Move SUPPORTED_FILE_EXTENSIONS to ImageLoader and remove unsupported formats. (#15917)

# Objective

Fixes #15730.

## Solution

As part of #15586, we made a constant to store all the supported image
formats. However since the `ImageFormat` does actually include Hdr and
OpenExr, it also included the `"hdr"` and `"exr"` file extensions. These
are supported by separate loaders though: `HdrTextureLoader` and
`ExrTextureLoader`. This led to a warning about duplicate asset loaders.

Therefore, instead of having the constant for `ImageFormat`, I made the
constant just for `ImageLoader`. This lets us correctly remove `"hdr"`
and `"exr"` from the image formats supported by `ImageLoader`, returning
us to having a single asset loader for every image format.

Note: we could have just removed `hdr` and `exr` from
`ImageFormat::SUPPORTED_FILE_EXTENSIONS`, but this would be very
confusing. Then the list of `ImageFormat`s would not match the list of
supported formats!

## Testing

- I ran the `sprite` example and got no warning! I also replaced the
sprite in that example with an HDR file and everything worked as
expected.

crates/bevy_image/src/image.rs

@@ -78,147 +78,6 @@ macro_rules! feature_gate {
 }
 
 impl ImageFormat {
-    /// Number of image formats, used for computing other constants.
-    const COUNT: usize = {
-        let mut count = 0;
-        #[cfg(feature = "avif")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "basis-universal")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "bmp")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "dds")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "ff")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "gif")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "exr")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "hdr")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "ico")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "jpeg")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "ktx2")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "pnm")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "png")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "qoi")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "tga")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "tiff")]
-        {
-            count += 1;
-        }
-        #[cfg(feature = "webp")]
-        {
-            count += 1;
-        }
-        count
-    };
-
-    /// Full list of supported formats.
-    pub const SUPPORTED: &'static [ImageFormat] = &[
-        #[cfg(feature = "avif")]
-        ImageFormat::Avif,
-        #[cfg(feature = "basis-universal")]
-        ImageFormat::Basis,
-        #[cfg(feature = "bmp")]
-        ImageFormat::Bmp,
-        #[cfg(feature = "dds")]
-        ImageFormat::Dds,
-        #[cfg(feature = "ff")]
-        ImageFormat::Farbfeld,
-        #[cfg(feature = "gif")]
-        ImageFormat::Gif,
-        #[cfg(feature = "exr")]
-        ImageFormat::OpenExr,
-        #[cfg(feature = "hdr")]
-        ImageFormat::Hdr,
-        #[cfg(feature = "ico")]
-        ImageFormat::Ico,
-        #[cfg(feature = "jpeg")]
-        ImageFormat::Jpeg,
-        #[cfg(feature = "ktx2")]
-        ImageFormat::Ktx2,
-        #[cfg(feature = "png")]
-        ImageFormat::Png,
-        #[cfg(feature = "pnm")]
-        ImageFormat::Pnm,
-        #[cfg(feature = "qoi")]
-        ImageFormat::Qoi,
-        #[cfg(feature = "tga")]
-        ImageFormat::Tga,
-        #[cfg(feature = "tiff")]
-        ImageFormat::Tiff,
-        #[cfg(feature = "webp")]
-        ImageFormat::WebP,
-    ];
-
-    /// Total count of file extensions, for computing supported file extensions list.
-    const COUNT_FILE_EXTENSIONS: usize = {
-        let mut count = 0;
-        let mut idx = 0;
-        while idx < ImageFormat::COUNT {
-            count += ImageFormat::SUPPORTED[idx].to_file_extensions().len();
-            idx += 1;
-        }
-        count
-    };
-
-    /// Gets the list of file extensions for all formats.
-    pub const SUPPORTED_FILE_EXTENSIONS: &'static [&'static str] = &{
-        let mut exts = [""; ImageFormat::COUNT_FILE_EXTENSIONS];
-        let mut ext_idx = 0;
-        let mut fmt_idx = 0;
-        while fmt_idx < ImageFormat::COUNT {
-            let mut off = 0;
-            let fmt_exts = ImageFormat::SUPPORTED[fmt_idx].to_file_extensions();
-            while off < fmt_exts.len() {
-                exts[ext_idx] = fmt_exts[off];
-                off += 1;
-                ext_idx += 1;
-            }
-            fmt_idx += 1;
-        }
-        exts
-    };
-
     /// Gets the file extensions for a given format.
     pub const fn to_file_extensions(&self) -> &'static [&'static str] {
         match self {

crates/bevy_image/src/image_loader.rs

@@ -12,6 +12,135 @@ pub struct ImageLoader {
 }
 
 impl ImageLoader {
+    /// Number of image formats, used for computing other constants.
+    const COUNT: usize = {
+        let mut count = 0;
+        #[cfg(feature = "avif")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "basis-universal")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "bmp")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "dds")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "ff")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "gif")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "ico")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "jpeg")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "ktx2")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "pnm")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "png")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "qoi")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "tga")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "tiff")]
+        {
+            count += 1;
+        }
+        #[cfg(feature = "webp")]
+        {
+            count += 1;
+        }
+        count
+    };
+
+    /// Full list of supported formats.
+    pub const SUPPORTED_FORMATS: &'static [ImageFormat] = &[
+        #[cfg(feature = "avif")]
+        ImageFormat::Avif,
+        #[cfg(feature = "basis-universal")]
+        ImageFormat::Basis,
+        #[cfg(feature = "bmp")]
+        ImageFormat::Bmp,
+        #[cfg(feature = "dds")]
+        ImageFormat::Dds,
+        #[cfg(feature = "ff")]
+        ImageFormat::Farbfeld,
+        #[cfg(feature = "gif")]
+        ImageFormat::Gif,
+        #[cfg(feature = "ico")]
+        ImageFormat::Ico,
+        #[cfg(feature = "jpeg")]
+        ImageFormat::Jpeg,
+        #[cfg(feature = "ktx2")]
+        ImageFormat::Ktx2,
+        #[cfg(feature = "png")]
+        ImageFormat::Png,
+        #[cfg(feature = "pnm")]
+        ImageFormat::Pnm,
+        #[cfg(feature = "qoi")]
+        ImageFormat::Qoi,
+        #[cfg(feature = "tga")]
+        ImageFormat::Tga,
+        #[cfg(feature = "tiff")]
+        ImageFormat::Tiff,
+        #[cfg(feature = "webp")]
+        ImageFormat::WebP,
+    ];
+
+    /// Total count of file extensions, for computing supported file extensions list.
+    const COUNT_FILE_EXTENSIONS: usize = {
+        let mut count = 0;
+        let mut idx = 0;
+        while idx < Self::COUNT {
+            count += Self::SUPPORTED_FORMATS[idx].to_file_extensions().len();
+            idx += 1;
+        }
+        count
+    };
+
+    /// Gets the list of file extensions for all formats.
+    pub const SUPPORTED_FILE_EXTENSIONS: &'static [&'static str] = &{
+        let mut exts = [""; Self::COUNT_FILE_EXTENSIONS];
+        let mut ext_idx = 0;
+        let mut fmt_idx = 0;
+        while fmt_idx < Self::COUNT {
+            let mut off = 0;
+            let fmt_exts = Self::SUPPORTED_FORMATS[fmt_idx].to_file_extensions();
+            while off < fmt_exts.len() {
+                exts[ext_idx] = fmt_exts[off];
+                off += 1;
+                ext_idx += 1;
+            }
+            fmt_idx += 1;
+        }
+        exts
+    };
+
     /// Creates a new image loader that supports the provided formats.
     pub fn new(supported_compressed_formats: CompressedImageFormats) -> Self {
         Self {
@@ -105,7 +234,7 @@ impl AssetLoader for ImageLoader {
     }
 
     fn extensions(&self) -> &[&str] {
-        ImageFormat::SUPPORTED_FILE_EXTENSIONS
+        Self::SUPPORTED_FILE_EXTENSIONS
     }
 }
 

crates/bevy_render/src/texture/mod.rs

@@ -111,13 +111,13 @@ impl Plugin for ImagePlugin {
             );
         }
 
-        if !ImageFormat::SUPPORTED_FILE_EXTENSIONS.is_empty() {
+        if !ImageLoader::SUPPORTED_FILE_EXTENSIONS.is_empty() {
-            app.preregister_asset_loader::<ImageLoader>(ImageFormat::SUPPORTED_FILE_EXTENSIONS);
+            app.preregister_asset_loader::<ImageLoader>(ImageLoader::SUPPORTED_FILE_EXTENSIONS);
         }
     }
 
     fn finish(&self, app: &mut App) {
-        if !ImageFormat::SUPPORTED.is_empty() {
+        if !ImageLoader::SUPPORTED_FORMATS.is_empty() {
             let supported_compressed_formats = match app.world().get_resource::<RenderDevice>() {
                 Some(render_device) => {
                     CompressedImageFormats::from_features(render_device.features())