use super::{really_unsafe_index, unsafe_assert, Image, Overlay, OverlayAt};
use std::simd::SimdInt;
use std::simd::SimdPartialOrd;
use std::simd::{simd_swizzle, Simd};
#[inline]
pub unsafe fn blit(rgb: &mut [u8], rgba: &[u8]) {
const LAST4: Simd<u8, 16> = Simd::from_array([
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 0, 0, 0, 0,
]);
let mut srci = 0;
let mut dsti = 0;
while dsti + 16 <= rgb.len() {
let old: Simd<u8, 16> = Simd::from_slice(rgb.get_unchecked(dsti..dsti + 16));
let new: Simd<u8, 16> = Simd::from_slice(rgba.get_unchecked(srci..srci + 16));
let threshold = new.simd_ge(Simd::splat(128)).to_int().cast::<u8>();
let mut mask = simd_swizzle!(
threshold,
[3, 3, 3, 7, 7, 7, 11, 11, 11, 15, 15, 15, 0, 0, 0, 0]
);
mask &= LAST4;
let new_rgb = simd_swizzle!(new, [0, 1, 2, 4, 5, 6, 8, 9, 10, 12, 13, 14, 0, 0, 0, 0]);
let blended = (new_rgb & mask) | (old & !mask);
blended.copy_to_slice(rgb.get_unchecked_mut(dsti..dsti + 16));
srci += 16;
dsti += 12;
}
while dsti + 3 <= rgb.len() {
if *rgba.get_unchecked(srci + 3) >= 128 {
std::ptr::copy_nonoverlapping(
rgba.get_unchecked(srci..srci + 3).as_ptr(),
rgb.get_unchecked_mut(dsti..dsti + 3).as_mut_ptr(),
3,
);
}
srci += 4;
dsti += 3;
}
}
impl OverlayAt<Image<&[u8], 4>> for Image<&mut [u8], 3> {
unsafe fn overlay_at(&mut self, with: &Image<&[u8], 4>, x: u32, y: u32) -> &mut Self {
unsafe_assert!(x + with.width() <= self.width());
unsafe_assert!(y + with.height() <= self.height());
for j in 0..with.height() {
let i_x = j as usize * with.width() as usize * 4
..(j as usize + 1) * with.width() as usize * 4;
let o_x = ((j as usize + y as usize) * self.width() as usize + x as usize) * 3
..((j as usize + y as usize) * self.width() as usize
+ x as usize
+ with.width() as usize)
* 3;
blit(
self.buffer.get_unchecked_mut(o_x),
with.buffer.get_unchecked(i_x),
)
}
self
}
}
impl Overlay<Image<&[u8], 4>> for Image<&mut [u8], 3> {
unsafe fn overlay(&mut self, with: &Image<&[u8], 4>) -> &mut Self {
unsafe_assert!(self.width() == with.width());
unsafe_assert!(self.height() == with.height());
for (i, chunk) in with
.buffer
.chunks_exact(with.width() as usize * 4)
.enumerate()
{
blit(
self.buffer.get_unchecked_mut(
i * with.width() as usize * 3..(i + 1) * with.width() as usize * 3,
),
chunk,
);
}
self
}
}
impl OverlayAt<Image<&[u8], 4>> for Image<&mut [u8], 4> {
unsafe fn overlay_at(&mut self, with: &Image<&[u8], 4>, x: u32, y: u32) -> &mut Self {
for j in 0..with.height() {
for i in 0..with.width() {
let with_index = really_unsafe_index(i, j, with.width()).unchecked_mul(4);
let their_px = with
.buffer
.get_unchecked(with_index..with_index.unchecked_add(4));
if *their_px.get_unchecked(3) >= 128 {
let our_index =
really_unsafe_index(i.unchecked_add(x), j.unchecked_add(y), self.width())
.unchecked_mul(4);
let our_px = self
.buffer
.get_unchecked_mut(our_index..our_index.unchecked_add(4));
std::ptr::copy_nonoverlapping(their_px.as_ptr(), our_px.as_mut_ptr(), 4);
}
}
}
self
}
}