Restructure mod paint

egui/src/context.rs

@@ -8,7 +8,7 @@ use std::sync::{
 use crate::{
     animation_manager::AnimationManager,
     mutex::{Mutex, MutexGuard},
-    paint::{stats::*, *},
+    paint::{stats::*, text::Fonts, *},
     *,
 };
 

egui/src/introspection.rs

@@ -54,7 +54,7 @@ impl Texture {
     }
 }
 
-impl paint::FontDefinitions {
+impl paint::text::FontDefinitions {
     pub fn ui(&mut self, ui: &mut Ui) {
         for (text_style, (_family, size)) in self.family_and_size.iter_mut() {
             // TODO: radio button for family

egui/src/lib.rs

@@ -108,8 +108,9 @@ pub use {
     math::{clamp, lerp, pos2, remap, remap_clamp, vec2, Align, Align2, NumExt, Pos2, Rect, Vec2},
     memory::Memory,
     paint::{
-        color, Color32, FontDefinitions, FontFamily, PaintJobs, Rgba, Shape, Stroke, TextStyle,
-        Texture, TextureId,
+        color,
+        text::{FontDefinitions, FontFamily, TextStyle},
+        Color32, PaintJobs, Rgba, Shape, Stroke, Texture, TextureId,
     },
     painter::Painter,
     style::Style,

egui/src/memory.rs

@@ -68,7 +68,7 @@ pub(crate) struct Options {
     /// Controls the tessellator.
     pub(crate) tessellation_options: crate::paint::TessellationOptions,
     /// Font sizes etc.
-    pub(crate) font_definitions: crate::paint::FontDefinitions,
+    pub(crate) font_definitions: crate::paint::text::FontDefinitions,
 }
 
 // ----------------------------------------------------------------------------

egui/src/paint/mod.rs

@@ -1,28 +1,51 @@
 //! 2D graphics/rendering. Fonts, textures, color, geometry, tessellation etc.
 
 pub mod color;
-pub mod font;
-pub mod fonts;
-mod galley;
 mod shadow;
 pub mod shape;
 pub mod stats;
+mod stroke;
 pub mod tessellator;
+pub mod text;
 mod texture_atlas;
+mod triangles;
 
 pub use {
     color::{Color32, Rgba},
-    fonts::{FontDefinitions, FontFamily, Fonts, TextStyle},
-    galley::*,
     shadow::Shadow,
-    shape::{Shape, Stroke},
+    shape::Shape,
     stats::PaintStats,
-    tessellator::{
-        PaintJob, PaintJobs, TessellationOptions, TextureId, Triangles, Vertex, WHITE_UV,
-    },
+    stroke::Stroke,
+    tessellator::{PaintJob, PaintJobs, TessellationOptions},
+    text::{Galley, TextStyle},
     texture_atlas::{Texture, TextureAtlas},
+    triangles::{Triangles, Vertex},
 };
 
+/// The UV coordinate of a white region of the texture mesh.
+/// The default Egui texture has the top-left corner pixel fully white.
+/// You need need use a clamping texture sampler for this to work
+/// (so it doesn't do bilinear blending with bottom right corner).
+pub const WHITE_UV: crate::Pos2 = crate::pos2(0.0, 0.0);
+
+/// What texture to use in a [`Triangles`] mesh.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum TextureId {
+    /// The Egui font texture.
+    /// If you don't want to use a texture, pick this and the [`WHITE_UV`] for uv-coord.
+    Egui,
+
+    /// Your own texture, defined in any which way you want.
+    /// Egui won't care. The backend renderer will presumably use this to look up what texture to use.
+    User(u64),
+}
+
+impl Default for TextureId {
+    fn default() -> Self {
+        Self::Egui
+    }
+}
+
 pub(crate) struct PaintRect {
     pub rect: crate::Rect,
     /// How rounded the corners are. Use `0.0` for no rounding.

egui/src/paint/shape.rs

@@ -1,5 +1,8 @@
 use {
-    super::{fonts::TextStyle, Color32, Fonts, Galley, Triangles},
+    super::{
+        text::{Fonts, Galley, TextStyle},
+        Color32, Triangles,
+    },
     crate::*,
 };
 
@@ -189,33 +192,3 @@ impl Shape {
         }
     }
 }
-
-/// Describes the width and color of a line.
-#[derive(Clone, Copy, Debug, Default, PartialEq)]
-#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
-pub struct Stroke {
-    pub width: f32,
-    pub color: Color32,
-}
-
-impl Stroke {
-    pub fn none() -> Self {
-        Self::new(0.0, Color32::TRANSPARENT)
-    }
-
-    pub fn new(width: impl Into<f32>, color: impl Into<Color32>) -> Self {
-        Self {
-            width: width.into(),
-            color: color.into(),
-        }
-    }
-}
-
-impl<Color> From<(f32, Color)> for Stroke
-where
-    Color: Into<Color32>,
-{
-    fn from((width, color): (f32, Color)) -> Stroke {
-        Stroke::new(width, color)
-    }
-}

egui/src/paint/stroke.rs

@@ -0,0 +1,31 @@
+use super::*;
+
+/// Describes the width and color of a line.
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+pub struct Stroke {
+    pub width: f32,
+    pub color: Color32,
+}
+
+impl Stroke {
+    pub fn none() -> Self {
+        Self::new(0.0, Color32::TRANSPARENT)
+    }
+
+    pub fn new(width: impl Into<f32>, color: impl Into<Color32>) -> Self {
+        Self {
+            width: width.into(),
+            color: color.into(),
+        }
+    }
+}
+
+impl<Color> From<(f32, Color)> for Stroke
+where
+    Color: Into<Color32>,
+{
+    fn from((width, color): (f32, Color)) -> Stroke {
+        Stroke::new(width, color)
+    }
+}

egui/src/paint/tessellator.rs

@@ -6,70 +6,11 @@
 #![allow(clippy::identity_op)]
 
 use {
-    super::{
-        color::{Color32, Rgba},
-        *,
-    },
+    super::{text::Fonts, *},
     crate::math::*,
     std::f32::consts::TAU,
 };
 
-/// What texture to use in a [`Triangles`] mesh.
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum TextureId {
-    /// The Egui font texture.
-    /// If you don't want to use a texture, pick this and the [`WHITE_UV`] for uv-coord.
-    Egui,
-
-    /// Your own texture, defined in any which way you want.
-    /// Egui won't care. The backend renderer will presumably use this to look up what texture to use.
-    User(u64),
-}
-
-impl Default for TextureId {
-    fn default() -> Self {
-        Self::Egui
-    }
-}
-
-/// The UV coordinate of a white region of the texture mesh.
-/// The default Egui texture has the top-left corner pixel fully white.
-/// You need need use a clamping texture sampler for this to work
-/// (so it doesn't do bilinear blending with bottom right corner).
-pub const WHITE_UV: Pos2 = pos2(0.0, 0.0);
-
-/// The vertex type.
-///
-/// Should be friendly to send to GPU as is.
-#[repr(C)]
-#[derive(Clone, Copy, Debug, Default)]
-pub struct Vertex {
-    /// Logical pixel coordinates (points).
-    /// (0,0) is the top left corner of the screen.
-    pub pos: Pos2, // 64 bit
-
-    /// Normalized texture coordinates.
-    /// (0, 0) is the top left corner of the texture.
-    /// (1, 1) is the bottom right corner of the texture.
-    pub uv: Pos2, // 64 bit
-
-    /// sRGBA with premultiplied alpha
-    pub color: Color32, // 32 bit
-}
-
-/// Textured triangles.
-#[derive(Clone, Debug, Default)]
-pub struct Triangles {
-    /// Draw as triangles (i.e. the length is always multiple of three).
-    pub indices: Vec<u32>,
-
-    /// The vertex data indexed by `indices`.
-    pub vertices: Vec<Vertex>,
-
-    /// The texture to use when drawing these triangles
-    pub texture_id: TextureId,
-}
-
 /// A clip triangle and some textured triangles.
 pub type PaintJob = (Rect, Triangles);
 
@@ -78,182 +19,6 @@ pub type PaintJobs = Vec<PaintJob>;
 
 // ----------------------------------------------------------------------------
 
-/// ## Helpers for adding
-impl Triangles {
-    pub fn with_texture(texture_id: TextureId) -> Self {
-        Self {
-            texture_id,
-            ..Default::default()
-        }
-    }
-
-    pub fn bytes_used(&self) -> usize {
-        std::mem::size_of::<Self>()
-            + self.vertices.len() * std::mem::size_of::<Vertex>()
-            + self.indices.len() * std::mem::size_of::<u32>()
-    }
-
-    /// Are all indices within the bounds of the contained vertices?
-    pub fn is_valid(&self) -> bool {
-        let n = self.vertices.len() as u32;
-        self.indices.iter().all(|&i| i < n)
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.indices.is_empty() && self.vertices.is_empty()
-    }
-
-    /// Append all the indices and vertices of `other` to `self`.
-    pub fn append(&mut self, other: Triangles) {
-        debug_assert!(other.is_valid());
-
-        if self.is_empty() {
-            *self = other;
-        } else {
-            assert_eq!(
-                self.texture_id, other.texture_id,
-                "Can't merge Triangles using different textures"
-            );
-
-            let index_offset = self.vertices.len() as u32;
-            for index in &other.indices {
-                self.indices.push(index_offset + index);
-            }
-            self.vertices.extend(other.vertices.iter());
-        }
-    }
-
-    pub fn colored_vertex(&mut self, pos: Pos2, color: Color32) {
-        debug_assert!(self.texture_id == TextureId::Egui);
-        self.vertices.push(Vertex {
-            pos,
-            uv: WHITE_UV,
-            color,
-        });
-    }
-
-    /// Add a triangle.
-    pub fn add_triangle(&mut self, a: u32, b: u32, c: u32) {
-        self.indices.push(a);
-        self.indices.push(b);
-        self.indices.push(c);
-    }
-
-    /// Make room for this many additional triangles (will reserve 3x as many indices).
-    /// See also `reserve_vertices`.
-    pub fn reserve_triangles(&mut self, additional_triangles: usize) {
-        self.indices.reserve(3 * additional_triangles);
-    }
-
-    /// Make room for this many additional vertices.
-    /// See also `reserve_triangles`.
-    pub fn reserve_vertices(&mut self, additional: usize) {
-        self.vertices.reserve(additional);
-    }
-
-    /// Rectangle with a texture and color.
-    pub fn add_rect_with_uv(&mut self, pos: Rect, uv: Rect, color: Color32) {
-        let idx = self.vertices.len() as u32;
-        self.add_triangle(idx + 0, idx + 1, idx + 2);
-        self.add_triangle(idx + 2, idx + 1, idx + 3);
-
-        let right_top = Vertex {
-            pos: pos.right_top(),
-            uv: uv.right_top(),
-            color,
-        };
-        let left_top = Vertex {
-            pos: pos.left_top(),
-            uv: uv.left_top(),
-            color,
-        };
-        let left_bottom = Vertex {
-            pos: pos.left_bottom(),
-            uv: uv.left_bottom(),
-            color,
-        };
-        let right_bottom = Vertex {
-            pos: pos.right_bottom(),
-            uv: uv.right_bottom(),
-            color,
-        };
-        self.vertices.push(left_top);
-        self.vertices.push(right_top);
-        self.vertices.push(left_bottom);
-        self.vertices.push(right_bottom);
-    }
-
-    /// Uniformly colored rectangle.
-    pub fn add_colored_rect(&mut self, rect: Rect, color: Color32) {
-        debug_assert!(self.texture_id == TextureId::Egui);
-        self.add_rect_with_uv(rect, [WHITE_UV, WHITE_UV].into(), color)
-    }
-
-    /// This is for platforms that only support 16-bit index buffers.
-    ///
-    /// Splits this mesh into many smaller meshes (if needed).
-    /// All the returned meshes will have indices that fit into a `u16`.
-    pub fn split_to_u16(self) -> Vec<Triangles> {
-        const MAX_SIZE: u32 = 1 << 16;
-
-        if self.vertices.len() < MAX_SIZE as usize {
-            return vec![self]; // Common-case optimization
-        }
-
-        let mut output = vec![];
-        let mut index_cursor = 0;
-
-        while index_cursor < self.indices.len() {
-            let span_start = index_cursor;
-            let mut min_vindex = self.indices[index_cursor];
-            let mut max_vindex = self.indices[index_cursor];
-
-            while index_cursor < self.indices.len() {
-                let (mut new_min, mut new_max) = (min_vindex, max_vindex);
-                for i in 0..3 {
-                    let idx = self.indices[index_cursor + i];
-                    new_min = new_min.min(idx);
-                    new_max = new_max.max(idx);
-                }
-
-                if new_max - new_min < MAX_SIZE {
-                    // Triangle fits
-                    min_vindex = new_min;
-                    max_vindex = new_max;
-                    index_cursor += 3;
-                } else {
-                    break;
-                }
-            }
-
-            assert!(
-                index_cursor > span_start,
-                "One triangle spanned more than {} vertices",
-                MAX_SIZE
-            );
-
-            output.push(Triangles {
-                indices: self.indices[span_start..index_cursor]
-                    .iter()
-                    .map(|vi| vi - min_vindex)
-                    .collect(),
-                vertices: self.vertices[(min_vindex as usize)..=(max_vindex as usize)].to_vec(),
-                texture_id: self.texture_id,
-            });
-        }
-        output
-    }
-
-    /// Translate location by this much, in-place
-    pub fn translate(&mut self, delta: Vec2) {
-        for v in &mut self.vertices {
-            v.pos += delta;
-        }
-    }
-}
-
-// ----------------------------------------------------------------------------
-
 #[derive(Clone, Debug, Default)]
 pub struct PathPoint {
     pos: Pos2,
@@ -669,10 +434,11 @@ fn mul_color(color: Color32, factor: f32) -> Color32 {
 
 // ----------------------------------------------------------------------------
 
+/// Converts [`Shape`]s into [`Triangles`].
 pub struct Tessellator {
-    pub options: TessellationOptions,
+    options: TessellationOptions,
     /// Only used for culling
-    pub clip_rect: Rect,
+    clip_rect: Rect,
     scratchpad_points: Vec<Pos2>,
     scratchpad_path: Path,
 }

egui/src/paint/text/cursor.rs

@@ -0,0 +1,108 @@
+//! Different types of text cursors, i.e. ways to point into a [`super::Galley`].
+
+/// Character cursor
+#[derive(Clone, Copy, Debug, Default)]
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+pub struct CCursor {
+    /// Character offset (NOT byte offset!).
+    pub index: usize,
+
+    /// If this cursors sits right at the border of a wrapped row break (NOT paragraph break)
+    /// do we prefer the next row?
+    /// This is *almost* always what you want, *except* for when
+    /// explicitly clicking the end of a row or pressing the end key.
+    pub prefer_next_row: bool,
+}
+
+impl CCursor {
+    pub fn new(index: usize) -> Self {
+        Self {
+            index,
+            prefer_next_row: false,
+        }
+    }
+}
+
+/// Two `CCursor`s are considered equal if they refer to the same character boundary,
+/// even if one prefers the start of the next row.
+impl PartialEq for CCursor {
+    fn eq(&self, other: &CCursor) -> bool {
+        self.index == other.index
+    }
+}
+
+impl std::ops::Add<usize> for CCursor {
+    type Output = CCursor;
+    fn add(self, rhs: usize) -> Self::Output {
+        CCursor {
+            index: self.index.saturating_add(rhs),
+            prefer_next_row: self.prefer_next_row,
+        }
+    }
+}
+
+impl std::ops::Sub<usize> for CCursor {
+    type Output = CCursor;
+    fn sub(self, rhs: usize) -> Self::Output {
+        CCursor {
+            index: self.index.saturating_sub(rhs),
+            prefer_next_row: self.prefer_next_row,
+        }
+    }
+}
+
+/// Row Cursor
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
+#[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.
+    /// (a paragraph is text separated by `\n`).
+    pub row: usize,
+
+    /// Character based (NOT bytes).
+    /// It is fine if this points to something beyond the end of the current row.
+    /// When moving up/down it may again be within the next row.
+    pub column: usize,
+}
+
+/// Paragraph Cursor
+#[derive(Clone, Copy, Debug, Default)]
+#[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.
+    /// (a paragraph is text separated by `\n`).
+    pub paragraph: usize,
+
+    /// Character based (NOT bytes).
+    /// It is fine if this points to something beyond the end of the current paragraph.
+    /// When moving up/down it may again be within the next paragraph.
+    pub offset: usize,
+
+    /// If this cursors sits right at the border of a wrapped row break (NOT paragraph break)
+    /// do we prefer the next row?
+    /// This is *almost* always what you want, *except* for when
+    /// explicitly clicking the end of a row or pressing the end key.
+    pub prefer_next_row: bool,
+}
+
+/// Two `PCursor`s are considered equal if they refer to the same character boundary,
+/// even if one prefers the start of the next row.
+impl PartialEq for PCursor {
+    fn eq(&self, other: &PCursor) -> bool {
+        self.paragraph == other.paragraph && self.offset == other.offset
+    }
+}
+
+/// All different types of cursors together.
+/// They all point to the same place, but in their own different ways.
+/// 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 = "persistence", derive(serde::Deserialize, serde::Serialize))]
+pub struct Cursor {
+    pub ccursor: CCursor,
+    pub rcursor: RCursor,
+    pub pcursor: PCursor,
+}

egui/src/paint/text/font.rs

@@ -8,11 +8,12 @@ use {
 use crate::{
     math::{vec2, Vec2},
     mutex::{Mutex, RwLock},
-    paint::{Galley, Row},
+    paint::{
+        text::galley::{Galley, Row},
+        TextureAtlas,
+    },
 };
 
-use super::texture_atlas::TextureAtlas;
-
 // ----------------------------------------------------------------------------
 
 #[derive(Clone, Copy, Debug)]

egui/src/paint/text/fonts.rs

@@ -4,12 +4,9 @@ use std::{
     sync::Arc,
 };
 
+use super::font::{Font, FontImpl};
 use crate::mutex::Mutex;
-
-use super::{
-    font::{Font, FontImpl},
-    texture_atlas::{Texture, TextureAtlas},
-};
+use crate::paint::{Texture, TextureAtlas};
 
 // TODO: rename
 /// One of a few categories of styles of text, e.g. body, button or heading.
@@ -118,22 +115,22 @@ impl Default for FontDefinitions {
             // Use size 13 for this. NOTHING ELSE:
             font_data.insert(
                 "ProggyClean".to_owned(),
-                std::borrow::Cow::Borrowed(include_bytes!("../../fonts/ProggyClean.ttf")),
+                std::borrow::Cow::Borrowed(include_bytes!("../../../fonts/ProggyClean.ttf")),
             );
             font_data.insert(
                 "Ubuntu-Light".to_owned(),
-                std::borrow::Cow::Borrowed(include_bytes!("../../fonts/Ubuntu-Light.ttf")),
+                std::borrow::Cow::Borrowed(include_bytes!("../../../fonts/Ubuntu-Light.ttf")),
             );
 
             // Some good looking emojis. Use as first priority:
             font_data.insert(
                 "NotoEmoji-Regular".to_owned(),
-                std::borrow::Cow::Borrowed(include_bytes!("../../fonts/NotoEmoji-Regular.ttf")),
+                std::borrow::Cow::Borrowed(include_bytes!("../../../fonts/NotoEmoji-Regular.ttf")),
             );
             // Bigger emojis, and more. <http://jslegers.github.io/emoji-icon-font/>:
             font_data.insert(
                 "emoji-icon-font".to_owned(),
-                std::borrow::Cow::Borrowed(include_bytes!("../../fonts/emoji-icon-font.ttf")),
+                std::borrow::Cow::Borrowed(include_bytes!("../../../fonts/emoji-icon-font.ttf")),
             );
 
             fonts_for_family.insert(

egui/src/paint/text/galley.rs

@@ -1,3 +1,6 @@
+//! A [`Galley`] is a piece of text after layout, i.e. where each character has been assigned a position.
+//!
+//! ## How it works
 //! This is going to get complicated.
 //!
 //! To avoid confusion, we never use the word "line".
@@ -14,117 +17,11 @@
 //!
 //! The offset `6` is both the end of the first row
 //! and the start of the second row.
-//! The `prefer_next_row` selects which.
+//! [`CCursor::prefer_next_row`] etc selects which.
 
+use super::cursor::*;
 use crate::math::{pos2, NumExt, Rect, Vec2};
 
-/// Character cursor
-#[derive(Clone, Copy, Debug, Default)]
-#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
-pub struct CCursor {
-    /// Character offset (NOT byte offset!).
-    pub index: usize,
-
-    /// If this cursors sits right at the border of a wrapped row break (NOT paragraph break)
-    /// do we prefer the next row?
-    /// This is *almost* always what you want, *except* for when
-    /// explicitly clicking the end of a row or pressing the end key.
-    pub prefer_next_row: bool,
-}
-
-impl CCursor {
-    pub fn new(index: usize) -> Self {
-        Self {
-            index,
-            prefer_next_row: false,
-        }
-    }
-}
-
-/// Two `CCursor`s are considered equal if they refer to the same character boundary,
-/// even if one prefers the start of the next row.
-impl PartialEq for CCursor {
-    fn eq(&self, other: &CCursor) -> bool {
-        self.index == other.index
-    }
-}
-
-impl std::ops::Add<usize> for CCursor {
-    type Output = CCursor;
-    fn add(self, rhs: usize) -> Self::Output {
-        CCursor {
-            index: self.index.saturating_add(rhs),
-            prefer_next_row: self.prefer_next_row,
-        }
-    }
-}
-
-impl std::ops::Sub<usize> for CCursor {
-    type Output = CCursor;
-    fn sub(self, rhs: usize) -> Self::Output {
-        CCursor {
-            index: self.index.saturating_sub(rhs),
-            prefer_next_row: self.prefer_next_row,
-        }
-    }
-}
-
-/// Row Cursor
-#[derive(Clone, Copy, Debug, Default, PartialEq)]
-#[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.
-    /// (a paragraph is text separated by `\n`).
-    pub row: usize,
-
-    /// Character based (NOT bytes).
-    /// It is fine if this points to something beyond the end of the current row.
-    /// When moving up/down it may again be within the next row.
-    pub column: usize,
-}
-
-/// Paragraph Cursor
-#[derive(Clone, Copy, Debug, Default)]
-#[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.
-    /// (a paragraph is text separated by `\n`).
-    pub paragraph: usize,
-
-    /// Character based (NOT bytes).
-    /// It is fine if this points to something beyond the end of the current paragraph.
-    /// When moving up/down it may again be within the next paragraph.
-    pub offset: usize,
-
-    /// If this cursors sits right at the border of a wrapped row break (NOT paragraph break)
-    /// do we prefer the next row?
-    /// This is *almost* always what you want, *except* for when
-    /// explicitly clicking the end of a row or pressing the end key.
-    pub prefer_next_row: bool,
-}
-
-/// Two `PCursor`s are considered equal if they refer to the same character boundary,
-/// even if one prefers the start of the next row.
-impl PartialEq for PCursor {
-    fn eq(&self, other: &PCursor) -> bool {
-        self.paragraph == other.paragraph && self.offset == other.offset
-    }
-}
-
-/// All different types of cursors together.
-/// They all point to the same place, but in their own different ways.
-/// 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 = "persistence", derive(serde::Deserialize, serde::Serialize))]
-pub struct Cursor {
-    pub ccursor: CCursor,
-    pub rcursor: RCursor,
-    pub pcursor: PCursor,
-}
-
 /// A collection of text locked into place.
 #[derive(Clone, Debug, Default)]
 pub struct Galley {
@@ -657,7 +554,7 @@ fn test_text_layout() {
     use crate::paint::*;
 
     let pixels_per_point = 1.0;
-    let fonts = Fonts::from_definitions(pixels_per_point, FontDefinitions::default());
+    let fonts = text::Fonts::from_definitions(pixels_per_point, text::FontDefinitions::default());
     let font = &fonts[TextStyle::Monospace];
 
     let galley = font.layout_multiline("".to_owned(), 1024.0);

egui/src/paint/text/mod.rs

@@ -0,0 +1,9 @@
+pub mod cursor;
+mod font;
+mod fonts;
+mod galley;
+
+pub use {
+    fonts::{FontDefinitions, FontFamily, Fonts, TextStyle},
+    galley::{Galley, Row},
+};

egui/src/paint/triangles.rs

@@ -0,0 +1,209 @@
+use super::*;
+use crate::*;
+
+/// The vertex type.
+///
+/// Should be friendly to send to GPU as is.
+#[repr(C)]
+#[derive(Clone, Copy, Debug, Default)]
+pub struct Vertex {
+    /// Logical pixel coordinates (points).
+    /// (0,0) is the top left corner of the screen.
+    pub pos: Pos2, // 64 bit
+
+    /// Normalized texture coordinates.
+    /// (0, 0) is the top left corner of the texture.
+    /// (1, 1) is the bottom right corner of the texture.
+    pub uv: Pos2, // 64 bit
+
+    /// sRGBA with premultiplied alpha
+    pub color: Color32, // 32 bit
+}
+
+/// Textured triangles.
+#[derive(Clone, Debug, Default)]
+pub struct Triangles {
+    /// Draw as triangles (i.e. the length is always multiple of three).
+    pub indices: Vec<u32>,
+
+    /// The vertex data indexed by `indices`.
+    pub vertices: Vec<Vertex>,
+
+    /// The texture to use when drawing these triangles
+    pub texture_id: TextureId,
+}
+
+impl Triangles {
+    pub fn with_texture(texture_id: TextureId) -> Self {
+        Self {
+            texture_id,
+            ..Default::default()
+        }
+    }
+
+    pub fn bytes_used(&self) -> usize {
+        std::mem::size_of::<Self>()
+            + self.vertices.len() * std::mem::size_of::<Vertex>()
+            + self.indices.len() * std::mem::size_of::<u32>()
+    }
+
+    /// Are all indices within the bounds of the contained vertices?
+    pub fn is_valid(&self) -> bool {
+        let n = self.vertices.len() as u32;
+        self.indices.iter().all(|&i| i < n)
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.indices.is_empty() && self.vertices.is_empty()
+    }
+
+    /// Append all the indices and vertices of `other` to `self`.
+    pub fn append(&mut self, other: Triangles) {
+        debug_assert!(other.is_valid());
+
+        if self.is_empty() {
+            *self = other;
+        } else {
+            assert_eq!(
+                self.texture_id, other.texture_id,
+                "Can't merge Triangles using different textures"
+            );
+
+            let index_offset = self.vertices.len() as u32;
+            for index in &other.indices {
+                self.indices.push(index_offset + index);
+            }
+            self.vertices.extend(other.vertices.iter());
+        }
+    }
+
+    pub fn colored_vertex(&mut self, pos: Pos2, color: Color32) {
+        debug_assert!(self.texture_id == TextureId::Egui);
+        self.vertices.push(Vertex {
+            pos,
+            uv: WHITE_UV,
+            color,
+        });
+    }
+
+    /// Add a triangle.
+    pub fn add_triangle(&mut self, a: u32, b: u32, c: u32) {
+        self.indices.push(a);
+        self.indices.push(b);
+        self.indices.push(c);
+    }
+
+    /// Make room for this many additional triangles (will reserve 3x as many indices).
+    /// See also `reserve_vertices`.
+    pub fn reserve_triangles(&mut self, additional_triangles: usize) {
+        self.indices.reserve(3 * additional_triangles);
+    }
+
+    /// Make room for this many additional vertices.
+    /// See also `reserve_triangles`.
+    pub fn reserve_vertices(&mut self, additional: usize) {
+        self.vertices.reserve(additional);
+    }
+
+    /// Rectangle with a texture and color.
+    pub fn add_rect_with_uv(&mut self, pos: Rect, uv: Rect, color: Color32) {
+        #![allow(clippy::identity_op)]
+
+        let idx = self.vertices.len() as u32;
+        self.add_triangle(idx + 0, idx + 1, idx + 2);
+        self.add_triangle(idx + 2, idx + 1, idx + 3);
+
+        let right_top = Vertex {
+            pos: pos.right_top(),
+            uv: uv.right_top(),
+            color,
+        };
+        let left_top = Vertex {
+            pos: pos.left_top(),
+            uv: uv.left_top(),
+            color,
+        };
+        let left_bottom = Vertex {
+            pos: pos.left_bottom(),
+            uv: uv.left_bottom(),
+            color,
+        };
+        let right_bottom = Vertex {
+            pos: pos.right_bottom(),
+            uv: uv.right_bottom(),
+            color,
+        };
+        self.vertices.push(left_top);
+        self.vertices.push(right_top);
+        self.vertices.push(left_bottom);
+        self.vertices.push(right_bottom);
+    }
+
+    /// Uniformly colored rectangle.
+    pub fn add_colored_rect(&mut self, rect: Rect, color: Color32) {
+        debug_assert!(self.texture_id == TextureId::Egui);
+        self.add_rect_with_uv(rect, [WHITE_UV, WHITE_UV].into(), color)
+    }
+
+    /// This is for platforms that only support 16-bit index buffers.
+    ///
+    /// Splits this mesh into many smaller meshes (if needed).
+    /// All the returned meshes will have indices that fit into a `u16`.
+    pub fn split_to_u16(self) -> Vec<Triangles> {
+        const MAX_SIZE: u32 = 1 << 16;
+
+        if self.vertices.len() < MAX_SIZE as usize {
+            return vec![self]; // Common-case optimization
+        }
+
+        let mut output = vec![];
+        let mut index_cursor = 0;
+
+        while index_cursor < self.indices.len() {
+            let span_start = index_cursor;
+            let mut min_vindex = self.indices[index_cursor];
+            let mut max_vindex = self.indices[index_cursor];
+
+            while index_cursor < self.indices.len() {
+                let (mut new_min, mut new_max) = (min_vindex, max_vindex);
+                for i in 0..3 {
+                    let idx = self.indices[index_cursor + i];
+                    new_min = new_min.min(idx);
+                    new_max = new_max.max(idx);
+                }
+
+                if new_max - new_min < MAX_SIZE {
+                    // Triangle fits
+                    min_vindex = new_min;
+                    max_vindex = new_max;
+                    index_cursor += 3;
+                } else {
+                    break;
+                }
+            }
+
+            assert!(
+                index_cursor > span_start,
+                "One triangle spanned more than {} vertices",
+                MAX_SIZE
+            );
+
+            output.push(Triangles {
+                indices: self.indices[span_start..index_cursor]
+                    .iter()
+                    .map(|vi| vi - min_vindex)
+                    .collect(),
+                vertices: self.vertices[(min_vindex as usize)..=(max_vindex as usize)].to_vec(),
+                texture_id: self.texture_id,
+            });
+        }
+        output
+    }
+
+    /// Translate location by this much, in-place
+    pub fn translate(&mut self, delta: Vec2) {
+        for v in &mut self.vertices {
+            v.pos += delta;
+        }
+    }
+}

egui/src/painter.rs

@@ -1,7 +1,10 @@
 use crate::{
     layers::ShapeIdx,
     math::{Align2, Pos2, Rect, Vec2},
-    paint::{Fonts, Galley, Shape, Stroke, TextStyle},
+    paint::{
+        text::{Fonts, Galley, TextStyle},
+        Shape, Stroke,
+    },
     Color32, CtxRef, LayerId,
 };
 

egui/src/ui.rs

@@ -2,7 +2,15 @@
 
 use std::{hash::Hash, sync::Arc};
 
-use crate::{color::*, containers::*, layout::*, mutex::MutexGuard, paint::*, widgets::*, *};
+use crate::{
+    color::*,
+    containers::*,
+    layout::*,
+    mutex::MutexGuard,
+    paint::{text::Fonts, *},
+    widgets::*,
+    *,
+};
 
 /// This is what you use to place widgets.
 ///

egui/src/widgets/label.rs

@@ -73,7 +73,7 @@ impl Label {
         }
     }
 
-    pub fn font_height(&self, fonts: &paint::Fonts, style: &Style) -> f32 {
+    pub fn font_height(&self, fonts: &paint::text::Fonts, style: &Style) -> f32 {
         let text_style = self.text_style_or_default(style);
         fonts[text_style].row_height()
     }

egui/src/widgets/text_edit.rs

@@ -1,4 +1,8 @@
-use crate::{paint::*, util::undoer::Undoer, *};
+use crate::{
+    paint::{text::cursor::*, *},
+    util::undoer::Undoer,
+    *,
+};
 
 #[derive(Clone, Debug, Default)]
 #[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]