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

72 lines
2.5 KiB
Rust

// Copyright 2013-2014 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.
//! View frustum for visibility determination
use array::Array2;
use matrix::Matrix4;
use num::BaseFloat;
use plane::Plane;
use point::Point3;
use vector::{Vector, EuclideanVector};
#[deriving(Clone, PartialEq)]
pub struct Frustum<S> {
pub left: Plane<S>,
pub right: Plane<S>,
pub bottom: Plane<S>,
pub top: Plane<S>,
pub near: Plane<S>,
pub far: Plane<S>,
}
impl<S: BaseFloat>
Frustum<S> {
/// Constructs a frustum
pub fn new(left: Plane<S>, right: Plane<S>,
bottom: Plane<S>, top: Plane<S>,
near: Plane<S>, far: Plane<S>) -> Frustum<S> {
Frustum {
left: left,
right: right,
bottom: bottom,
top: top,
near: near,
far: far,
}
}
/// Extracts frustum planes from a projection matrix
pub fn from_matrix4(mat: Matrix4<S>) -> Frustum<S> {
Frustum::new(Plane::from_vector4(mat.r(3).add_v(&mat.r(0)).normalize()),
Plane::from_vector4(mat.r(3).sub_v(&mat.r(0)).normalize()),
Plane::from_vector4(mat.r(3).add_v(&mat.r(1)).normalize()),
Plane::from_vector4(mat.r(3).sub_v(&mat.r(1)).normalize()),
Plane::from_vector4(mat.r(3).add_v(&mat.r(2)).normalize()),
Plane::from_vector4(mat.r(3).sub_v(&mat.r(2)).normalize()))
}
}
#[deriving(Clone, PartialEq)]
pub struct FrustumPoints<S> {
pub near_top_left: Point3<S>,
pub near_top_right: Point3<S>,
pub near_bottom_left: Point3<S>,
pub near_bottom_right: Point3<S>,
pub far_top_left: Point3<S>,
pub far_top_right: Point3<S>,
pub far_bottom_left: Point3<S>,
pub far_bottom_right: Point3<S>,
}