bendns' repos / fimg
fast image operations
Diffstat (limited to 'src/convert.rs')
-rw-r--r--src/convert.rs64
1 files changed, 64 insertions, 0 deletions
diff --git a/src/convert.rs b/src/convert.rs
new file mode 100644
index 0000000..5704f26
--- /dev/null
+++ b/src/convert.rs
@@ -0,0 +1,64 @@
+//! define From's for images.
+//! these conversions are defined by [`PFrom`].
+use crate::{pixels::convert::PFrom, Image};
+
+fn map<const A: usize, const B: usize>(image: Image<&[u8], A>) -> Image<Box<[u8]>, B>
+where
+ [u8; B]: PFrom<A>,
+{
+ let buffer = image
+ .chunked()
+ .copied()
+ .flat_map(<[u8; B] as PFrom<A>>::pfrom)
+ .collect::<Vec<_>>()
+ .into();
+ // SAFETY: ctor
+ unsafe { Image::new(image.width, image.height, buffer) }
+}
+
+macro_rules! convert {
+ ($a:literal => $b:literal) => {
+ impl From<Image<&[u8], $b>> for Image<Box<[u8]>, $a> {
+ fn from(value: Image<&[u8], $b>) -> Self {
+ map(value)
+ }
+ }
+ };
+}
+
+macro_rules! cv {
+ [$($n:literal),+] => {
+ $(convert!($n => 1);
+ convert!($n => 2);
+ convert!($n => 3);
+ convert!($n => 4);)+
+ };
+}
+
+cv![1, 2, 3, 4];
+
+macro_rules! boxconv {
+ ($a:literal => $b: literal) => {
+ impl From<Image<Box<[u8]>, $b>> for Image<Box<[u8]>, $a> {
+ fn from(value: Image<Box<[u8]>, $b>) -> Self {
+ value.as_ref().into()
+ }
+ }
+ };
+}
+
+boxconv!(1 => 2);
+boxconv!(1 => 3);
+boxconv!(1 => 4);
+
+boxconv!(2 => 1);
+boxconv!(2 => 3);
+boxconv!(2 => 4);
+
+boxconv!(3 => 1);
+boxconv!(3 => 2);
+boxconv!(3 => 4);
+
+boxconv!(4 => 1);
+boxconv!(4 => 2);
+boxconv!(4 => 3);