Implemented IFence interface in all backends

5 files changed, 89 insertions, 4 deletions

diff --git a/Graphics/GraphicsEngineOpenGL/include/DeviceContextGLImpl.h b/Graphics/GraphicsEngineOpenGL/include/DeviceContextGLImpl.h
index 3a28312a..f757f771 100644
--- a/Graphics/GraphicsEngineOpenGL/include/DeviceContextGLImpl.h
+++ b/Graphics/GraphicsEngineOpenGL/include/DeviceContextGLImpl.h
@@ -79,6 +79,8 @@ public:
 
     virtual void ExecuteCommandList(class ICommandList *pCommandList)override final;
 
+    virtual void SignalFence(IFence* pFence, Uint64 Value)override final;
+
     virtual bool UpdateCurrentGLContext()override final;
 
     void BindProgramResources( Uint32 &NewMemoryBarriers, IShaderResourceBinding *pResBinding );
diff --git a/Graphics/GraphicsEngineOpenGL/include/FenceGLImpl.h b/Graphics/GraphicsEngineOpenGL/include/FenceGLImpl.h
index 6756c467..e62a2a5c 100644
--- a/Graphics/GraphicsEngineOpenGL/include/FenceGLImpl.h
+++ b/Graphics/GraphicsEngineOpenGL/include/FenceGLImpl.h
@@ -26,9 +26,11 @@
 /// \file
 /// Declaration of Diligent::FenceGLImpl class
 
+#include <deque>
 #include "FenceGL.h"
 #include "RenderDeviceGL.h"
 #include "FenceBase.h"
+#include "GLObjectWrapper.h"
 
 namespace Diligent
 {
@@ -51,8 +53,15 @@ public:
     /// Resets the fence to the specified value. 
     virtual void Reset(Uint64 Value)override final;
 
-private:
+    void AddPendingFence(GLObjectWrappers::GLSyncObj&& Fence, Uint64 Value)
+    {
+        m_PendingFences.emplace_back(Value, std::move(Fence));
+    }
 
+private:
+    std::deque<std::pair<Uint64, GLObjectWrappers::GLSyncObj> > m_PendingFences;
+    volatile Uint64 m_LastCompletedFenceValue = 0;
 };
 
 }
+
diff --git a/Graphics/GraphicsEngineOpenGL/include/GLObjectWrapper.h b/Graphics/GraphicsEngineOpenGL/include/GLObjectWrapper.h
index 4da5932d..2ae4e74d 100644
--- a/Graphics/GraphicsEngineOpenGL/include/GLObjectWrapper.h
+++ b/Graphics/GraphicsEngineOpenGL/include/GLObjectWrapper.h
@@ -261,4 +261,44 @@ public:
 };
 typedef GLObjWrapper<GLRBOCreateReleaseHelper> GLRenderBufferObj;
     
+struct GLSyncObj
+{
+    GLSyncObj() {}
+    GLSyncObj(GLsync _SyncHandle) : SyncHandle(_SyncHandle) {}
+
+    GLSyncObj             (const GLSyncObj&) = delete;
+    GLSyncObj& operator = (const GLSyncObj&) = delete;
+    
+    GLSyncObj(GLSyncObj&& rhs)
+    {
+        SyncHandle     = rhs.SyncHandle;
+        rhs.SyncHandle = GLsync{};
+    }
+
+    GLSyncObj& operator = (GLSyncObj&& rhs)
+    {
+        Release();
+        SyncHandle     = rhs.SyncHandle;
+        rhs.SyncHandle = GLsync{};
+        return *this;
+    }
+
+    void Release()
+    {
+        if (SyncHandle != GLsync{})
+            glDeleteSync(SyncHandle);
+        SyncHandle = GLsync{};
+    }
+
+    ~GLSyncObj()
+    {
+        Release();
+    }
+
+    operator GLsync()const{return SyncHandle;}
+
+private:
+    GLsync SyncHandle = {};
+};
+
 }
diff --git a/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp b/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
index e07ce58f..a1509fbb 100644
--- a/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
@@ -43,6 +43,7 @@
 #include "GraphicsAccessories.h"
 #include "BufferViewGLImpl.h"
 #include "PipelineStateGLImpl.h"
+#include "FenceGLImpl.h"
 #include "ShaderResourceBindingGLImpl.h"
 
 using namespace std;
@@ -985,6 +986,19 @@ namespace Diligent
         LOG_ERROR("Deferred contexts are not supported in OpenGL mode");
     }
 
+    void DeviceContextGLImpl::SignalFence(IFence* pFence, Uint64 Value)
+    {
+        VERIFY(!m_bIsDeferred, "Fence can only be signalled from immediate context");
+        GLObjectWrappers::GLSyncObj GLFence( glFenceSync(
+                GL_SYNC_GPU_COMMANDS_COMPLETE, // Condition must always be GL_SYNC_GPU_COMMANDS_COMPLETE
+                0 // Flags, must be 0
+            )
+        );
+        CHECK_GL_ERROR( "Failed to create gl fence" );
+        auto* pFenceGLImpl = ValidatedCast<FenceGLImpl>(pFence);
+        pFenceGLImpl->AddPendingFence(std::move(GLFence), Value);
+    };
+
     bool DeviceContextGLImpl::UpdateCurrentGLContext()
     {
         auto *pRenderDeviceGL = m_pDevice.RawPtr<RenderDeviceGLImpl>();
diff --git a/Graphics/GraphicsEngineOpenGL/src/FenceGLImpl.cpp b/Graphics/GraphicsEngineOpenGL/src/FenceGLImpl.cpp
index 5074e364..3c222b41 100644
--- a/Graphics/GraphicsEngineOpenGL/src/FenceGLImpl.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/FenceGLImpl.cpp
@@ -42,13 +42,33 @@ FenceGLImpl :: ~FenceGLImpl()
 
 Uint64 FenceGLImpl :: GetCompletedValue()
 {
-    UNSUPPORTED("Not yet implemented");
-    return 0;
+    while (!m_PendingFences.empty())
+    {
+        auto& val_fence = m_PendingFences.front();
+        auto res = glClientWaitSync(val_fence.second, 
+            0, // Can be SYNC_FLUSH_COMMANDS_BIT
+            0  // Timeout in nanoseconds
+        );
+        if(res == GL_ALREADY_SIGNALED)
+        {
+            if (val_fence.first > m_LastCompletedFenceValue)
+                m_LastCompletedFenceValue = val_fence.first;
+            m_PendingFences.pop_front();
+        }
+        else
+        {
+            break;
+        }
+    }
+
+    return m_LastCompletedFenceValue;
 }
 
 void FenceGLImpl :: Reset(Uint64 Value)
 {
-    UNSUPPORTED("Not yet implemented");
+    DEV_CHECK_ERR(Value >= m_LastCompletedFenceValue, "Resetting fence '", m_Desc.Name, "' to the value (", Value, ") that is smaller than the last completed value (", m_LastCompletedFenceValue, ")");
+    if (Value > m_LastCompletedFenceValue)
+        m_LastCompletedFenceValue = Value;
 }
 
 }