improve image mime type guessing

unavi-xyz · Feb 23, 2024 · 898462c · 898462c
1 parent 7829921
commit 898462c
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Showing 2 changed files with 41 additions and 8 deletions.
diff --git a/bevy_gltf_kun/src/import/gltf/image.rs b/bevy_gltf_kun/src/import/gltf/image.rs
@@ -26,8 +26,6 @@ use super::document::ImportContext;
 pub enum ImageImportError {
     #[error("Failed to load texture: {0}")]
     Texture(#[from] TextureError),
-    #[error("Missing mime type")]
-    MissingMimeType,
 }
 
 pub fn import_images<E: BevyImportExtensions<GltfDocument>>(
@@ -94,14 +92,27 @@ pub fn load_texture(
 
     let image_weight = image.get(context.graph);
     let supported_compressed_formats = CompressedImageFormats::default();
-    let mime_type = image_weight
-        .mime_type
-        .as_deref()
-        .ok_or(ImageImportError::MissingMimeType)?;
+
+    let image_type = match image_weight.mime_type.as_deref() {
+        Some(mime_type) => ImageType::MimeType(mime_type),
+        None => match &image_weight.uri {
+            Some(uri) => match uri.split('.').last() {
+                Some(ext) => ImageType::Extension(ext),
+                None => {
+                    warn!("No extension found for image uri, defaulting to image/png.");
+                    ImageType::MimeType("image/png")
+                }
+            },
+            None => {
+                warn!("No mime type or uri found for image, defaulting to image/png.");
+                ImageType::MimeType("image/png")
+            }
+        },
+    };
 
     let texture = Image::from_buffer(
         &image_weight.data,
-        ImageType::MimeType(mime_type),
+        image_type,
         supported_compressed_formats,
         is_srgb,
         ImageSampler::Descriptor(sampler_descriptor),

diff --git a/gltf_kun/src/io/format/gltf/import.rs b/gltf_kun/src/io/format/gltf/import.rs
@@ -144,10 +144,14 @@ pub async fn import(
         weight.name = img.name.clone();
         weight.extras = img.extras.clone();
         weight.mime_type = img.mime_type.clone().map(|m| m.0);
-
         if let Some(uri) = img.uri.as_ref() {
             weight.uri = img.uri.clone();
 
+            // If no mime type, guess from the URI
+            if weight.mime_type.is_none() {
+                weight.mime_type = guess_mime_type(uri).map(|s| s.to_string())
+            }
+
             if let Some(resolver) = resolver {
                 if let Ok(data) = resolver.resolve(uri).await {
                     debug!("Resolved image: {} ({} bytes)", uri, data.len());
@@ -470,6 +474,24 @@ fn import_texture_info(
     texture_info
 }
 
+fn guess_mime_type(uri: &str) -> Option<&'static str> {
+    if uri.ends_with(".png") {
+        Some("image/png")
+    } else if uri.ends_with(".jpg") || uri.ends_with(".jpeg") {
+        Some("image/jpeg")
+    } else if uri.ends_with(".gif") {
+        Some("image/gif")
+    } else if uri.ends_with(".bmp") {
+        Some("image/bmp")
+    } else if uri.ends_with(".tiff") {
+        Some("image/tiff")
+    } else if uri.ends_with(".webp") {
+        Some("image/webp")
+    } else {
+        None
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use gltf::json::{self, texture::Info, validation::USize64, Index};