Crate embedded_graphics

source ·
Expand description

Embedded-graphics is a 2D graphics library that is focused on memory constrained embedded devices.

A core goal of embedded-graphics is to draw graphics without using any buffers; the crate is no_std compatible and works without a dynamic memory allocator, and without pre-allocating large chunks of memory. To achieve this, it takes an Iterator based approach, where pixel colors and positions are calculated on the fly, with the minimum of saved state. This allows the consuming application to use far less RAM at little to no performance penalty.

It contains built in items that make it easy to draw 2D graphics primitives:

§Additional functions provided by external crates

Embedded-graphics is designed to be extended by the application or other crates. Examples of this are adding support for different image formats or implementing custom fonts.

Note that some of these crates may not support the latest version of embedded-graphics.

If you know of a crate that is not in this list, please open an issue to add it.

§Display drivers

To support many different kinds of display, embedded-graphics doesn’t include any drivers directly but provides the DrawTarget API in embedded-graphics-core that can be implemented by external crates. In addition to the drivers for real displays, the simulator can be used to test code during development.

Photographs showing embedded-graphics running on physical display hardware.

These are just some of the displays the community has added embedded-graphics support to. This list is taken from the dependent crates list on crates.io so might be missing some unpublished entries. Please open an issue if there’s a display driver that should be added to this list.

Note that some drivers may not support the latest version of embedded-graphics.

  • embedded-graphics-web-simulator: Simulated display in your browser via Webassembly
  • epd-waveshare Driver for various ePaper displays (EPD) from Waveshare
  • hub75: A rust driver for hub75 rgb matrix displays
  • ili9341: A platform agnostic driver to interface with the ILI9341 (and ILI9340C) TFT LCD display
  • ls010b7dh01: A platform agnostic driver for the LS010B7DH01 memory LCD display
  • push2_display: Ableton Push2 embedded-graphics display driver
  • sh1106: I2C driver for the SH1106 OLED display
  • smart-leds-matrix: Driver for smart LED (like ws2812) based LED matrixes.
  • ssd1306: I2C and SPI (4 wire) driver for the SSD1306 OLED display
  • ssd1309: I2C/SPI driver for the SSD1309 OLED display written in 100% Rust.
  • ssd1322: Pure Rust driver for the SSD1322 OLED display chip
  • ssd1331: SPI (4 wire) driver for the SSD1331 OLED display
  • ssd1351: SSD1351 driver
  • ssd1675: Rust driver for the Solomon Systech SSD1675 e-Paper display (EPD) controller
  • st7565: SPI driver for ST7565 based displays
  • st7735-lcd: Rust library for displays using the ST7735 driver
  • st7789: A Rust driver library for ST7789 displays
  • st7920: ST7920 LCD driver in Rust
  • gc9a01-rs: SPI 4-wire driver for the Gc9a01 display driver

§Simulator

Embedded graphics comes with a simulator! The simulator can be used to test and debug embedded graphics code, or produce examples and interactive demos to show off embedded graphics features.

A screenshot of embedded-graphics running in its simulator.

Take a look at the examples repository to see what embedded-graphics can do, and how it might look on a display. You can run the examples like this:

git clone https://github.com/embedded-graphics/examples.git
cd examples/eg-0.7

cargo run --example hello-world

§Crate features

Additional features can be enabled by adding the following features to your Cargo.toml.

  • nalgebra_support - use the Nalgebra crate with no_std support to enable conversions from nalgebra::Vector2 to Point and Size.

  • fixed_point - use fixed point arithmetic instead of floating point for all trigonometric calculation.

  • defmt - provide implementations of defmt::Format for all types where possible. defmt is a library for logging that moves as much work as possible over to a separate logging machine, making it especially suited to low-resource MCUs. Note that defmt might not work with older versions of rustc that are otherwise supported by embedded-graphics.

§Migrating from older versions

§Implementing embedded_graphics support for a display driver

To add support for embedded-graphics to a display driver, DrawTarget from embedded-graphics-core must be implemented. This allows all embedded-graphics items to be rendered by the display. See the DrawTarget documentation for implementation details.

§Examples

§Drawing examples

A grid of screenshots showing primitives, text and other items that can be drawn using embedded-graphics.

Example usage of drawing primitives, text and images with embedded-graphics can be found here.

§Shapes and text

The following example draws some shapes and text to a MockDisplay in place of target hardware. The simulator can also be used for debugging, development or if hardware is not available.

use embedded_graphics::{
    mono_font::{ascii::FONT_6X10, MonoTextStyle},
    pixelcolor::BinaryColor,
    prelude::*,
    primitives::{
        Circle, PrimitiveStyle, PrimitiveStyleBuilder, Rectangle, StrokeAlignment, Triangle,
    },
    text::{Alignment, Text},
    mock_display::MockDisplay,
};

fn main() -> Result<(), std::convert::Infallible> {
    // Create a new mock display
    let mut display: MockDisplay<BinaryColor> = MockDisplay::new();

    // Create styles used by the drawing operations.
    let thin_stroke = PrimitiveStyle::with_stroke(BinaryColor::On, 1);
    let thick_stroke = PrimitiveStyle::with_stroke(BinaryColor::On, 3);
    let border_stroke = PrimitiveStyleBuilder::new()
        .stroke_color(BinaryColor::On)
        .stroke_width(3)
        .stroke_alignment(StrokeAlignment::Inside)
        .build();
    let fill = PrimitiveStyle::with_fill(BinaryColor::On);
    let character_style = MonoTextStyle::new(&FONT_6X10, BinaryColor::On);

    let yoffset = 10;

    // Draw a 3px wide outline around the display.
    display
        .bounding_box()
        .into_styled(border_stroke)
        .draw(&mut display)?;

    // Draw a triangle.
    Triangle::new(
        Point::new(16, 16 + yoffset),
        Point::new(16 + 16, 16 + yoffset),
        Point::new(16 + 8, yoffset),
    )
    .into_styled(thin_stroke)
    .draw(&mut display)?;

    // Draw a filled square
    Rectangle::new(Point::new(52, yoffset), Size::new(16, 16))
        .into_styled(fill)
        .draw(&mut display)?;

    // Draw a circle with a 3px wide stroke.
    Circle::new(Point::new(88, yoffset), 17)
        .into_styled(thick_stroke)
        .draw(&mut display)?;

    // Draw centered text.
    let text = "embedded-graphics";
    Text::with_alignment(
        text,
        display.bounding_box().center() + Point::new(0, 15),
        character_style,
        Alignment::Center,
    )
    .draw(&mut display)?;

    Ok(())
}

This example is also included in the examples repository and can be run using cargo run --example hello-world. It produces this output:

Embedded Graphics Simulator example screenshot

Additional examples can be found in the examples repository.

Modules§

Structs§

Traits§

  • Drawable
    Marks an object as “drawable”. Must be implemented for all graphics objects