OpenGL backend: disable scissor test when copying/blitting textures

DiligentGraphics · Nov 5, 2023 · f9ea53a · f9ea53a
1 parent 464571d
commit f9ea53a
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Showing 4 changed files with 52 additions and 10 deletions.
diff --git a/Graphics/GraphicsEngineOpenGL/include/GLContextState.hpp b/Graphics/GraphicsEngineOpenGL/include/GLContextState.hpp
@@ -120,6 +120,18 @@ class GLContextState
     };
     const ContextCaps& GetContextCaps() { return m_Caps; }
 
+    // glBlitFramebuffer respects scissor test, which is never what we want
+    void BlitFramebufferNoScissor(GLint      srcX0,
+                                  GLint      srcY0,
+                                  GLint      srcX1,
+                                  GLint      srcY1,
+                                  GLint      dstX0,
+                                  GLint      dstY0,
+                                  GLint      dstX1,
+                                  GLint      dstY1,
+                                  GLbitfield mask,
+                                  GLenum     filter);
+
 private:
     // It is unsafe to use GL handle to keep track of bound objects
     // When an object is released, GL is free to reuse its handle for

diff --git a/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp b/Graphics/GraphicsEngineOpenGL/src/DeviceContextGLImpl.cpp
@@ -563,12 +563,12 @@ void DeviceContextGLImpl::EndSubpass()
         DEV_CHECK_GL_ERROR("Failed to bind resolve destination FBO as draw framebuffer");
 
         const auto& FBODesc = m_pBoundFramebuffer->GetDesc();
-        glBlitFramebuffer(0, 0, static_cast<GLint>(FBODesc.Width), static_cast<GLint>(FBODesc.Height),
-                          0, 0, static_cast<GLint>(FBODesc.Width), static_cast<GLint>(FBODesc.Height),
-                          GL_COLOR_BUFFER_BIT,
-                          GL_NEAREST // Filter is ignored
+        m_ContextState.BlitFramebufferNoScissor(
+            0, 0, static_cast<GLint>(FBODesc.Width), static_cast<GLint>(FBODesc.Height),
+            0, 0, static_cast<GLint>(FBODesc.Width), static_cast<GLint>(FBODesc.Height),
+            GL_COLOR_BUFFER_BIT,
+            GL_NEAREST // Filter is ignored
         );
-        DEV_CHECK_GL_ERROR("glBlitFramebuffer() failed when resolving multi-sampled attachments");
     }
 
     if (glInvalidateFramebuffer != nullptr)
@@ -1741,12 +1741,12 @@ void DeviceContextGLImpl::ResolveTextureSubresource(ITexture*
     DEV_CHECK_GL_ERROR("Failed to bind FBO as read framebuffer");
 
     const auto& MipAttribs = GetMipLevelProperties(SrcTexDesc, ResolveAttribs.SrcMipLevel);
-    glBlitFramebuffer(0, 0, static_cast<GLint>(MipAttribs.LogicalWidth), static_cast<GLint>(MipAttribs.LogicalHeight),
-                      0, 0, static_cast<GLint>(MipAttribs.LogicalWidth), static_cast<GLint>(MipAttribs.LogicalHeight),
-                      GL_COLOR_BUFFER_BIT,
-                      GL_NEAREST // Filter is ignored
+    m_ContextState.BlitFramebufferNoScissor(
+        0, 0, static_cast<GLint>(MipAttribs.LogicalWidth), static_cast<GLint>(MipAttribs.LogicalHeight),
+        0, 0, static_cast<GLint>(MipAttribs.LogicalWidth), static_cast<GLint>(MipAttribs.LogicalHeight),
+        GL_COLOR_BUFFER_BIT,
+        GL_NEAREST // Filter is ignored
     );
-    DEV_CHECK_GL_ERROR("glBlitFramebuffer() failed when resolving multi-sampled texture");
 
     // Restore original FBO
     m_ContextState.InvalidateFBO();

diff --git a/Graphics/GraphicsEngineOpenGL/src/GLContextState.cpp b/Graphics/GraphicsEngineOpenGL/src/GLContextState.cpp
@@ -880,4 +880,26 @@ void GLContextState::SetNumPatchVertices(Int32 NumVertices)
 #endif
 }
 
+void GLContextState::BlitFramebufferNoScissor(GLint      srcX0,
+                                              GLint      srcY0,
+                                              GLint      srcX1,
+                                              GLint      srcY1,
+                                              GLint      dstX0,
+                                              GLint      dstY0,
+                                              GLint      dstX1,
+                                              GLint      dstY1,
+                                              GLbitfield mask,
+                                              GLenum     filter)
+{
+    bool ScissorEnabled = m_RSState.ScissorTestEnable;
+    if (ScissorEnabled)
+        EnableScissorTest(false);
+
+    glBlitFramebuffer(srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
+    DEV_CHECK_GL_ERROR("glBlitFramebuffer() failed");
+
+    if (ScissorEnabled)
+        EnableScissorTest(true);
+}
+
 } // namespace Diligent
diff --git a/Graphics/GraphicsEngineOpenGL/src/TextureBaseGL.cpp b/Graphics/GraphicsEngineOpenGL/src/TextureBaseGL.cpp
@@ -627,6 +627,11 @@ void TextureBaseGL::CopyData(DeviceContextGLImpl* pDeviceCtxGL,
     {
         auto& GLState = pDeviceCtxGL->GetContextState();
 
+        // Copy operations (glCopyTexSubImage2D and family, glBindFramebuffer) are affected by scissor test!
+        GLboolean ScissorEnabled = GLState.GetScissorTestEnabled();
+        if (ScissorEnabled)
+            GLState.EnableScissorTest(false);
+
         for (Uint32 DepthSlice = 0; DepthSlice < pSrcBox->Depth(); ++DepthSlice)
         {
             GLuint SrcFboHandle = 0;
@@ -688,6 +693,9 @@ void TextureBaseGL::CopyData(DeviceContextGLImpl* pDeviceCtxGL,
             }
         }
 
+        if (ScissorEnabled)
+            GLState.EnableScissorTest(true);
+
         // Invalidate FBO as we used glBindFramebuffer directly
         GLState.InvalidateFBO();