cgmath/src/approx.rs
2014-06-23 23:49:29 -07:00

45 lines
1.3 KiB
Rust

// Copyright 2014 The CGMath Developers. For a full listing of the authors,
// refer to the AUTHORS file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use std::num;
pub trait ApproxEq<T: Float> {
fn approx_epsilon(_hack: Option<Self>) -> T {
num::cast(1.0e-5).unwrap()
}
fn approx_eq(&self, other: &Self) -> bool {
let eps: T = ApproxEq::approx_epsilon(None::<Self>);
self.approx_eq_eps(other, &eps)
}
fn approx_eq_eps(&self, other: &Self, epsilon: &T) -> bool;
}
macro_rules! approx_float(
($S:ident) => (
impl ApproxEq<$S> for $S {
#[inline]
fn approx_eq_eps(&self, other: &$S, epsilon: &$S) -> bool {
num::abs(*self - *other) < *epsilon
}
}
)
)
approx_float!(f32)
approx_float!(f64)