Added DrawMeshIndirectCount command.

3 files changed, 154 insertions, 16 deletions

diff --git a/Graphics/GraphicsEngine/include/DeviceContextBase.hpp b/Graphics/GraphicsEngine/include/DeviceContextBase.hpp
index 87433ea5..769f8f01 100644
--- a/Graphics/GraphicsEngine/include/DeviceContextBase.hpp
+++ b/Graphics/GraphicsEngine/include/DeviceContextBase.hpp
@@ -57,6 +57,7 @@ bool VerifyDispatchComputeIndirectAttribs(const DispatchComputeIndirectAttribs&
 
 bool VerifyDrawMeshAttribs(Uint32 MaxDrawMeshTasksCount, const DrawMeshAttribs& Attribs);
 bool VerifyDrawMeshIndirectAttribs(const DrawMeshIndirectAttribs& Attribs, const IBuffer* pAttribsBuffer);
+bool VerifyDrawMeshIndirectCountAttribs(const DrawMeshIndirectCountAttribs& Attribs, const IBuffer* pAttribsBuffer, const IBuffer* pCountBuff, Uint32 IndirectCmdStride);
 
 bool VerifyResolveTextureSubresourceAttribs(const ResolveTextureSubresourceAttribs& ResolveAttribs,
                                             const TextureDesc&                      SrcTexDesc,
@@ -72,7 +73,10 @@ bool VerifyCopyTLASAttribs(const CopyTLASAttribs& Attribs);
 bool VerifyWriteBLASCompactedSizeAttribs(const IRenderDevice* pDevice, const WriteBLASCompactedSizeAttribs& Attribs);
 bool VerifyWriteTLASCompactedSizeAttribs(const IRenderDevice* pDevice, const WriteTLASCompactedSizeAttribs& Attribs);
 bool VerifyTraceRaysAttribs(const TraceRaysAttribs& Attribs);
-bool VerifyTraceRaysIndirectAttribs(const IRenderDevice* pDevice, const TraceRaysIndirectAttribs& Attribs, const IBuffer* pAttribsBuffer, Uint32 SBTSize);
+bool VerifyTraceRaysIndirectAttribs(const IRenderDevice*            pDevice,
+                                    const TraceRaysIndirectAttribs& Attribs,
+                                    const IBuffer*                  pAttribsBuffer,
+                                    Uint32                          SBTSize);
 
 
 
@@ -290,12 +294,13 @@ protected:
 
 #ifdef DILIGENT_DEVELOPMENT
     // clang-format off
-    bool DvpVerifyDrawArguments               (const DrawAttribs&                Attribs) const;
-    bool DvpVerifyDrawIndexedArguments        (const DrawIndexedAttribs&         Attribs) const;
-    bool DvpVerifyDrawMeshArguments           (const DrawMeshAttribs&            Attribs) const;
-    bool DvpVerifyDrawIndirectArguments       (const DrawIndirectAttribs&        Attribs, const IBuffer* pAttribsBuffer) const;
-    bool DvpVerifyDrawIndexedIndirectArguments(const DrawIndexedIndirectAttribs& Attribs, const IBuffer* pAttribsBuffer) const;
-    bool DvpVerifyDrawMeshIndirectArguments   (const DrawMeshIndirectAttribs&    Attribs, const IBuffer* pAttribsBuffer) const;
+    bool DvpVerifyDrawArguments                 (const DrawAttribs&                  Attribs) const;
+    bool DvpVerifyDrawIndexedArguments          (const DrawIndexedAttribs&           Attribs) const;
+    bool DvpVerifyDrawMeshArguments             (const DrawMeshAttribs&              Attribs) const;
+    bool DvpVerifyDrawIndirectArguments         (const DrawIndirectAttribs&          Attribs, const IBuffer* pAttribsBuffer) const;
+    bool DvpVerifyDrawIndexedIndirectArguments  (const DrawIndexedIndirectAttribs&   Attribs, const IBuffer* pAttribsBuffer) const;
+    bool DvpVerifyDrawMeshIndirectArguments     (const DrawMeshIndirectAttribs&      Attribs, const IBuffer* pAttribsBuffer) const;
+    bool DvpVerifyDrawMeshIndirectCountArguments(const DrawMeshIndirectCountAttribs& Attribs, const IBuffer* pAttribsBuffer, const IBuffer* pCountBuff) const;
 
     bool DvpVerifyDispatchArguments        (const DispatchComputeAttribs& Attribs) const;
     bool DvpVerifyDispatchIndirectArguments(const DispatchComputeIndirectAttribs& Attribs, const IBuffer* pAttribsBuffer) const;
@@ -307,12 +312,13 @@ protected:
     bool DvpVerifyBLASState   (const BottomLevelASType& BLAS,    RESOURCE_STATE RequiredState, const char* OperationName) const;
     bool DvpVerifyTLASState   (const TopLevelASType&    TLAS,    RESOURCE_STATE RequiredState, const char* OperationName) const;
 #else
-    bool DvpVerifyDrawArguments               (const DrawAttribs&                Attribs)const {return true;}
-    bool DvpVerifyDrawIndexedArguments        (const DrawIndexedAttribs&         Attribs)const {return true;}
-    bool DvpVerifyDrawMeshArguments           (const DrawMeshAttribs&            Attribs)const {return true;}
-    bool DvpVerifyDrawIndirectArguments       (const DrawIndirectAttribs&        Attribs, const IBuffer* pAttribsBuffer)const {return true;}
-    bool DvpVerifyDrawIndexedIndirectArguments(const DrawIndexedIndirectAttribs& Attribs, const IBuffer* pAttribsBuffer)const {return true;}
-    bool DvpVerifyDrawMeshIndirectArguments   (const DrawMeshIndirectAttribs&    Attribs, const IBuffer* pAttribsBuffer)const {return true;}
+    bool DvpVerifyDrawArguments                 (const DrawAttribs&                  Attribs)const {return true;}
+    bool DvpVerifyDrawIndexedArguments          (const DrawIndexedAttribs&           Attribs)const {return true;}
+    bool DvpVerifyDrawMeshArguments             (const DrawMeshAttribs&              Attribs)const {return true;}
+    bool DvpVerifyDrawIndirectArguments         (const DrawIndirectAttribs&          Attribs, const IBuffer* pAttribsBuffer)const {return true;}
+    bool DvpVerifyDrawIndexedIndirectArguments  (const DrawIndexedIndirectAttribs&   Attribs, const IBuffer* pAttribsBuffer)const {return true;}
+    bool DvpVerifyDrawMeshIndirectArguments     (const DrawMeshIndirectAttribs&      Attribs, const IBuffer* pAttribsBuffer)const {return true;}
+    bool DvpVerifyDrawMeshIndirectCountArguments(const DrawMeshIndirectCountAttribs& Attribs, const IBuffer* pAttribsBuffer, const IBuffer* pCountBuff) const {return true;}
 
     bool DvpVerifyDispatchArguments        (const DispatchComputeAttribs& Attribs)const {return true;}
     bool DvpVerifyDispatchIndirectArguments(const DispatchComputeIndirectAttribs& Attribs, const IBuffer* pAttribsBuffer)const {return true;}
@@ -335,8 +341,10 @@ protected:
     bool TraceRays(const TraceRaysAttribs& Attribs, int) const;
     bool TraceRaysIndirect(const TraceRaysIndirectAttribs& Attribs, IBuffer* pAttribsBuffer, int) const;
 
-    static constexpr Uint32 TraceRaysIndirectCommandSBTSize = 88; // D3D12: 88 bytes, size of SBT offsets
-                                                                  // Vulkan: 0 bytes, SBT offsets placed directly into function call
+    static constexpr Uint32 DrawMeshIndirectCommandStride = sizeof(uint) * 3; // D3D12: 12 bytes (x, y, z dimension)
+                                                                              // Vulkan: 8 bytes (task count, first task)
+    static constexpr Uint32 TraceRaysIndirectCommandSBTSize = 88;             // D3D12: 88 bytes, size of SBT offsets
+                                                                              // Vulkan: 0 bytes, SBT offsets placed directly into function call
 
     /// Strong reference to the device.
     RefCntAutoPtr<DeviceImplType> m_pDevice;
@@ -1895,6 +1903,37 @@ inline bool DeviceContextBase<ImplementationTraits>::DvpVerifyDrawMeshIndirectAr
 }
 
 template <typename ImplementationTraits>
+inline bool DeviceContextBase<ImplementationTraits>::DvpVerifyDrawMeshIndirectCountArguments(
+    const DrawMeshIndirectCountAttribs& Attribs,
+    const IBuffer*                      pAttribsBuffer,
+    const IBuffer*                      pCountBuff) const
+{
+    if ((Attribs.Flags & DRAW_FLAG_VERIFY_DRAW_ATTRIBS) == 0)
+        return true;
+
+    if (m_pDevice->GetDeviceCaps().Features.MeshShaders != DEVICE_FEATURE_STATE_ENABLED)
+    {
+        LOG_ERROR_MESSAGE("DrawMeshIndirectCount: mesh shaders are not supported by this device");
+        return false;
+    }
+
+    if (!m_pPipelineState)
+    {
+        LOG_ERROR_MESSAGE("DrawMeshIndirectCount command arguments are invalid: no pipeline state is bound.");
+        return false;
+    }
+
+    if (m_pPipelineState->GetDesc().PipelineType != PIPELINE_TYPE_MESH)
+    {
+        LOG_ERROR_MESSAGE("DrawMeshIndirectCount command arguments are invalid: pipeline state '",
+                          m_pPipelineState->GetDesc().Name, "' is not a mesh pipeline.");
+        return false;
+    }
+
+    return VerifyDrawMeshIndirectCountAttribs(Attribs, pAttribsBuffer, pCountBuff, DrawMeshIndirectCommandStride);
+}
+
+template <typename ImplementationTraits>
 inline bool DeviceContextBase<ImplementationTraits>::DvpVerifyRenderTargets() const
 {
     if (!m_pPipelineState)
diff --git a/Graphics/GraphicsEngine/interface/DeviceContext.h b/Graphics/GraphicsEngine/interface/DeviceContext.h
index 5800ad76..b5909451 100644
--- a/Graphics/GraphicsEngine/interface/DeviceContext.h
+++ b/Graphics/GraphicsEngine/interface/DeviceContext.h
@@ -434,6 +434,49 @@ struct DrawMeshIndirectAttribs
 typedef struct DrawMeshIndirectAttribs DrawMeshIndirectAttribs;
 
 
+/// Defines the mesh indirect draw count command attributes.
+
+/// This structure is used by IDeviceContext::DrawMeshIndirectCount().
+struct DrawMeshIndirectCountAttribs
+{
+    /// Additional flags, see Diligent::DRAW_FLAGS.
+    DRAW_FLAGS Flags                DEFAULT_INITIALIZER(DRAW_FLAG_NONE);
+
+    /// The maximum number of commands that will be read from the count buffer.
+    Uint32     MaxCommandCount      DEFAULT_INITIALIZER(1);
+
+    /// State transition mode for indirect draw arguments buffer.
+    RESOURCE_STATE_TRANSITION_MODE IndirectAttribsBufferStateTransitionMode DEFAULT_INITIALIZER(RESOURCE_STATE_TRANSITION_MODE_NONE);
+
+    /// Offset from the beginning of the buffer to the location of draw command attributes.
+    Uint32 IndirectDrawArgsOffset        DEFAULT_INITIALIZER(0);
+
+    /// State transition mode for the count buffer.
+    RESOURCE_STATE_TRANSITION_MODE CountBufferStateTransitionMode DEFAULT_INITIALIZER(RESOURCE_STATE_TRANSITION_MODE_NONE);
+
+    /// Offset from the beginning of the buffer to the location of the command counter.
+    Uint32 CountBufferOffset        DEFAULT_INITIALIZER(0);
+
+#if DILIGENT_CPP_INTERFACE
+    DrawMeshIndirectCountAttribs()noexcept{}
+
+    /// Initializes the structure members with user-specified values.
+    DrawMeshIndirectCountAttribs(DRAW_FLAGS                     _Flags,
+                                 RESOURCE_STATE_TRANSITION_MODE _IndirectAttribsBufferStateTransitionMode,
+                                 Uint32                         _IndirectDrawArgsOffset,
+                                 RESOURCE_STATE_TRANSITION_MODE _CountBufferStateTransitionMode,
+                                 Uint32                         _CountBufferOffset)noexcept : 
+        Flags                                   {_Flags                                   },
+        IndirectAttribsBufferStateTransitionMode{_IndirectAttribsBufferStateTransitionMode},
+        IndirectDrawArgsOffset                  {_IndirectDrawArgsOffset                  },
+        CountBufferStateTransitionMode          {_CountBufferStateTransitionMode          },
+        CountBufferOffset                       {_CountBufferOffset                       }
+    {}
+#endif
+};
+typedef struct DrawMeshIndirectCountAttribs DrawMeshIndirectCountAttribs;
+
+
 /// Defines which parts of the depth-stencil buffer to clear.
 
 /// These flags are used by IDeviceContext::ClearDepthStencil().
@@ -1765,8 +1808,38 @@ DILIGENT_BEGIN_INTERFACE(IDeviceContext, IObject)
                                           IBuffer*                          pAttribsBuffer) PURE;
 
 
+    /// Executes an mesh indirect draw command with indirect command count buffer.
+
+    /// \param [in] Attribs        - Structure describing the command attributes, see Diligent::DrawMeshIndirectCountAttribs for details.
+    /// \param [in] pAttribsBuffer - Pointer to the buffer, from which indirect draw attributes will be read.
+    ///                              The buffer must contain the following arguments at the specified offset:
+    ///                                Direct3D12:
+    ///                                     Uint32 ThreadGroupCountX;
+    ///                                     Uint32 ThreadGroupCountY;
+    ///                                     Uint32 ThreadGroupCountZ;
+    ///                                Vulkan:
+    ///                                     Uint32 TaskCount;
+    ///                                     Uint32 FirstTask;
+    ///                              Size of the buffer must be sizeof(Uint32[3]) * Attribs.MaxDrawCommands.
+    /// \param [in] pCountBuffer   - Pointer to the buffer, from which Uint32 value with draw count will be read.
+    /// 
+    /// \remarks  For compatibility between Direct3D12 and Vulkan and with direct call (DrawMesh) use the first element in the structure,
+    ///           for example: Direct3D12 {TaskCount, 1, 1}, Vulkan {TaskCount, 0}.
+    /// 
+    /// \remarks  If IndirectAttribsBufferStateTransitionMode member is Diligent::RESOURCE_STATE_TRANSITION_MODE_TRANSITION,
+    ///           the method may transition the state of the indirect draw arguments buffer. This is not a thread safe operation, 
+    ///           so no other thread is allowed to read or write the state of the buffer.
+    /// 
+    ///           If the application intends to use the same resources in other threads simultaneously, it needs to 
+    ///           explicitly manage the states using IDeviceContext::TransitionResourceStates() method.
+    VIRTUAL void METHOD(DrawMeshIndirectCount)(THIS_
+                                               const DrawMeshIndirectCountAttribs REF Attribs,
+                                               IBuffer*                               pAttribsBuffer,
+                                               IBuffer*                               pCountBuffer) PURE;
+
+
     /// Executes a dispatch compute command.
-    
+
     /// \param [in] Attribs - Dispatch command attributes, see Diligent::DispatchComputeAttribs for details.
     VIRTUAL void METHOD(DispatchCompute)(THIS_
                                          const DispatchComputeAttribs REF Attribs) PURE;
@@ -2264,6 +2337,7 @@ DILIGENT_END_INTERFACE
 #    define IDeviceContext_DrawIndexedIndirect(This, ...)       CALL_IFACE_METHOD(DeviceContext, DrawIndexedIndirect,       This, __VA_ARGS__)
 #    define IDeviceContext_DrawMesh(This, ...)                  CALL_IFACE_METHOD(DeviceContext, DrawMesh,                  This, __VA_ARGS__)
 #    define IDeviceContext_DrawMeshIndirect(This, ...)          CALL_IFACE_METHOD(DeviceContext, DrawMeshIndirect,          This, __VA_ARGS__)
+#    define IDeviceContext_DrawMeshIndirectCount(This, ...)     CALL_IFACE_METHOD(DeviceContext, DrawMeshIndirectCount,     This, __VA_ARGS__)
 #    define IDeviceContext_DispatchCompute(This, ...)           CALL_IFACE_METHOD(DeviceContext, DispatchCompute,           This, __VA_ARGS__)
 #    define IDeviceContext_DispatchComputeIndirect(This, ...)   CALL_IFACE_METHOD(DeviceContext, DispatchComputeIndirect,   This, __VA_ARGS__)
 #    define IDeviceContext_ClearDepthStencil(This, ...)         CALL_IFACE_METHOD(DeviceContext, ClearDepthStencil,         This, __VA_ARGS__)
diff --git a/Graphics/GraphicsEngine/src/DeviceContextBase.cpp b/Graphics/GraphicsEngine/src/DeviceContextBase.cpp
index 1e0a3b11..2561db62 100644
--- a/Graphics/GraphicsEngine/src/DeviceContextBase.cpp
+++ b/Graphics/GraphicsEngine/src/DeviceContextBase.cpp
@@ -136,6 +136,31 @@ bool VerifyDrawMeshIndirectAttribs(const DrawMeshIndirectAttribs& Attribs, const
     return true;
 }
 
+bool VerifyDrawMeshIndirectCountAttribs(const DrawMeshIndirectCountAttribs& Attribs, const IBuffer* pAttribsBuffer, const IBuffer* pCountBuff, Uint32 IndirectCmdStride)
+{
+#define CHECK_DRAW_MESH_INDIRECT_COUNT_ATTRIBS(Expr, ...) CHECK_PARAMETER(Expr, "Draw mesh indirect count attribs are invalid: ", __VA_ARGS__)
+
+    CHECK_DRAW_MESH_INDIRECT_COUNT_ATTRIBS(pAttribsBuffer != nullptr, "indirect draw arguments buffer must not be null.");
+
+    const auto& IDesc = pAttribsBuffer->GetDesc();
+    CHECK_DRAW_MESH_INDIRECT_COUNT_ATTRIBS((IDesc.BindFlags & BIND_INDIRECT_DRAW_ARGS) != 0,
+                                           "indirect draw arguments buffer '", IDesc.Name, "' was not created with BIND_INDIRECT_DRAW_ARGS flag.");
+    CHECK_DRAW_MESH_INDIRECT_COUNT_ATTRIBS(Attribs.IndirectDrawArgsOffset + IndirectCmdStride * Attribs.MaxCommandCount <= IDesc.uiSizeInBytes,
+                                           "invalid IndirectDrawArgsOffset or indirect draw arguments buffer '", IDesc.Name, "' is too small.");
+
+    CHECK_DRAW_MESH_INDIRECT_COUNT_ATTRIBS(pCountBuff != nullptr, "count buffer must not be null.");
+
+    const auto& CDesc = pAttribsBuffer->GetDesc();
+    CHECK_DRAW_MESH_INDIRECT_COUNT_ATTRIBS((CDesc.BindFlags & BIND_INDIRECT_DRAW_ARGS) != 0,
+                                           "count buffer '", CDesc.Name, "' was not created with BIND_INDIRECT_DRAW_ARGS flag.");
+    CHECK_DRAW_MESH_INDIRECT_COUNT_ATTRIBS(Attribs.CountBufferOffset + 4 <= CDesc.uiSizeInBytes,
+                                           "invalid CountBufferOffset or count buffer '", CDesc.Name, "' is too small.");
+
+#undef CHECK_DRAW_MESH_INDIRECT_COUNT_ATTRIBS
+
+    return true;
+}
+
 
 bool VerifyDispatchComputeAttribs(const DispatchComputeAttribs& Attribs)
 {