Vulkan: Descriptor Set Layouts by ArthurFriedri-ch · Pull Request #3679 · OGRECave/ogre

ArthurFriedri-ch · 2026-07-20T15:22:09Z

This pull request implements Vulkan's descriptor set layouts.

The primary use case is for enabling compute shaders under Vulkan.
A further layout provides double the texture units for multitexturing use cases; the Terrain sample has been updated to take advantage of it.

# Conflicts: # RenderSystems/Vulkan/src/OgreVulkanDevice.cpp # RenderSystems/Vulkan/src/OgreVulkanRenderSystem.cpp

ArthurFriedri-ch · 2026-07-23T11:28:02Z

+        // Automatically disable normal & parallax mapping if card cannot handle it
+        // We do this rather than having a specific technique for it since it's simpler
+        auto rsc = Root::getSingletonPtr()->getRenderSystem()->getCapabilities();
+        const uint8 requiredLayers = getRequiredLayers(terrain, mPSSM);
+
+        if( requiredLayers > rsc->getNumTextureUnits() )
+        {
+            if( requiredLayers <= rsc->getNumTextureUnitsWide() )
+            {
+                // fits in the wider profile — no need to disable features
+                pass->setDescriptorProfileHint( DescriptorProfileHint::AllUnits );
+            }
+            else
+            {
+                // still doesn't fit even with the widest available profile — fall back as before
+                setLayerNormalMappingEnabled(false);
+                setLayerParallaxMappingEnabled(false);
+                LogManager::getSingleton().logWarning(
+                    "TerrainMaterialGeneratorA: Normal mapping disabled due to lack of texture units");
+            }
+        }
+


Simply set the profile, more is not necessary.

ArthurFriedri-ch · 2026-07-23T11:28:58Z

Revert - do DescriptorProfileHint on the GpuProgram, not here in pass.

ArthurFriedri-ch · 2026-07-23T11:30:03Z

ArthurFriedri-ch · 2026-07-23T11:31:16Z

Catch this case in Vulkan
Specifically:
In _setTexture, not here.

ArthurFriedri-ch · 2026-07-23T11:33:09Z

ArthurFriedri-ch · 2026-07-23T11:33:58Z

        setupBaseParamDictionary();
+        ParamDictionary* dict = getParamDictionary();
+        dict->addParameter(ParameterDef("descriptor_set_profile", "Descriptor set profile override. Values: Auto, "
+                                          "Graphics, Compute, AllUnits", PT_STRING), &msCmdDescriptorSetProfile);


This is unused, delete comment.

ArthurFriedri-ch · 2026-07-23T11:34:42Z


    mAssemblerProgram =
        GpuProgramManager::getSingleton().createProgram(mName + "/Delegate", mGroup, mSyntaxCode, mType);
+    if (!mDescriptorSetProfile.empty())


remove empty check

ArthurFriedri-ch · 2026-07-23T11:37:08Z


        static VkInstance createInstance( FastArray<const char *> &extensions,
                                          FastArray<const char *> &layers,
-                                          PFN_vkDebugReportCallbackEXT debugCallback );


Revert here, include in another branch.

ArthurFriedri-ch · 2026-07-23T11:38:52Z

        ///
        /// Thus we generate VkRenderPass and FBOs together
        VkRenderPass mRenderPass;
+        VkRenderPass mRenderPassLoad;


Revert in this branch

ArthurFriedri-ch · 2026-07-23T11:41:05Z

        VkPipelineShaderStageCreateInfo getPipelineShaderStageCi() const;

        uint32 getDrawIdLocation() const { return mDrawIdLocation; }
+        DescriptorSetProfileHint getDescriptorSetProfileHint() const { return mDescriptorSetProfileHint; }


same naming as GLSLANG

ArthurFriedri-ch · 2026-07-23T11:42:14Z

+                                              "Descriptor set profile override. Values: Auto, "
+                                              "Graphics, Compute, AllUnits",
+                                              PT_STRING ),
+                                &msDescriptorSetProfileCmd );


delete comment

ArthurFriedri-ch · 2026-07-23T11:43:55Z

+            allUnits.writes[i + 2].dstBinding = 2 + i;
+            allUnits.writes[i + 2].descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
+            allUnits.writes[i + 2].pImageInfo = mImageInfos.data() + i;
+            allUnits.writes[i + 2].descriptorCount = 1;


Split into sub functions for initialisation

ArthurFriedri-ch · 2026-07-23T11:46:46Z

+        }
+
+        mActiveDevice->mGraphicsQueue.getComputeEncoder();
+        VkCommandBuffer cmdBuffer = mActiveDevice->mGraphicsQueue.mCurrentCmdBuffer;


remove debug content; assert invariants instead of silently doing nothing

ArthurFriedri-ch · 2026-07-23T11:50:06Z

+        if(!prg)
+        {
+            LogManager::getSingleton().logError("[Vulkan] bindGpuProgram got null program");
+            return;
+        }
+
+        auto shader = dynamic_cast<VulkanProgram*>(prg);
+        if(!shader)
+        {
+            LogManager::getSingleton().logError(
+                "[Vulkan] bindGpuProgram got non-Vulkan program: name='" + prg->getName() +
+                "' syntax='" + prg->getSyntaxCode() + "'");
+            return;
+        }
+


compute program automatically switches to compute profile;
else fragment program sets the profile

ArthurFriedri-ch · 2026-07-23T11:51:10Z

-        int dstUBO = gptype % GPT_PIPELINE_COUNT;
+        // Graphics: vertex → slot 0, fragment → slot 1
+        // Compute:  always → slot 1  (matches Compute descriptor layout)
+        int dstUBO;
+        if( gptype == GPT_COMPUTE_PROGRAM )
+            dstUBO = 1;
+        else
+            dstUBO = gptype % GPT_PIPELINE_COUNT;


ArthurFriedri-ch · 2026-07-23T11:52:01Z

+    ushort VulkanRenderSystem::_getCurrentPassNumTextureUnits() const
+    {
+        return ( mBoundGraphicsProfile == AllUnits )
+            ? mRealCapabilities->getNumTextureUnitsWide()
+            : mRealCapabilities->getNumTextureUnits();
+    }


ArthurFriedri-ch · 2026-07-23T11:52:24Z

+    {
+        (void)access;
+        (void)textureArrayIndex;
+        (void)format;


not necessary, remove

ArthurFriedri-ch · 2026-07-23T11:52:51Z

+        (void)textureArrayIndex;
+        (void)format;
+
+        auto *rs = dynamic_cast<VulkanRenderSystem *>( Root::getSingleton().getRenderSystem() );


no dynamic_cast necessary, no if

ArthurFriedri-ch · 2026-07-23T11:53:48Z

@@ -2,8 +2,9 @@



introduce OgreUnifiedCompute.h

ArthurFriedri-ch · 2026-07-23T11:54:31Z

 //////////
 // GLSL //
 //////////
-compute_program Compute/CS_GLSL glsl


glsl + glslang

ArthurFriedri-ch · 2026-07-23T11:54:44Z

        source ComputeCS.glsl
-        syntax glsl430
-        has_sampler_binding true
+        descriptor_set_profile Compute


revert except syntax

ArthurFriedri-ch and others added 15 commits April 25, 2026 14:09

Added additional descriptor set layout in Vulkan for compute shader

534db15

Compute profile implementation

d424c65

Added shader texture access point for Vulkan compute

5e088e2

Added profile selection to materials

67936d1

Added Compute flag to Vulkan renderer capabilities

ea1144b

Merge branch 'master' into vulkan_descriptor_sets

5cbaea9

GLSLang can read custom descriptor set tag

934a138

lots of progress

b1bd629

almost there

0660819

done

5a3ec03

done

bbb8097

Merge branch 'master' into vulkan_descriptor_sets

290d738

done

0349ee3

Merge branch 'master' into vulkan_descriptor_sets

baf2b78

# Conflicts: # RenderSystems/Vulkan/src/OgreVulkanDevice.cpp # RenderSystems/Vulkan/src/OgreVulkanRenderSystem.cpp

done

8940b82

ArthurFriedri-ch changed the title ~~Vulkan: Descriptor Sets Layouts~~ Vulkan: Descriptor Set Layouts Jul 20, 2026

ArthurFriedri-ch added 3 commits July 23, 2026 12:38

Remove extraneous comments

23349c9

fix formatting

7a7b086

revert unintended edit

75f9644

ArthurFriedri-ch commented Jul 23, 2026

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Comment thread OgreMain/include/OgreRenderSystemCapabilities.h

ArthurFriedri-ch Jul 23, 2026

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Revert all

ArthurFriedri-ch commented Jul 23, 2026

View reviewed changes

Comment thread OgreMain/src/OgreSceneManager.cpp

ArthurFriedri-ch Jul 23, 2026

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Revert

ArthurFriedri-ch commented Jul 23, 2026

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ArthurFriedri-ch Jul 23, 2026 •

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