use std::fmt;
use approx::ApproxEq;
use matrix::{Matrix, Matrix4, ToMatrix4};
use num::{BaseNum, BaseFloat, zero, one};
use point::{Point, Point3};
use ray::Ray;
use rotation::{Rotation, Rotation3};
use std::marker::PhantomFn;
use vector::{Vector, Vector3};
pub trait Transform<S: BaseNum, V: Vector<S>, P: Point<S,V>>: Sized + PhantomFn<S> {
fn identity() -> Self;
fn look_at(eye: &P, center: &P, up: &V) -> Self;
fn transform_vector(&self, vec: &V) -> V;
fn transform_point(&self, point: &P) -> P;
#[inline]
fn transform_ray(&self, ray: &Ray<P,V>) -> Ray<P,V> {
Ray::new(self.transform_point(&ray.origin), self.transform_vector(&ray.direction))
}
#[inline]
fn transform_as_point(&self, vec: &V) -> V {
self.transform_point(&Point::from_vec(vec)).to_vec()
}
fn concat(&self, other: &Self) -> Self;
fn invert(&self) -> Option<Self>;
#[inline]
fn concat_self(&mut self, other: &Self) {
*self = Transform::concat(self, other);
}
#[inline]
fn invert_self(&mut self) {
*self = self.invert().unwrap()
}
}
#[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
pub struct Decomposed<S, V, R> {
pub scale: S,
pub rot: R,
pub disp: V,
}
impl<S: BaseFloat, V: Vector<S>, P: Point<S, V>, R: Rotation<S, V, P>> Transform<S, V, P> for Decomposed<S, V, R> {
#[inline]
fn identity() -> Decomposed<S, V, R> {
Decomposed {
scale: one(),
rot: Rotation::identity(),
disp: zero(),
}
}
#[inline]
fn look_at(eye: &P, center: &P, up: &V) -> Decomposed<S, V, R> {
let origin: P = Point::origin();
let rot: R = Rotation::look_at(¢er.sub_p(eye), up);
let disp: V = rot.rotate_vector(&origin.sub_p(eye));
Decomposed {
scale: one(),
rot: rot,
disp: disp,
}
}
#[inline]
fn transform_vector(&self, vec: &V) -> V {
self.rot.rotate_vector(&vec.mul_s(self.scale.clone()))
}
#[inline]
fn transform_point(&self, point: &P) -> P {
self.rot.rotate_point(&point.mul_s(self.scale.clone())).add_v(&self.disp)
}
fn concat(&self, other: &Decomposed<S, V, R>) -> Decomposed<S, V, R> {
Decomposed {
scale: self.scale * other.scale,
rot: self.rot.concat(&other.rot),
disp: self.transform_as_point(&other.disp),
}
}
fn invert(&self) -> Option<Decomposed<S, V, R>> {
if self.scale.approx_eq(&zero()) {
None
} else {
let s = one::<S>() / self.scale;
let r = self.rot.invert();
let d = r.rotate_vector(&self.disp).mul_s(-s);
Some(Decomposed {
scale: s,
rot: r,
disp: d,
})
}
}
}
pub trait Transform3<S>: Transform<S, Vector3<S>, Point3<S>>+ ToMatrix4<S> {}
impl<S: BaseFloat + 'static, R: Rotation3<S>> ToMatrix4<S> for Decomposed<S, Vector3<S>, R> {
fn to_matrix4(&self) -> Matrix4<S> {
let mut m = self.rot.to_matrix3().mul_s(self.scale.clone()).to_matrix4();
m.w = self.disp.extend(one());
m
}
}
impl<S: BaseFloat, R: Rotation3<S>> Transform3<S> for Decomposed<S,Vector3<S>,R> where S: 'static {}
impl<S: BaseFloat, R: fmt::Debug + Rotation3<S>> fmt::Debug for Decomposed<S,Vector3<S>,R> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "(scale({:?}), rot({:?}), disp{:?})",
self.scale, self.rot, self.disp)
}
}
#[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
pub struct AffineMatrix3<S> {
pub mat: Matrix4<S>,
}
impl<S: BaseFloat + 'static> Transform<S, Vector3<S>, Point3<S>> for AffineMatrix3<S> {
#[inline]
fn identity() -> AffineMatrix3<S> {
AffineMatrix3 { mat: Matrix4::identity() }
}
#[inline]
fn look_at(eye: &Point3<S>, center: &Point3<S>, up: &Vector3<S>) -> AffineMatrix3<S> {
AffineMatrix3 { mat: Matrix4::look_at(eye, center, up) }
}
#[inline]
fn transform_vector(&self, vec: &Vector3<S>) -> Vector3<S> {
self.mat.mul_v(&vec.extend(zero())).truncate()
}
#[inline]
fn transform_point(&self, point: &Point3<S>) -> Point3<S> {
Point3::from_homogeneous(&self.mat.mul_v(&point.to_homogeneous()))
}
#[inline]
fn concat(&self, other: &AffineMatrix3<S>) -> AffineMatrix3<S> {
AffineMatrix3 { mat: self.mat.mul_m(&other.mat) }
}
#[inline]
fn invert(&self) -> Option<AffineMatrix3<S>> {
self.mat.invert().map(|m| AffineMatrix3{ mat: m })
}
}
impl<S: BaseNum> ToMatrix4<S> for AffineMatrix3<S> {
#[inline] fn to_matrix4(&self) -> Matrix4<S> { self.mat.clone() }
}
impl<S: BaseFloat> Transform3<S> for AffineMatrix3<S> where S: 'static {}