Fix alignment on ios simulator

crates/bevy_render/src/render_resource/uniform_buffer.rs

@@ -265,8 +265,16 @@ impl<T: ShaderType + WriteInto> DynamicUniformBuffer<T> {
         device: &RenderDevice,
         queue: &'a RenderQueue,
     ) -> Option<DynamicUniformBufferWriter<'a, T>> {
-        let alignment =
-            AlignmentValue::new(device.limits().min_uniform_buffer_offset_alignment as u64);
+        let alignment = if cfg!(ios_simulator) {
+            // On iOS simulator on silicon macs, metal validation check that the host OS alignment
+            // is respected, but the device reports the correct value for iOS, which is smaller.
+            // Use the larger value.
+            // See https://github.com/bevyengine/bevy/pull/10178 - remove if it's not needed anymore.
+            AlignmentValue::new(256)
+        } else {
+            AlignmentValue::new(device.limits().min_uniform_buffer_offset_alignment as u64)
+        };
+
         let mut capacity = self.buffer.as_deref().map(wgpu::Buffer::size).unwrap_or(0);
         let size = alignment
             .round_up(T::min_size().get())

examples/mobile/.cargo/config.toml

@@ -0,0 +1,5 @@
+# Flag to notify the compiler we're building for the iOS simulator from an Apple silicon mac
+# This needs some workarounds for now
+# See https://github.com/bevyengine/bevy/pull/10178 - remove if it's not needed anymore.
+[target.aarch64-apple-ios-sim]
+rustflags = ["--cfg=ios_simulator"]

examples/mobile/build_rust_deps.sh

@@ -48,7 +48,7 @@ for arch in $ARCHS; do
         # Hardware iOS targets
         cargo rustc --crate-type staticlib --lib $RELFLAG --target aarch64-apple-ios
       else
-        # M1 iOS simulator -- currently in Nightly only and requires to build `libstd`
+        # M1 iOS simulator
         cargo rustc --crate-type staticlib --lib $RELFLAG --target aarch64-apple-ios-sim
       fi
   esac