Crate epaint 

A simple 2D graphics library for turning simple 2D shapes and text into textured triangles.

Made for egui.

Create some Shape:s and pass them to Tessellator::tessellate_shapes to generate Mesh:es that you can then paint using some graphics API of your choice (e.g. OpenGL).

Coordinate system

The left-top corner of the screen is (0.0, 0.0), with X increasing to the right and Y increasing downwards.

epaint uses logical points as its coordinate system. Those related to physical pixels by the pixels_per_point scale factor. For example, a high-dpi screen can have pixels_per_point = 2.0, meaning there are two physical screen pixels for each logical point.

Angles are in radians, and are measured clockwise from the X-axis, which has angle=0.

Feature flags

• bytemuck — bytemuck enables you to cast Vertex to &[u8].

• cint — cint enables interoperability with other color libraries.

• color-hex — Enable the hex_color macro.

• color_fonts — Support bitmap (sbix, CBDT) and COLR glyphs, i.e. color emoji fonts like Apple Color Emoji and Segoe UI Emoji.

  Adds a PNG decoder to the binary, so it is off by default. eframe enables it on native via egui_system_fonts.

• default_fonts — If set, epaint will use include_bytes! to bundle some fonts.

  This is off by default, because only the application should decide whether to pay for the bundled fonts. eframe enables it by default; an integration that is not eframe must either enable it, or install a text::FontProvider of its own.

• mint — mint enables interoperability with other math libraries such as glam and nalgebra.

• monochrome_emoji_fonts — Bundle the monochrome emoji fonts NotoEmoji-Regular and emoji-icon-font, and put them in the default text::FontDefinitions.

  They add about 1 MB to the binary, and are only needed if you want the same (monochrome) emoji on every platform, instead of the platform’s own color emoji (see text::GlyphRasterizer and text::FontProvider).

• rayon — Enable parallel tessellation using rayon.

  This can help performance for graphics-intense applications.

• serde — Allow serialization using serde.

• unity — Change Vertex layout to be compatible with unity

• _override_unity — Override and disable the unity feature This exists, so that when testing with –all-features, snapshots render correctly.

Optional dependencies

• document-features — Enable this when generating docs.
• serde — Allow serialization using serde .

Re-exports

pub use self::brush::Brush;

pub use self::color::ColorMode;

pub use self::corner_radius::CornerRadius;

pub use self::corner_radius_f32::CornerRadiusF32;

pub use self::direction::Direction;

pub use self::image::ColorImage;

pub use self::image::FontColorTransferFunction;

pub use self::image::ImageData;

pub use self::image::ImageDelta;

pub use self::margin::Margin;

pub use self::mesh::Mesh;

pub use self::mesh::Mesh16;

pub use self::mesh::Vertex;

pub use self::rounded_rect::RoundedRect;

pub use self::shadow::Shadow;

pub use self::shapes::BandPoint;

pub use self::shapes::BandShape;

pub use self::shapes::CircleShape;

pub use self::shapes::CubicBezierShape;

pub use self::shapes::EllipseShape;

pub use self::shapes::PaintCallback;

pub use self::shapes::PaintCallbackInfo;

pub use self::shapes::PathShape;

pub use self::shapes::QuadraticBezierShape;

pub use self::shapes::RectShape;

pub use self::shapes::Shape;

pub use self::shapes::TextShape;

pub use self::stats::PaintStats;

pub use self::stroke::PathStroke;

pub use self::stroke::Stroke;

pub use self::stroke::StrokeKind;

pub use self::tessellator::TessellationOptions;

pub use self::tessellator::Tessellator;

pub use self::text::FontFamily;

pub use self::text::FontId;

pub use self::text::Fonts;

pub use self::text::FontsView;

pub use self::text::Galley;

pub use self::text::TextOptions;

pub use self::texture_atlas::TextureAtlas;

pub use self::texture_handle::TextureHandle;

pub use self::textures::TextureManager;

pub use self::viewport::ViewportInPixels;

pub use ecolor;

pub use emath;

pub use self::margin_f32::*;

Modules

color

image

mutex

Wrappers around parking_lot locks, with a simple deadlock detection mechanism.

shape_transform

special_emojis

A few special emojis that are not part of the unicode standard.

stats

Collect statistics about what is being painted.

tessellator

Converts graphics primitives into textured triangles.

text

Everything related to text, fonts, text layout, cursors etc.

textures

util

Macros

hex_color

Construct a crate::Color32 from a hex RGB or RGBA string literal.

Structs

BandPoint

A sample in a BandShape.

BandShape

A varying-width band along a line segment.

Brush

Controls texturing of a crate::RectShape.

CircleShape

How to paint a circle.

ClippedPrimitive

A Mesh or PaintCallback within a clip rectangle.

ClippedShape

A Shape within a clip rectangle.

Color32

This format is used for space-efficient color representation (32 bits).

CornerRadius

How rounded the corners of things should be.

CornerRadiusF32

How rounded the corners of things should be, in f32.

CubicBezierShape

A cubic Bézier Curve.

EllipseShape

How to paint an ellipse.

Hsva

Hue, saturation, value, alpha. All in the range [0, 1]. No premultiplied alpha.

HsvaGamma

Like Hsva but with the v value (brightness) being gamma corrected so that it is somewhat perceptually even.

Margin

A value for all four sides of a rectangle, often used to express padding or spacing.

MarginF32

A value for all four sides of a rectangle, often used to express padding or spacing.

Mesh

Textured triangles in two dimensions.

Mesh16

A version of Mesh that uses 16-bit indices.

PaintCallback

If you want to paint some 3D shapes inside an egui region, you can use this.

PaintCallbackInfo

Information passed along with PaintCallback (Shape::Callback).

PathShape

A path which can be stroked and/or filled (if closed).

PathStroke

Describes the width and color of paths. The color can either be solid or provided by a callback. For more information, see ColorMode

Pos2

A position on screen.

QuadraticBezierShape

A quadratic Bézier Curve.

Rect

A rectangular region of space.

RectShape

How to paint a rectangle.

Rgba

0-1 linear space RGBA color with premultiplied alpha.

RoundedRect

A rectangle geometry with rounded corners.

Shadow

The color and fuzziness of a fuzzy shape.

Stroke

Describes the width and color of a line.

TextShape

How to paint some text on screen.

TextureAtlas

Contains font data in an atlas, where each character occupied a small rectangle.

TextureHandle

Used to paint images.

Vec2

A vector has a direction and length. A Vec2 is often used to represent a size.

Vertex

The 2D vertex type.

ViewportInPixels

Size of the viewport in whole, physical pixels.

Enums

Direction

A cardinal direction, one of LeftToRight, RightToLeft, TopDown, BottomUp.

Primitive

A rendering primitive - either a Mesh or a PaintCallback.

Shape

A paint primitive such as a circle or a piece of text. Coordinates are all screen space points (not physical pixels).

StrokeKind

Describes how the stroke of a shape should be painted.

TextureId

What texture to use in a Mesh mesh.

Constants

HAS_RAYON

Was epaint compiled with the rayon feature?

WHITE_UV

The UV coordinate of a white region of the texture mesh.

Functions

pos2

pos2(x, y) == Pos2::new(x, y)

vec2

vec2(x, y) == Vec2::new(x, y)