core: Add `Bitmap::to_rgba`

core/src/backend/render.rs

@@ -247,6 +247,19 @@ impl Bitmap {
         }
     }
 
+    pub fn to_rgba(mut self) -> Self {
+        // Converts this bitmap to RGBA, if it is not already.
+        if self.format == BitmapFormat::Rgb {
+            self.data = self
+                .data
+                .chunks_exact(3)
+                .flat_map(|rgb| [rgb[0], rgb[1], rgb[2], 255])
+                .collect();
+            self.format = BitmapFormat::Rgba;
+        }
+        self
+    }
+
     #[inline]
     pub fn width(&self) -> u32 {
         self.width

render/canvas/src/lib.rs

@@ -374,38 +374,15 @@ impl WebCanvasRenderBackend {
 
     /// Puts the contents of the given Bitmap into an ImageData on the browser side,
     /// doing the RGB to RGBA expansion if needed.
-    fn swf_bitmap_to_js_imagedata(bitmap: &mut Bitmap) -> ImageData {
-        match &bitmap.format() {
-            BitmapFormat::Rgb => {
-                let mut rgba_data =
-                    Vec::with_capacity(bitmap.width() as usize * bitmap.height() as usize * 4);
-                for rgb in bitmap.data().chunks_exact(3) {
-                    rgba_data.extend_from_slice(rgb);
-                    rgba_data.push(255);
-                }
-                *bitmap = Bitmap::from_data(
-                    bitmap.width(),
-                    bitmap.height(),
-                    BitmapFormat::Rgba,
-                    rgba_data,
-                );
-                let image_data =
-                    ImageData::new_with_u8_clamped_array(Clamped(bitmap.data()), bitmap.width())
-                        .unwrap();
-                image_data
-            }
-            BitmapFormat::Rgba => {
-                ImageData::new_with_u8_clamped_array(Clamped(bitmap.data()), bitmap.width())
-                    .unwrap()
-            }
-        }
+    fn swf_bitmap_to_js_imagedata(bitmap: Bitmap) -> ImageData {
+        let bitmap = bitmap.to_rgba();
+        assert!(bitmap.format() == BitmapFormat::Rgba);
+        ImageData::new_with_u8_clamped_array(Clamped(bitmap.data()), bitmap.width()).unwrap()
     }
 
-    fn register_bitmap_raw(&mut self, mut bitmap: Bitmap) -> Result<BitmapInfo, Error> {
+    fn register_bitmap_raw(&mut self, bitmap: Bitmap) -> Result<BitmapInfo, Error> {
         let (width, height) = (bitmap.width(), bitmap.height());
-
-        let image = Self::swf_bitmap_to_js_imagedata(&mut bitmap);
-
+        let image = Self::swf_bitmap_to_js_imagedata(bitmap);
         let handle = BitmapHandle(self.bitmaps.len());
         self.bitmaps.push(BitmapData {
             image: BitmapDataStorage::from_image_data(image),
@@ -493,8 +470,8 @@ impl RenderBackend for WebCanvasRenderBackend {
         &mut self,
         swf_tag: &swf::DefineBitsLossless,
     ) -> Result<BitmapInfo, Error> {
-        let mut bitmap = ruffle_core::backend::render::decode_define_bits_lossless(swf_tag)?;
-        let image = Self::swf_bitmap_to_js_imagedata(&mut bitmap);
+        let bitmap = ruffle_core::backend::render::decode_define_bits_lossless(swf_tag)?;
+        let image = Self::swf_bitmap_to_js_imagedata(bitmap);
         let handle = BitmapHandle(self.bitmaps.len());
         self.bitmaps.push(BitmapData {
             image: BitmapDataStorage::from_image_data(image),

render/wgpu/src/lib.rs

@@ -4,7 +4,7 @@ use ruffle_core::backend::render::{
 };
 use ruffle_core::shape_utils::DistilledShape;
 use ruffle_core::swf;
-use std::{borrow::Cow, num::NonZeroU32};
+use std::num::NonZeroU32;
 
 use bytemuck::{Pod, Zeroable};
 
@@ -734,29 +734,13 @@ impl<T: RenderTarget> WgpuRenderBackend<T> {
     }
 
     fn register_bitmap(&mut self, bitmap: Bitmap, debug_str: &str) -> BitmapInfo {
+        let bitmap = bitmap.to_rgba();
         let extent = wgpu::Extent3d {
             width: bitmap.width(),
             height: bitmap.height(),
             depth_or_array_layers: 1,
         };
 
-        let data: Cow<[u8]> = match &bitmap.format() {
-            BitmapFormat::Rgba => Cow::Borrowed(bitmap.data()),
-            BitmapFormat::Rgb => {
-                // Expand to RGBA.
-                let data = bitmap.data();
-                let mut as_rgba =
-                    Vec::with_capacity(extent.width as usize * extent.height as usize * 4);
-                for i in (0..data.len()).step_by(3) {
-                    as_rgba.push(data[i]);
-                    as_rgba.push(data[i + 1]);
-                    as_rgba.push(data[i + 2]);
-                    as_rgba.push(255);
-                }
-                Cow::Owned(as_rgba)
-            }
-        };
-
         let texture_label = create_debug_label!("{} Texture", debug_str);
         let texture = self
             .descriptors
@@ -778,7 +762,7 @@ impl<T: RenderTarget> WgpuRenderBackend<T> {
                 origin: Default::default(),
                 aspect: wgpu::TextureAspect::All,
             },
-            &data,
+            bitmap.data(),
             wgpu::ImageDataLayout {
                 offset: 0,
                 bytes_per_row: NonZeroU32::new(4 * extent.width),