math2d 0.2.0-alpha3

2D Mathematics library designed for use with 2D drawing applications. Primarily designed for the needs of Direct2D, but this library should be perfectly capable of filling in the needs of other libraries such as Cairo. If you would like interoperability defitions added please feel free to open a pull request on the repository. Currently compatible with: - `Direct2D` (winapi types) - `Mint` (crate)
Documentation 
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//! Mathematical point on the 2D (x, y) plane.

use crate::point2f::Point2f;
use crate::point2i::Point2i;

#[cfg(all(windows, feature = "d2d"))]
use winapi::um::dcommon::D2D_POINT_2U;

/// Mathematical point on the 2D (x, y) plane.
#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
#[cfg_attr(feature = "serde_derive", derive(Serialize, Deserialize))]
#[repr(C)]
pub struct Point2u {
    /// Horizontal component
    pub x: u32,
    /// Vertical component
    pub y: u32,
}

impl Point2u {
    /// Mathematical origin point
    pub const ORIGIN: Point2u = Point2u { x: 0, y: 0 };

    /// Construct a point from its components
    #[inline]
    pub fn new(x: u32, y: u32) -> Point2u {
        Point2u { x, y }
    }

    /// Convert this value to a floating point
    #[inline]
    pub fn to_f32(self) -> Point2f {
        Point2f {
            x: self.x as f32,
            y: self.y as f32,
        }
    }

    /// Convert this value to an unsigned point. It is the caller's duty
    /// to ensure the values are not negative to avoid casting underflow.
    #[inline]
    pub fn to_i32(self) -> Point2i {
        Point2i {
            x: self.x as i32,
            y: self.y as i32,
        }
    }
}

impl From<(u32, u32)> for Point2u {
    #[inline]
    fn from((x, y): (u32, u32)) -> Point2u {
        Point2u { x, y }
    }
}

impl From<[u32; 2]> for Point2u {
    #[inline]
    fn from(p: [u32; 2]) -> Point2u {
        Point2u { x: p[0], y: p[0] }
    }
}

impl From<Point2u> for [u32; 2] {
    #[inline]
    fn from(p: Point2u) -> [u32; 2] {
        [p.x, p.y]
    }
}

#[cfg(all(windows, feature = "d2d"))]
impl From<Point2u> for D2D_POINT_2U {
    #[inline]
    fn from(point: Point2u) -> D2D_POINT_2U {
        D2D_POINT_2U {
            x: point.x,
            y: point.y,
        }
    }
}

#[cfg(all(windows, feature = "d2d"))]
impl From<D2D_POINT_2U> for Point2u {
    #[inline]
    fn from(point: D2D_POINT_2U) -> Point2u {
        Point2u {
            x: point.x,
            y: point.y,
        }
    }
}

#[cfg(feature = "mint")]
impl From<Point2u> for mint::Point2<u32> {
    #[inline]
    fn from(p: Point2u) -> mint::Point2<u32> {
        mint::Point2 { x: p.x, y: p.y }
    }
}

#[cfg(feature = "mint")]
impl From<mint::Point2<u32>> for Point2u {
    #[inline]
    fn from(p: mint::Point2<u32>) -> Point2u {
        Point2u { x: p.x, y: p.y }
    }
}

#[cfg(all(test, windows, feature = "d2d"))]
#[test]
fn pt2u_d2d_bin_compat() {
    use std::mem::size_of_val;

    fn ptr_eq<T>(a: &T, b: &T) -> bool {
        (a as *const T) == (b as *const T)
    }

    let pt = Point2u::ORIGIN;
    let d2d = unsafe { &*((&pt) as *const _ as *const D2D_POINT_2U) };

    assert!(ptr_eq(&pt.x, &d2d.x));
    assert!(ptr_eq(&pt.y, &d2d.y));
    assert_eq!(size_of_val(&pt), size_of_val(d2d));
}