bendns' repos / fimg
fast image operations
Diffstat (limited to 'src/lib.rs')
-rw-r--r--src/lib.rs24
1 files changed, 24 insertions, 0 deletions
diff --git a/src/lib.rs b/src/lib.rs
index e72ea42..9de0643 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -29,6 +29,7 @@ mod affine;
pub mod builder;
mod drawing;
mod overlay;
+pub mod scale;
pub use overlay::{Overlay, OverlayAt};
/// like assert!(), but causes undefined behaviour at runtime when the condition is not met.
@@ -361,6 +362,29 @@ macro_rules! save {
};
}
+impl<const CHANNELS: usize> Image<Vec<u8>, CHANNELS> {
+ #[cfg(feature = "save")]
+ /// Open a PNG image
+ pub fn open(f: impl AsRef<std::path::Path>) -> Self {
+ let p = std::fs::File::open(f).unwrap();
+ let r = std::io::BufReader::new(p);
+ let dec = png::Decoder::new(r);
+ let mut reader = dec.read_info().unwrap();
+ let mut buf = vec![0; reader.output_buffer_size()];
+ let info = reader.next_frame(&mut buf).unwrap();
+ use png::ColorType::*;
+ match info.color_type {
+ Indexed | Grayscale => {
+ assert_eq!(CHANNELS, 1, "indexed | grayscale requires one channel")
+ }
+ Rgb => assert_eq!(CHANNELS, 3, "rgb requires three channels"),
+ Rgba => assert_eq!(CHANNELS, 4, "rgba requires four channels"),
+ GrayscaleAlpha => assert_eq!(CHANNELS, 2, "ya requires two channels"),
+ }
+ Self::build(info.width, info.height).buf(buf)
+ }
+}
+
save!(3 == Rgb("RGB"));
save!(4 == Rgba("RGBA"));
save!(2 == GrayscaleAlpha("YA"));