Module graphics

Graphic Device Operations

Control an existing graphic device

TODO

Implement a new graphic device

The following two things are needed to implement a graphic device.

• DeviceDriver trait: the actual implementation of graphic device methods.
• DeviceDescriptor struct: the parameters that might differ per device instance (e.g. sizes, and colors).

For example, the following code implements a simple graphic device that shows a message when it’s activated (and ignores everything else).

use extendr_api::{
    graphics::{DeviceDescriptor, DeviceDriver, DevDesc},
    prelude::*,
};

struct MyDevice<'a> {
    welcome_message: &'a str,
}

impl<'a> DeviceDriver for MyDevice<'a> {
    fn activate(&mut self, _dd: DevDesc) {
        let welcome_message = self.welcome_message;
        rprintln!("message from device: {welcome_message}");
    }
}

/// Create a new device.
///
/// @export
#[extendr]
fn my_device(welcome_message: String) {
    let device_driver = MyDevice {
        welcome_message: welcome_message.as_str(),
    };
     
    let device_descriptor = DeviceDescriptor::new();
    let device = device_driver.create_device::<MyDevice>(device_descriptor, "my device");
}

This can be called from R.

my_device("I'm so active!!!")
#> message from device: I'm so active!!!

Re-exports

pub use device_descriptor::*;

pub use device_driver::*;

Modules

color

device_descriptor

device_driver

Structs

Context

Device

Pattern

R_GE_gcontext

A structure containing graphical parameters

Raster

A row-major array of pixels. One pixel is 32-bit, whose each byte represents alpha, blue, green, and red in the order.

TextMetric

Enums

FontFace

LineEnd

LineJoin

LineType

Unit

Type Aliases

DevDesc

——— New (in 1.4.0) device driver structure ——— NOTES: