declare_tween!(
pub struct Linear;
pub fn linear;
pub fn linear_at;
pub fn tween<Value: crate::TweenValue>(&mut self, value_delta: Value, percent: f32) -> Value {
value_delta.scale(percent)
}
);
#[cfg(test)]
mod tests {
use super::Linear;
use approx::assert_ulps_eq;
#[test]
fn linear_over_frames() {
let mut value;
let mut tweener = crate::Tweener::new(0.0, 100.0, 10, Linear);
for val in 1..=10 {
value = tweener.move_to(val);
assert_ulps_eq!(value, val as f32 * 10.0);
}
}
#[test]
fn linear_over_frames_rev() {
let mut value;
let mut tweener = crate::Tweener::new(100.0, 0.0, 10, Linear);
for val in 1..=10 {
value = tweener.move_to(val);
assert_ulps_eq!(value, 100.0 - val as f32 * 10.0);
}
}
}