fast image operations
Diffstat (limited to 'src/overlay.rs')
| -rw-r--r-- | src/overlay.rs | 21 |
1 files changed, 4 insertions, 17 deletions
diff --git a/src/overlay.rs b/src/overlay.rs index 06b6c79..d85d384 100644 --- a/src/overlay.rs +++ b/src/overlay.rs @@ -1,7 +1,7 @@ //! Handles image overlay use crate::cloner::ImageCloner; -use super::{assert_unchecked, really_unsafe_index, Image}; +use super::{assert_unchecked, Image}; use std::ops::{Deref, DerefMut}; use std::simd::{simd_swizzle, Simd, SimdInt, SimdPartialOrd}; @@ -242,27 +242,14 @@ impl<T: DerefMut<Target = [u8]>, U: Deref<Target = [u8]>> OverlayAt<Image<U, 4>> /// /// # Safety /// - UB if x, y is out of bounds - /// - UB if x + with.width() > [`u32::MAX`] - /// - UB if y + with.height() > [`u32::MAX`] unsafe fn overlay_at(&mut self, with: &Image<U, 4>, x: u32, y: u32) -> &mut Self { for j in 0..with.height() { for i in 0..with.width() { // SAFETY: i, j is in bounds. - let index = unsafe { really_unsafe_index(i, j, with.width()) }; - // SAFETY: using .pixel() results in horrible asm (+5k ns/iter) - let their_px = unsafe { with.buffer.get_unchecked(index * 4..index * 4 + 4) }; - // SAFETY: must be sized right - if unsafe { *their_px.get_unchecked(3) } >= 128 { - // SAFETY: - // they said it cant go over. - // i dont know why, but this has performance importance™ - let x = unsafe { i.unchecked_add(x) }; - // SAFETY: caller gurantees this cannot overflow. - let y = unsafe { j.unchecked_add(y) }; - // SAFETY: compute the offset index. - let index = unsafe { really_unsafe_index(x, y, self.width()) }; + let their_px = unsafe { &with.pixel(i, j) }; + if their_px[3] >= 128 { // SAFETY: if everything else goes well, this is fine - let our_px = unsafe { self.buffer.get_unchecked_mut(index * 4..index * 4 + 4) }; + let our_px = unsafe { self.pixel_mut(i + x, j + y) }; our_px.copy_from_slice(their_px); } } |