google · rafadevai · Feb 13, 2026
diff --git a/filament/backend/src/vulkan/VulkanDescriptorSetCache.cpp b/filament/backend/src/vulkan/VulkanDescriptorSetCache.cpp
@@ -355,35 +355,8 @@ void VulkanDescriptorSetCache::updateBuffer(fvkmemory::resource_ptr<VulkanDescri
 }
 
 void VulkanDescriptorSetCache::updateSampler(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
-        uint8_t binding, fvkmemory::resource_ptr<VulkanTexture> texture, VkSampler sampler,
-        VkDescriptorSetLayout externalSamplerLayout) noexcept {
-
-    // We have to update a bound set for two use cases
-    //   - streaming API (a changing feed of AHardwareBuffer)
-    //   - external samplers - potential changing of dataspace per-frame
-
-    // TODO: Fix the stream flow case base on the above comment!!
-    if (set->isAnExternalSamplerBound) {
-        auto layout = set->getLayout();
-        // Build a new descriptor set from the new layout
-        VkDescriptorSetLayout const genLayout = set->boundLayout;
-        VkDescriptorSet const newSet = getVkSet(layout->count, genLayout);
-        Bitmask const ubo = layout->bitmask.ubo | layout->bitmask.dynamicUbo;
-        Bitmask samplers = layout->bitmask.sampler;
-        samplers.unset(binding);
-
-        // Each bitmask denotes a binding index, and separated into two stages - vertex and buffer
-        // We fold the two stages into just the lower half of the bits to denote a combined set of
-        // bindings.
-        Bitmask const copyBindings = foldBitsInHalf(ubo | samplers);
-        VkDescriptorSet const srcSet = set->getVkSet();
-        copySet(srcSet, newSet, copyBindings);
-        set->addNewSet(newSet,
-                [this, layoutCount = layout->count, genLayout, newSet](VulkanDescriptorSet*) {
-                    this->manualRecycle(layoutCount, genLayout, newSet);
-                });
-    }
-
+        uint8_t binding, fvkmemory::resource_ptr<VulkanTexture> texture,
+        VkSampler sampler) noexcept {
     VkDescriptorSet const vkset = set->getVkSet();
     VkImageSubresourceRange range = texture->getPrimaryViewRange();
     VkImageViewType const expectedType = texture->getViewType();
@@ -432,6 +405,28 @@ fvkmemory::resource_ptr<VulkanDescriptorSet> VulkanDescriptorSetCache::createSet
     return set;
 }
 
+void VulkanDescriptorSetCache::cloneSet(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
+        fvkutils::SamplerBitmask samplerMask) noexcept {
+    auto const& layout = set->getLayout();
+    // Build a new descriptor set from layout
+    VkDescriptorSetLayout const genLayout = set->boundLayout;
+    VkDescriptorSet const newSet = getVkSet(layout->count, genLayout);
+
+    // Each bitmask denotes a binding index, and separated into two stages - vertex and buffer
+    // We fold the two stages into just the lower half of the bits to denote a combined set of
+    // bindings.
+    Bitmask const ubo = layout->bitmask.ubo | layout->bitmask.dynamicUbo;
+    // Don't copy the samplers in the mask
+    Bitmask samplers = layout->bitmask.sampler ^ samplerMask;
+    Bitmask const copyBindings = foldBitsInHalf(ubo | samplers);
+
+    VkDescriptorSet const srcSet = set->getVkSet();
+    copySet(srcSet, newSet, copyBindings);
+    set->addNewSet(newSet,
+            [this, layoutCount = layout->count, genLayout, newSet](
+                    VulkanDescriptorSet*) { this->manualRecycle(layoutCount, genLayout, newSet); });
+}
+
 VkDescriptorSet VulkanDescriptorSetCache::getVkSet(DescriptorCount const& count,
         VkDescriptorSetLayout vklayout) {
     return mDescriptorPool->obtainSet(count, vklayout);

diff --git a/filament/backend/src/vulkan/VulkanDescriptorSetCache.h b/filament/backend/src/vulkan/VulkanDescriptorSetCache.h
@@ -55,12 +55,7 @@ class VulkanDescriptorSetCache {
             VkDeviceSize size) noexcept;
 
     void updateSampler(fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t binding,
-            fvkmemory::resource_ptr<VulkanTexture> texture, VkSampler sampler,
-            VkDescriptorSetLayout externalSamplerLayout = VK_NULL_HANDLE) noexcept;
-
-    void updateSamplerForExternalSamplerSet(fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t binding,
-            fvkmemory::resource_ptr<VulkanTexture> texture) noexcept;
-
+            fvkmemory::resource_ptr<VulkanTexture> texture, VkSampler sampler) noexcept;
 
     void updateInputAttachment(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
             VulkanAttachment const& attachment) noexcept;
@@ -76,6 +71,9 @@ class VulkanDescriptorSetCache {
     fvkmemory::resource_ptr<VulkanDescriptorSet> createSet(Handle<HwDescriptorSet> handle,
             fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);
 
+    void cloneSet(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
+            fvkutils::SamplerBitmask samplerMask) noexcept;
+
     // This method is meant to be used with external samplers
     VkDescriptorSet getVkSet(DescriptorCount const& count, VkDescriptorSetLayout vklayout);
 

diff --git a/filament/backend/src/vulkan/VulkanDriver.cpp b/filament/backend/src/vulkan/VulkanDriver.cpp
@@ -507,7 +507,7 @@ void VulkanDriver::updateDescriptorSetTexture(
     auto set = resource_ptr<VulkanDescriptorSet>::cast(&mResourceManager, dsh);
     auto texture = resource_ptr<VulkanTexture>::cast(&mResourceManager, th);
 
-    if (UTILS_UNLIKELY(mExternalImageManager.isExternallySampledTexture(texture))) {
+    if (UTILS_UNLIKELY(texture->isExternallySampled())) {
         mExternalImageManager.bindExternallySampledTexture(set, binding, texture, params);
         mAppState.hasBoundExternalImages = true;
         set->isAnExternalSamplerBound = true;
@@ -523,8 +523,6 @@ void VulkanDriver::updateDescriptorSetTexture(
         };
         VkSampler const vksampler = mSamplerCache.getSampler(cacheParams);
         mDescriptorSetCache.updateSampler(set, binding, texture, vksampler);
-        mExternalImageManager.clearTextureBinding(set, binding);
-        mStreamedImageManager.unbindStreamedTexture(set, binding);
     }
 }
 
@@ -767,10 +765,6 @@ void VulkanDriver::createTextureExternalImage2R(Handle<HwTexture> th, backend::S
     // texture into the read layout.
     texture->transitionLayout(&commands, texture->getPrimaryViewRange(), VulkanLayout::FRAG_READ);
 
-    if (imgData.external.valid()) {
-        mExternalImageManager.addExternallySampledTexture(texture, conversion);
-    }
-
     texture.inc();
     mResourceManager.associateHandle(th.getId(), std::move(tag));
 }
@@ -814,8 +808,6 @@ void VulkanDriver::destroyTexture(Handle<HwTexture> th) {
     }
     auto texture = resource_ptr<VulkanTexture>::cast(&mResourceManager, th);
     texture.dec();
-
-    mExternalImageManager.removeExternallySampledTexture(texture);
 }
 
 void VulkanDriver::createProgramR(Handle<HwProgram> ph, Program&& program, utils::ImmutableCString&& tag) {
@@ -1429,8 +1421,6 @@ void VulkanDriver::updateStreams(CommandStream* driver) {
                             VulkanLayout::FRAG_READ);
 
                     if (imgData.external.valid()) {
-                        mExternalImageManager.addExternallySampledTexture(newTexture,
-                                conversion);
                         // Cache the AHB backed image. Acquires the image here.
                         s->pushImage(image, newTexture);
                     }
@@ -2409,7 +2399,6 @@ void VulkanDriver::bindPipeline(PipelineState const& pipelineState) {
         if (std::any_of(layoutHandles.begin(), layoutHandles.end(), haveExternalSamplers)) {
             BindInDrawBundle bundle = {
                 .pipelineState = pipelineState,
-                .dsLayoutHandles = layoutHandles,
                 .descriptorSetMask = descriptorSetMask,
             };
             mPipelineState.bindInDraw = { true, bundle };
@@ -2555,7 +2544,6 @@ void VulkanDriver::draw2(uint32_t indexOffset, uint32_t indexCount, uint32_t ins
     VkCommandBuffer cmdbuffer = mCurrentRenderPass.commandBuffer->buffer();
     auto const& [doBindInDraw, bundle] = mPipelineState.bindInDraw;
 
-    fvkutils::DescriptorSetMask setsWithExternalSamplers = {};
     if (doBindInDraw) {
         // Create the new pipeline layout from the current bounded descriptor sets.
         // The layout of the descriptor sets at this point should have the final one taking into account

diff --git a/filament/backend/src/vulkan/VulkanDriver.h b/filament/backend/src/vulkan/VulkanDriver.h
@@ -177,7 +177,6 @@ class VulkanDriver final : public DriverBase {
 
     struct BindInDrawBundle {
         PipelineState pipelineState = {};
-        DescriptorSetLayoutHandleList dsLayoutHandles = {};
         fvkutils::DescriptorSetMask descriptorSetMask = {};
         resource_ptr<VulkanProgram> program = {};
     };

diff --git a/filament/backend/src/vulkan/VulkanExternalImageManager.cpp b/filament/backend/src/vulkan/VulkanExternalImageManager.cpp
@@ -37,16 +37,6 @@ void erasep(std::vector<T>& v, std::function<bool(T const&)> f) {
     v.erase(newEnd, v.end());
 }
 
-using ImageData = VulkanExternalImageManager::VulkanExternalImageManager::ImageData;
-ImageData& findImage(std::vector<ImageData>& images,
-        fvkmemory::resource_ptr<VulkanTexture> texture) {
-    auto itr = std::find_if(images.begin(), images.end(), [&](ImageData const& data) {
-        return data.image == texture;
-    });
-    assert_invariant(itr != images.end());
-    return *itr;
-}
-
 }// namespace
 
 VulkanExternalImageManager::VulkanExternalImageManager(VulkanSamplerCache* samplerCache,
@@ -61,7 +51,6 @@ VulkanExternalImageManager::~VulkanExternalImageManager() = default;
 
 void VulkanExternalImageManager::terminate() {
     mSetBindings.clear();
-    mImages.clear();
 }
 
 void VulkanExternalImageManager::updateSetAndLayout(
@@ -94,11 +83,12 @@ void VulkanExternalImageManager::updateSetAndLayout(
     fvkmemory::resource_ptr<VulkanDescriptorSetLayout> const& layout = set->getLayout();
     set->boundLayout = mDescriptorSetLayoutCache->getVkLayout(layout->bitmask,
             actualExternalSamplers, outSamplers);
+
+    mDescriptorSetCache->cloneSet(set, actualExternalSamplers);
+
     // Update the external samplers in the set
     for (auto& [binding, sampler, image]: samplerAndBindings) {
-        // We cannot call updateSamplerForExternalSamplerSet because some samplers are non NULL
-        // (RGB) and we cannot do a combined update with a NULL sampler.
-        mDescriptorSetCache->updateSampler(set, binding, image, sampler, set->boundLayout);
+        mDescriptorSetCache->updateSampler(set, binding, image, sampler);
     }
 }
 
@@ -137,8 +127,6 @@ void VulkanExternalImageManager::removeDescriptorSet(
 void VulkanExternalImageManager::bindExternallySampledTexture(
         fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t bindingPoint,
         fvkmemory::resource_ptr<VulkanTexture> image, SamplerParams samplerParams) {
-    // Should we do duplicate validation here?
-    auto& imageData = findImage(mImages, image);
     // according to spec, these must match chromaFilter
     // https://registry.khronos.org/vulkan/specs/latest/man/html/VkSamplerCreateInfo.html#VUID-VkSamplerCreateInfo-minFilter-01645
     samplerParams.filterMag = SamplerMagFilter::NEAREST;
@@ -153,34 +141,10 @@ void VulkanExternalImageManager::bindExternallySampledTexture(
 
     VkSampler const sampler = mSamplerCache->getSampler({
         .sampler = samplerParams,
-        .conversion = imageData.conversion,
-    });
-
-    mSetBindings.push_back({ bindingPoint, imageData.image, set, sampler });
-}
-
-void VulkanExternalImageManager::addExternallySampledTexture(
-        fvkmemory::resource_ptr<VulkanTexture> image, VkSamplerYcbcrConversion const conversion) {
-    mImages.push_back({
-        .image = image,
-        .conversion = conversion,
+        .conversion = image->getYcbcrConversion(),
     });
-}
-
-void VulkanExternalImageManager::removeExternallySampledTexture(
-        fvkmemory::resource_ptr<VulkanTexture> image) {
-    erasep<SetBindingInfo>(mSetBindings,
-            [&](auto const& bindingInfo) { return (bindingInfo.image == image); });
-    erasep<ImageData>(mImages, [&](auto const& imageData) {
-        return imageData.image == image;
-    });
-}
 
-bool VulkanExternalImageManager::isExternallySampledTexture(
-        fvkmemory::resource_ptr<VulkanTexture> image) const {
-    return std::find_if(mImages.begin(), mImages.end(), [&](auto const& imageData) {
-        return imageData.image == image;
-    }) != mImages.end();
+    mSetBindings.push_back({ bindingPoint, image, set, sampler });
 }
 
 void VulkanExternalImageManager::clearTextureBinding(

diff --git a/filament/backend/src/vulkan/VulkanExternalImageManager.h b/filament/backend/src/vulkan/VulkanExternalImageManager.h
@@ -62,21 +62,9 @@ class VulkanExternalImageManager {
     void clearTextureBinding(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
                              uint8_t bindingPoint);
 
-    void addExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> external,
-            VkSamplerYcbcrConversion const conversion);
-
-    void removeExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image);
-
-    bool isExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image) const;
-
     VkSamplerYcbcrConversion getVkSamplerYcbcrConversion(
             VulkanPlatform::ExternalImageMetadata const& metadata);
 
-    struct ImageData {
-        fvkmemory::resource_ptr<VulkanTexture> image;
-        VkSamplerYcbcrConversion conversion = VK_NULL_HANDLE;
-    };
-
     // - Update the descriptor set layout with the external samplers. This layout will be assign the
     // respective immutable samplers to the layout.
     // - Switch from binding the base layout to the new one.
@@ -104,7 +92,6 @@ class VulkanExternalImageManager {
 
     // Use vectors instead of hash maps because we only expect small number of entries.
     std::vector<SetBindingInfo> mSetBindings;
-    std::vector<ImageData> mImages;
 };
 
 } // filament::backend

diff --git a/filament/backend/src/vulkan/VulkanTexture.cpp b/filament/backend/src/vulkan/VulkanTexture.cpp
@@ -840,19 +840,6 @@ void VulkanTexture::setLayout(VkImageSubresourceRange const& range, VulkanLayout
     }
 }
 
-void VulkanTexture::setYcbcrConversion(VkSamplerYcbcrConversion conversion) {
-    // Note that this comparison is valid because we only ever create VkSamplerYcbcrConversion from
-    // a cache.  So for each set of parameters, there is exactly one conversion (similar to
-    // samplers).
-    VulkanTextureState::Ycbcr ycbcr = {
-        .conversion = conversion,
-    };
-    if (mState->mYcbcr != ycbcr) {
-        mState->mYcbcr = ycbcr;
-        mState->clearCachedImageViews();
-    }
-}
-
 VulkanLayout VulkanTexture::getLayout(uint32_t layer, uint32_t level) const {
     assert_invariant(level <= 0xffff && layer <= 0xffff);
     const uint32_t key = (layer << 16) | level;

diff --git a/filament/backend/src/vulkan/VulkanTexture.h b/filament/backend/src/vulkan/VulkanTexture.h
@@ -242,6 +242,8 @@ struct VulkanTexture : public HwTexture, fvkmemory::Resource {
         return mState->mIsProtected;
     }
 
+    bool isExternallySampled() const { return mState->mYcbcr.conversion != VK_NULL_HANDLE; }
+
     bool transitionLayout(VulkanCommandBuffer* commands, VkImageSubresourceRange const& range,
             VulkanLayout newLayout);
 
@@ -262,10 +264,7 @@ struct VulkanTexture : public HwTexture, fvkmemory::Resource {
     // manually (outside of calls to transitionLayout).
     void setLayout(VkImageSubresourceRange const& range, VulkanLayout newLayout);
 
-    // This is used in the case of external images and external samplers. AHB might update the
-    // conversion per-frame. This implies that we need to invalidate the view cache when that
-    // happens.
-    void setYcbcrConversion(VkSamplerYcbcrConversion conversion);
+    VkSamplerYcbcrConversion getYcbcrConversion() const { return mState->mYcbcr.conversion; }
 
 #if FVK_ENABLED(FVK_DEBUG_TEXTURE)
     void print() const;