//! Module containing the bounding box struct.

use math::Number;

macro_rules! make_bounding_box {

    ($name: ident, $vector: ident, $size: expr) => {

        use math::vector::$vector;

        /// Represents a bounding box.
        pub struct $name<T> {
            min: $vector<T>,
            max: $vector<T>,
        }

        impl<T: PartialOrd + Copy + Clone> $name<T> {
            /// Creates a bounding box from its min and max coordinates.
            pub fn new(min: $vector<T>, max: $vector<T>) -> $name<T> {
                $name {
                    min: min,
                    max: max,
                }
            }

            /// Enlarges the bounding box so it contains the point passed as parameter.
            pub fn add_point(&mut self, point: &$vector<T>) {
                for i in 0..$size {
                    if point[i] < self.min[i] {
                        self.min[i] = point[i];
                    }
                    if point[i] > self.max[i] {
                        self.max[i] = point[i];
                    }
                }
            }

            /// Returns the minimum value of the bounding box.
            pub fn min(&self) -> $vector<T> {
                self.min
            }

            /// Returns the maximum value of the bounding box.
            pub fn max(&self) -> $vector<T> {
                self.max
            }

        }

        impl<T: Number> $name<T> {
            /// Scales a bounding box from its center.
            pub fn scale(&mut self, factor: T) {
                let diag = self.max - self.min;

                self.min -= diag * factor;
                self.max += diag * factor;
            }
        }

    }
}

make_bounding_box!(BoundingBox2, Vector2, 2);
make_bounding_box!(BoundingBox3, Vector3, 3);
make_bounding_box!(BoundingBox4, Vector4, 4);