optimize blur and provide in place options

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "fimg"
-version = "0.4.26"
+version = "0.4.28"
 authors = ["bend-n <bend.n@outlook.com>"]
 license = "MIT"
 edition = "2021"
@@ -17,7 +17,7 @@ fontdue = { version = "0.7.3", optional = true }
 vecto = "0.1.0"
 umath = "0.0.7"
 fr = { version = "0.1.1", package = "fer", optional = true }
-stackblur-iter = { version = "0.2.0", features = ["simd"], optional = true }
+slur = { version = "0.1.0", optional = true }
 clipline = "0.1.1"
 minifb = { version = "0.25.0", default-features = false, features = [
     "x11",
@@ -56,7 +56,7 @@ harness = false
 scale = ["fr"]
 save = ["png"]
 text = ["fontdue"]
-blur = ["stackblur-iter"]
+blur = ["slur"]
 real-show = ["minifb", "text"]
 default = ["save", "scale"]
 

src/blur.rs

@@ -1,4 +1,11 @@
-use stackblur_iter::imgref::ImgRefMut;
+use slur::{
+    color::{u32xN, BlurU32},
+    imgref::ImgRefMut,
+};
+use std::{
+    ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign},
+    simd::Simd,
+};
 
 use crate::Image;
 
@@ -7,43 +14,156 @@ impl<T: AsMut<[u32]> + AsRef<[u32]>> Image<T, 1> {
     pub fn blur_argb(&mut self, radius: usize) {
         let w = self.width() as usize;
         let h = self.height() as usize;
-        stackblur_iter::simd_blur_argb::<4>(&mut ImgRefMut::new(self.buffer.as_mut(), w, h), radius)
+        slur::simd_blur_argb::<4>(&mut ImgRefMut::new(self.buffer.as_mut(), w, h), radius)
     }
 }
 
-impl<const N: usize> Image<Box<[u8]>, N>
-where
-    [u8; N]: crate::Pack,
-{
+macro_rules! simd {
+    ($n:literal) => {
+        impl<T: AsMut<[u8]> + AsRef<[u8]>> Image<T, $n> {
+            /// Blur a image.
+            pub fn blur_in(&mut self, radius: usize) {
+                let (w, h) = (self.width() as usize, self.height() as usize);
+                let px = self.flatten_mut();
+                slur::blur(
+                    &mut ImgRefMut::new(px, w, h),
+                    radius,
+                    |x| slur::color::u32xN(std::simd::Simd::from_array(x.map(|x| x as u32))),
+                    |x| x.0.to_array().map(|x| x as u8),
+                );
+            }
+        }
+    };
+}
+
+simd!(4);
+simd!(2);
+
+impl<T: AsMut<[u8]> + AsRef<[u8]>> Image<T, 3> {
     /// Blur a image.
     /// ```
     /// # use fimg::Image;
     /// let mut i = Image::alloc(300, 300).boxed();
+    /// // draw a trongle
+    /// i.poly((150., 150.), 3, 100.0, 0.0, [255, 255, 255]);
+    /// // give it some blur
+    /// i.blur_in(25);
+    /// ```
+    pub fn blur_in(&mut self, radius: usize) {
+        let (w, h) = (self.width() as usize, self.height() as usize);
+        let px = self.flatten_mut();
+        slur::blur(
+            &mut ImgRefMut::new(px, w, h),
+            radius,
+            |x| Px::from(*x),
+            |x| x.into(),
+        );
+    }
+}
+
+impl<T: AsMut<[u8]> + AsRef<[u8]>> Image<T, 1> {
+    /// Blur a image. No copy.
+    /// ```
+    /// # use fimg::Image;
+    /// let mut i = Image::alloc(300, 300);
     /// // draw a lil pentagon
     /// i.poly((150., 150.), 5, 100.0, 0.0, [255]);
     /// // give it some blur
     /// i.blur(25);
-    /// assert_eq!(include_bytes!("../tdata/blurred_pentagon.imgbuf"), i.bytes())
+    /// # assert_eq!(include_bytes!("../tdata/blurred_pentagon.imgbuf"), i.bytes())
     /// ```
     pub fn blur(&mut self, radius: usize) {
-        // you know, i optimized blurslice a fair bit, and yet, despite all the extra bit twiddling stackblur-iter is faster.
-        let mut argb = Image::<Box<[u32]>, 1>::from(self.as_ref());
-        argb.blur_argb(radius);
-        for (i, n) in crate::convert::unpack_all(&argb.buffer).enumerate() {
-            *unsafe { self.buffer.get_unchecked_mut(i) } = n;
-        }
+        let (w, h) = (self.width() as usize, self.height() as usize);
+        slur::simd_blur::<_, _, _, 8>(
+            &mut ImgRefMut::new(self.buffer.as_mut(), w, h),
+            radius,
+            |x| u32xN(Simd::from_array(x.map(|&x| x as u32))),
+            |x| x.0.as_array().map(|x| x as u8),
+            |&x| BlurU32(x as u32),
+            |x| x.0 as u8,
+        );
     }
 }
 
-impl<const N: usize> Image<&[u8], N>
-where
-    [u8; N]: crate::Pack,
-{
-    /// Blur a image.
-    pub fn blur(self, radius: usize) -> Image<Box<[u8]>, N> {
-        let mut argb = Image::<Box<[u32]>, 1>::from(self);
-        argb.blur_argb(radius);
-        // SAFETY: ctor
-        unsafe { Image::new(argb.width, argb.height, &**argb.buffer()) }.into()
+macro_rules! blur_packing {
+    ($n:literal) => {
+        impl<T: AsRef<[u8]> + AsMut<[u8]>> Image<T, $n> {
+            /// Blur a image. This will allocate a <code>[Image]<[Box]<[[u32]]>, 1></code>.
+            /// If you want no copy, but slower if you dont have a simd-able cpu, check out [`Image::blur_in`].
+            /// ```
+            /// # use fimg::Image;
+            /// let mut i = Image::alloc(300, 300);
+            /// // draw a sqar
+            /// i.poly((150., 150.), 4, 100.0, 0.0, [255]);
+            /// // give it some blur
+            /// i.blur(25);
+            /// ```
+            pub fn blur(&mut self, radius: usize) {
+                // the bit twiddling lets it simd better
+                let mut argb = Image::<Box<[u32]>, 1>::from(self.as_ref());
+                argb.blur_argb(radius);
+                for (i, n) in crate::convert::unpack_all::<$n>(&argb.buffer).enumerate() {
+                    *unsafe { self.buffer.as_mut().get_unchecked_mut(i) } = n;
+                }
+            }
+        }
+    };
+}
+blur_packing!(2);
+blur_packing!(3);
+blur_packing!(4);
+
+#[repr(transparent)]
+#[derive(Copy, Clone)]
+struct Px<const N: usize>([u32; N]);
+
+impl<const N: usize> Default for Px<N> {
+    fn default() -> Self {
+        Self([0; N])
     }
 }
+
+impl<const N: usize> From<[u8; N]> for Px<N> {
+    fn from(x: [u8; N]) -> Self {
+        Self(x.map(|x| x as u32))
+    }
+}
+
+impl<const N: usize> From<Px<N>> for [u8; N] {
+    fn from(v: Px<N>) -> Self {
+        v.0.map(|x| x as u8)
+    }
+}
+
+macro_rules! op {
+    ($name:ident, $as:ident, $fn:ident, $ass_fn:ident, $meth:ident) => {
+        impl<const N: usize> $name<usize> for Px<N> {
+            type Output = Px<N>;
+
+            fn $fn(self, rhs: usize) -> Self::Output {
+                Self(self.0.map(|x| x.$meth(rhs as u32)))
+            }
+        }
+
+        impl<const N: usize> $name for Px<N> {
+            type Output = Px<N>;
+            fn $fn(self, rhs: Px<N>) -> Self::Output {
+                let mut out = [0; N];
+                for ((a, b), x) in self.0.iter().zip(rhs.0.iter()).zip(out.iter_mut()) {
+                    *x = a.$meth(*b);
+                }
+                Self(out)
+            }
+        }
+
+        impl<const N: usize> $as for Px<N> {
+            fn $ass_fn(&mut self, rhs: Self) {
+                *self = self.$fn(rhs);
+            }
+        }
+    };
+}
+op!(Mul, MulAssign, mul, mul_assign, wrapping_mul);
+op!(Sub, SubAssign, sub, sub_assign, wrapping_sub);
+op!(Add, AddAssign, add, add_assign, wrapping_add);
+op!(Div, DivAssign, div, div_assign, wrapping_div);