /// ctx.set_fonts(fonts);
 /// ```
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct FontDefinitions {
     /// List of font names and their definitions.
     /// The definition must be the contents of either a `.ttf` or `.otf` font file.
     ///
     /// Egui has built-in-default for these,
     /// but you can override them if you like.
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     pub font_data: BTreeMap<String, FontData>,
 
     /// Which fonts (names) to use for each [`FontFamily`].

egui/src/paint/galley.rs

@@ -20,7 +20,7 @@ use crate::math::{pos2, NumExt, Rect, Vec2};
 
 /// Character cursor
 #[derive(Clone, Copy, Debug, Default)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct CCursor {
     /// Character offset (NOT byte offset!).
     pub index: usize,
@@ -71,7 +71,7 @@ impl std::ops::Sub<usize> for CCursor {
 
 /// Row Cursor
 #[derive(Clone, Copy, Debug, Default, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct RCursor {
     /// 0 is first row, and so on.
     /// Note that a single paragraph can span multiple rows.
@@ -86,7 +86,7 @@ pub struct RCursor {
 
 /// Paragraph Cursor
 #[derive(Clone, Copy, Debug, Default)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct PCursor {
     /// 0 is first paragraph, and so on.
     /// Note that a single paragraph can span multiple rows.
@@ -118,7 +118,7 @@ impl PartialEq for PCursor {
 /// pcursor/rcursor can also point to after the end of the paragraph/row.
 /// Does not implement `PartialEq` because you must think which cursor should be equivalent.
 #[derive(Clone, Copy, Debug, Default)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct Cursor {
     pub ccursor: CCursor,
     pub rcursor: RCursor,

egui/src/paint/shadow.rs

@@ -1,7 +1,7 @@
 use super::*;
 
 #[derive(Clone, Copy, Debug, Default, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct Shadow {
     // The shadow extends this much outside the rect.
     pub extrusion: f32,

egui/src/paint/tessellator.rs

@@ -446,8 +446,8 @@ use self::PathType::{Closed, Open};
 
 /// Tessellation quality options
 #[derive(Clone, Copy, Debug)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct TessellationOptions {
     /// Size of a pixel in points, e.g. 0.5
     pub aa_size: f32,

egui/src/style.rs

@@ -1,3 +1,5 @@
+//! Egui theme (spacing, colors, etc).
+
 #![allow(clippy::if_same_then_else)]
 
 use crate::{
@@ -9,8 +11,8 @@ use crate::{
 
 /// Specifies the look and feel of a [`Ui`].
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct Style {
     /// Default `TextStyle` for normal text (i.e. for `Label` and `TextEdit`).
     pub body_text_style: TextStyle,
@@ -39,8 +41,8 @@ impl Style {
 }
 
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct Spacing {
     /// Horizontal and vertical spacing between widgets
     pub item_spacing: Vec2,
@@ -95,8 +97,8 @@ impl Spacing {
 }
 
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct Interaction {
     /// Mouse must be the close to the side of a window to resize
     pub resize_grab_radius_side: f32,
@@ -106,8 +108,8 @@ pub struct Interaction {
 }
 
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct Visuals {
     /// Override default text color for all text.
     ///
@@ -168,16 +170,16 @@ impl Visuals {
 
 /// Selected text, selected elements etc
 #[derive(Clone, Copy, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct Selection {
     pub bg_fill: Color32,
     pub stroke: Stroke,
 }
 
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub struct Widgets {
     /// For an interactive widget that is being interacted with
     pub active: WidgetVisuals,
@@ -207,7 +209,7 @@ impl Widgets {
 
 /// bg = background, fg = foreground.
 #[derive(Clone, Copy, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct WidgetVisuals {
     /// Background color of widget
     pub bg_fill: Color32,

egui/src/types.rs

@@ -5,7 +5,7 @@ use crate::{lerp, math::Rect, Align, CtxRef, Id, LayerId, Ui};
 /// What Egui emits each frame.
 /// The backend should use this.
 #[derive(Clone, Default)]
-// #[cfg_attr(feature = "serde", derive(serde::Serialize))]
+// #[cfg_attr(feature = "persistence", derive(serde::Serialize))]
 pub struct Output {
     /// Set the cursor to this icon.
     pub cursor_icon: CursorIcon,
@@ -26,8 +26,8 @@ pub struct Output {
 ///
 /// Egui emits a `CursorIcond` in [`Output`] each frame as a request to the integration.
 #[derive(Clone, Copy)]
-// #[cfg_attr(feature = "serde", derive(serde::Serialize))]
-// #[cfg_attr(feature = "serde", serde(rename_all = "snake_case"))]
+// #[cfg_attr(feature = "persistence", derive(serde::Serialize))]
+// #[cfg_attr(feature = "persistence", serde(rename_all = "snake_case"))]
 pub enum CursorIcon {
     Default,
     /// Pointing hand, used for e.g. web links
@@ -187,7 +187,7 @@ impl Response {
     /// });
     /// ```
     pub fn scroll_to_me(&self, align: Align) {
-        let scroll_target = lerp(self.rect.y_range(), align.scroll_center_factor());
+        let scroll_target = lerp(self.rect.y_range(), align.to_factor());
         self.ctx.frame_state().scroll_target = Some((scroll_target, align));
     }
 }
@@ -254,7 +254,7 @@ impl std::ops::BitOrAssign for Response {
 
 /// What sort of interaction is a widget sensitive to?
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
-// #[cfg_attr(feature = "serde", derive(serde::Serialize))]
+// #[cfg_attr(feature = "persistence", derive(serde::Serialize))]
 pub struct Sense {
     /// buttons, sliders, windows ...
     pub click: bool,

egui/src/util/undoer.rs

@@ -1,7 +1,7 @@
 use std::collections::VecDeque;
 
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct Settings {
     /// Maximum number of undos.
     /// If your state is resource intensive, you should keep this low.
@@ -48,7 +48,7 @@ impl Default for Settings {
 /// Rule 1) will make sure an undo point is not created until you _stop_ dragging that slider.
 /// Rule 2) will make sure that you will get some undo points even if you are constantly changing the state.
 #[derive(Clone, Default)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 pub struct Undoer<State> {
     settings: Settings,
 
@@ -57,7 +57,7 @@ pub struct Undoer<State> {
     /// The latest undo point may (often) be the current state.
     undos: VecDeque<State>,
 
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     flux: Option<Flux<State>>,
 }
 

egui/src/widgets/drag_value.rs

@@ -149,7 +149,7 @@ impl<'a> Widget for DragValue<'a> {
         let auto_decimals = (aim_rad / speed.abs()).log10().ceil().at_least(0.0) as usize;
         let max_decimals = max_decimals.unwrap_or(auto_decimals + 2);
         let auto_decimals = clamp(auto_decimals, min_decimals..=max_decimals);
-        let value_text = format_with_decimals_in_range(value, auto_decimals..=max_decimals);
+        let value_text = math::format_with_decimals_in_range(value, auto_decimals..=max_decimals);
 
         let kb_edit_id = ui.auto_id_with("edit");
         let is_kb_editing = ui.memory().has_kb_focus(kb_edit_id);
@@ -193,7 +193,7 @@ impl<'a> Widget for DragValue<'a> {
                 let delta_value = speed * delta_points;
                 if delta_value != 0.0 {
                     let new_value = value + delta_value as f64;
-                    let new_value = round_to_decimals(new_value, auto_decimals);
+                    let new_value = math::round_to_decimals(new_value, auto_decimals);
                     let new_value = clamp(new_value, range);
                     set(&mut value_function, new_value);
                     // TODO: To make use or `smart_aim` for `DragValue` we need to store some state somewhere,

egui/src/widgets/slider.rs

@@ -2,7 +2,7 @@
 
 use std::ops::RangeInclusive;
 
-use crate::{math::NumExt, paint::*, widgets::Label, *};
+use crate::{paint::*, widgets::Label, *};
 
 // ----------------------------------------------------------------------------
 
@@ -209,7 +209,7 @@ impl<'a> Slider<'a> {
 
     fn set_value(&mut self, mut value: f64) {
         if let Some(max_decimals) = self.max_decimals {
-            value = round_to_decimals(value, max_decimals);
+            value = math::round_to_decimals(value, max_decimals);
         }
         set(&mut self.get_set_value, value);
     }
@@ -366,13 +366,13 @@ impl<'a> Slider<'a> {
         let auto_decimals = clamp(auto_decimals, min_decimals..=max_decimals);
 
         if min_decimals == max_decimals {
-            format_with_minimum_decimals(value, max_decimals)
+            math::format_with_minimum_decimals(value, max_decimals)
         } else if value == 0.0 {
             "0".to_owned()
         } else if range == 0.0 {
             value.to_string()
         } else {
-            format_with_decimals_in_range(value, auto_decimals..=max_decimals)
+            math::format_with_decimals_in_range(value, auto_decimals..=max_decimals)
         }
     }
 }

egui/src/widgets/text_edit.rs

@@ -1,17 +1,17 @@
 use crate::{paint::*, util::undoer::Undoer, *};
 
 #[derive(Clone, Debug, Default)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
-#[cfg_attr(feature = "serde", serde(default))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", serde(default))]
 pub(crate) struct State {
     cursorp: Option<CursorPair>,
 
-    #[cfg_attr(feature = "serde", serde(skip))]
+    #[cfg_attr(feature = "persistence", serde(skip))]
     undoer: Undoer<(CCursorPair, String)>,
 }
 
 #[derive(Clone, Copy, Debug, Default)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 struct CursorPair {
     /// When selecting with a mouse, this is where the mouse was released.
     /// When moving with e.g. shift+arrows, this is what moves.
@@ -75,7 +75,7 @@ impl CursorPair {
 }
 
 #[derive(Clone, Copy, Debug, Default, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 struct CCursorPair {
     /// When selecting with a mouse, this is where the mouse was released.
     /// When moving with e.g. shift+arrows, this is what moves.

egui_demo_lib/src/apps/fractal_clock.rs

@@ -144,8 +144,8 @@ impl FractalClock {
         ];
 
         let hand_rotors = [
-            hands[0].length * Rot2::from_angle(hand_rotations[0]),
-            hands[1].length * Rot2::from_angle(hand_rotations[1]),
+            hands[0].length * math::Rot2::from_angle(hand_rotations[0]),
+            hands[1].length * math::Rot2::from_angle(hand_rotations[1]),
         ];
 
         #[derive(Clone, Copy)]

egui_glium/Cargo.toml

@@ -35,7 +35,7 @@ default = []
 http = ["ureq"]
 persistence = [
     "directories-next",
-    "egui/serde",
+    "egui/persistence",
     "epi/serde_json",
     "epi/serde",
     "serde_json",

emath/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "emath"
+version = "0.7.0"
+authors = ["Emil Ernerfeldt <emil.ernerfeldt@gmail.com>"]
+description = "Minimal 2D math library for GUI work"
+edition = "2018"
+homepage = "https://github.com/emilk/egui"
+license = "MIT OR Apache-2.0"
+readme = "README.md"
+repository = "https://github.com/emilk/egui"
+categories = ["gui", "math"]
+keywords = ["gui", "math"]
+include = [
+  "**/*.rs",
+  "Cargo.toml",
+]
+
+[lib]
+
+[dependencies]
+serde = { version = "1", features = ["derive"], optional = true }
+
+[features]
+default = []

emath/README.md

@@ -0,0 +1,5 @@
+# emath - Egui Math Library
+
+A bare-bones 2D math library with types and functions useful for GUI building.
+
+Made for [`egui`](https://github.com/emilk/egui/).

egui/src/math/align.rs → emath/src/align.rs

@@ -1,6 +1,6 @@
-//! One- and two-dimensional alignment ([`Align::Center`], [`LEFT_TOP`] etc).
+//! One- and two-dimensional alignment ([`Align::Center`], [`Align2::LEFT_TOP`] etc).
 
-use crate::math::*;
+use crate::*;
 
 /// left/center/right or top/center/bottom alignment for e.g. anchors and `Layout`s.
 #[derive(Clone, Copy, Debug, PartialEq)]
@@ -35,7 +35,8 @@ impl Align {
         Self::Max
     }
 
-    pub(crate) fn scroll_center_factor(&self) -> f32 {
+    /// Convert `Min => 0.0`, `Center => 0.5` or `Max => 1.0`.
+    pub fn to_factor(&self) -> f32 {
         match self {
             Self::Min => 0.0,
             Self::Center => 0.5,
@@ -52,6 +53,7 @@ impl Default for Align {
 
 // ----------------------------------------------------------------------------
 
+/// Two-dimension alignment, e.g. [`Align2::LEFT_TOP`].
 #[derive(Clone, Copy, Debug, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 #[cfg_attr(feature = "serde", serde(rename_all = "snake_case"))]
@@ -79,7 +81,7 @@ impl Align2 {
 
     /// Used e.g. to anchor a piece of text to a part of the rectangle.
     /// Give a position within the rect, specified by the aligns
-    pub(crate) fn anchor_rect(self, rect: Rect) -> Rect {
+    pub fn anchor_rect(self, rect: Rect) -> Rect {
         let x = match self.x() {
             Align::Min => rect.left(),
             Align::Center => rect.left() - 0.5 * rect.width(),

egui/src/math/mod.rs → emath/src/lib.rs

@@ -1,8 +1,55 @@
 //! Vectors, positions, rectangles etc.
 //!
 //! Conventions (unless otherwise specified):
+//!
 //! * All angles are in radians
-//! * All metrics are in points (logical pixels)
+//! * X+ is right and Y+ is down.
+//! * (0,0) is left top.
+//! * Dimension order is always `x y`
+
+#![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![forbid(unsafe_code)]
+#![warn(
+    clippy::all,
+    clippy::await_holding_lock,
+    clippy::dbg_macro,
+    clippy::doc_markdown,
+    clippy::empty_enum,
+    clippy::enum_glob_use,
+    clippy::exit,
+    clippy::filter_map_next,
+    clippy::fn_params_excessive_bools,
+    clippy::if_let_mutex,
+    clippy::imprecise_flops,
+    clippy::inefficient_to_string,
+    clippy::linkedlist,
+    clippy::lossy_float_literal,
+    clippy::macro_use_imports,
+    clippy::match_on_vec_items,
+    clippy::match_wildcard_for_single_variants,
+    clippy::mem_forget,
+    clippy::mismatched_target_os,
+    clippy::missing_errors_doc,
+    clippy::missing_safety_doc,
+    clippy::needless_borrow,
+    clippy::needless_continue,
+    clippy::needless_pass_by_value,
+    clippy::option_option,
+    clippy::pub_enum_variant_names,
+    clippy::rest_pat_in_fully_bound_structs,
+    clippy::todo,
+    clippy::unimplemented,
+    clippy::unnested_or_patterns,
+    clippy::verbose_file_reads,
+    future_incompatible,
+    missing_crate_level_docs,
+    missing_doc_code_examples,
+    // missing_docs,
+    nonstandard_style,
+    rust_2018_idioms,
+    unused_doc_comments,
+)]
+#![allow(clippy::manual_range_contains)]
 
 use std::ops::{Add, Div, Mul, RangeInclusive, Sub};
 
@@ -130,14 +177,11 @@ pub fn round_to_decimals(value: f64, decimal_places: usize) -> f64 {
         .unwrap_or(value)
 }
 
-pub(crate) fn format_with_minimum_decimals(value: f64, decimals: usize) -> String {
+pub fn format_with_minimum_decimals(value: f64, decimals: usize) -> String {
     format_with_decimals_in_range(value, decimals..=6)
 }
 
-pub(crate) fn format_with_decimals_in_range(
-    value: f64,
-    decimal_range: RangeInclusive<usize>,
-) -> String {
+pub fn format_with_decimals_in_range(value: f64, decimal_range: RangeInclusive<usize>) -> String {
     let min_decimals = *decimal_range.start();
     let max_decimals = *decimal_range.end();
     debug_assert!(min_decimals <= max_decimals);

egui/src/math/pos2.rs → emath/src/pos2.rs

@@ -1,6 +1,6 @@
 use std::ops::{Add, AddAssign, RangeInclusive, Sub, SubAssign};
 
-use crate::math::*;
+use crate::*;
 
 /// A position on screen.
 ///

egui/src/math/rect.rs → emath/src/rect.rs

@@ -1,6 +1,6 @@
 use std::ops::RangeInclusive;
 
-use crate::math::*;
+use crate::*;
 
 /// A rectangular region of space.
 ///

egui/src/math/vec2.rs → emath/src/vec2.rs

@@ -1,6 +1,6 @@
 use std::ops::{Add, AddAssign, Div, Mul, MulAssign, Neg, RangeInclusive, Sub, SubAssign};
 
-use crate::math::*;
+use crate::*;
 
 /// A vector has a direction and length.
 /// A [`Vec2`] is often used to represent a size.