[Fix] (DirectVulkan): support UBO instance arrays as arrayed descriptors - uniform Block{...}b[N] reflected as one binding with descriptorCount=N, per-element GL block mapping, per-element buffer infos and dynamic offsets; non-UBO descriptor arrays now fail program creation cleanly instead of continuing corrupt

MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.cpp

@@ -1094,9 +1094,17 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 for (auto* binding : bindings) {
                     MOBILEGL_ASSERT(binding != nullptr, "ProgramFactory: null descriptor binding reflection record");
                     const auto kind = ReflectDescriptorTypeToBindingKind(binding->descriptor_type);
-                    MOBILEGL_ASSERT(binding->count == 1,
+                    // UBO instance arrays (uniform Block {...} b[N];) occupy one binding with
-                                    "ProgramFactory: descriptor arrays are unsupported (name='%s' count=%u)",
+                    // descriptorCount = N; other descriptor arrays stay unsupported and must
-                                    binding->name ? binding->name : "<null>", binding->count);
+                    // fail program creation cleanly rather than continue with corrupt state.
+                    if (binding->count != 1 && kind != ProgramFactory::DescriptorBindingKind::UniformBufferDynamic) {
+                        MGLOG_E("ProgramFactory: descriptor arrays are unsupported for this descriptor "
+                                "kind (name='%s' count=%u type=%d)",
+                                binding->name ? binding->name : "<null>", binding->count,
+                                static_cast<Int>(binding->descriptor_type));
+                        destroyReflectModules();
+                        return false;
+                    }
 
                     DescriptorKey key{};
                     key.kind = kind;
@@ -1613,6 +1621,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         entry.storageBlockIndexByBinding.assign(m_maxBindings, -1);
         entry.globalUboBinding = -1;
         entry.dynamicBindings.clear();
+        entry.bindingDescriptorCounts.assign(m_maxBindings, 1);
+        entry.arrayedUniformBlockIndicesByBinding.clear();
 
         // Use SpvcSession (Reflection mode) to reflect all SPIR-V modules in a single pass per module
         for (const auto& module : spirv) {
@@ -1628,6 +1638,27 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                             "ProgramFactory::ReflectLayout: failed to create reflection module (result=%d)",
                             static_cast<Int>(createReflectResult));
 
+            // Descriptor counts per binding (UBO instance arrays reflect count > 1).
+            UnorderedMap<Uint32, Uint32> descriptorCountByBinding;
+            {
+                uint32_t countProbe = 0;
+                if (spvReflectEnumerateDescriptorBindings(&reflectModule, &countProbe, nullptr) ==
+                        SPV_REFLECT_RESULT_SUCCESS &&
+                    countProbe > 0) {
+                    Vector<SpvReflectDescriptorBinding*> probeBindings(countProbe);
+                    if (spvReflectEnumerateDescriptorBindings(&reflectModule, &countProbe,
+                                                              probeBindings.data()) ==
+                        SPV_REFLECT_RESULT_SUCCESS) {
+                        for (const auto* probeBinding : probeBindings) {
+                            if (probeBinding != nullptr) {
+                                descriptorCountByBinding[probeBinding->binding] =
+                                    std::max<Uint32>(1, probeBinding->count);
+                            }
+                        }
+                    }
+                }
+            }
+
             // Reflect uniform buffers
             auto ubos = session.GetShaderInterface(SPVC_RESOURCE_TYPE_UNIFORM_BUFFER);
             for (const auto& ubo : ubos) {
@@ -1653,9 +1684,69 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                     continue;
                 }
 
-                const Uint blockIndex = program.GetUniformBlockIndex(ubo.name.c_str());
+                const auto countIt = descriptorCountByBinding.find(binding);
-                if (blockIndex == 0xFFFFFFFFu) {
+                const Uint32 descriptorCount =
-                    MGLOG_D("ProgramFactory::ReflectLayout: skipping inactive UBO '%s' at binding %u",
+                    countIt != descriptorCountByBinding.end() ? countIt->second : 1u;
+
+                if (descriptorCount <= 1) {
+                    const Uint blockIndex = program.GetUniformBlockIndex(ubo.name.c_str());
+                    if (blockIndex == 0xFFFFFFFFu) {
+                        MGLOG_D("ProgramFactory::ReflectLayout: skipping inactive UBO '%s' at binding %u",
+                                ubo.name.c_str(), binding);
+                        continue;
+                    }
+
+                    MOBILEGL_ASSERT(entry.bindingKinds[binding] == DescriptorBindingKind::None ||
+                                        entry.bindingKinds[binding] == DescriptorBindingKind::UniformBufferDynamic,
+                                    "ProgramFactory::ReflectLayout: descriptor binding %u has conflicting kinds for UBO '%s'",
+                                    binding, ubo.name.c_str());
+                    entry.bindingKinds[binding] = DescriptorBindingKind::UniformBufferDynamic;
+                    MOBILEGL_ASSERT(entry.globalUboBinding != static_cast<Int>(binding),
+                                    "ProgramFactory::ReflectLayout: regular UBO '%s' collides with global UBO binding %u",
+                                    ubo.name.c_str(), binding);
+                    MOBILEGL_ASSERT(entry.uniformBlockIndexByBinding[binding] < 0 ||
+                                        entry.uniformBlockIndexByBinding[binding] == static_cast<Int>(blockIndex),
+                                    "ProgramFactory::ReflectLayout: descriptor binding %u maps to conflicting UBO blocks (%d vs %u)",
+                                    binding, entry.uniformBlockIndexByBinding[binding], blockIndex);
+                    entry.uniformBlockIndexByBinding[binding] = static_cast<Int>(blockIndex);
+                    continue;
+                }
+
+                // UBO instance array: one binding, descriptorCount elements. GL exposes each
+                // element as its own active block named "Name[i]"; map every element to its
+                // GL block index so the descriptor write can gather per-element buffer ranges.
+                if (descriptorCount > m_maxBindings) {
+                    MGLOG_E("ProgramFactory::ReflectLayout: UBO array '%s' count %u exceeds maxBindings=%u; "
+                            "leaving binding %u unmapped",
+                            ubo.name.c_str(), descriptorCount, m_maxBindings, binding);
+                    continue;
+                }
+                Vector<Int> elementBlockIndices;
+                elementBlockIndices.reserve(descriptorCount);
+                for (Uint32 element = 0; element < descriptorCount; ++element) {
+                    String elementName = ubo.name + "[" + std::to_string(element) + "]";
+                    Uint elementBlockIndex = program.GetUniformBlockIndex(elementName.c_str());
+                    if (elementBlockIndex == 0xFFFFFFFFu && element == 0) {
+                        // Some frontends report the first element under the bare block name.
+                        elementBlockIndex = program.GetUniformBlockIndex(ubo.name.c_str());
+                    }
+                    if (elementBlockIndex == 0xFFFFFFFFu) {
+                        // Degrade rather than corrupt: reuse element 0's block if we have one,
+                        // otherwise give up on the binding (same observable behavior as an
+                        // inactive block: wrong values, but no crash).
+                        MGLOG_E("ProgramFactory::ReflectLayout: UBO array '%s' element %u has no active "
+                                "GL uniform block",
+                                ubo.name.c_str(), element);
+                        if (!elementBlockIndices.empty()) {
+                            elementBlockIndex = static_cast<Uint>(elementBlockIndices.front());
+                        } else {
+                            break;
+                        }
+                    }
+                    elementBlockIndices.push_back(static_cast<Int>(elementBlockIndex));
+                }
+                if (elementBlockIndices.size() != descriptorCount) {
+                    MGLOG_E("ProgramFactory::ReflectLayout: skipping unresolved UBO array '%s' at binding %u",
                             ubo.name.c_str(), binding);
                     continue;
                 }
@@ -1665,14 +1756,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                 "ProgramFactory::ReflectLayout: descriptor binding %u has conflicting kinds for UBO '%s'",
                                 binding, ubo.name.c_str());
                 entry.bindingKinds[binding] = DescriptorBindingKind::UniformBufferDynamic;
-                MOBILEGL_ASSERT(entry.globalUboBinding != static_cast<Int>(binding),
+                entry.bindingDescriptorCounts[binding] = static_cast<Uint16>(descriptorCount);
-                                "ProgramFactory::ReflectLayout: regular UBO '%s' collides with global UBO binding %u",
+                entry.uniformBlockIndexByBinding[binding] = elementBlockIndices[0];
-                                ubo.name.c_str(), binding);
+                entry.arrayedUniformBlockIndicesByBinding[binding] = Move(elementBlockIndices);
-                MOBILEGL_ASSERT(entry.uniformBlockIndexByBinding[binding] < 0 ||
-                                    entry.uniformBlockIndexByBinding[binding] == static_cast<Int>(blockIndex),
-                                "ProgramFactory::ReflectLayout: descriptor binding %u maps to conflicting UBO blocks (%d vs %u)",
-                                binding, entry.uniformBlockIndexByBinding[binding], blockIndex);
-                entry.uniformBlockIndexByBinding[binding] = static_cast<Int>(blockIndex);
             }
 
             // Reflect sampled images, storage images, samplerBuffer uniforms, and SSBOs.
@@ -1819,7 +1905,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
             VkDescriptorSetLayoutBinding layoutBinding{};
             layoutBinding.binding = binding;
-            layoutBinding.descriptorCount = 1;
+            layoutBinding.descriptorCount = entry.bindingDescriptorCounts[binding];
             layoutBinding.stageFlags = VK_SHADER_STAGE_ALL;
             layoutBinding.pImmutableSamplers = nullptr;
             if (kind == DescriptorBindingKind::UniformBufferDynamic) {

MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.h

@@ -59,6 +59,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             Vector<DescriptorBindingKind> bindingKinds;
             Vector<Uint32> dynamicBindings;
             Vector<Int> uniformBlockIndexByBinding;
+            // Descriptor count per binding (1 except for UBO instance arrays, which occupy one
+            // binding with descriptorCount = N).
+            Vector<Uint16> bindingDescriptorCounts;
+            // Per-element GL uniform block indices for arrayed UBO bindings (count > 1);
+            // element 0 of a non-arrayed binding stays in uniformBlockIndexByBinding.
+            UnorderedMap<Uint32, Vector<Int>> arrayedUniformBlockIndicesByBinding;
             Vector<String> samplerNameByBinding;
             Vector<Int> samplerUniformLocationByBinding;
             Vector<TextureTarget> samplerTextureTargetByBinding;
@@ -97,6 +103,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 bindingKinds = std::move(other.bindingKinds);
                 dynamicBindings = std::move(other.dynamicBindings);
                 uniformBlockIndexByBinding = std::move(other.uniformBlockIndexByBinding);
+                bindingDescriptorCounts = std::move(other.bindingDescriptorCounts);
+                arrayedUniformBlockIndicesByBinding = std::move(other.arrayedUniformBlockIndicesByBinding);
                 samplerNameByBinding = std::move(other.samplerNameByBinding);
                 samplerUniformLocationByBinding = std::move(other.samplerUniformLocationByBinding);
                 samplerTextureTargetByBinding = std::move(other.samplerTextureTargetByBinding);
@@ -141,6 +149,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 bindingKinds = std::move(other.bindingKinds);
                 dynamicBindings = std::move(other.dynamicBindings);
                 uniformBlockIndexByBinding = std::move(other.uniformBlockIndexByBinding);
+                bindingDescriptorCounts = std::move(other.bindingDescriptorCounts);
+                arrayedUniformBlockIndicesByBinding = std::move(other.arrayedUniformBlockIndicesByBinding);
                 samplerNameByBinding = std::move(other.samplerNameByBinding);
                 samplerUniformLocationByBinding = std::move(other.samplerUniformLocationByBinding);
                 samplerTextureTargetByBinding = std::move(other.samplerTextureTargetByBinding);

MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.cpp

@@ -765,7 +765,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
     Bool UniformManager::ResolveUniformBufferPayload(const MG_State::GLState::ProgramObject& program,
                                                      const ProgramFactory::VkProgramObject& programObj, Uint32 binding,
-                                                     UboBindResult& out) const {
+                                                     Uint32 arrayElement, UboBindResult& out) const {
         const void* outData = nullptr;
         VkDeviceSize outSize = 0;
 
@@ -791,7 +791,19 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
         MOBILEGL_ASSERT(binding < programObj.uniformBlockIndexByBinding.size(),
                         "ResolveUniformBufferPayload: UBO mapping binding %u out of range", binding);
-        const Int blockIndex = programObj.uniformBlockIndexByBinding[binding];
+        Int blockIndex = programObj.uniformBlockIndexByBinding[binding];
+        if (arrayElement > 0) {
+            const auto arrayIt = programObj.arrayedUniformBlockIndicesByBinding.find(binding);
+            const Bool elementValid = arrayIt != programObj.arrayedUniformBlockIndicesByBinding.end() &&
+                                      arrayElement < arrayIt->second.size();
+            MOBILEGL_ASSERT(elementValid,
+                            "ResolveUniformBufferPayload: UBO binding %u has no array element %u", binding,
+                            arrayElement);
+            if (!elementValid) {
+                return false;
+            }
+            blockIndex = arrayIt->second[arrayElement];
+        }
         MOBILEGL_ASSERT(blockIndex >= 0,
                         "ResolveUniformBufferPayload: no uniform block mapped to descriptor binding %u", binding);
 
@@ -1038,11 +1050,17 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         imageInfos.clear();
         texelBufferViews.clear();
         dynamicOffsets.clear();
+        // Arrayed UBO bindings contribute extra buffer infos and dynamic offsets; reserve for
+        // the worst case so the pBufferInfo pointers taken below never dangle on reallocation.
+        Uint32 uboArrayExtra = 0;
+        for (const auto& arrayEntry : programObj.arrayedUniformBlockIndicesByBinding) {
+            uboArrayExtra += static_cast<Uint32>(arrayEntry.second.size()) - 1u;
+        }
         writes.reserve(m_maxBindings);
-        bufferInfos.reserve(m_maxBindings);
+        bufferInfos.reserve(m_maxBindings + uboArrayExtra);
         imageInfos.reserve(m_maxBindings);
         texelBufferViews.reserve(m_maxBindings);
-        dynamicOffsets.reserve(programObj.dynamicBindings.size());
+        dynamicOffsets.reserve(programObj.dynamicBindings.size() + uboArrayExtra);
 
         const Uint32 bindingCount =
             std::min<Uint32>(m_maxBindings, static_cast<Uint32>(programObj.bindingKinds.size()));
@@ -1060,40 +1078,51 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             write.descriptorCount = 1;
 
             if (kind == ProgramFactory::DescriptorBindingKind::UniformBufferDynamic) {
-                UboBindResult ubo{};
+                const Uint32 descriptorCount =
-                const Bool hasPayload = ResolveUniformBufferPayload(program, programObj, binding, ubo);
+                    binding < programObj.bindingDescriptorCounts.size()
-                MOBILEGL_ASSERT(hasPayload && ubo.payload != nullptr && ubo.payloadSize > 0,
+                        ? std::max<Uint32>(1, programObj.bindingDescriptorCounts[binding])
-                                "UniformDescriptorBinder::BindProgramUniformBuffers failed: missing UBO payload on binding %u",
+                        : 1u;
-                                binding);
+                const SizeT firstBufferInfoIndex = bufferInfos.size();
+                for (Uint32 element = 0; element < descriptorCount; ++element) {
+                    UboBindResult ubo{};
+                    const Bool hasPayload =
+                        ResolveUniformBufferPayload(program, programObj, binding, element, ubo);
+                    MOBILEGL_ASSERT(hasPayload && ubo.payload != nullptr && ubo.payloadSize > 0,
+                                    "UniformDescriptorBinder::BindProgramUniformBuffers failed: missing UBO payload on binding %u element %u",
+                                    binding, element);
 
-                VkDescriptorBufferInfo bufferInfo{};
+                    VkDescriptorBufferInfo bufferInfo{};
-                // Keep offset 0 (sub-range selected via the dynamic offset) so the hashed bufferInfo
+                    // Keep offset 0 (sub-range selected via the dynamic offset) so the hashed bufferInfo
-                // is stable across draws and the descriptor-set reuse cache keeps hitting.
+                    // is stable across draws and the descriptor-set reuse cache keeps hitting.
-                bufferInfo.offset = 0;
+                    bufferInfo.offset = 0;
-                Uint32 dynOffset;
+                    Uint32 dynOffset;
-                if (ubo.directBindable) {
+                    if (ubo.directBindable) {
-                    // Zero-copy: bind the app's resident VkBuffer directly, no per-draw memcpy.
+                        // Zero-copy: bind the app's resident VkBuffer directly, no per-draw memcpy.
-                    bufferInfo.buffer = ubo.buffer;
+                        bufferInfo.buffer = ubo.buffer;
-                    bufferInfo.range = ubo.range;
+                        bufferInfo.range = ubo.range;
-                    dynOffset = static_cast<Uint32>(ubo.dynamicOffset);
+                        dynOffset = static_cast<Uint32>(ubo.dynamicOffset);
-                } else {
+                    } else {
-                    BufferSlice slice{};
+                        BufferSlice slice{};
-                    if (!m_bufferManager->UploadTransient(BufferKind::Uniform, frameIndex, ubo.payload,
+                        if (!m_bufferManager->UploadTransient(BufferKind::Uniform, frameIndex, ubo.payload,
-                                                          ubo.payloadSize, m_minDynamicOffsetAlignment, slice)) {
+                                                              ubo.payloadSize, m_minDynamicOffsetAlignment, slice)) {
-                        MOBILEGL_ASSERT(false, "UniformDescriptorBinder::BindProgramUniformBuffers failed: UBO upload failed on binding %u",
+                            MOBILEGL_ASSERT(false, "UniformDescriptorBinder::BindProgramUniformBuffers failed: UBO upload failed on binding %u element %u",
-                                binding);
+                                    binding, element);
-                        return false;
+                            return false;
+                        }
+                        bufferInfo.buffer = slice.buffer;
+                        bufferInfo.range = ubo.payloadSize;
+                        dynOffset = static_cast<Uint32>(slice.offset);
                     }
-                    bufferInfo.buffer = slice.buffer;
+                    bufferInfos.push_back(bufferInfo);
-                    bufferInfo.range = ubo.payloadSize;
+                    // Dynamic offsets are consumed in binding order, then array element order,
-                    dynOffset = static_cast<Uint32>(slice.offset);
+                    // matching Vulkan's dynamic-offset consumption rules.
+                    dynamicOffsets.push_back(dynOffset);
                 }
-                bufferInfos.push_back(bufferInfo);
 
                 write.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC;
-                write.pBufferInfo = &bufferInfos.back();
+                write.descriptorCount = descriptorCount;
+                write.pBufferInfo = &bufferInfos[firstBufferInfoIndex];
                 writes.push_back(write);
-                dynamicOffsets.push_back(dynOffset);
             } else if (kind == ProgramFactory::DescriptorBindingKind::UniformTexelBuffer) {
                 VkBufferView bufferView = VK_NULL_HANDLE;
                 if (!ResolveTexelBufferDescriptor(program, programObj, binding, frameIndex, bufferView) ||

MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.h

@@ -116,7 +116,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         };
         Bool ResolveUniformBufferPayload(const MG_State::GLState::ProgramObject& program,
                                          const ProgramFactory::VkProgramObject& programObj, Uint32 binding,
-                                         UboBindResult& out) const;
+                                         Uint32 arrayElement, UboBindResult& out) const;
         Bool CreateDescriptorPool(Uint32 maxSets, VkDescriptorPool& outPool) const;
         Bool GrowFrameDescriptorPool(FrameResources& frame, Uint32 frameIndex);
         VkResult AllocateDescriptorSetsFromActivePool(