Stop shrinking GIFs for now

Shrinking GIFs to PNGs removes all their animations, so optimally we'd
like to shrink them to GIFs and retain their animation. However it looks
like the image crate is brushing over too many properties of GIFs. This
makes it infeasible to do this without breaking GIFs. We could
eventually look into using the underlying gif crate directly. For now
we'll just not shrink GIFs at all.

Cargo.toml

@@ -84,7 +84,7 @@ tokio = { version = "0.2", features = ["macros"] }
 default = ["image-shrinking", "std"]
 doesnt-have-atomics = []
 std = ["byteorder", "chrono/std", "chrono/clock", "image", "indexmap", "livesplit-hotkey/std", "palette/std", "parking_lot", "quick-xml", "serde_json", "serde/std", "snafu/std", "utf-8"]
-more-image-formats = ["image/webp", "image/pnm", "image/ico", "image/jpeg", "image/gif", "image/tiff", "image/tga", "image/bmp", "image/hdr"]
+more-image-formats = ["image/webp", "image/pnm", "image/ico", "image/jpeg", "image/tiff", "image/tga", "image/bmp", "image/hdr"]
 image-shrinking = ["std", "bytemuck", "more-image-formats"]
 rendering = ["std", "more-image-formats", "euclid", "lyon", "rusttype", "smallvec"]
 software-rendering = ["rendering", "euc", "vek", "derive_more/mul"]

src/settings/image/shrinking.rs

@@ -1,6 +1,6 @@
 use alloc::borrow::Cow;
 use image::{
-    bmp, gif, guess_format, hdr, ico, jpeg, load_from_memory_with_format, png, pnm, tiff, webp,
+    bmp, guess_format, hdr, ico, jpeg, load_from_memory_with_format, png, pnm, tiff, webp,
     DynamicImage, GenericImageView, ImageDecoder, ImageError, ImageFormat,
 };
 use std::io::Cursor;
@@ -12,17 +12,21 @@ fn shrink_inner(data: &[u8], max_dim: u32) -> Result<Cow<'_, [u8]>, ImageError>
     let (width, height) = match format {
         ImageFormat::Png => png::PngDecoder::new(cursor)?.dimensions(),
         ImageFormat::Jpeg => jpeg::JpegDecoder::new(cursor)?.dimensions(),
-        ImageFormat::Gif => gif::GifDecoder::new(cursor)?.dimensions(),
         ImageFormat::WebP => webp::WebPDecoder::new(cursor)?.dimensions(),
         ImageFormat::Tiff => tiff::TiffDecoder::new(cursor)?.dimensions(),
         ImageFormat::Bmp => bmp::BmpDecoder::new(cursor)?.dimensions(),
         ImageFormat::Ico => ico::IcoDecoder::new(cursor)?.dimensions(),
         ImageFormat::Hdr => hdr::HDRAdapter::new(cursor)?.dimensions(),
         ImageFormat::Pnm => pnm::PnmDecoder::new(cursor)?.dimensions(),
+        // FIXME: For GIF we would need to properly shrink the whole animation.
+        // The image crate can't properly handle this at this point in time.
+        // Some properties are not translated over properly it seems. We could
+        // shrink GIFs that are a single frame, but we also can't tell how many
+        // frames there are.
         // TGA doesn't have a Header.
         // DDS isn't a format we really care for.
         // And the image format is non-exhaustive.
-        ImageFormat::Tga | ImageFormat::Dds | _ => return Ok(data.into()),
+        ImageFormat::Gif | ImageFormat::Tga | ImageFormat::Dds | _ => return Ok(data.into()),
     };
 
     let is_too_large = width > max_dim || height > max_dim;