Struct Tri 

#[repr(transparent)]
pub struct Tri<V>(pub [V; 3]);

Triangle, defined by three vertices.

Tuple Fields

0: [V; 3]

Implementations

impl<V> Tri<V>

pub fn edges(&self) -> [Edge<&V>; 3]

Given a triangle ABC, returns the edges [AB, BC, CA].

Examples

use retrofire_core::geom::{Tri, Edge};
use retrofire_core::math::{Point2, pt2};

let pts: [Point2; _] = [pt2(-1.0, 0.0), pt2(2.0, 0.0), pt2(1.0, 2.0)];
let tri = Tri(pts);

let [e0, e1, e2] = tri.edges();
assert_eq!(e0, Edge(&pts[0], &pts[1]));
assert_eq!(e1, Edge(&pts[1], &pts[2]));
assert_eq!(e2, Edge(&pts[2], &pts[0]));

impl<P: Affine, A> Tri<Vertex<P, A>>

pub fn tangents(&self) -> [P::Diff; 2]

Given a triangle ABC, returns the vectors [AB, AC].

impl<A, B> Tri<Vertex2<A, B>>

pub fn winding(&self) -> Winding

Returns the winding order of self.

Examples

use retrofire_core::geom::{Tri, vertex, Winding};
use retrofire_core::math::pt2;

let mut tri = Tri([
    vertex(pt2::<_, ()>(0.0, 0.0), ()),
    vertex(pt2(0.0, 3.0), ()),
    vertex(pt2(4.0, 0.0), ()),
]);
assert_eq!(tri.winding(), Winding::Cw);

tri.0.swap(1, 2);
assert_eq!(tri.winding(), Winding::Ccw);

pub fn signed_area(&self) -> f32

Returns the signed area of self.

The area is positive iff self is wound counter-clockwise.

Examples

use retrofire_core::geom::{Tri, vertex};
use retrofire_core::math::pt2;

let tri = Tri([
    vertex(pt2::<_, ()>(0.0, 0.0), ()),
    vertex(pt2(0.0, 3.0), ()),
    vertex(pt2(4.0, 0.0), ()),
]);
assert_eq!(tri.signed_area(), -6.0);

pub fn area(&self) -> f32

Returns the (positive) area of self.

Examples

use retrofire_core::geom::{vertex, Tri};
use retrofire_core::math::pt2;

let tri = Tri([
    vertex(pt2::<_, ()>(0.0, 0.0), ()),
    vertex(pt2(0.0, 3.0), ()),
    vertex(pt2(4.0, 0.0), ()),
]);
assert_eq!(tri.area(), 6.0);

impl<A, B> Tri<Vertex3<A, B>>

pub fn normal(&self) -> Normal3

Returns the normal vector of self.

The result is normalized to unit length.

Examples

use core::f32::consts::SQRT_2;
use retrofire_core::geom::{Tri, vertex};
use retrofire_core::math::{pt3, vec3};

// Triangle lying in a 45° angle
let tri = Tri([
    vertex(pt3::<_, ()>(0.0, 0.0, 0.0), ()),
    vertex(pt3(0.0, 3.0, 3.0), ()),
    vertex(pt3(4.0, 0.0,0.0), ()),
]);
assert_eq!(tri.normal(), vec3(0.0, SQRT_2 / 2.0, -SQRT_2 / 2.0));

pub fn plane(&self) -> Plane3<B>

Returns the plane that self lies on.

Examples

use retrofire_core::geom::{Tri, Plane3, vertex};
use retrofire_core::math::{pt3, Vec3};

let tri = Tri([
    vertex(pt3::<f32, ()>(0.0, 0.0, 2.0), ()),
    vertex(pt3(1.0, 0.0, 2.0), ()),
    vertex(pt3(0.0, 1.0, 2.0), ())
]);
assert_eq!(tri.plane().normal(), Vec3::Z);
assert_eq!(tri.plane().offset(), 2.0);

pub fn winding(&self) -> Winding

Returns the winding order of self, as projected to the XY plane.

pub fn area(&self) -> f32

Returns the area of self.

Examples

use retrofire_core::geom::{tri, vertex};
use retrofire_core::math::pt3;

let tri = tri(
    vertex(pt3::<_, ()>(0.0, 0.0, 0.0), ()),
    vertex(pt3(4.0, 0.0, 0.0), ()),
    vertex(pt3(0.0, 3.0, 0.0), ()),
);
assert_eq!(tri.area(), 6.0);

Trait Implementations

impl<V: Clone> Clone for Tri<V>

fn clone(&self) -> Tri<V>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<V: Debug> Debug for Tri<V>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<V: PartialEq> PartialEq for Tri<V>

fn eq(&self, other: &Tri<V>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<V: Vary> Render<V> for Tri<usize>

type Clip = Tri<ClipVert<V>>

The type of this primitive in clip space

type Clips = [Tri<ClipVert<V>>]

The type for which Clip is implemented.

type Screen = Tri<Vertex<Point<[f32; 3], Real<3, Screen>>, V>>

The type of this primitive in screen space.

fn inline(ixd: Tri<usize>, vs: &[ClipVert<V>]) -> Tri<ClipVert<V>>

Maps the indexes of the argument to vertices.

fn depth(Tri: &Self::Clip) -> f32

Returns the (average) depth of the argument.

fn is_backface(tri: &Self::Screen) -> bool

Returns whether the argument is facing away from the camera.

fn to_screen(clip: Tri<ClipVert<V>>, tf: &Mat4x4<NdcToScreen>) -> Self::Screen

Transforms the argument from NDC to screen space.

fn rasterize<F: FnMut(Scanline<V>)>(scr: Self::Screen, scanline_fn: F)

Rasterizes the argument by calling the function for each scanline.

impl<V: Copy> Copy for Tri<V>

impl<V: Eq> Eq for Tri<V>

impl<V> StructuralPartialEq for Tri<V>