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use crate::error::Error;
use crate::utils::status_to_result;
use libc::c_double;
#[repr(C)]
#[derive(Debug, Clone, Copy, PartialEq)]
pub struct Matrix {
pub xx: c_double,
pub yx: c_double,
pub xy: c_double,
pub yy: c_double,
pub x0: c_double,
pub y0: c_double,
}
impl Default for Matrix {
fn default() -> Self {
Self::identity()
}
}
impl Matrix {
pub(crate) fn ptr(&self) -> *const ffi::Matrix {
self as *const Matrix as _
}
pub(crate) fn mut_ptr(&mut self) -> *mut ffi::Matrix {
self as *mut Matrix as _
}
pub(crate) fn null() -> Self {
Self {
xx: 0.0,
yx: 0.0,
xy: 0.0,
yy: 0.0,
x0: 0.0,
y0: 0.0,
}
}
pub fn identity() -> Self {
Self {
xx: 1.0,
yx: 0.0,
xy: 0.0,
yy: 1.0,
x0: 0.0,
y0: 0.0,
}
}
pub fn new(xx: f64, yx: f64, xy: f64, yy: f64, x0: f64, y0: f64) -> Self {
Self {
xx,
yx,
xy,
yy,
x0,
y0,
}
}
#[doc(alias = "cairo_matrix_multiply")]
pub fn multiply(left: &Matrix, right: &Matrix) -> Matrix {
let mut matrix = Self::null();
unsafe {
ffi::cairo_matrix_multiply(matrix.mut_ptr(), left.ptr(), right.ptr());
}
matrix
}
#[doc(alias = "cairo_matrix_translate")]
pub fn translate(&mut self, tx: f64, ty: f64) {
unsafe { ffi::cairo_matrix_translate(self.mut_ptr(), tx, ty) }
}
#[doc(alias = "cairo_matrix_scale")]
pub fn scale(&mut self, sx: f64, sy: f64) {
unsafe { ffi::cairo_matrix_scale(self.mut_ptr(), sx, sy) }
}
#[doc(alias = "cairo_matrix_rotate")]
pub fn rotate(&mut self, angle: f64) {
unsafe { ffi::cairo_matrix_rotate(self.mut_ptr(), angle) }
}
#[doc(alias = "cairo_matrix_invert")]
pub fn invert(&mut self) {
let status = unsafe { ffi::cairo_matrix_invert(self.mut_ptr()) };
status_to_result(status).expect("Failed to invert the matrix")
}
#[doc(alias = "cairo_matrix_invert")]
pub fn try_invert(&self) -> Result<Matrix, Error> {
let mut matrix = *self;
let status = unsafe { ffi::cairo_matrix_invert(matrix.mut_ptr()) };
status_to_result(status)?;
Ok(matrix)
}
#[doc(alias = "cairo_matrix_transform_distance")]
pub fn transform_distance(&self, _dx: f64, _dy: f64) -> (f64, f64) {
let mut dx = _dx;
let mut dy = _dy;
unsafe {
ffi::cairo_matrix_transform_distance(self.ptr(), &mut dx, &mut dy);
}
(dx, dy)
}
#[doc(alias = "cairo_matrix_transform_point")]
pub fn transform_point(&self, _x: f64, _y: f64) -> (f64, f64) {
let mut x = _x;
let mut y = _y;
unsafe {
ffi::cairo_matrix_transform_point(self.ptr(), &mut x, &mut y);
}
(x, y)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn memory_layout_is_ffi_equivalent() {
macro_rules! dummy_values {
($Matrix: ident) => {
$Matrix {
xx: 1.0,
yx: 2.0,
xy: 3.0,
yy: 4.0,
x0: 5.0,
y0: 6.0,
}
};
}
use crate::ffi::Matrix as FfiMatrix;
let transmuted: Matrix = unsafe { std::mem::transmute(dummy_values!(FfiMatrix)) };
assert_eq!(transmuted, dummy_values!(Matrix));
}
#[test]
fn invalid_matrix_does_not_invert() {
let matrix = Matrix::null();
assert!(matrix.try_invert().is_err());
}
#[test]
#[should_panic]
fn inverting_invalid_matrix_panics() {
let mut matrix = Matrix::null();
matrix.invert();
}
#[test]
fn valid_matrix_try_invert() {
let matrix = Matrix::identity();
assert_eq!(matrix.try_invert().unwrap(), Matrix::identity());
}
#[test]
fn valid_matrix_invert() {
let mut matrix = Matrix::identity();
matrix.invert();
assert_eq!(matrix, Matrix::identity());
}
}
