message: impl projection() and mul_projection()
diff: @@ -406,6 +406,12 @@ impl<'a> Canvas<'a> {
  self.blend_mode = blend_mode;
  }
  + /// Gets a copy of the canvas's raw projection matrix.
  + #[inline]
  + pub fn projection(&self) -> mint::ColumnMatrix4<f32> {
  + self.transform.into()
  + }
  +
  /// Sets the bounds of the screen viewport. This is a shortcut for `set_projection`
  /// and thus will override any previous projection matrix set.
  ///
  @@ -435,6 +441,11 @@ impl<'a> Canvas<'a> {
  );
  }
  + /// Premultiplies the given transformation matrix with the current projection matrix.
  + pub fn mul_projection(&mut self, transform: impl Into<mint::ColumnMatrix4<f32>>) {
  + self.set_projection(glam::Mat4::from(transform.into()) * self.transform);
  + }
  +
  /// Draws a mesh.
  ///
  /// If no [`Image`] is given then the image color will be white.
  