bendns' repos / fimg
fast image operations
Diffstat (limited to 'src/pack.rs')
-rw-r--r--src/pack.rs55
1 files changed, 55 insertions, 0 deletions
diff --git a/src/pack.rs b/src/pack.rs
new file mode 100644
index 0000000..82d41bb
--- /dev/null
+++ b/src/pack.rs
@@ -0,0 +1,55 @@
+//! trait for packing pixels
+
+use crate::pixels::convert::{PFrom, RGB, RGBA, Y, YA};
+
+#[inline]
+pub const fn pack([r, g, b, a]: [u8; 4]) -> u32 {
+ ((a as u32) << 24) | ((r as u32) << 16) | ((g as u32) << 8) | (b as u32)
+}
+
+#[inline]
+pub const fn unpack(n: u32) -> [u8; 4] {
+ [
+ ((n >> 16) & 0xFF) as u8,
+ ((n >> 8) & 0xFF) as u8,
+ (n & 0xFF) as u8,
+ ((n >> 24) & 0xFF) as u8,
+ ]
+}
+
+/// packs and unpacks this pixel
+/// note that `unpack(pack(p))` may not equal `p`
+pub trait Pack<P = u32> {
+ /// pack this pixel
+ fn pack(&self) -> P;
+ /// unpacks this pixel
+ fn unpack(from: P) -> Self;
+}
+
+macro_rules! simple {
+ ($p:ident) => {
+ impl Pack for $p {
+ fn pack(&self) -> u32 {
+ pack(PFrom::pfrom(*self))
+ }
+
+ fn unpack(from: u32) -> $p {
+ PFrom::pfrom(unpack(from))
+ }
+ }
+ };
+}
+simple!(RGBA);
+simple!(RGB);
+simple!(YA);
+simple!(Y);
+
+impl Pack<u8> for Y {
+ fn pack(&self) -> u8 {
+ self[0]
+ }
+
+ fn unpack(from: u8) -> Self {
+ [from]
+ }
+}