46 lines
1 KiB
Rust
46 lines
1 KiB
Rust
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/// Returns a vector's magnitude
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fn magnitude<const DIM: usize>(vec: &[f32; DIM]) -> f32 {
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let mut a = 0.;
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for x in vec {
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a += x * x;
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}
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a
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}
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/// Normalizes a vector
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pub fn normalize<const DIM: usize>(mut vec: [f32; DIM]) -> [f32; DIM] {
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let mag = magnitude(&vec);
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for x in &mut vec {
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*x /= mag;
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}
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vec
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}
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/// Advances position
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/// Deals with bounces on the box
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/// Returns an array of bools, one per dimension, where true indicates a collision in that dim
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pub fn advance<const DIM: usize>(
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speed: f32,
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position: &mut [f32; DIM],
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velocity: &mut [f32; DIM],
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) -> [bool; DIM] {
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let mut res = [false; DIM];
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for (i, (x, v)) in position.iter_mut().zip(velocity.iter_mut()).enumerate() {
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// Advance position in this axis
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*x += *v * speed;
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// If we're out of bounds in this coordinate, change velocity
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if x.abs() > 1.0 {
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*v = -*v;
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// Mark as collision
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res[i] = true;
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}
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}
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res
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}
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