OpenGL backend: added handling of Buffers and RW Buffers

6 files changed, 98 insertions, 41 deletions

diff --git a/Graphics/GraphicsEngineOpenGL/include/GLContextState.h b/Graphics/GraphicsEngineOpenGL/include/GLContextState.h
index 3753b6b2..0e78be78 100644
--- a/Graphics/GraphicsEngineOpenGL/include/GLContextState.h
+++ b/Graphics/GraphicsEngineOpenGL/include/GLContextState.h
@@ -44,6 +44,7 @@ public:
     void BindTexture( Int32 Index, GLenum BindTarget, const GLObjectWrappers::GLTextureObj &Tex);
     void BindSampler( Uint32 Index, const GLObjectWrappers::GLSamplerObj &GLSampler);
     void BindImage( Uint32 Index, class TextureViewGLImpl *pTexView, GLint MipLevel, GLboolean IsLayered, GLint Layer, GLenum Access, GLenum Format );
+    void BindImage( Uint32 Index, class BufferViewGLImpl *pBuffView, GLenum Access, GLenum Format );
     void EnsureMemoryBarrier(Uint32 RequiredBarriers, class AsyncWritableResource *pRes = nullptr);
     void SetPendingMemoryBarriers( Uint32 PendingBarriers );
     
diff --git a/Graphics/GraphicsEngineOpenGL/src/BufferGLImpl.cpp b/Graphics/GraphicsEngineOpenGL/src/BufferGLImpl.cpp
index 5b23d346..0114db3c 100644
--- a/Graphics/GraphicsEngineOpenGL/src/BufferGLImpl.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/BufferGLImpl.cpp
@@ -338,7 +338,8 @@ void BufferGLImpl::BufferMemoryBarrier( Uint32 RequiredBarriers, GLContextState
             GL_BUFFER_UPDATE_BARRIER_BIT        |
             GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT |
             GL_SHADER_STORAGE_BARRIER_BIT       |
-            GL_TEXTURE_FETCH_BARRIER_BIT;
+            GL_TEXTURE_FETCH_BARRIER_BIT        |
+            GL_SHADER_IMAGE_ACCESS_BARRIER_BIT;
         VERIFY( (RequiredBarriers & BufferBarriers) !=0,   "At least one buffer memory barrier flag should be set" );
         VERIFY( (RequiredBarriers & ~BufferBarriers) == 0, "Inappropriate buffer memory barrier flag" );
     }
diff --git a/Graphics/GraphicsEngineOpenGL/src/BufferViewGLImpl.cpp b/Graphics/GraphicsEngineOpenGL/src/BufferViewGLImpl.cpp
index 8097f9f2..d41cb0ca 100644
--- a/Graphics/GraphicsEngineOpenGL/src/BufferViewGLImpl.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/BufferViewGLImpl.cpp
@@ -40,7 +40,7 @@ namespace Diligent
         TBuffViewBase(pRefCounters, pDevice, ViewDesc, pBuffer, bIsDefaultView ),
         m_GLTexBuffer(false)
     {
-        if( ViewDesc.ViewType == BUFFER_VIEW_SHADER_RESOURCE && 
+        if( (ViewDesc.ViewType == BUFFER_VIEW_SHADER_RESOURCE || ViewDesc.ViewType == BUFFER_VIEW_UNORDERED_ACCESS) && 
             (pBuffer->GetDesc().Mode == BUFFER_MODE_FORMATTED || pBuffer->GetDesc().Mode == BUFFER_MODE_RAW) )
         {
 #ifdef _MSC_VER
diff --git a/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp b/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
index 55fa5435..0dfff8a5 100644
--- a/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
@@ -532,13 +532,16 @@ namespace Diligent
                         auto& Resource = Img.pResources[ArrInd];
                         if (Resource)
                         {
-                            auto* pTexViewOGL = Resource.RawPtr<TextureViewGLImpl>();
-                            const auto& ViewDesc = pTexViewOGL->GetDesc();
-
-                            if (ViewDesc.AccessFlags & UAV_ACCESS_FLAG_WRITE)
+                            if (Img.ImageType == GL_IMAGE_BUFFER     ||
+                                Img.ImageType == GL_INT_IMAGE_BUFFER ||
+                                Img.ImageType == GL_UNSIGNED_INT_IMAGE_BUFFER)
                             {
-                                auto* pTexGL = pTexViewOGL->GetTexture<TextureBaseGL>();
-                                pTexGL->TextureMemoryBarrier(
+                                auto* pBuffViewOGL = Resource.RawPtr<BufferViewGLImpl>();
+                                const auto& ViewDesc = pBuffViewOGL->GetDesc();
+                                VERIFY( ViewDesc.ViewType == BUFFER_VIEW_UNORDERED_ACCESS, "Unexpected buffer view type" );
+
+                                auto* pBufferOGL = pBuffViewOGL->GetBuffer<BufferGLImpl>();
+                                pBufferOGL->BufferMemoryBarrier(
                                     GL_SHADER_IMAGE_ACCESS_BARRIER_BIT,// Memory accesses using shader image load, store, and atomic built-in 
                                                                        // functions issued after the barrier will reflect data written by shaders 
                                                                        // prior to the barrier. Additionally, image stores and atomics issued after 
@@ -546,38 +549,61 @@ namespace Diligent
                                                                        // stores, texture fetches, vertex fetches) initiated prior to the barrier 
                                                                        // complete.
                                     m_ContextState);
-                                // We cannot set pending memory barriers here, because
-                                // if some texture is bound twice, the logic will fail
-                                m_BoundWritableTextures.push_back( pTexGL );
+                                m_BoundWritableBuffers.push_back(pBufferOGL);
+
+                                auto GlFormat = TypeToGLTexFormat(ViewDesc.Format.ValueType, ViewDesc.Format.NumComponents, ViewDesc.Format.IsNormalized);
+                                m_ContextState.BindImage(Img.BindingPoint + ArrInd, pBuffViewOGL, GL_READ_WRITE, GlFormat);
                             }
+                            else
+                            {
+                                auto* pTexViewOGL = Resource.RawPtr<TextureViewGLImpl>();
+                                const auto& ViewDesc = pTexViewOGL->GetDesc();
+                                VERIFY( ViewDesc.ViewType == TEXTURE_VIEW_UNORDERED_ACCESS, "Unexpected buffer view type" );
+
+                                if (ViewDesc.AccessFlags & UAV_ACCESS_FLAG_WRITE)
+                                {
+                                    auto* pTexGL = pTexViewOGL->GetTexture<TextureBaseGL>();
+                                    pTexGL->TextureMemoryBarrier(
+                                        GL_SHADER_IMAGE_ACCESS_BARRIER_BIT,// Memory accesses using shader image load, store, and atomic built-in 
+                                                                           // functions issued after the barrier will reflect data written by shaders 
+                                                                           // prior to the barrier. Additionally, image stores and atomics issued after 
+                                                                           // the barrier will not execute until all memory accesses (e.g., loads, 
+                                                                           // stores, texture fetches, vertex fetches) initiated prior to the barrier 
+                                                                           // complete.
+                                        m_ContextState);
+                                    // We cannot set pending memory barriers here, because
+                                    // if some texture is bound twice, the logic will fail
+                                    m_BoundWritableTextures.push_back( pTexGL );
+                                }
 
         #ifdef _DEBUG
-                            // Check that the texure being bound has immutable storage
-                            {
-                                m_ContextState.BindTexture(-1, pTexViewOGL->GetBindTarget(), pTexViewOGL->GetHandle());
-                                GLint IsImmutable = 0;
-                                glGetTexParameteriv( pTexViewOGL->GetBindTarget(), GL_TEXTURE_IMMUTABLE_FORMAT, &IsImmutable );
-                                CHECK_GL_ERROR( "glGetTexParameteriv() failed" );
-                                VERIFY( IsImmutable, "Only immutable textures can be bound to pipeline using glBindImageTexture()" );
-                                m_ContextState.BindTexture( -1, pTexViewOGL->GetBindTarget(), GLObjectWrappers::GLTextureObj(false) );
-                            }
+                                // Check that the texure being bound has immutable storage
+                                {
+                                    m_ContextState.BindTexture(-1, pTexViewOGL->GetBindTarget(), pTexViewOGL->GetHandle());
+                                    GLint IsImmutable = 0;
+                                    glGetTexParameteriv( pTexViewOGL->GetBindTarget(), GL_TEXTURE_IMMUTABLE_FORMAT, &IsImmutable );
+                                    CHECK_GL_ERROR( "glGetTexParameteriv() failed" );
+                                    VERIFY( IsImmutable, "Only immutable textures can be bound to pipeline using glBindImageTexture()" );
+                                    m_ContextState.BindTexture( -1, pTexViewOGL->GetBindTarget(), GLObjectWrappers::GLTextureObj(false) );
+                                }
         #endif
-                            auto GlTexFormat = TexFormatToGLInternalTexFormat( ViewDesc.Format );
-                            // Note that if a format qulifier is specified in the shader, the format
-                            // must match it
-
-                            GLboolean Layered = ViewDesc.NumArraySlices > 1 && ViewDesc.FirstArraySlice == 0;
-                            // If "layered" is TRUE, the entire Mip level is bound. Layer parameter is ignored in this
-                            // case. If "layered" is FALSE, only the single layer identified by "layer" will
-                            // be bound. When "layered" is FALSE, the single bound layer is treated as a 2D texture.
-                            GLint Layer = ViewDesc.FirstArraySlice;
-
-                            auto GLAccess = AccessFlags2GLAccess(ViewDesc.AccessFlags);
-                            // WARNING: Texture being bound to the image unit must be complete
-                            // That means that if an integer texture is being bound, its 
-                            // GL_TEXTURE_MIN_FILTER and GL_TEXTURE_MAG_FILTER must be NEAREST,
-                            // otherwise it will be incomplete
-                            m_ContextState.BindImage(Img.BindingPoint + ArrInd, pTexViewOGL, ViewDesc.MostDetailedMip, Layered, Layer, GLAccess, GlTexFormat);
+                                auto GlTexFormat = TexFormatToGLInternalTexFormat( ViewDesc.Format );
+                                // Note that if a format qulifier is specified in the shader, the format
+                                // must match it
+
+                                GLboolean Layered = ViewDesc.NumArraySlices > 1 && ViewDesc.FirstArraySlice == 0;
+                                // If "layered" is TRUE, the entire Mip level is bound. Layer parameter is ignored in this
+                                // case. If "layered" is FALSE, only the single layer identified by "layer" will
+                                // be bound. When "layered" is FALSE, the single bound layer is treated as a 2D texture.
+                                GLint Layer = ViewDesc.FirstArraySlice;
+
+                                auto GLAccess = AccessFlags2GLAccess(ViewDesc.AccessFlags);
+                                // WARNING: Texture being bound to the image unit must be complete
+                                // That means that if an integer texture is being bound, its 
+                                // GL_TEXTURE_MIN_FILTER and GL_TEXTURE_MAG_FILTER must be NEAREST,
+                                // otherwise it will be incomplete
+                                m_ContextState.BindImage(Img.BindingPoint + ArrInd, pTexViewOGL, ViewDesc.MostDetailedMip, Layered, Layer, GLAccess, GlTexFormat);
+                            }
                         }
                         else
                         {
@@ -598,7 +624,7 @@ namespace Diligent
                         {
                             auto* pBufferViewOGL = Resource.RawPtr<BufferViewGLImpl>();
                             const auto& ViewDesc = pBufferViewOGL->GetDesc();
-                            VERIFY( ViewDesc.ViewType == BUFFER_VIEW_UNORDERED_ACCESS || ViewDesc.ViewType == BUFFER_VIEW_SHADER_RESOURCE, "Unexpceted buffer view type" );
+                            VERIFY( ViewDesc.ViewType == BUFFER_VIEW_UNORDERED_ACCESS || ViewDesc.ViewType == BUFFER_VIEW_SHADER_RESOURCE, "Unexpected buffer view type" );
 
                             auto* pBufferOGL = pBufferViewOGL->GetBuffer<BufferGLImpl>();
                             pBufferOGL->BufferMemoryBarrier(
diff --git a/Graphics/GraphicsEngineOpenGL/src/GLContextState.cpp b/Graphics/GraphicsEngineOpenGL/src/GLContextState.cpp
index 246f1806..e49be10e 100644
--- a/Graphics/GraphicsEngineOpenGL/src/GLContextState.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/GLContextState.cpp
@@ -261,6 +261,31 @@ namespace Diligent
 #endif
     }
 
+    void GLContextState::BindImage( Uint32 Index, BufferViewGLImpl* pBuffView, GLenum Access, GLenum Format )
+    {
+#if GL_ARB_shader_image_load_store
+        BoundImageInfo NewImageInfo(
+            pBuffView->GetUniqueID(),
+            0,
+            GL_FALSE,
+            0,
+            Access,
+            Format
+            );
+        if( Index >= m_BoundImages.size() )
+            m_BoundImages.resize( Index + 1 );
+        if( !(m_BoundImages[Index] == NewImageInfo) )
+        {
+            m_BoundImages[Index] = NewImageInfo;
+            GLint GLBuffHandle = pBuffView->GetTexBufferHandle();
+            glBindImageTexture( Index, GLBuffHandle, 0, GL_FALSE, 0, Access, Format );
+            CHECK_GL_ERROR( "glBindImageTexture() failed" );
+        }
+#else
+        UNSUPPORTED("GL_ARB_shader_image_load_store is not supported");
+#endif
+    }
+
     void GLContextState::EnsureMemoryBarrier( Uint32 RequiredBarriers, AsyncWritableResource *pRes/* = nullptr */ )
     {
 #if GL_ARB_shader_image_load_store
diff --git a/Graphics/GraphicsEngineOpenGL/src/GLProgramResources.cpp b/Graphics/GraphicsEngineOpenGL/src/GLProgramResources.cpp
index 00f07ea0..1ad1b73c 100644
--- a/Graphics/GraphicsEngineOpenGL/src/GLProgramResources.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/GLProgramResources.cpp
@@ -415,9 +415,9 @@ namespace Diligent
                     // glGetProgramResourceLocation( program, GL_UNIFORM, name );
                     // The latter is only available in GL 4.4 and GLES 3.1
 
-                    auto ResourceType = dataType == GL_SAMPLER_BUFFER     || 
-                                        dataType == GL_INT_SAMPLER_BUFFER || 
-                                        dataType == GL_UNSIGNED_INT_SAMPLER_BUFFER ? 
+                    const auto ResourceType = dataType == GL_SAMPLER_BUFFER     || 
+                                              dataType == GL_INT_SAMPLER_BUFFER || 
+                                              dataType == GL_UNSIGNED_INT_SAMPLER_BUFFER ? 
                         SHADER_RESOURCE_TYPE_BUFFER_SRV : SHADER_RESOURCE_TYPE_TEXTURE_SRV;
 
                     RemoveArrayBrackets(Name.data());
@@ -482,11 +482,15 @@ namespace Diligent
 
                     RemoveArrayBrackets(Name.data());
 
+                    const auto ResourceType = dataType == GL_IMAGE_BUFFER     ||
+                                              dataType == GL_INT_IMAGE_BUFFER ||
+                                              dataType == GL_UNSIGNED_INT_IMAGE_BUFFER ?
+                        SHADER_RESOURCE_TYPE_BUFFER_UAV : SHADER_RESOURCE_TYPE_TEXTURE_UAV;
                     Images.emplace_back(
                         Owner,
                         NamesPool.emplace(Name.data()).first->c_str(),
                         SHADER_RESOURCE_VARIABLE_TYPE_STATIC, 
-                        SHADER_RESOURCE_TYPE_TEXTURE_UAV,
+                        ResourceType,
                         Uint16{0xFFFF}, // Variable index is assigned by AllocateResources
                         static_cast<Uint32>(size),
                         nullptr,        // pResources