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

GESystemDesc

Pattern

R_GE_gcontext

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

_DevDesc

_GEDevDesc

Enums

FontFace

GEUnit

GEevent

LineEnd

LineJoin

LineType

R_GE_lineend

R_GE_linejoin

Unit

cetype_t

cetype_t is an identifier reseved by POSIX, but it is well established as public. Could remap by a #define though

Constants

LTY_BLANK

LTY_DASHED

LTY_DOTDASH

LTY_DOTTED

LTY_LONGDASH

LTY_SOLID

LTY_TWODASH

R_GE_definitions

R_GE_version

Statics

R_NilValue

The nil object

Functions

GECap^⚠

GECircle^⚠

GEExpressionHeight^⚠

GEExpressionMetric^⚠

GEExpressionWidth^⚠

GELine^⚠

GEMathText^⚠

GEMetricInfo^⚠

GEMode^⚠

GENewPage^⚠

GEPath^⚠

GEPolygon^⚠

GEPolyline^⚠

GERaster^⚠

GERect^⚠

GESetClip^⚠

GEStrHeight^⚠

GEStrMetric^⚠

GEStrWidth^⚠

GESymbol^⚠

GEText^⚠

GEaddDevice2^⚠

GEcreateDevDesc^⚠

GEcurrentDevice^⚠

GEdeviceNumber^⚠

GEfromDeviceHeight^⚠

GEfromDeviceWidth^⚠

GEfromDeviceX^⚠

GEfromDeviceY^⚠

GEgetDevice^⚠

GEinitDisplayList^⚠

GEtoDeviceHeight^⚠

GEtoDeviceWidth^⚠

GEtoDeviceX^⚠

GEtoDeviceY^⚠

R_CheckDeviceAvailable^⚠

R_GE_checkVersionOrDie^⚠

Rf_NoDevices^⚠

Rf_NumDevices^⚠

unit_to_ge 🔒

Type Aliases

DevDesc

GEDevDesc

GEcallback

pDevDesc

pGEDevDesc

pGEcontext