library: core: add Film implementation

This commit is contained in:
Bruno BELANYI 2020-03-17 13:41:44 +01:00
parent 8d6d4cf7d7
commit a4caa456ce
2 changed files with 156 additions and 0 deletions

153
src/core/film.rs Normal file
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use super::super::{Point, Vector};
/// Represent an abstract camera film, to know where each pixel is in space.
#[derive(Debug, PartialEq)]
pub struct Film {
x: u32,
y: u32,
center: Point,
ratio_up: Vector,
ratio_right: Vector,
}
impl Film {
pub fn new(x: u32, y: u32, screen_size: f32, center: Point, up: Vector, right: Vector) -> Self {
let (x_size, y_size) = if x > y {
(screen_size, screen_size * y as f32 / x as f32)
} else {
(screen_size * x as f32 / y as f32, screen_size)
};
Film {
x,
y,
center,
ratio_up: up.normalize() * x_size,
ratio_right: right.normalize() * y_size,
}
}
pub fn pixel_ratio(&self, x: u32, y: u32) -> (f32, f32) {
(x as f32 / self.x as f32, y as f32 / self.y as f32)
}
pub fn pixel_at_ratio(&self, x: f32, y: f32) -> Point {
let delt_x = x - 0.5;
let delt_y = 0.5 - y;
self.center + self.ratio_right * delt_x + self.ratio_up * delt_y
}
pub fn pixel_at_coord(&self, x: u32, y: u32) -> Point {
let (x, y) = self.pixel_ratio(x, y);
self.pixel_at_ratio(x, y)
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn simple_new_works() {
let film = Film::new(
1080,
1080,
1.,
Point::origin(),
Vector::new(0., 1., 0.),
Vector::new(0., 0., 1.),
);
assert_eq!(
film,
Film {
x: 1080,
y: 1080,
center: Point::origin(),
ratio_up: Vector::new(0., 1., 0.),
ratio_right: Vector::new(0., 0., 1.),
}
)
}
#[test]
fn new_with_smaller_x_works() {
let film = Film::new(
1080,
1440,
1.,
Point::origin(),
Vector::new(0., 1., 0.),
Vector::new(0., 0., 1.),
);
assert_eq!(
film,
Film {
x: 1080,
y: 1440,
center: Point::origin(),
ratio_up: Vector::new(0., 0.75, 0.),
ratio_right: Vector::new(0., 0., 1.),
}
)
}
#[test]
fn new_with_smaller_y_works() {
let film = Film::new(
1080,
540,
1.,
Point::origin(),
Vector::new(0., 1., 0.),
Vector::new(0., 0., 1.),
);
assert_eq!(
film,
Film {
x: 1080,
y: 540,
center: Point::origin(),
ratio_up: Vector::new(0., 1., 0.),
ratio_right: Vector::new(0., 0., 0.5),
}
)
}
fn simple_film() -> Film {
Film::new(
1080,
1080,
1.,
Point::origin(),
Vector::new(0., 1., 0.),
Vector::new(0., 0., 1.),
)
}
#[test]
fn pixel_ratio_works() {
let film = simple_film();
assert_eq!(film.pixel_ratio(0, 0), (0., 0.));
assert_eq!(film.pixel_ratio(1080, 1080), (1., 1.));
assert_eq!(film.pixel_ratio(1080, 540), (1., 0.5));
assert_eq!(film.pixel_ratio(540, 1080), (0.5, 1.));
assert_eq!(film.pixel_ratio(1080, 810), (1., 0.75));
assert_eq!(film.pixel_ratio(810, 1080), (0.75, 1.))
}
#[test]
fn pixel_at_ratio_works() {
let film = simple_film();
assert_eq!(film.pixel_at_ratio(0., 0.), Point::new(0., 0.5, -0.5));
assert_eq!(film.pixel_at_ratio(1., 1.), Point::new(0., -0.5, 0.5));
assert_eq!(film.pixel_at_ratio(1., 0.5), Point::new(0., 0., 0.5));
assert_eq!(film.pixel_at_ratio(0.5, 1.), Point::new(0., -0.5, 0.));
}
#[test]
fn pixel_at_coord_works() {
let film = simple_film();
assert_eq!(film.pixel_at_coord(0, 0), Point::new(0., 0.5, -0.5));
assert_eq!(film.pixel_at_coord(1080, 1080), Point::new(0., -0.5, 0.5));
assert_eq!(film.pixel_at_coord(1080, 540), Point::new(0., 0., 0.5));
assert_eq!(film.pixel_at_coord(540, 1080), Point::new(0., -0.5, 0.));
}
}

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pub mod color; pub mod color;
pub use color::*; pub use color::*;
pub mod film;
pub use film::*;