FIX: iOS Simulator not rendering due to missing CUBE_ARRAY_TEXTURES (#12052)

This PR closes #11978

# Objective

Fix rendering on iOS Simulators.

iOS Simulator doesn't support the capability CUBE_ARRAY_TEXTURES, since
0.13 this started to make iOS Simulator not render anything with the
following message being outputted:

```
2024-02-19T14:59:34.896266Z ERROR bevy_render::render_resource::pipeline_cache: failed to create shader module: Validation Error

Caused by:
    In Device::create_shader_module
    
Shader validation error: 


    Type [40] '' is invalid
    Capability Capabilities(CUBE_ARRAY_TEXTURES) is required
```

## Solution

- Split up NO_ARRAY_TEXTURES_SUPPORT into both NO_ARRAY_TEXTURES_SUPPORT
and NO_CUBE_ARRAY_TEXTURES_SUPPORT and correctly apply
NO_ARRAY_TEXTURES_SUPPORT for iOS Simulator using the cfg flag
introduced in #10178.

---

## Changelog

### Fixed
- Rendering on iOS Simulator due to missing CUBE_ARRAY_TEXTURES support.

---------

Co-authored-by: Sam Pettersson <[email protected]>

Author: sampettersson

crates/bevy_pbr/src/render/light.rs

@@ -1210,16 +1210,20 @@ pub fn prepare_lights(
                 .create_view(&TextureViewDescriptor {
                     label: Some("point_light_shadow_map_array_texture_view"),
                     format: None,
-                    #[cfg(any(
-                        not(feature = "webgl"),
-                        not(target_arch = "wasm32"),
-                        feature = "webgpu"
+                    // NOTE: iOS Simulator is missing CubeArray support so we use Cube instead.
+                    // See https://github.com/bevyengine/bevy/pull/12052 - remove if support is added.
+                    #[cfg(all(
+                        not(ios_simulator),
+                        any(
+                            not(feature = "webgl"),
+                            not(target_arch = "wasm32"),
+                            feature = "webgpu"
+                        )
                     ))]
                     dimension: Some(TextureViewDimension::CubeArray),
-                    #[cfg(all(
-                        feature = "webgl",
-                        target_arch = "wasm32",
-                        not(feature = "webgpu")
+                    #[cfg(any(
+                        ios_simulator,
+                        all(feature = "webgl", target_arch = "wasm32", not(feature = "webgpu"))
                     ))]
                     dimension: Some(TextureViewDimension::Cube),
                     aspect: TextureAspect::DepthOnly,

crates/bevy_pbr/src/render/mesh_view_bindings.rs

@@ -191,13 +191,19 @@ fn layout_entries(
             // Point Shadow Texture Cube Array
             (
                 2,
-                #[cfg(any(
-                    not(feature = "webgl"),
-                    not(target_arch = "wasm32"),
-                    feature = "webgpu"
+                #[cfg(all(
+                    not(ios_simulator),
+                    any(
+                        not(feature = "webgl"),
+                        not(target_arch = "wasm32"),
+                        feature = "webgpu"
+                    )
                 ))]
                 texture_cube_array(TextureSampleType::Depth),
-                #[cfg(all(feature = "webgl", target_arch = "wasm32", not(feature = "webgpu")))]
+                #[cfg(any(
+                    ios_simulator,
+                    all(feature = "webgl", target_arch = "wasm32", not(feature = "webgpu"))
+                ))]
                 texture_cube(TextureSampleType::Depth),
             ),
             // Point Shadow Texture Array Sampler

crates/bevy_pbr/src/render/mesh_view_bindings.wgsl

@@ -8,7 +8,7 @@
 
 @group(0) @binding(0) var<uniform> view: View;
 @group(0) @binding(1) var<uniform> lights: types::Lights;
-#ifdef NO_ARRAY_TEXTURES_SUPPORT
+#ifdef NO_CUBE_ARRAY_TEXTURES_SUPPORT
 @group(0) @binding(2) var point_shadow_textures: texture_depth_cube;
 #else
 @group(0) @binding(2) var point_shadow_textures: texture_depth_cube_array;

crates/bevy_pbr/src/render/shadows.wgsl

@@ -44,7 +44,7 @@ fn fetch_point_shadow(light_id: u32, frag_position: vec4<f32>, surface_normal: v
     // a quad (2x2 fragments) being processed not being sampled, and this messing with
     // mip-mapping functionality. The shadow maps have no mipmaps so Level just samples
     // from LOD 0.
-#ifdef NO_ARRAY_TEXTURES_SUPPORT
+#ifdef NO_CUBE_ARRAY_TEXTURES_SUPPORT
     return textureSampleCompare(view_bindings::point_shadow_textures, view_bindings::point_shadow_textures_sampler, frag_ls * flip_z, depth);
 #else
     return textureSampleCompareLevel(view_bindings::point_shadow_textures, view_bindings::point_shadow_textures_sampler, frag_ls * flip_z, i32(light_id), depth);

crates/bevy_render/src/lib.rs

@@ -363,6 +363,7 @@ impl Plugin for RenderPlugin {
                 .insert_resource(instance)
                 .insert_resource(PipelineCache::new(
                     device.clone(),
+                    render_adapter.clone(),
                     self.synchronous_pipeline_compilation,
                 ))
                 .insert_resource(device)

crates/bevy_render/src/render_resource/pipeline_cache.rs

@@ -1,3 +1,4 @@
+use crate::renderer::RenderAdapter;
 use crate::{render_resource::*, renderer::RenderDevice, Extract};
 use bevy_asset::{AssetEvent, AssetId, Assets};
 use bevy_ecs::system::{Res, ResMut};
@@ -21,7 +22,7 @@ use thiserror::Error;
 #[cfg(feature = "shader_format_spirv")]
 use wgpu::util::make_spirv;
 use wgpu::{
-    Features, PipelineLayoutDescriptor, PushConstantRange, ShaderModuleDescriptor,
+    DownlevelFlags, Features, PipelineLayoutDescriptor, PushConstantRange, ShaderModuleDescriptor,
     VertexBufferLayout as RawVertexBufferLayout,
 };
 
@@ -167,7 +168,7 @@ impl ShaderDefVal {
 }
 
 impl ShaderCache {
-    fn new(render_device: &RenderDevice) -> Self {
+    fn new(render_device: &RenderDevice, render_adapter: &RenderAdapter) -> Self {
         const CAPABILITIES: &[(Features, Capabilities)] = &[
             (Features::PUSH_CONSTANTS, Capabilities::PUSH_CONSTANT),
             (Features::SHADER_F64, Capabilities::FLOAT64),
@@ -196,9 +197,13 @@ impl ShaderCache {
             }
         }
 
-        // TODO: Check if this is supported, though I'm not sure if bevy works without this feature?
-        // We can't compile for native at least without it.
-        capabilities |= Capabilities::CUBE_ARRAY_TEXTURES;
+        if render_adapter
+            .get_downlevel_capabilities()
+            .flags
+            .contains(DownlevelFlags::CUBE_ARRAY_TEXTURES)
+        {
+            capabilities |= Capabilities::CUBE_ARRAY_TEXTURES;
+        }
 
         #[cfg(debug_assertions)]
         let composer = naga_oil::compose::Composer::default();
@@ -279,9 +284,14 @@ impl ShaderCache {
                 #[cfg(all(feature = "webgl", target_arch = "wasm32", not(feature = "webgpu")))]
                 {
                     shader_defs.push("NO_ARRAY_TEXTURES_SUPPORT".into());
+                    shader_defs.push("NO_CUBE_ARRAY_TEXTURES_SUPPORT".into());
                     shader_defs.push("SIXTEEN_BYTE_ALIGNMENT".into());
                 }
 
+                if cfg!(ios_simulator) {
+                    shader_defs.push("NO_CUBE_ARRAY_TEXTURES_SUPPORT".into());
+                }
+
                 shader_defs.push(ShaderDefVal::UInt(
                     String::from("AVAILABLE_STORAGE_BUFFER_BINDINGS"),
                     render_device.limits().max_storage_buffers_per_shader_stage,
@@ -491,9 +501,13 @@ impl PipelineCache {
     }
 
     /// Create a new pipeline cache associated with the given render device.
-    pub fn new(device: RenderDevice, synchronous_pipeline_compilation: bool) -> Self {
+    pub fn new(
+        device: RenderDevice,
+        render_adapter: RenderAdapter,
+        synchronous_pipeline_compilation: bool,
+    ) -> Self {
         Self {
-            shader_cache: Arc::new(Mutex::new(ShaderCache::new(&device))),
+            shader_cache: Arc::new(Mutex::new(ShaderCache::new(&device, &render_adapter))),
             device,
             layout_cache: default(),
             waiting_pipelines: default(),