det-rs

Calculate the determinant of a square matrix using a Rust macro

This macro should not be used directly. Instead, it should be called inside a function that is used elsewhere.

Usage

Calculate the area of a parallelogram:

pub fn find_orthonormal_4(a: &Vector2<f32>, b: &Vector2<f32>) -> f32 {
    det_copy!(a.x, a.y,
              b.x, b.y)
}

Calculate a 4D orthogonal vector using nalgebra:

pub fn find_orthonormal_4(a: &Vector4<f32>, b: &Vector4<f32>, c: &Vector4<f32>) -> Vector4<f32> {
    det_copy!(Vector4::x(), Vector4::y(), Vector4::z(), Vector4::w(),
              a.x,          a.y,          a.z,          a.w,
              b.x,          b.y,          b.z,          b.w,
              c.x,          c.y,          c.z,          c.w         )
}

Usually det! should be used in these cases, but strangely, it causes a type recursion error, so we use det_copy! instead. Note, that the constructors (eg. Vector4::x()) are executed multiple times. To avoid this, bind the vectors to a variable first and pass in the variable instead.

Requirements

There are various macros for various types of values.

• det_copy!
  1. T: Copy
  2. T: Mul<T, Output=T>
  3. T: Sub<T, Output=T>
  4. T: Add<T, Output=T>
• det_clone!
  1. T: Clone
  2. T: Mul<T, Output=T>
  3. T: Sub<T, Output=T>
  4. T: Add<T, Output=T>
• det!
  1. T: Mul<T, Output=T>
  2. for<'a> &'a T: Mul<T, Output=T>
  3. for<'a, 'b> &'a T: Mul<&'b T, Output=T>
  4. T: Sub<T, Output=T>
  5. T: Add<T, Output=T>