51 lines
1.5 KiB
Rust
51 lines
1.5 KiB
Rust
use anyhow::Result;
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use rtchallenge::{
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canvas::Canvas,
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float::consts::PI,
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matrices::Matrix4x4,
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tuples::{Color, Tuple},
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Float,
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};
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fn draw_dot(c: &mut Canvas, x: usize, y: usize) {
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let red = Color::new(1., 0., 0.);
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c.set(x.saturating_sub(1), y.saturating_sub(1), red);
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c.set(x, y.saturating_sub(1), red);
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c.set(x + 1, y.saturating_sub(1), red);
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c.set(x.saturating_sub(1), y, red);
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c.set(x, y, red);
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c.set(x + 1, y, red);
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c.set(x.saturating_sub(1), y + 1, red);
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c.set(x, y + 1, red);
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c.set(x + 1, y + 1, red);
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}
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fn main() -> Result<()> {
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let w = 200;
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let h = w;
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let bg = Color::new(0.2, 0.2, 0.2);
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let mut c = Canvas::new(w, h, bg);
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let t = Matrix4x4::translation(0., 0.4, 0.);
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let p = Tuple::point(0., 0., 0.);
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let rot_hour = Matrix4x4::rotation_z(-PI / 6.);
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let mut p = t * p;
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let w = w as Float;
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let h = h as Float;
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// The 'world' exists between -0.5 - 0.5 in X-Y plane.
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// To convert to screen space, we translate by 0.5, scale to canvas size,
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// and invert the Y-axis.
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let world_to_screen =
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Matrix4x4::scaling(w as Float, -h as Float, 1.0) * Matrix4x4::translation(0.5, -0.5, 0.);
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for _ in 0..12 {
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let canvas_pixel = world_to_screen * p;
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draw_dot(&mut c, canvas_pixel.x as usize, canvas_pixel.y as usize);
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p = rot_hour * p;
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}
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let path = "/tmp/eoc4.png";
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println!("saving output to {}", path);
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c.write_to_file(path)?;
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Ok(())
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}
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