iced-yoda/wgpu/src/transformation.rs

use nalgebra::Matrix3;
use std::ops::Mul;

/// A 2D transformation matrix.
#[derive(Debug, Clone, Copy, PartialEq)]
pub struct Transformation(Matrix3<f32>);

impl Transformation {
    /// Get the identity transformation.
    pub fn identity() -> Transformation {
        Transformation(Matrix3::identity())
    }

    /// Creates an orthographic projection.
    #[rustfmt::skip]
    pub fn orthographic(width: u16, height: u16) -> Transformation {
        Transformation(nalgebra::Matrix3::new(
            2.0 / f32::from(width), 0.0, -1.0,
            0.0, 2.0 / f32::from(height), -1.0,
            0.0, 0.0, 1.0
        ))
    }

    /// Creates a translate transformation.
    pub fn translate(x: f32, y: f32) -> Transformation {
        Transformation(Matrix3::new_translation(&nalgebra::Vector2::new(x, y)))
    }
}

impl Mul for Transformation {
    type Output = Self;

    fn mul(self, rhs: Self) -> Self {
        Transformation(self.0 * rhs.0)
    }
}

impl From<Transformation> for [f32; 16] {
    #[rustfmt::skip]
    fn from(t: Transformation) -> [f32; 16] {
        [
            t.0[0], t.0[1], 0.0, t.0[2],
            t.0[3], t.0[4], 0.0, t.0[5],
            0.0, 0.0, -1.0, 0.0,
            t.0[6], t.0[7], 0.0, t.0[8]
        ]
    }
}