Struct Perspective 

pub struct Perspective { /* private fields */ }

Rotates the plane z = 0 about a pivot and projects it onto the viewport.

The camera sits distance units in front of the plane on the z axis, looking toward the plane, and the pivot stays fixed on screen. Rotations apply in the order z (in-plane), y, then x, in radians. Positive rotation_x swings the bottom edge toward the viewer, and positive rotation_y swings the left edge toward the viewer. A point at depth z scales by distance / (distance - z).

Clipping is explicit: a point closer than a thousandth of distance to the camera plane, or behind it, is an error rather than being clipped or wrapped. A plane seen from behind remains drawable (mirrored); Self::faces_camera reports the side so callers can hide it. Only geometry is projected, so the result renders identically on the CPU and GPU backends.

use motion_core::{Perspective, Point};
let tilt = Perspective::new(Point::new(100.0, 100.0), 0.0, 0.5, 0.0, 800.0)?;
let near = tilt.project(Point::new(0.0, 100.0))?;
let far = tilt.project(Point::new(200.0, 100.0))?;
assert!(100.0 - near.x > far.x - 100.0);
assert!(tilt.faces_camera());

Implementations

impl Perspective

pub fn new( pivot: Point, rotation_x: f64, rotation_y: f64, rotation_z: f64, distance: f64, ) -> Result<Self, ValidationError>

Creates a projection; angles are finite radians and distance is finite and positive.

pub fn pivot(&self) -> Point

The fixed point of the projection.

pub fn rotation(&self) -> [f64; 3]

Rotation angles about the x, y and z axes, in radians.

pub fn distance(&self) -> f64

Camera distance from the plane, in the same units as path coordinates.

pub fn faces_camera(&self) -> bool

Whether the rotated plane’s front side points toward the camera.

pub fn project(&self, point: Point) -> Result<Point, ValidationError>

Projects one plane point, failing when it reaches the camera plane.

pub fn project_path( &self, path: &Path2D, pieces: u32, ) -> Result<Path2D, ValidationError>

Projects every verb of a path; each curve becomes pieces cubics whose controls are projected, which approximates the exact rational curve.

Lines stay lines, because projection preserves straight edges. Fails when pieces is outside 1..=MAX_PERSPECTIVE_CURVE_PIECES, a point reaches the camera plane, or the result exceeds the path verb limit.

Trait Implementations

impl Clone for Perspective

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Perspective

impl Debug for Perspective

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

Formats the value using the given formatter.

impl PartialEq for Perspective

fn eq(&self, other: &Self) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Perspective