generate the proper per-view descriptor-set layout in the shader

the per-view descriptor-set layout depends on both the material
and the variant.

libs/filabridge/include/private/filament/DescriptorSets.h

@@ -32,7 +32,6 @@ backend::DescriptorSetLayout const& getDepthVariantLayout() noexcept;
 backend::DescriptorSetLayout const& getSsrVariantLayout() noexcept;
 backend::DescriptorSetLayout const& getPerRenderableLayout() noexcept;
 
-backend::DescriptorSetLayout const& getPerViewLayout() noexcept;  // @deprecated
 backend::DescriptorSetLayout getPerViewDescriptorSetLayout(
         MaterialDomain domain,
         UserVariantFilterMask variantFilter,

libs/filabridge/src/DescriptorSets.cpp

@@ -102,10 +102,6 @@ DescriptorSetLayout const& getSsrVariantLayout() noexcept {
     return ssrVariantDescriptorSetLayout;
 }
 
-DescriptorSetLayout const& getPerViewLayout() noexcept {
-    return perViewDescriptorSetLayout;
-}
-
 DescriptorSetLayout const& getPerRenderableLayout() noexcept {
     return perRenderableDescriptorSetLayout;
 }
@@ -160,6 +156,10 @@ DescriptorSetLayout getPerViewDescriptorSetLayout(
         bool isLit,
         ReflectionMode reflectionMode,
         RefractionMode refractionMode) noexcept {
+
+    bool const ssr = reflectionMode == ReflectionMode::SCREEN_SPACE ||
+                     refractionMode == RefractionMode::SCREEN_SPACE;
+
     switch (domain) {
         case MaterialDomain::SURFACE: {
             //
@@ -171,14 +171,13 @@ DescriptorSetLayout getPerViewDescriptorSetLayout(
                 layout.bindings.erase(
                         std::remove_if(layout.bindings.begin(), layout.bindings.end(),
                                 [](auto const& entry) {
-                                    return entry.binding == PerViewBindingPoints::IBL_DFG_LUT ||
-                                           entry.binding == PerViewBindingPoints::IBL_SPECULAR;
+                                    return  entry.binding == PerViewBindingPoints::IBL_DFG_LUT ||
+                                            entry.binding == PerViewBindingPoints::IBL_SPECULAR;
                                 }),
                         layout.bindings.end());
             }
             // remove descriptors not needed for SSRs
-            if (reflectionMode != ReflectionMode::SCREEN_SPACE &&
-                refractionMode != RefractionMode::SCREEN_SPACE) {
+            if (!ssr) {
                 layout.bindings.erase(
                         std::remove_if(layout.bindings.begin(), layout.bindings.end(),
                                 [](auto const& entry) {

libs/filamat/src/shaders/ShaderGenerator.cpp

@@ -604,12 +604,30 @@ std::string ShaderGenerator::createFragmentProgram(ShaderModel shaderModel,
     CodeGenerator::generateSeparator(fs);
 
     if (featureLevel >= FeatureLevel::FEATURE_LEVEL_1) {
+        assert_invariant(mMaterialDomain == MaterialDomain::SURFACE);
 
-        // We need to filter out all the descriptors not included in the "resolved" layout below
-        backend::DescriptorSetLayout const perViewDescriptorSetLayout =
-                descriptor_sets::getPerViewDescriptorSetLayout(
-                        mMaterialDomain, variantFilter,
-                        material.isLit, material.reflectionMode, material.refractionMode);
+        auto getPerViewDescriptorSetLayoutWithVariant = [](
+                filament::Variant variant,
+                UserVariantFilterMask variantFilter,
+                bool isLit,
+                ReflectionMode reflectionMode,
+                RefractionMode refractionMode) -> backend::DescriptorSetLayout {
+
+            if (filament::Variant::isValidDepthVariant(variant)) {
+                return descriptor_sets::getDepthVariantLayout();
+            }
+            if (filament::Variant::isSSRVariant(variant)) {
+                return descriptor_sets::getSsrVariantLayout();
+            }
+            // We need to filter out all the descriptors not included in the "resolved" layout below
+            return descriptor_sets::getPerViewDescriptorSetLayout(
+                    MaterialDomain::SURFACE, variantFilter,
+                    isLit, reflectionMode, refractionMode);
+        };
+
+        auto const perViewDescriptorSetLayout = getPerViewDescriptorSetLayoutWithVariant(
+                variant, variantFilter,
+                material.isLit, material.reflectionMode, material.refractionMode);
 
         // this is the list of samplers we need to filter
         auto list = SibGenerator::getPerViewSib(variant).getSamplerInfoList();