Embedded graphics simulator

It can display all sorts of embedded-graphics test code.

The simulator can be used to test and debug embedded-graphics code, or produce snazzy examples for people to try drivers out without needing physical hardware to run on.

Examples

Simulate a 128x64 SSD1306 OLED

use embedded_graphics::{
    fonts::{Font6x8, Text},
    pixelcolor::BinaryColor,
    prelude::*,
    primitives::{Circle, Line},
    style::{PrimitiveStyle, TextStyle},
};
use embedded_graphics_simulator::{BinaryColorTheme, SimulatorDisplay, Window, OutputSettingsBuilder};

fn main() -> Result<(), core::convert::Infallible> {
    let mut display: SimulatorDisplay<BinaryColor> = SimulatorDisplay::new(Size::new(129, 129));

    let line_style = PrimitiveStyle::with_stroke(BinaryColor::On, 1);

    Circle::new(Point::new(64, 64), 64)
        .into_styled(line_style)
        .draw(&mut display)?;

    Line::new(Point::new(64, 64), Point::new(0, 64))
        .into_styled(line_style)
        .draw(&mut display)?;

    Line::new(Point::new(64, 64), Point::new(80, 80))
        .into_styled(line_style)
        .draw(&mut display)?;

    Text::new("Hello World!", Point::new(5, 50))
        .into_styled(TextStyle::new(Font6x8, BinaryColor::On))
        .draw(&mut display)?;

    let output_settings = OutputSettingsBuilder::new()
        .theme(BinaryColorTheme::OledBlue)
        .build();
    Window::new("Hello World", &output_settings).show_static(&display);

    Ok(())
}

Creating screenshots

Screenshots of programs, that use Window to display a simulated display, can be created by setting the EG_SIMULATOR_DUMP environment variable:

EG_SIMULATOR_DUMP=screenshot.png cargo run

By setting the variable the display passed to the first Window::update call gets exported as a PNG file to the specified path. After the file is exported the process is terminated.

Exporting images

If a program doesn't require to display a window and only needs to export one or more images, a SimulatorDisplay can also be converted to an image crate ImageBuffer by using the to_image_buffer method. The resulting buffer can then be used to save the display content to any format supported by image.

Usage without SDL2

When the simulator is used in headless/CI environments that don't require showing a window, SDL2 support can be disabled. This removes the requirement of SDL2 being installed on the target machine, but still allows the simulator to be used to generate images.

The with-sdl feature is enabled by default and can be disabled by adding default-features = false to the dependency:

[dependencies.embedded-graphics-simulator]
version = "0.2.0"
default-features = false