quest – Rust: Vector math

Game Dev Advanced

21 Vector math

Every engine leans on a small vector type. Here you give a Vec2 the two operations everything else builds on, then use them to advance a body one physics step.

Step 2 / 2

Implement one semi-implicit Euler step: apply gravity to the velocity, then move the position by the new velocity. Return (pos, vel).

Hints

Update velocity first: v += gravity * dt, then pos += v * dt.
Do it component by component; there is no operator overload here.

21_vec_math.rs

#[derive(Clone, Copy, PartialEq, Debug)]
struct Vec2 { x: f32, y: f32 }

// v += gravity*dt; then pos += v*dt. Return (new_pos, new_vel).
fn step(pos: Vec2, vel: Vec2, gravity: Vec2, dt: f32) -> (Vec2, Vec2) {
    todo!()
}

Reset to starterCompiled in a sandbox; hidden checks must pass.

Reveal solution

#[derive(Clone, Copy, PartialEq, Debug)]
struct Vec2 { x: f32, y: f32 }

fn step(pos: Vec2, vel: Vec2, gravity: Vec2, dt: f32) -> (Vec2, Vec2) {
    let nv = Vec2 { x: vel.x + gravity.x * dt, y: vel.y + gravity.y * dt };
    let np = Vec2 { x: pos.x + nv.x * dt, y: pos.y + nv.y * dt };
    (np, nv)
}