Move `Transformation` to `iced_graphics`

1 files changed, 54 insertions, 0 deletions

diff --git a/graphics/src/transformation.rs b/graphics/src/transformation.rs
new file mode 100644
index 00000000..ff3b1d00
--- /dev/null
+++ b/graphics/src/transformation.rs
@@ -0,0 +1,54 @@
+use glam::{Mat4, Vec3, Vec4};
+use std::ops::Mul;
+
+/// A 2D transformation matrix.
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub struct Transformation(Mat4);
+
+impl Transformation {
+    /// Get the identity transformation.
+    pub fn identity() -> Transformation {
+        Transformation(Mat4::identity())
+    }
+
+    /// Creates an orthographic projection.
+    #[rustfmt::skip]
+    pub fn orthographic(width: u32, height: u32) -> Transformation {
+        Transformation(Mat4::from_cols(
+            Vec4::new(2.0 / width as f32, 0.0, 0.0, 0.0),
+            Vec4::new(0.0, -2.0 / height as f32, 0.0, 0.0),
+            Vec4::new(0.0, 0.0, -1.0, 0.0),
+            Vec4::new(-1.0, 1.0, 0.0, 1.0)
+        ))
+    }
+
+    /// Creates a translate transformation.
+    pub fn translate(x: f32, y: f32) -> Transformation {
+        Transformation(Mat4::from_translation(Vec3::new(x, y, 0.0)))
+    }
+
+    /// Creates a scale transformation.
+    pub fn scale(x: f32, y: f32) -> Transformation {
+        Transformation(Mat4::from_scale(Vec3::new(x, y, 1.0)))
+    }
+}
+
+impl Mul for Transformation {
+    type Output = Self;
+
+    fn mul(self, rhs: Self) -> Self {
+        Transformation(self.0 * rhs.0)
+    }
+}
+
+impl AsRef<[f32; 16]> for Transformation {
+    fn as_ref(&self) -> &[f32; 16] {
+        self.0.as_ref()
+    }
+}
+
+impl From<Transformation> for [f32; 16] {
+    fn from(t: Transformation) -> [f32; 16] {
+        *t.as_ref()
+    }
+}