bendns' repos / fimg
fast image operations
Diffstat
-rw-r--r--src/lib.rs30
1 files changed, 28 insertions, 2 deletions
diff --git a/src/lib.rs b/src/lib.rs
index fca08c8..355f4f0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -536,20 +536,46 @@ impl<T, const CHANNELS: usize> Image<T, CHANNELS> {
unsafe { *ptr }
}
+ /// Returns a [`PixelEntry`]
+ pub fn replace<U: Copy>(
+ &mut self,
+ x: u32,
+ y: u32,
+ f: impl FnOnce([U; CHANNELS]) -> [U; CHANNELS],
+ ) -> Option<[U; CHANNELS]>
+ where
+ T: AsRef<[U]> + AsMut<[U]>,
+ {
+ if x < self.width() && y < self.height() {
+ let x = unsafe { self.pixel_mut(x, y) };
+ let v = *x;
+ *x = f(v);
+ Some(v)
+ } else {
+ None
+ }
+ }
+
/// Return a mutable reference to a pixel at (x, y).
/// # Safety
///
/// - UB if x, y is out of bounds
/// - UB if buffer is too small
#[inline]
- pub unsafe fn pixel_mut<U: Copy>(&mut self, x: u32, y: u32) -> &mut [U]
+ pub unsafe fn pixel_mut<U: Copy>(&mut self, x: u32, y: u32) -> &mut [U; CHANNELS]
where
T: AsMut<[U]> + AsRef<[U]>,
{
// SAFETY: we have been told x, y is in bounds.
let idx = self.slice(x, y);
// SAFETY: slice should always return a valid index
- unsafe { self.buffer.as_mut().get_unchecked_mut(idx) }
+ unsafe {
+ self.buffer
+ .as_mut()
+ .get_unchecked_mut(idx)
+ .try_into()
+ .unwrap_unchecked()
+ }
}
/// iterator over columns