Implemented queries in OpenGL

6 files changed, 144 insertions, 2 deletions

diff --git a/Graphics/GraphicsEngineOpenGL/include/GLObjectWrapper.h b/Graphics/GraphicsEngineOpenGL/include/GLObjectWrapper.h
index 80694be8..5e963b61 100644
--- a/Graphics/GraphicsEngineOpenGL/include/GLObjectWrapper.h
+++ b/Graphics/GraphicsEngineOpenGL/include/GLObjectWrapper.h
@@ -330,4 +330,14 @@ private:
     GLsync SyncHandle = {};
 };
 
+class GLQueryCreateReleaseHelper
+{
+public:
+    void Create(GLuint& Query) { glGenQueries(1, &Query); }
+    void Release(GLuint Query) { glDeleteQueries(1, &Query); }
+
+    static const char* Name;
+};
+typedef GLObjWrapper<GLQueryCreateReleaseHelper> GLQueryObj;
+
 } // namespace GLObjectWrappers
diff --git a/Graphics/GraphicsEngineOpenGL/include/QueryGLImpl.h b/Graphics/GraphicsEngineOpenGL/include/QueryGLImpl.h
index 08b2ed74..71379b66 100644
--- a/Graphics/GraphicsEngineOpenGL/include/QueryGLImpl.h
+++ b/Graphics/GraphicsEngineOpenGL/include/QueryGLImpl.h
@@ -54,9 +54,18 @@ public:
 
     IMPLEMENT_QUERY_INTERFACE_IN_PLACE(IID_QueryGL, TQueryBase);
 
+    /// Implementation of IQuery::GetData() in OpenGL backend.
     virtual bool GetData(void* pData, Uint32 DataSize) override final;
 
+
+    /// Implementation of IQueryGL::GetGlQueryHandle().
+    virtual GLuint GetGlQueryHandle() const override final
+    {
+        return m_GlQuery;
+    }
+
 private:
+    GLObjectWrappers::GLQueryObj m_GlQuery;
 };
 
 } // namespace Diligent
diff --git a/Graphics/GraphicsEngineOpenGL/interface/QueryGL.h b/Graphics/GraphicsEngineOpenGL/interface/QueryGL.h
index 9339626a..dc11eb86 100644
--- a/Graphics/GraphicsEngineOpenGL/interface/QueryGL.h
+++ b/Graphics/GraphicsEngineOpenGL/interface/QueryGL.h
@@ -43,6 +43,8 @@ static constexpr INTERFACE_ID IID_QueryGL =
 /// Exposes OpenGL-specific functionality of a Query object.
 class IQueryGL : public IQuery
 {
+    /// Returns OpenGL handle of an internal query object.
+    virtual GLuint GetGlQueryHandle() const = 0;
 };
 
 } // namespace Diligent
diff --git a/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp b/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
index beb549f8..6726eb6d 100644
--- a/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
@@ -1067,6 +1067,29 @@ void DeviceContextGLImpl::BeginQuery(IQuery* pQuery)
         return;
 
     auto* pQueryGLImpl = ValidatedCast<QueryGLImpl>(pQuery);
+    auto  QueryType    = pQueryGLImpl->GetDesc().Type;
+    auto  glQuery      = pQueryGLImpl->GetGlQueryHandle();
+
+    switch (QueryType)
+    {
+        case QUERY_TYPE_OCCLUSION:
+            glBeginQuery(GL_SAMPLES_PASSED, glQuery);
+            CHECK_GL_ERROR("Failed to begin GL_SAMPLES_PASSED query");
+            break;
+
+        case QUERY_TYPE_BINARY_OCCLUSION:
+            glBeginQuery(GL_ANY_SAMPLES_PASSED, glQuery);
+            CHECK_GL_ERROR("Failed to begin GL_ANY_SAMPLES_PASSED query");
+            break;
+
+        case QUERY_TYPE_PIPELINE_STATISTICS:
+            glBeginQuery(GL_PRIMITIVES_GENERATED, glQuery);
+            CHECK_GL_ERROR("Failed to begin GL_PRIMITIVES_GENERATED query");
+            break;
+
+        default:
+            UNEXPECTED("Unexpected query type");
+    }
 }
 
 void DeviceContextGLImpl::EndQuery(IQuery* pQuery)
@@ -1075,6 +1098,36 @@ void DeviceContextGLImpl::EndQuery(IQuery* pQuery)
         return;
 
     auto* pQueryGLImpl = ValidatedCast<QueryGLImpl>(pQuery);
+    auto  QueryType    = pQueryGLImpl->GetDesc().Type;
+    switch (QueryType)
+    {
+        case QUERY_TYPE_OCCLUSION:
+            glEndQuery(GL_SAMPLES_PASSED);
+            CHECK_GL_ERROR("Failed to end GL_SAMPLES_PASSED query");
+            break;
+
+        case QUERY_TYPE_BINARY_OCCLUSION:
+            glEndQuery(GL_ANY_SAMPLES_PASSED);
+            CHECK_GL_ERROR("Failed to end GL_ANY_SAMPLES_PASSED query");
+            break;
+
+        case QUERY_TYPE_PIPELINE_STATISTICS:
+            glEndQuery(GL_PRIMITIVES_GENERATED);
+            CHECK_GL_ERROR("Failed to end GL_PRIMITIVES_GENERATED query");
+            break;
+
+        case QUERY_TYPE_TIMESTAMP:
+#if GL_ARB_timer_query
+            glQueryCounter(pQueryGLImpl->GetGlQueryHandle(), GL_TIMESTAMP);
+            CHECK_GL_ERROR("glQueryCounter failed");
+#else
+            LOG_WARNING_MESSAGE_ONCE("Timer queries are not supported by this device");
+#endif
+            break;
+
+        default:
+            UNEXPECTED("Unexpected query type");
+    }
 }
 
 bool DeviceContextGLImpl::UpdateCurrentGLContext()
diff --git a/Graphics/GraphicsEngineOpenGL/src/GLObjectWrapper.cpp b/Graphics/GraphicsEngineOpenGL/src/GLObjectWrapper.cpp
index 6b8fa93a..c894d340 100644
--- a/Graphics/GraphicsEngineOpenGL/src/GLObjectWrapper.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/GLObjectWrapper.cpp
@@ -41,6 +41,7 @@ const char *GLTextureCreateReleaseHelper    :: Name = "texture";
 const char *GLSamplerCreateReleaseHelper    :: Name = "sampler";
 const char *GLFBOCreateReleaseHelper        :: Name = "framebuffer";
 const char *GLRBOCreateReleaseHelper        :: Name = "renderbuffer";
+const char *GLQueryCreateReleaseHelper      :: Name = "query";
 // clang-format on
 
 } // namespace GLObjectWrappers
diff --git a/Graphics/GraphicsEngineOpenGL/src/QueryGLImpl.cpp b/Graphics/GraphicsEngineOpenGL/src/QueryGLImpl.cpp
index f65f8809..f2601f4a 100644
--- a/Graphics/GraphicsEngineOpenGL/src/QueryGLImpl.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/QueryGLImpl.cpp
@@ -42,7 +42,8 @@ QueryGLImpl::QueryGLImpl(IReferenceCounters* pRefCounters,
         pRefCounters,
         pDevice,
         Desc
-    }
+    },
+    m_GlQuery{true}
 // clang-format on
 {
 }
@@ -53,7 +54,73 @@ QueryGLImpl::~QueryGLImpl()
 
 bool QueryGLImpl::GetData(void* pData, Uint32 DataSize)
 {
-    return false;
+    GLint ResultAvailable = 0;
+#if !GL_ARB_timer_query
+    if (m_Desc.Type != QUERY_TYPE_TIMESTAMP)
+#endif
+    {
+        glGetQueryObjectiv(m_GlQuery, GL_QUERY_RESULT_AVAILABLE, &ResultAvailable);
+        CHECK_GL_ERROR("Failed to get query result");
+    }
+
+    if (ResultAvailable)
+    {
+        switch (m_Desc.Type)
+        {
+            case QUERY_TYPE_OCCLUSION:
+            {
+                auto& QueryData = *reinterpret_cast<QueryDataOcclusion*>(pData);
+
+                GLuint SamplesPassed = 0;
+                glGetQueryObjectuiv(m_GlQuery, GL_QUERY_RESULT, &SamplesPassed);
+                CHECK_GL_ERROR("Failed to get query result");
+                QueryData.NumSamples = SamplesPassed;
+            }
+            break;
+
+            case QUERY_TYPE_BINARY_OCCLUSION:
+            {
+                auto& QueryData = *reinterpret_cast<QueryDataBinaryOcclusion*>(pData);
+
+                GLuint AnySamplePassed = 0;
+                glGetQueryObjectuiv(m_GlQuery, GL_QUERY_RESULT, &AnySamplePassed);
+                CHECK_GL_ERROR("Failed to get query result");
+                QueryData.AnySamplePassed = AnySamplePassed != 0;
+            }
+            break;
+
+            case QUERY_TYPE_PIPELINE_STATISTICS:
+            {
+                auto& QueryData = *reinterpret_cast<QueryDataPipelineStatistics*>(pData);
+
+                GLuint PrimitivesGenerated = 0;
+                glGetQueryObjectuiv(m_GlQuery, GL_QUERY_RESULT, &PrimitivesGenerated);
+                CHECK_GL_ERROR("Failed to get query result");
+                QueryData.ClippingInvocations = PrimitivesGenerated;
+            }
+            break;
+
+            case QUERY_TYPE_TIMESTAMP:
+            {
+#if GL_ARB_timer_query
+                auto&    QueryData = *reinterpret_cast<QueryDataTimestamp*>(pData);
+                GLuint64 Counter   = 0;
+                glGetQueryObjectui64v(m_GlQuery, GL_QUERY_RESULT, &Counter);
+                CHECK_GL_ERROR("Failed to get query result");
+                QueryData.Counter = Counter;
+                // Counter is always measured in nanoseconds (10^-9 seconds)
+                QueryData.Frequency = 1000000000;
+#endif
+            }
+            break;
+
+            default:
+                UNEXPECTED("Unexpected query type");
+                return false;
+        }
+    }
+
+    return ResultAvailable != 0;
 }
 
 } // namespace Diligent