fix(web): Fix damage regions outside the pixel buffer

Author: madsmtm

CHANGELOG.md

@@ -6,7 +6,7 @@
 - **Breaking:** Removed generic type parameters `D` and `W` from `Buffer<'_>` struct.
 - **Breaking:** Removed `Deref[Mut]` implementation on `Buffer<'_>`. Use `Buffer::pixels()` instead.
 - **Breaking:** Removed `DamageOutOfRange` error case. If the damage value is greater than the backend supports, it is instead clamped to an appropriate value.
-- Fixed `present_with_damage` with bounds out of range on Windows.
+- Fixed `present_with_damage` with bounds out of range on Windows and Web.
 
 # 0.4.7
 

src/backends/web.rs

@@ -332,7 +332,7 @@ impl BufferInterface for BufferImpl<'_> {
 
     /// Push the buffer to the canvas.
     fn present_with_damage(self, damage: &[Rect]) -> Result<(), SoftBufferError> {
-        let (buffer_width, _buffer_height) = self
+        let (buffer_width, buffer_height) = self
             .size
             .expect("Must set size of surface before calling `present_with_damage()`");
 
@@ -358,8 +358,10 @@ impl BufferInterface for BufferImpl<'_> {
             .collect();
 
         debug_assert_eq!(
-            bitmap.len() as u32,
-            union_damage.width.get() * union_damage.height.get() * 4
+            bitmap.len(),
+            union_damage.width.get().min(buffer_width.get()) as usize
+                * union_damage.height.get().min(buffer_height.get()) as usize
+                * 4
         );
 
         #[cfg(target_feature = "atomics")]
@@ -382,14 +384,14 @@ impl BufferInterface for BufferImpl<'_> {
             let array = Uint8Array::new_with_length(bitmap.len() as u32);
             array.copy_from(&bitmap);
             let array = Uint8ClampedArray::new(&array);
-            ImageDataExt::new(array, union_damage.width.get())
+            ImageDataExt::new(array, union_damage.width.get().min(buffer_width.get()))
                 .map(JsValue::from)
                 .map(ImageData::unchecked_from_js)
         };
         #[cfg(not(target_feature = "atomics"))]
         let result = ImageData::new_with_u8_clamped_array(
             wasm_bindgen::Clamped(&bitmap),
-            union_damage.width.get(),
+            union_damage.width.get().min(buffer_width.get()),
         );
         // This should only throw an error if the buffer we pass's size is incorrect.
         let image_data = result.unwrap();
@@ -399,12 +401,12 @@ impl BufferInterface for BufferImpl<'_> {
             self.canvas
                 .put_image_data(
                     &image_data,
-                    union_damage.x.into(),
-                    union_damage.y.into(),
+                    union_damage.x.min(buffer_width.get()).into(),
+                    union_damage.y.min(buffer_height.get()).into(),
                     (rect.x - union_damage.x).into(),
                     (rect.y - union_damage.y).into(),
-                    rect.width.get().into(),
-                    rect.height.get().into(),
+                    rect.width.get().min(buffer_width.get()).into(),
+                    rect.height.get().min(buffer_height.get()).into(),
                 )
                 .unwrap();
         }