Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 3180 insertions, 0 deletions

diff --git a/vcl/source/opengl/GLMHelper.hxx b/vcl/source/opengl/GLMHelper.hxx
new file mode 100644
index 000000000..9694a3c34
--- /dev/null
+++ b/vcl/source/opengl/GLMHelper.hxx
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+#include <glm/glm.hpp>
+#include <vcl/dllapi.h>
+
+#include <ostream>
+
+std::ostream& operator<<(std::ostream& rStrm, const glm::mat4& rMatrix);
+std::ostream& operator<<(std::ostream& rStrm, const glm::vec4& rPos);
+std::ostream& operator<<(std::ostream& rStrm, const glm::vec3& rPos);
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/opengl/OpenGLContext.cxx b/vcl/source/opengl/OpenGLContext.cxx
new file mode 100644
index 000000000..b703356ee
--- /dev/null
+++ b/vcl/source/opengl/OpenGLContext.cxx
@@ -0,0 +1,495 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <chrono>
+
+#include <vcl/opengl/OpenGLContext.hxx>
+#include <vcl/opengl/OpenGLHelper.hxx>
+#include <vcl/opengl/OpenGLWrapper.hxx>
+#include <vcl/syschild.hxx>
+#include <vcl/sysdata.hxx>
+
+#include <osl/thread.hxx>
+#include <sal/log.hxx>
+
+#include <svdata.hxx>
+#include <salgdi.hxx>
+#include <salinst.hxx>
+
+#include <opengl/zone.hxx>
+
+#include <config_features.h>
+
+using namespace com::sun::star;
+
+static sal_Int64 nBufferSwapCounter = 0;
+
+GLWindow::~GLWindow()
+{
+}
+
+bool GLWindow::Synchronize(bool /*bOnoff*/) const
+{
+    return false;
+}
+
+OpenGLContext::OpenGLContext():
+    mpWindow(nullptr),
+    m_pChildWindow(nullptr),
+    mbInitialized(false),
+    mnRefCount(0),
+    mbRequestLegacyContext(false),
+    mpPrevContext(nullptr),
+    mpNextContext(nullptr)
+{
+    VCL_GL_INFO("new context: " << this);
+
+    ImplSVData* pSVData = ImplGetSVData();
+    if( pSVData->maGDIData.mpLastContext )
+    {
+        pSVData->maGDIData.mpLastContext->mpNextContext = this;
+        mpPrevContext = pSVData->maGDIData.mpLastContext;
+    }
+    pSVData->maGDIData.mpLastContext = this;
+
+    // FIXME: better hope we call 'makeCurrent' soon to preserve
+    // the invariant that the last item is the current context.
+}
+
+OpenGLContext::~OpenGLContext()
+{
+    assert (mnRefCount == 0);
+
+    mnRefCount = 1; // guard the shutdown paths.
+    VCL_GL_INFO("delete context: " << this);
+
+    reset();
+
+    ImplSVData* pSVData = ImplGetSVData();
+    if( mpPrevContext )
+        mpPrevContext->mpNextContext = mpNextContext;
+    if( mpNextContext )
+        mpNextContext->mpPrevContext = mpPrevContext;
+    else
+        pSVData->maGDIData.mpLastContext = mpPrevContext;
+
+    m_pChildWindow.disposeAndClear();
+    assert (mnRefCount == 1);
+}
+
+// release associated child-window if we have one
+void OpenGLContext::dispose()
+{
+    reset();
+    m_pChildWindow.disposeAndClear();
+}
+
+rtl::Reference<OpenGLContext> OpenGLContext::Create()
+{
+    return rtl::Reference<OpenGLContext>(ImplGetSVData()->mpDefInst->CreateOpenGLContext());
+}
+
+void OpenGLContext::requestLegacyContext()
+{
+    mbRequestLegacyContext = true;
+}
+
+#ifdef DBG_UTIL
+
+namespace {
+
+const char* getSeverityString(GLenum severity)
+{
+    switch(severity)
+    {
+        case GL_DEBUG_SEVERITY_LOW:
+            return "low";
+        case GL_DEBUG_SEVERITY_MEDIUM:
+            return "medium";
+        case GL_DEBUG_SEVERITY_HIGH:
+            return "high";
+        default:
+            ;
+    }
+
+    return "unknown";
+}
+
+const char* getSourceString(GLenum source)
+{
+    switch(source)
+    {
+        case GL_DEBUG_SOURCE_API:
+            return "API";
+        case GL_DEBUG_SOURCE_SHADER_COMPILER:
+            return "shader compiler";
+        case GL_DEBUG_SOURCE_WINDOW_SYSTEM:
+            return "window system";
+        case GL_DEBUG_SOURCE_THIRD_PARTY:
+            return "third party";
+        case GL_DEBUG_SOURCE_APPLICATION:
+            return "Libreoffice";
+        case GL_DEBUG_SOURCE_OTHER:
+            return "unknown";
+        default:
+            ;
+    }
+
+    return "unknown";
+}
+
+const char* getTypeString(GLenum type)
+{
+    switch(type)
+    {
+        case GL_DEBUG_TYPE_DEPRECATED_BEHAVIOR:
+            return "deprecated behavior";
+        case GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR:
+            return "undefined behavior";
+        case GL_DEBUG_TYPE_PERFORMANCE:
+            return "performance";
+        case GL_DEBUG_TYPE_PORTABILITY:
+            return "portability";
+        case GL_DEBUG_TYPE_MARKER:
+            return "marker";
+        case GL_DEBUG_TYPE_PUSH_GROUP:
+            return "push group";
+        case GL_DEBUG_TYPE_POP_GROUP:
+            return "pop group";
+        case GL_DEBUG_TYPE_OTHER:
+            return "other";
+        case GL_DEBUG_TYPE_ERROR:
+            return "error";
+        default:
+            ;
+    }
+
+    return "unknown";
+}
+
+extern "C" void
+#if defined _WIN32
+APIENTRY
+#endif
+debug_callback(GLenum source, GLenum type, GLuint id,
+               GLenum severity, GLsizei , const GLchar* message,
+               const GLvoid*)
+{
+    // ignore Nvidia's 131218: "Program/shader state performance warning: Fragment Shader is going to be recompiled because the shader key based on GL state mismatches."
+    // the GLSL compiler is a bit too aggressive in optimizing the state based on the current OpenGL state
+
+    // ignore 131185: "Buffer detailed info: Buffer object x (bound to GL_ARRAY_BUFFER_ARB,
+    // usage hint is GL_STATIC_DRAW) will use VIDEO memory as the source for buffer object operations."
+    if (id == 131218 || id == 131185)
+        return;
+
+    SAL_WARN("vcl.opengl", "OpenGL debug message: source: " << getSourceString(source) << ", type: "
+            << getTypeString(type) << ", id: " << id << ", severity: " << getSeverityString(severity) << ", with message: " << message);
+}
+
+}
+
+#endif
+
+bool OpenGLContext::init( vcl::Window* pParent )
+{
+    if(mbInitialized)
+        return true;
+
+    OpenGLZone aZone;
+
+    m_xWindow.reset(pParent ? nullptr : VclPtr<vcl::Window>::Create(nullptr, WB_NOBORDER|WB_NODIALOGCONTROL));
+    mpWindow = pParent ? pParent : m_xWindow.get();
+    if(m_xWindow)
+        m_xWindow->setPosSizePixel(0,0,0,0);
+    //tdf#108069 we may be initted twice, so dispose earlier effort
+    m_pChildWindow.disposeAndClear();
+    initWindow();
+    return ImplInit();
+}
+
+bool OpenGLContext::ImplInit()
+{
+    VCL_GL_INFO("OpenGLContext not implemented for this platform");
+    return false;
+}
+
+static OUString getGLString(GLenum eGlEnum)
+{
+    OUString sString;
+    const GLubyte* pString = glGetString(eGlEnum);
+    if (pString)
+    {
+        sString = OUString::createFromAscii(reinterpret_cast<const char*>(pString));
+    }
+
+    CHECK_GL_ERROR();
+    return sString;
+}
+
+bool OpenGLContext::InitGL()
+{
+    VCL_GL_INFO("OpenGLContext::ImplInit----end");
+    VCL_GL_INFO("Vendor: " << getGLString(GL_VENDOR) << " Renderer: " << getGLString(GL_RENDERER) << " GL version: " << OpenGLHelper::getGLVersion());
+    mbInitialized = true;
+
+    // I think we need at least GL 3.0
+    if (epoxy_gl_version() < 30)
+    {
+        SAL_WARN("vcl.opengl", "We don't have at least OpenGL 3.0");
+        return false;
+    }
+
+    // Check that some "optional" APIs that we use unconditionally are present
+    if (!glBindFramebuffer)
+    {
+        SAL_WARN("vcl.opengl", "We don't have glBindFramebuffer");
+        return false;
+    }
+
+    return true;
+}
+
+void OpenGLContext::InitGLDebugging()
+{
+#ifdef DBG_UTIL
+    // only enable debug output in dbgutil build
+    if (epoxy_has_gl_extension("GL_ARB_debug_output"))
+    {
+        OpenGLZone aZone;
+
+        if (glDebugMessageCallbackARB)
+        {
+            glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB);
+            glDebugMessageCallbackARB(&debug_callback, nullptr);
+
+#ifdef GL_DEBUG_SEVERITY_NOTIFICATION_ARB
+            // Ignore i965’s shader compiler notification flood.
+            glDebugMessageControlARB(GL_DEBUG_SOURCE_SHADER_COMPILER_ARB, GL_DEBUG_TYPE_OTHER_ARB, GL_DEBUG_SEVERITY_NOTIFICATION_ARB, 0, nullptr, true);
+#endif
+        }
+        else if ( glDebugMessageCallback )
+        {
+            glEnable(GL_DEBUG_OUTPUT);
+            glDebugMessageCallback(&debug_callback, nullptr);
+
+            // Ignore i965’s shader compiler notification flood.
+            glDebugMessageControl(GL_DEBUG_SOURCE_SHADER_COMPILER, GL_DEBUG_TYPE_OTHER, GL_DEBUG_SEVERITY_NOTIFICATION, 0, nullptr, true);
+        }
+    }
+
+    // Test hooks for inserting tracing messages into the stream
+    VCL_GL_INFO("LibreOffice GLContext initialized");
+#endif
+}
+
+void OpenGLContext::restoreDefaultFramebuffer()
+{
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
+void OpenGLContext::setWinPosAndSize(const Point &rPos, const Size& rSize)
+{
+    if (m_xWindow)
+        m_xWindow->SetPosSizePixel(rPos, rSize);
+    if (m_pChildWindow)
+        m_pChildWindow->SetPosSizePixel(rPos, rSize);
+
+    GLWindow& rGLWin = getModifiableOpenGLWindow();
+    rGLWin.Width = rSize.Width();
+    rGLWin.Height = rSize.Height();
+    adjustToNewSize();
+}
+
+void OpenGLContext::adjustToNewSize()
+{
+    const GLWindow& rGLWin = getOpenGLWindow();
+    glViewport(0, 0, rGLWin.Width, rGLWin.Height);
+}
+
+void OpenGLContext::InitChildWindow(SystemChildWindow *pChildWindow)
+{
+    pChildWindow->SetMouseTransparent(true);
+    pChildWindow->SetParentClipMode(ParentClipMode::Clip);
+    pChildWindow->EnableEraseBackground(false);
+    pChildWindow->SetControlForeground();
+    pChildWindow->SetControlBackground();
+}
+
+void OpenGLContext::initWindow()
+{
+}
+
+void OpenGLContext::destroyCurrentContext()
+{
+    //nothing by default
+}
+
+void OpenGLContext::reset()
+{
+    if( !mbInitialized )
+        return;
+
+    OpenGLZone aZone;
+
+    if( isCurrent() )
+        resetCurrent();
+
+    mbInitialized = false;
+
+    // destroy the context itself
+    destroyCurrentContext();
+}
+
+SystemWindowData OpenGLContext::generateWinData(vcl::Window* /*pParent*/, bool /*bRequestLegacyContext*/)
+{
+    return {};
+}
+
+bool OpenGLContext::isCurrent()
+{
+    (void) this; // loplugin:staticmethods
+    return false;
+}
+
+void OpenGLContext::makeCurrent()
+{
+    if (isCurrent())
+        return;
+
+    OpenGLZone aZone;
+
+    clearCurrent();
+
+    // by default nothing else to do
+
+    registerAsCurrent();
+}
+
+bool OpenGLContext::isAnyCurrent()
+{
+    return false;
+}
+
+bool OpenGLContext::hasCurrent()
+{
+    ImplSVData* pSVData = ImplGetSVData();
+    rtl::Reference<OpenGLContext> pCurrentCtx = pSVData->maGDIData.mpLastContext;
+    return pCurrentCtx.is() && pCurrentCtx->isAnyCurrent();
+}
+
+void OpenGLContext::clearCurrent()
+{
+}
+
+void OpenGLContext::prepareForYield()
+{
+    ImplSVData* pSVData = ImplGetSVData();
+
+    // release all framebuffers from the old context so we can re-attach the
+    // texture in the new context
+    rtl::Reference<OpenGLContext> pCurrentCtx = pSVData->maGDIData.mpLastContext;
+
+    if ( !pCurrentCtx.is() )
+        return;                 // Not using OpenGL
+
+    SAL_INFO("vcl.opengl", "Unbinding contexts in preparation for yield");
+
+    // Find the first context that is current and reset it.
+    // Usually the last context is the current, but not in case a new
+    // OpenGLContext is created already but not yet initialized.
+    while (pCurrentCtx.is())
+    {
+        if (pCurrentCtx->isCurrent())
+        {
+            pCurrentCtx->resetCurrent();
+            break;
+        }
+
+        pCurrentCtx = pCurrentCtx->mpPrevContext;
+    }
+
+    assert (!hasCurrent());
+}
+
+void OpenGLContext::registerAsCurrent()
+{
+    ImplSVData* pSVData = ImplGetSVData();
+
+    // move the context to the end of the contexts list
+    static int nSwitch = 0;
+    VCL_GL_INFO("******* CONTEXT SWITCH " << ++nSwitch << " *********");
+    if( mpNextContext )
+    {
+        if( mpPrevContext )
+            mpPrevContext->mpNextContext = mpNextContext;
+        mpNextContext->mpPrevContext = mpPrevContext;
+
+        mpPrevContext = pSVData->maGDIData.mpLastContext;
+        mpNextContext = nullptr;
+        pSVData->maGDIData.mpLastContext->mpNextContext = this;
+        pSVData->maGDIData.mpLastContext = this;
+    }
+}
+
+void OpenGLContext::resetCurrent()
+{
+    clearCurrent();
+    // by default nothing else to do
+}
+
+void OpenGLContext::swapBuffers()
+{
+    // by default nothing else to do
+    BuffersSwapped();
+}
+
+void OpenGLContext::BuffersSwapped()
+{
+    nBufferSwapCounter++;
+
+    static bool bSleep = getenv("SAL_GL_SLEEP_ON_SWAP");
+    if (bSleep)
+    {
+        // half a second.
+        osl::Thread::wait( std::chrono::milliseconds(500) );
+    }
+}
+
+
+sal_Int64 OpenGLWrapper::getBufferSwapCounter()
+{
+    return nBufferSwapCounter;
+}
+
+void OpenGLContext::sync()
+{
+    // default is nothing
+    (void) this; // loplugin:staticmethods
+}
+
+void OpenGLContext::show()
+{
+    if (m_pChildWindow)
+        m_pChildWindow->Show();
+    else if (m_xWindow)
+        m_xWindow->Show();
+}
+
+SystemChildWindow* OpenGLContext::getChildWindow()
+{
+    return m_pChildWindow;
+}
+
+const SystemChildWindow* OpenGLContext::getChildWindow() const
+{
+    return m_pChildWindow;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/opengl/OpenGLHelper.cxx b/vcl/source/opengl/OpenGLHelper.cxx
new file mode 100644
index 000000000..a0dff4a5f
--- /dev/null
+++ b/vcl/source/opengl/OpenGLHelper.cxx
@@ -0,0 +1,939 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <vcl/opengl/OpenGLHelper.hxx>
+#include <config_vclplug.h>
+
+#include <osl/file.hxx>
+#include <rtl/bootstrap.hxx>
+#include <rtl/digest.h>
+#include <rtl/strbuf.hxx>
+#include <rtl/ustring.hxx>
+#include <sal/log.hxx>
+#include <tools/stream.hxx>
+#include <config_folders.h>
+#include <memory>
+#include <vcl/pngwrite.hxx>
+#include <vcl/svapp.hxx>
+#include <officecfg/Office/Common.hxx>
+#include <com/sun/star/util/XFlushable.hpp>
+#include <com/sun/star/configuration/theDefaultProvider.hpp>
+
+#include <stdarg.h>
+#include <string_view>
+#include <vector>
+#include <unordered_map>
+
+#include <opengl/zone.hxx>
+#include <vcl/opengl/OpenGLWrapper.hxx>
+#include <vcl/opengl/OpenGLContext.hxx>
+#include <desktop/crashreport.hxx>
+#include <bitmap/BitmapWriteAccess.hxx>
+#include <watchdog.hxx>
+#include <vcl/skia/SkiaHelper.hxx>
+#include <salinst.hxx>
+#include <svdata.hxx>
+
+#if defined (_WIN32)
+#include <opengl/win/WinDeviceInfo.hxx>
+#endif
+
+#include "GLMHelper.hxx"
+
+static bool volatile gbInShaderCompile = false;
+
+namespace {
+
+using namespace rtl;
+
+OUString getShaderFolder()
+{
+    OUString aUrl("$BRAND_BASE_DIR/" LIBO_ETC_FOLDER);
+    rtl::Bootstrap::expandMacros(aUrl);
+
+    return aUrl + "/opengl/";
+}
+
+OString loadShader(std::u16string_view rFilename)
+{
+    OUString aFileURL = getShaderFolder() + rFilename +".glsl";
+    osl::File aFile(aFileURL);
+    if(aFile.open(osl_File_OpenFlag_Read) == osl::FileBase::E_None)
+    {
+        sal_uInt64 nSize = 0;
+        aFile.getSize(nSize);
+        std::unique_ptr<char[]> content(new char[nSize+1]);
+        sal_uInt64 nBytesRead = 0;
+        aFile.read(content.get(), nSize, nBytesRead);
+        assert(nSize == nBytesRead);
+        content.get()[nBytesRead] = 0;
+        SAL_INFO("vcl.opengl", "Read " << nBytesRead << " bytes from " << aFileURL);
+        return content.get();
+    }
+    else
+    {
+        SAL_WARN("vcl.opengl", "Could not open " << aFileURL);
+    }
+
+    return OString();
+}
+
+OString& getShaderSource(const OUString& rFilename)
+{
+    static std::unordered_map<OUString, OString> aMap;
+
+    if (aMap.find(rFilename) == aMap.end())
+    {
+        aMap[rFilename] = loadShader(rFilename);
+    }
+
+    return aMap[rFilename];
+}
+
+}
+
+namespace {
+    int LogCompilerError(GLuint nId, const OUString &rDetail,
+                         const OUString &rName, bool bShaderNotProgram)
+    {
+        OpenGLZone aZone;
+
+        int InfoLogLength = 0;
+
+        CHECK_GL_ERROR();
+
+        if (bShaderNotProgram)
+            glGetShaderiv (nId, GL_INFO_LOG_LENGTH, &InfoLogLength);
+        else
+            glGetProgramiv(nId, GL_INFO_LOG_LENGTH, &InfoLogLength);
+
+        CHECK_GL_ERROR();
+
+        if ( InfoLogLength > 0 )
+        {
+            std::vector<char> ErrorMessage(InfoLogLength+1);
+            if (bShaderNotProgram)
+                glGetShaderInfoLog (nId, InfoLogLength, nullptr, ErrorMessage.data());
+            else
+                glGetProgramInfoLog(nId, InfoLogLength, nullptr, ErrorMessage.data());
+            CHECK_GL_ERROR();
+
+            ErrorMessage.push_back('\0');
+            SAL_WARN("vcl.opengl", rDetail << " shader " << nId << " compile for " << rName << " failed : " << ErrorMessage.data());
+        }
+        else
+            SAL_WARN("vcl.opengl", rDetail << " shader: " << rName << " compile " << nId << " failed without error log");
+
+#ifdef DBG_UTIL
+        abort();
+#endif
+        return 0;
+    }
+}
+
+static void addPreamble(OString& rShaderSource, std::string_view rPreamble)
+{
+    if (rPreamble.empty())
+        return;
+
+    int nVersionStrStartPos = rShaderSource.indexOf("#version");
+
+    if (nVersionStrStartPos == -1)
+    {
+        rShaderSource = OString::Concat(rPreamble) + "\n" + rShaderSource;
+    }
+    else
+    {
+        int nVersionStrEndPos = rShaderSource.indexOf('\n', nVersionStrStartPos);
+
+        SAL_WARN_IF(nVersionStrEndPos == -1, "vcl.opengl", "syntax error in shader");
+
+        if (nVersionStrEndPos == -1)
+            nVersionStrEndPos = nVersionStrStartPos + 8;
+
+        OString aVersionLine = rShaderSource.copy(0, nVersionStrEndPos);
+        OString aShaderBody = rShaderSource.copy(nVersionStrEndPos + 1);
+
+        rShaderSource = aVersionLine + "\n" + rPreamble + "\n" + aShaderBody;
+    }
+}
+
+namespace
+{
+    const sal_uInt32 GLenumSize = sizeof(GLenum);
+
+#if defined _WIN32
+    OString getHexString(const sal_uInt8* pData, sal_uInt32 nLength)
+    {
+        static const char* const pHexData = "0123456789ABCDEF";
+
+        bool bIsZero = true;
+        OStringBuffer aHexStr;
+        for(size_t i = 0; i < nLength; ++i)
+        {
+            sal_uInt8 val = pData[i];
+            if( val != 0 )
+                bIsZero = false;
+            aHexStr.append( pHexData[ val & 0xf ] );
+            aHexStr.append( pHexData[ val >> 4 ] );
+        }
+        if( bIsZero )
+            return OString();
+        else
+            return aHexStr.makeStringAndClear();
+    }
+
+    OString generateMD5(const void* pData, size_t length)
+    {
+        sal_uInt8 pBuffer[RTL_DIGEST_LENGTH_MD5];
+        rtlDigestError aError = rtl_digest_MD5(pData, length,
+                pBuffer, RTL_DIGEST_LENGTH_MD5);
+        SAL_WARN_IF(aError != rtl_Digest_E_None, "vcl.opengl", "md5 generation failed");
+
+        return getHexString(pBuffer, RTL_DIGEST_LENGTH_MD5);
+    }
+
+    OString getDeviceInfoString()
+    {
+        const WinOpenGLDeviceInfo aInfo;
+        return OUStringToOString(aInfo.GetAdapterVendorID(), RTL_TEXTENCODING_UTF8) +
+            OUStringToOString(aInfo.GetAdapterDeviceID(), RTL_TEXTENCODING_UTF8) +
+            OUStringToOString(aInfo.GetDriverVersion(), RTL_TEXTENCODING_UTF8) +
+            OString::number(DriverBlocklist::GetWindowsVersion());
+    }
+
+    OString getStringDigest( const OUString& rVertexShaderName,
+                             const OUString& rFragmentShaderName,
+                             std::string_view rPreamble )
+    {
+        // read shaders source
+        OString aVertexShaderSource = getShaderSource( rVertexShaderName );
+        OString aFragmentShaderSource = getShaderSource( rFragmentShaderName );
+
+        // get info about the graphic device
+        static const OString aDeviceInfo (getDeviceInfoString());
+
+        OString aMessage = rPreamble +
+            aVertexShaderSource +
+            aFragmentShaderSource +
+            aDeviceInfo;
+
+        return generateMD5(aMessage.getStr(), aMessage.getLength());
+    }
+#endif
+
+    OString getCacheFolder()
+    {
+        OUString url("${$BRAND_BASE_DIR/" LIBO_ETC_FOLDER "/" SAL_CONFIGFILE("bootstrap") ":UserInstallation}/cache/");
+        rtl::Bootstrap::expandMacros(url);
+
+        osl::Directory::create(url);
+
+        return OUStringToOString(url, RTL_TEXTENCODING_UTF8);
+    }
+
+
+    bool writeProgramBinary( const OString& rBinaryFileName,
+                             const std::vector<sal_uInt8>& rBinary )
+    {
+        osl::File aFile(OStringToOUString(rBinaryFileName, RTL_TEXTENCODING_UTF8));
+        osl::FileBase::RC eStatus = aFile.open(
+                osl_File_OpenFlag_Write | osl_File_OpenFlag_Create );
+
+        if( eStatus != osl::FileBase::E_None )
+        {
+            // when file already exists we do not have to save it:
+            // we can be sure that the binary to save is exactly equal
+            // to the already saved binary, since they have the same hash value
+            if( eStatus == osl::FileBase::E_EXIST )
+            {
+                SAL_INFO( "vcl.opengl",
+                        "No binary program saved. A file with the same hash already exists: '" << rBinaryFileName << "'" );
+                return true;
+            }
+            return false;
+        }
+
+        sal_uInt64 nBytesWritten = 0;
+        aFile.write( rBinary.data(), rBinary.size(), nBytesWritten );
+
+        assert( rBinary.size() == nBytesWritten );
+
+        return true;
+    }
+
+    bool readProgramBinary( const OString& rBinaryFileName,
+                            std::vector<sal_uInt8>& rBinary )
+    {
+        osl::File aFile( OStringToOUString( rBinaryFileName, RTL_TEXTENCODING_UTF8 ) );
+        if(aFile.open( osl_File_OpenFlag_Read ) == osl::FileBase::E_None)
+        {
+            sal_uInt64 nSize = 0;
+            aFile.getSize( nSize );
+            rBinary.resize( nSize );
+            sal_uInt64 nBytesRead = 0;
+            aFile.read( rBinary.data(), nSize, nBytesRead );
+            assert( nSize == nBytesRead );
+            VCL_GL_INFO("Loading file: '" << rBinaryFileName << "': success" );
+            return true;
+        }
+        else
+        {
+            VCL_GL_INFO("Loading file: '" << rBinaryFileName << "': FAIL");
+        }
+
+        return false;
+    }
+
+    OString createFileName( std::u16string_view rVertexShaderName,
+                            std::u16string_view rFragmentShaderName,
+                            std::u16string_view rGeometryShaderName,
+                            std::string_view rDigest )
+    {
+        OString aFileName = getCacheFolder() +
+            OUStringToOString( rVertexShaderName, RTL_TEXTENCODING_UTF8 ) + "-" +
+            OUStringToOString( rFragmentShaderName, RTL_TEXTENCODING_UTF8 ) + "-";
+        if (!rGeometryShaderName.empty())
+            aFileName += OUStringToOString( rGeometryShaderName, RTL_TEXTENCODING_UTF8 ) + "-";
+        aFileName += OString::Concat(rDigest) + ".bin";
+        return aFileName;
+    }
+
+    GLint loadProgramBinary( GLuint nProgramID, const OString& rBinaryFileName )
+    {
+        GLint nResult = GL_FALSE;
+        GLenum nBinaryFormat;
+        std::vector<sal_uInt8> aBinary;
+        if( readProgramBinary( rBinaryFileName, aBinary ) && aBinary.size() > GLenumSize )
+        {
+            GLint nBinaryLength = aBinary.size() - GLenumSize;
+
+            // Extract binary format
+            sal_uInt8* pBF = reinterpret_cast<sal_uInt8*>(&nBinaryFormat);
+            for( size_t i = 0; i < GLenumSize; ++i )
+            {
+                pBF[i] = aBinary[nBinaryLength + i];
+            }
+
+            // Load the program
+            glProgramBinary( nProgramID, nBinaryFormat, aBinary.data(), nBinaryLength );
+
+            // Check the program
+            glGetProgramiv(nProgramID, GL_LINK_STATUS, &nResult);
+        }
+        return nResult;
+    }
+
+    void saveProgramBinary( GLint nProgramID, const OString& rBinaryFileName )
+    {
+        GLint nBinaryLength = 0;
+        GLenum nBinaryFormat = GL_NONE;
+
+        glGetProgramiv( nProgramID, GL_PROGRAM_BINARY_LENGTH, &nBinaryLength );
+        if( nBinaryLength <= 0 )
+        {
+            SAL_WARN( "vcl.opengl", "Binary size is zero" );
+            return;
+        }
+
+        std::vector<sal_uInt8> aBinary( nBinaryLength + GLenumSize );
+
+        glGetProgramBinary( nProgramID, nBinaryLength, nullptr, &nBinaryFormat, aBinary.data() );
+
+        const sal_uInt8* pBF = reinterpret_cast<const sal_uInt8*>(&nBinaryFormat);
+        aBinary.insert( aBinary.end(), pBF, pBF + GLenumSize );
+
+        SAL_INFO("vcl.opengl", "Program id: " << nProgramID );
+        SAL_INFO("vcl.opengl", "Binary length: " << nBinaryLength );
+        SAL_INFO("vcl.opengl", "Binary format: " << nBinaryFormat );
+
+        if( !writeProgramBinary( rBinaryFileName, aBinary ) )
+            SAL_WARN("vcl.opengl", "Writing binary file '" << rBinaryFileName << "': FAIL");
+        else
+            SAL_INFO("vcl.opengl", "Writing binary file '" << rBinaryFileName << "': success");
+    }
+}
+
+#if defined _WIN32
+OString OpenGLHelper::GetDigest( const OUString& rVertexShaderName,
+                                      const OUString& rFragmentShaderName,
+                                      std::string_view rPreamble )
+{
+    return getStringDigest(rVertexShaderName, rFragmentShaderName, rPreamble);
+}
+#endif
+
+GLint OpenGLHelper::LoadShaders(const OUString& rVertexShaderName,
+                                const OUString& rFragmentShaderName,
+                                const OUString& rGeometryShaderName,
+                                std::string_view preamble,
+                                std::string_view rDigest)
+{
+    OpenGLZone aZone;
+
+    gbInShaderCompile = true;
+
+    bool bHasGeometryShader = !rGeometryShaderName.isEmpty();
+
+    // create the program object
+    GLint ProgramID = glCreateProgram();
+
+    // read shaders from file
+    OString aVertexShaderSource = getShaderSource(rVertexShaderName);
+    OString aFragmentShaderSource = getShaderSource(rFragmentShaderName);
+    OString aGeometryShaderSource;
+    if (bHasGeometryShader)
+        aGeometryShaderSource = getShaderSource(rGeometryShaderName);
+
+    GLint bBinaryResult = GL_FALSE;
+    if (epoxy_has_gl_extension("GL_ARB_get_program_binary") && !rDigest.empty())
+    {
+        OString aFileName =
+                createFileName(rVertexShaderName, rFragmentShaderName, rGeometryShaderName, rDigest);
+        bBinaryResult = loadProgramBinary(ProgramID, aFileName);
+        CHECK_GL_ERROR();
+    }
+
+    if( bBinaryResult != GL_FALSE )
+        return ProgramID;
+
+    if (bHasGeometryShader)
+        VCL_GL_INFO("Load shader: vertex " << rVertexShaderName << " fragment " << rFragmentShaderName << " geometry " << rGeometryShaderName);
+    else
+        VCL_GL_INFO("Load shader: vertex " << rVertexShaderName << " fragment " << rFragmentShaderName);
+    // Create the shaders
+    GLuint VertexShaderID = glCreateShader(GL_VERTEX_SHADER);
+    GLuint FragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);
+    GLuint GeometryShaderID = 0;
+    if (bHasGeometryShader)
+        GeometryShaderID = glCreateShader(GL_GEOMETRY_SHADER);
+
+    GLint Result = GL_FALSE;
+
+    // Compile Vertex Shader
+    if( !preamble.empty())
+        addPreamble( aVertexShaderSource, preamble );
+    char const * VertexSourcePointer = aVertexShaderSource.getStr();
+    glShaderSource(VertexShaderID, 1, &VertexSourcePointer , nullptr);
+    glCompileShader(VertexShaderID);
+
+    // Check Vertex Shader
+    glGetShaderiv(VertexShaderID, GL_COMPILE_STATUS, &Result);
+    if (!Result)
+        return LogCompilerError(VertexShaderID, "vertex",
+                                rVertexShaderName, true);
+
+    // Compile Fragment Shader
+    if( !preamble.empty())
+        addPreamble( aFragmentShaderSource, preamble );
+    char const * FragmentSourcePointer = aFragmentShaderSource.getStr();
+    glShaderSource(FragmentShaderID, 1, &FragmentSourcePointer , nullptr);
+    glCompileShader(FragmentShaderID);
+
+    // Check Fragment Shader
+    glGetShaderiv(FragmentShaderID, GL_COMPILE_STATUS, &Result);
+    if (!Result)
+        return LogCompilerError(FragmentShaderID, "fragment",
+                                rFragmentShaderName, true);
+
+    if (bHasGeometryShader)
+    {
+        // Compile Geometry Shader
+        if( !preamble.empty())
+            addPreamble( aGeometryShaderSource, preamble );
+        char const * GeometrySourcePointer = aGeometryShaderSource.getStr();
+        glShaderSource(GeometryShaderID, 1, &GeometrySourcePointer , nullptr);
+        glCompileShader(GeometryShaderID);
+
+        // Check Geometry Shader
+        glGetShaderiv(GeometryShaderID, GL_COMPILE_STATUS, &Result);
+        if (!Result)
+            return LogCompilerError(GeometryShaderID, "geometry",
+                                    rGeometryShaderName, true);
+    }
+
+    // Link the program
+    glAttachShader(ProgramID, VertexShaderID);
+    glAttachShader(ProgramID, FragmentShaderID);
+    if (bHasGeometryShader)
+        glAttachShader(ProgramID, GeometryShaderID);
+
+    if (epoxy_has_gl_extension("GL_ARB_get_program_binary") && !rDigest.empty())
+    {
+        glProgramParameteri(ProgramID, GL_PROGRAM_BINARY_RETRIEVABLE_HINT, GL_TRUE);
+        glLinkProgram(ProgramID);
+        glGetProgramiv(ProgramID, GL_LINK_STATUS, &Result);
+        if (!Result)
+        {
+            SAL_WARN("vcl.opengl", "linking failed: " << Result );
+            return LogCompilerError(ProgramID, "program", "<both>", false);
+        }
+        OString aFileName =
+                createFileName(rVertexShaderName, rFragmentShaderName, rGeometryShaderName, rDigest);
+        saveProgramBinary(ProgramID, aFileName);
+    }
+    else
+    {
+        glLinkProgram(ProgramID);
+    }
+
+    glDeleteShader(VertexShaderID);
+    glDeleteShader(FragmentShaderID);
+    if (bHasGeometryShader)
+        glDeleteShader(GeometryShaderID);
+
+    // Check the program
+    glGetProgramiv(ProgramID, GL_LINK_STATUS, &Result);
+    if (!Result)
+        return LogCompilerError(ProgramID, "program", "<both>", false);
+
+    CHECK_GL_ERROR();
+
+    // Ensure we bump our counts before we leave the shader zone.
+    { OpenGLZone aMakeProgress; }
+    gbInShaderCompile = false;
+
+    return ProgramID;
+}
+
+GLint OpenGLHelper::LoadShaders(const OUString& rVertexShaderName,
+                                const OUString& rFragmentShaderName,
+                                std::string_view preamble,
+                                std::string_view rDigest)
+{
+    return LoadShaders(rVertexShaderName, rFragmentShaderName, OUString(), preamble, rDigest);
+}
+
+GLint OpenGLHelper::LoadShaders(const OUString& rVertexShaderName,
+                                const OUString& rFragmentShaderName,
+                                const OUString& rGeometryShaderName)
+{
+    return LoadShaders(rVertexShaderName, rFragmentShaderName, rGeometryShaderName, std::string_view(), std::string_view());
+}
+
+GLint OpenGLHelper::LoadShaders(const OUString& rVertexShaderName,
+                                const OUString& rFragmentShaderName)
+{
+    return LoadShaders(rVertexShaderName, rFragmentShaderName, OUString(), "", "");
+}
+
+void OpenGLHelper::renderToFile(tools::Long nWidth, tools::Long nHeight, const OUString& rFileName)
+{
+    OpenGLZone aZone;
+
+    std::unique_ptr<sal_uInt8[]> pBuffer(new sal_uInt8[nWidth*nHeight*4]);
+    glReadPixels(0, 0, nWidth, nHeight, OptimalBufferFormat(), GL_UNSIGNED_BYTE, pBuffer.get());
+    BitmapEx aBitmap = ConvertBufferToBitmapEx(pBuffer.get(), nWidth, nHeight);
+    try {
+        vcl::PNGWriter aWriter( aBitmap );
+        SvFileStream sOutput( rFileName, StreamMode::WRITE );
+        aWriter.Write( sOutput );
+        sOutput.Close();
+    } catch (...) {
+        SAL_WARN("vcl.opengl", "Error writing png to " << rFileName);
+    }
+
+    CHECK_GL_ERROR();
+}
+
+GLenum OpenGLHelper::OptimalBufferFormat()
+{
+#ifdef _WIN32
+    return GL_BGRA; // OpenGLSalBitmap is internally ScanlineFormat::N24BitTcBgr
+#else
+    return GL_RGBA; // OpenGLSalBitmap is internally ScanlineFormat::N24BitTcRgb
+#endif
+}
+
+BitmapEx OpenGLHelper::ConvertBufferToBitmapEx(const sal_uInt8* const pBuffer, tools::Long nWidth, tools::Long nHeight)
+{
+    assert(pBuffer);
+    Bitmap aBitmap(Size(nWidth, nHeight), vcl::PixelFormat::N24_BPP);
+    AlphaMask aAlpha(Size(nWidth, nHeight));
+
+    {
+        BitmapScopedWriteAccess pWriteAccess( aBitmap );
+        AlphaScopedWriteAccess pAlphaWriteAccess( aAlpha );
+#ifdef _WIN32
+        assert(pWriteAccess->GetScanlineFormat() == ScanlineFormat::N24BitTcBgr);
+        assert(pWriteAccess->IsTopDown());
+        assert(pAlphaWriteAccess->IsTopDown());
+#else
+        assert(pWriteAccess->GetScanlineFormat() == ScanlineFormat::N24BitTcRgb);
+        assert(!pWriteAccess->IsTopDown());
+        assert(!pAlphaWriteAccess->IsTopDown());
+#endif
+        assert(pAlphaWriteAccess->GetScanlineFormat() == ScanlineFormat::N8BitPal);
+
+        size_t nCurPos = 0;
+        for( tools::Long y = 0; y < nHeight; ++y)
+        {
+#ifdef _WIN32
+            Scanline pScan = pWriteAccess->GetScanline(y);
+            Scanline pAlphaScan = pAlphaWriteAccess->GetScanline(y);
+#else
+            Scanline pScan = pWriteAccess->GetScanline(nHeight-1-y);
+            Scanline pAlphaScan = pAlphaWriteAccess->GetScanline(nHeight-1-y);
+#endif
+            for( tools::Long x = 0; x < nWidth; ++x )
+            {
+                *pScan++ = pBuffer[nCurPos];
+                *pScan++ = pBuffer[nCurPos+1];
+                *pScan++ = pBuffer[nCurPos+2];
+
+                nCurPos += 3;
+                *pAlphaScan++ = static_cast<sal_uInt8>( 255 - pBuffer[nCurPos++] );
+            }
+        }
+    }
+    return BitmapEx(aBitmap, aAlpha);
+}
+
+const char* OpenGLHelper::GLErrorString(GLenum errorCode)
+{
+    static const struct {
+        GLenum code;
+        const char *string;
+    } errors[]=
+    {
+        /* GL */
+        {GL_NO_ERROR, "no error"},
+        {GL_INVALID_ENUM, "invalid enumerant"},
+        {GL_INVALID_VALUE, "invalid value"},
+        {GL_INVALID_OPERATION, "invalid operation"},
+        {GL_STACK_OVERFLOW, "stack overflow"},
+        {GL_STACK_UNDERFLOW, "stack underflow"},
+        {GL_OUT_OF_MEMORY, "out of memory"},
+        {GL_INVALID_FRAMEBUFFER_OPERATION, "invalid framebuffer operation"},
+
+        {0, nullptr }
+    };
+
+    int i;
+
+    for (i=0; errors[i].string; i++)
+    {
+        if (errors[i].code == errorCode)
+        {
+            return errors[i].string;
+        }
+    }
+
+    return nullptr;
+}
+
+std::ostream& operator<<(std::ostream& rStrm, const glm::vec4& rPos)
+{
+    rStrm << "( " << rPos[0] << ", " << rPos[1] << ", " << rPos[2] << ", " << rPos[3] << ")";
+    return rStrm;
+}
+
+std::ostream& operator<<(std::ostream& rStrm, const glm::vec3& rPos)
+{
+    rStrm << "( " << rPos[0] << ", " << rPos[1] << ", " << rPos[2] << ")";
+    return rStrm;
+}
+
+std::ostream& operator<<(std::ostream& rStrm, const glm::mat4& rMatrix)
+{
+    for(int i = 0; i < 4; ++i)
+    {
+        rStrm << "\n( ";
+        for(int j = 0; j < 4; ++j)
+        {
+            rStrm << rMatrix[j][i];
+            rStrm << " ";
+        }
+        rStrm << ")\n";
+    }
+    return rStrm;
+}
+
+void OpenGLHelper::createFramebuffer(tools::Long nWidth, tools::Long nHeight, GLuint& nFramebufferId,
+        GLuint& nRenderbufferDepthId, GLuint& nRenderbufferColorId)
+{
+    OpenGLZone aZone;
+
+    // create a renderbuffer for depth attachment
+    glGenRenderbuffers(1, &nRenderbufferDepthId);
+    glBindRenderbuffer(GL_RENDERBUFFER, nRenderbufferDepthId);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, nWidth, nHeight);
+    glBindRenderbuffer(GL_RENDERBUFFER, 0);
+
+    glGenTextures(1, &nRenderbufferColorId);
+    glBindTexture(GL_TEXTURE_2D, nRenderbufferColorId);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, nWidth, nHeight, 0,
+                         GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+    glBindTexture(GL_TEXTURE_2D, 0);
+
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+            GL_TEXTURE_2D, nRenderbufferColorId, 0);
+
+    // create a framebuffer object and attach renderbuffer
+    glGenFramebuffers(1, &nFramebufferId);
+    glCheckFramebufferStatus(GL_FRAMEBUFFER);
+    glBindFramebuffer(GL_FRAMEBUFFER, nFramebufferId);
+    // attach a renderbuffer to FBO color attachment point
+    glBindRenderbuffer(GL_RENDERBUFFER, nRenderbufferColorId);
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, nRenderbufferColorId);
+    glCheckFramebufferStatus(GL_FRAMEBUFFER);
+    // attach a renderbuffer to depth attachment point
+    glBindRenderbuffer(GL_RENDERBUFFER, nRenderbufferDepthId);
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, nRenderbufferDepthId);
+    GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+    if (status != GL_FRAMEBUFFER_COMPLETE)
+    {
+        SAL_WARN("vcl.opengl", "invalid framebuffer status");
+    }
+    glBindRenderbuffer(GL_RENDERBUFFER, 0);
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+    CHECK_GL_ERROR();
+}
+
+float OpenGLHelper::getGLVersion()
+{
+    float fVersion = 1.0;
+    const GLubyte* aVersion = glGetString( GL_VERSION );
+    if( aVersion && aVersion[0] )
+    {
+        fVersion = aVersion[0] - '0';
+        if( aVersion[1] == '.' && aVersion[2] )
+        {
+            fVersion += (aVersion[2] - '0')/10.0;
+        }
+    }
+
+    CHECK_GL_ERROR();
+    return fVersion;
+}
+
+void OpenGLHelper::checkGLError(const char* pFile, size_t nLine)
+{
+    OpenGLZone aZone;
+
+    int nErrors = 0;
+    for (;;)
+    {
+        GLenum glErr = glGetError();
+        if (glErr == GL_NO_ERROR)
+        {
+            break;
+        }
+        const char* sError = OpenGLHelper::GLErrorString(glErr);
+        if (!sError)
+            sError = "no message available";
+
+        SAL_WARN("vcl.opengl", "GL Error " << std::hex << std::setw(4) << std::setfill('0') << glErr << std::dec << std::setw(0) << std::setfill(' ') << " (" << sError << ") in file " << pFile << " at line " << nLine);
+
+        // tdf#93798 - apitrace appears to sometimes cause issues with an infinite loop here.
+        if (++nErrors >= 8)
+        {
+            SAL_WARN("vcl.opengl", "Breaking potentially recursive glGetError loop");
+            break;
+        }
+    }
+}
+
+bool OpenGLHelper::isDeviceDenylisted()
+{
+    static bool bSet = false;
+    static bool bDenylisted = true; // assume the worst
+    if (!bSet)
+    {
+        OpenGLZone aZone;
+
+#if defined( _WIN32 )
+        WinOpenGLDeviceInfo aInfo;
+        bDenylisted = aInfo.isDeviceBlocked();
+
+        if (DriverBlocklist::GetWindowsVersion() == 0x00060001 && /* Windows 7 */
+            (aInfo.GetAdapterVendorID() == "0x1002" || aInfo.GetAdapterVendorID() == "0x1022")) /* AMD */
+        {
+            SAL_INFO("vcl.opengl", "Relaxing watchdog timings.");
+            OpenGLZone::relaxWatchdogTimings();
+        }
+#else
+        bDenylisted = false;
+#endif
+        bSet = true;
+    }
+
+    return bDenylisted;
+}
+
+bool OpenGLHelper::supportsOpenGL()
+{
+    if( getenv("SAL_DISABLEGL") != nullptr )
+        return false;
+    if (!ImplGetSVData()->mpDefInst->supportsOpenGL())
+        return false;
+    if( isDeviceDenylisted())
+        return false;
+    if( officecfg::Office::Common::VCL::DisableOpenGL::get())
+        return false;
+    WatchdogThread::start();
+    return true;
+}
+
+namespace
+{
+
+enum class CrashWatchdogTimingMode
+{
+    NORMAL,
+    SHADER_COMPILE
+};
+
+class CrashWatchdogTimings
+{
+private:
+    std::vector<CrashWatchdogTimingsValues> maTimingValues;
+    std::atomic<bool> mbRelaxed;
+
+public:
+    CrashWatchdogTimings();
+
+    void setRelax(bool bRelaxed)
+    {
+        mbRelaxed = bRelaxed;
+    }
+
+    CrashWatchdogTimingsValues const & getWatchdogTimingsValues(CrashWatchdogTimingMode eMode)
+    {
+        size_t index = (eMode == CrashWatchdogTimingMode::SHADER_COMPILE) ? 1 : 0;
+        index = mbRelaxed ? index + 2 : index;
+
+        return maTimingValues[index];
+    }
+};
+
+CrashWatchdogTimings gWatchdogTimings;
+
+CrashWatchdogTimings::CrashWatchdogTimings()
+    : maTimingValues{
+                     {{6,   20} /* 1.5s,  5s */, {20, 120} /*  5s, 30s */,
+                      {60, 240} /*  15s, 60s */, {60, 240} /* 15s, 60s */}
+                    }
+    , mbRelaxed(false)
+{
+}
+
+} // namespace
+
+/**
+ * Called from a signal handler or watchdog thread if we get
+ * a crash or hang in some GL code.
+ */
+void OpenGLZone::hardDisable()
+{
+    // protect ourselves from double calling etc.
+    static bool bDisabled = false;
+    if (bDisabled)
+        return;
+
+    bDisabled = true;
+
+    // Disable the OpenGL support
+    std::shared_ptr<comphelper::ConfigurationChanges> xChanges(
+        comphelper::ConfigurationChanges::create());
+    officecfg::Office::Common::VCL::DisableOpenGL::set(true, xChanges);
+    xChanges->commit();
+
+    // Force synchronous config write
+    css::uno::Reference< css::util::XFlushable >(
+        css::configuration::theDefaultProvider::get(
+            comphelper::getProcessComponentContext()),
+        css::uno::UNO_QUERY_THROW)->flush();
+}
+
+void OpenGLZone::relaxWatchdogTimings()
+{
+    gWatchdogTimings.setRelax(true);
+}
+
+void OpenGLZone::checkDebug( int nUnchanged, const CrashWatchdogTimingsValues& aTimingValues )
+{
+    SAL_INFO("vcl.watchdog", "GL watchdog - unchanged "
+                                 << nUnchanged << " enter count " << enterCount() << " type "
+                                 << (gbInShaderCompile ? "in shader" : "normal gl")
+                                 << " breakpoints mid: " << aTimingValues.mnDisableEntries
+                                 << " max " << aTimingValues.mnAbortAfter);
+}
+
+const CrashWatchdogTimingsValues& OpenGLZone::getCrashWatchdogTimingsValues()
+{
+    // The shader compiler can take a long time, first time.
+    CrashWatchdogTimingMode eMode = gbInShaderCompile ? CrashWatchdogTimingMode::SHADER_COMPILE : CrashWatchdogTimingMode::NORMAL;
+    return gWatchdogTimings.getWatchdogTimingsValues(eMode);
+}
+
+void OpenGLHelper::debugMsgStream(std::ostringstream const &pStream)
+{
+    debugMsgPrint(
+        0, "%" SAL_PRIxUINT32 ": %s", osl_getThreadIdentifier(nullptr), pStream.str().c_str());
+}
+
+void OpenGLHelper::debugMsgStreamWarn(std::ostringstream const &pStream)
+{
+    debugMsgPrint(
+        1, "%" SAL_PRIxUINT32 ": %s", osl_getThreadIdentifier(nullptr), pStream.str().c_str());
+}
+
+void OpenGLHelper::debugMsgPrint(const int nType, const char *pFormat, ...)
+{
+    va_list aArgs;
+    va_start (aArgs, pFormat);
+
+    char pStr[1044];
+#ifdef _WIN32
+#define vsnprintf _vsnprintf
+#endif
+    vsnprintf(pStr, sizeof(pStr), pFormat, aArgs);
+    pStr[sizeof(pStr)-20] = '\0';
+
+    bool bHasContext = OpenGLContext::hasCurrent();
+    if (!bHasContext)
+        strcat(pStr, " (no GL context)");
+
+    if (nType == 0)
+    {
+        SAL_INFO("vcl.opengl", pStr);
+    }
+    else if (nType == 1)
+    {
+        SAL_WARN("vcl.opengl", pStr);
+    }
+
+    if (bHasContext)
+    {
+        OpenGLZone aZone;
+
+        if (epoxy_has_gl_extension("GL_KHR_debug"))
+            glDebugMessageInsert(GL_DEBUG_SOURCE_APPLICATION,
+                                 GL_DEBUG_TYPE_OTHER,
+                                 1, // one[sic] id is as good as another ?
+                                 // GL_DEBUG_SEVERITY_NOTIFICATION for >= GL4.3 ?
+                                 GL_DEBUG_SEVERITY_LOW,
+                                 strlen(pStr), pStr);
+        else if (epoxy_has_gl_extension("GL_AMD_debug_output"))
+            glDebugMessageInsertAMD(GL_DEBUG_CATEGORY_APPLICATION_AMD,
+                                    GL_DEBUG_SEVERITY_LOW_AMD,
+                                    1, // one[sic] id is as good as another ?
+                                    strlen(pStr), pStr);
+    }
+
+    va_end (aArgs);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/opengl/README.deprecated b/vcl/source/opengl/README.deprecated
new file mode 100644
index 000000000..eb033a0fd
--- /dev/null
+++ b/vcl/source/opengl/README.deprecated
@@ -0,0 +1,23 @@
+deprecated features
+
+GL_LIGHTING
+GL_TEXTURE_2D
+GL_POINT_SMOOTH
+GL_TEXTURE_WRAP_S
+GL_TEXTURE_WRAP_T
+glBegin
+glEnd
+
+
+GLSL
+
+texture*D
+varying
+attribute
+missing version string
+
+gl_FragColor
+gl_FragData
+gl_Normal
+gl_NormalMatrix
+gl_Vertex
diff --git a/vcl/source/opengl/opengl_denylist_windows.xml b/vcl/source/opengl/opengl_denylist_windows.xml
new file mode 100644
index 000000000..70f4e0192
--- /dev/null
+++ b/vcl/source/opengl/opengl_denylist_windows.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+* This file is part of the LibreOffice project.
+*
+* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at http://mozilla.org/MPL/2.0/.
+-->
+
+<!--
+    entry attributes:
+    os - "all", "7", "8", "8_1", "10"
+    vendor - "all", "intel", "amd", "nvidia", "microsoft"
+    compare - "less", "less_equal", "greater", "greater_equal", "equal", "not_equal", "between_exclusive", "between_inclusive", "between_inclusive_start"
+    version
+    minVersion
+    maxVersion
+-->
+
+<root>
+    <allowlist>
+    </allowlist>
+    <denylist>
+        <!-- tdf#125516: crash on preview of slide transitions, or in slideshow, when OpenGL rendering enabled Windows 10, with Intel DCH packaged driver -->
+        <entry os="10" vendor="intel" compare="between_inclusive_start" minVersion="26.20.100.6861" maxVersion="26.20.100.7584"><!-- tdf#125516 -->
+            <device id="all"/>
+        </entry>
+    </denylist>
+</root>
diff --git a/vcl/source/opengl/win/WinDeviceInfo.cxx b/vcl/source/opengl/win/WinDeviceInfo.cxx
new file mode 100644
index 000000000..ef6a840f5
--- /dev/null
+++ b/vcl/source/opengl/win/WinDeviceInfo.cxx
@@ -0,0 +1,491 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <opengl/win/WinDeviceInfo.hxx>
+
+#include <driverblocklist.hxx>
+#include <config_folders.h>
+
+#if !defined WIN32_LEAN_AND_MEAN
+# define WIN32_LEAN_AND_MEAN
+#endif
+#include <windows.h>
+#include <objbase.h>
+#include <setupapi.h>
+#include <algorithm>
+#include <cstdint>
+#include <memory>
+#include <string_view>
+
+#include <osl/file.hxx>
+#include <rtl/bootstrap.hxx>
+#include <rtl/ustrbuf.hxx>
+#include <sal/log.hxx>
+#include <tools/stream.hxx>
+#include <o3tl/char16_t2wchar_t.hxx>
+
+#include <desktop/crashreport.hxx>
+
+namespace {
+
+bool GetKeyValue(const WCHAR* keyLocation, const WCHAR* keyName, OUString& destString, int type)
+{
+    HKEY key;
+    DWORD dwcbData;
+    DWORD dValue;
+    DWORD resultType;
+    LONG result;
+    bool retval = true;
+
+    result = RegOpenKeyExW(HKEY_LOCAL_MACHINE, keyLocation, 0, KEY_QUERY_VALUE, &key);
+    if (result != ERROR_SUCCESS)
+    {
+        return false;
+    }
+
+    switch (type)
+    {
+        case REG_DWORD:
+            {
+                // We only use this for vram size
+                dwcbData = sizeof(dValue);
+                result = RegQueryValueExW(key, keyName, nullptr, &resultType,
+                        reinterpret_cast<LPBYTE>(&dValue), &dwcbData);
+                if (result == ERROR_SUCCESS && resultType == REG_DWORD)
+                {
+                    dValue = dValue / 1024 / 1024;
+                    destString += OUString::number(int32_t(dValue));
+                }
+                else
+                {
+                    retval = false;
+                }
+                break;
+            }
+        case REG_MULTI_SZ:
+            {
+                // A chain of null-separated strings; we convert the nulls to spaces
+                WCHAR wCharValue[1024];
+                dwcbData = sizeof(wCharValue);
+
+                result = RegQueryValueExW(key, keyName, nullptr, &resultType,
+                        reinterpret_cast<LPBYTE>(wCharValue), &dwcbData);
+                if (result == ERROR_SUCCESS && resultType == REG_MULTI_SZ)
+                {
+                    // This bit here could probably be cleaner.
+                    bool isValid = false;
+
+                    DWORD strLen = dwcbData/sizeof(wCharValue[0]);
+                    for (DWORD i = 0; i < strLen; i++)
+                    {
+                        if (wCharValue[i] == '\0')
+                        {
+                            if (i < strLen - 1 && wCharValue[i + 1] == '\0')
+                            {
+                                isValid = true;
+                                break;
+                            }
+                            else
+                            {
+                                wCharValue[i] = ' ';
+                            }
+                        }
+                    }
+
+                    // ensure wCharValue is null terminated
+                    wCharValue[strLen-1] = '\0';
+
+                    if (isValid)
+                        destString = OUString(o3tl::toU(wCharValue));
+
+                }
+                else
+                {
+                    retval = false;
+                }
+
+                break;
+            }
+    }
+    RegCloseKey(key);
+
+    return retval;
+}
+
+// The device ID is a string like PCI\VEN_15AD&DEV_0405&SUBSYS_040515AD
+// this function is used to extract the id's out of it
+uint32_t ParseIDFromDeviceID(const OUString &key, const char *prefix, int length)
+{
+    OUString id = key.toAsciiUpperCase();
+    OUString aPrefix = OUString::fromUtf8(prefix);
+    int32_t start = id.indexOf(aPrefix);
+    if (start != -1)
+    {
+        id = id.copy(start + aPrefix.getLength(), length);
+    }
+    return id.toUInt32(16);
+}
+
+/* Other interesting places for info:
+ *   IDXGIAdapter::GetDesc()
+ *   IDirectDraw7::GetAvailableVidMem()
+ *   e->GetAvailableTextureMem()
+ * */
+
+template<typename T> void appendIntegerWithPadding(OUString& rString, T value, sal_uInt32 nChars)
+{
+    rString += "0x";
+    OUString aValue = OUString::number(value, 16);
+    sal_Int32 nLength = aValue.getLength();
+    sal_uInt32 nPadLength = nChars - nLength;
+    assert(nPadLength >= 0);
+    OUStringBuffer aBuffer;
+    for (sal_uInt32 i = 0; i < nPadLength; ++i)
+    {
+        aBuffer.append("0");
+    }
+    rString += aBuffer.makeStringAndClear() + aValue;
+}
+
+#define DEVICE_KEY_PREFIX L"\\Registry\\Machine\\"
+}
+
+WinOpenGLDeviceInfo::WinOpenGLDeviceInfo():
+    mbHasDualGPU(false),
+    mbRDP(false)
+{
+    GetData();
+}
+
+static OUString getDenylistFile()
+{
+    OUString url("$BRAND_BASE_DIR/" LIBO_SHARE_FOLDER);
+    rtl::Bootstrap::expandMacros(url);
+
+    return url + "/opengl/opengl_denylist_windows.xml";
+}
+
+bool WinOpenGLDeviceInfo::FindBlocklistedDeviceInList()
+{
+    return DriverBlocklist::IsDeviceBlocked( getDenylistFile(), DriverBlocklist::VersionType::OpenGL,
+        maDriverVersion, maAdapterVendorID, maAdapterDeviceID);
+}
+
+namespace {
+
+OUString getCacheFolder()
+{
+    OUString url("${$BRAND_BASE_DIR/" LIBO_ETC_FOLDER "/" SAL_CONFIGFILE("bootstrap") ":UserInstallation}/cache/");
+    rtl::Bootstrap::expandMacros(url);
+
+    osl::Directory::create(url);
+
+    return url;
+}
+
+void writeToLog(SvStream& rStrm, const char* pKey, std::u16string_view rVal)
+{
+    rStrm.WriteCharPtr(pKey);
+    rStrm.WriteCharPtr(": ");
+    rStrm.WriteOString(OUStringToOString(rVal, RTL_TEXTENCODING_UTF8));
+    rStrm.WriteChar('\n');
+}
+
+}
+
+bool WinOpenGLDeviceInfo::isDeviceBlocked()
+{
+    CrashReporter::addKeyValue("OpenGLVendor", maAdapterVendorID, CrashReporter::AddItem);
+    CrashReporter::addKeyValue("OpenGLDevice", maAdapterDeviceID, CrashReporter::AddItem);
+    CrashReporter::addKeyValue("OpenGLDriver", maDriverVersion, CrashReporter::Write);
+
+    SAL_INFO("vcl.opengl", maDriverVersion);
+    SAL_INFO("vcl.opengl", maDriverDate);
+    SAL_INFO("vcl.opengl", maDeviceID);
+    SAL_INFO("vcl.opengl", maAdapterVendorID);
+    SAL_INFO("vcl.opengl", maAdapterDeviceID);
+    SAL_INFO("vcl.opengl", maAdapterSubsysID);
+    SAL_INFO("vcl.opengl", maDeviceKey);
+    SAL_INFO("vcl.opengl", maDeviceString);
+
+    OUString aCacheFolder = getCacheFolder();
+
+    OUString aCacheFile(aCacheFolder + "/opengl_device.log");
+    SvFileStream aOpenGLLogFile(aCacheFile, StreamMode::WRITE|StreamMode::TRUNC);
+
+    writeToLog(aOpenGLLogFile, "DriverVersion", maDriverVersion);
+    writeToLog(aOpenGLLogFile, "DriverDate", maDriverDate);
+    writeToLog(aOpenGLLogFile, "DeviceID", maDeviceID);
+    writeToLog(aOpenGLLogFile, "AdapterVendorID", maAdapterVendorID);
+    writeToLog(aOpenGLLogFile, "AdapterDeviceID", maAdapterDeviceID);
+    writeToLog(aOpenGLLogFile, "AdapterSubsysID", maAdapterSubsysID);
+    writeToLog(aOpenGLLogFile, "DeviceKey", maDeviceKey);
+    writeToLog(aOpenGLLogFile, "DeviceString", maDeviceString);
+
+    // Check if the device is blocked from the downloaded blocklist. If not, check
+    // the static list after that. This order is used so that we can later escape
+    // out of static blocks (i.e. if we were wrong or something was patched, we
+    // can back out our static block without doing a release).
+    if (mbRDP)
+    {
+        SAL_WARN("vcl.opengl", "all OpenGL blocked for RDP sessions");
+        return true;
+    }
+
+    return FindBlocklistedDeviceInList();
+}
+
+void WinOpenGLDeviceInfo::GetData()
+{
+    DISPLAY_DEVICEW displayDevice;
+    displayDevice.cb = sizeof(displayDevice);
+
+    int deviceIndex = 0;
+
+    while (EnumDisplayDevicesW(nullptr, deviceIndex, &displayDevice, 0))
+    {
+        if (displayDevice.StateFlags & DISPLAY_DEVICE_PRIMARY_DEVICE)
+        {
+            break;
+        }
+        deviceIndex++;
+    }
+
+    // make sure the string is null terminated
+    // (using the term "null" here to mean a zero UTF-16 unit)
+    if (wcsnlen(displayDevice.DeviceKey, SAL_N_ELEMENTS(displayDevice.DeviceKey))
+            == SAL_N_ELEMENTS(displayDevice.DeviceKey))
+    {
+        // we did not find a null
+        SAL_WARN("vcl.opengl", "string not null terminated");
+        return;
+    }
+
+    /* DeviceKey is "reserved" according to MSDN so we'll be careful with it */
+    /* check that DeviceKey begins with DEVICE_KEY_PREFIX */
+    /* some systems have a DeviceKey starting with \REGISTRY\Machine\ so we need to compare case insensitively */
+    if (_wcsnicmp(displayDevice.DeviceKey, DEVICE_KEY_PREFIX, SAL_N_ELEMENTS(DEVICE_KEY_PREFIX)-1) != 0)
+    {
+        SAL_WARN("vcl.opengl", "incorrect DeviceKey");
+        return;
+    }
+
+    // chop off DEVICE_KEY_PREFIX
+    maDeviceKey = o3tl::toU(displayDevice.DeviceKey) + SAL_N_ELEMENTS(DEVICE_KEY_PREFIX)-1;
+
+    maDeviceID = o3tl::toU(displayDevice.DeviceID);
+    maDeviceString = o3tl::toU(displayDevice.DeviceString);
+
+    if (maDeviceID.isEmpty() &&
+        (maDeviceString == "RDPDD Chained DD" ||
+         (maDeviceString == "RDPUDD Chained DD")))
+    {
+        // we need to block RDP as it does not provide OpenGL 2.1+
+        mbRDP = true;
+        SAL_WARN("vcl.opengl", "RDP => blocked");
+        return;
+    }
+
+    /* create a device information set composed of the current display device */
+    HDEVINFO devinfo = SetupDiGetClassDevsW(nullptr, o3tl::toW(maDeviceID.getStr()), nullptr,
+            DIGCF_PRESENT | DIGCF_PROFILE | DIGCF_ALLCLASSES);
+
+    if (devinfo != INVALID_HANDLE_VALUE)
+    {
+        HKEY key;
+        LONG result;
+        WCHAR value[255];
+        DWORD dwcbData;
+        SP_DEVINFO_DATA devinfoData;
+        DWORD memberIndex = 0;
+
+        devinfoData.cbSize = sizeof(devinfoData);
+        /* enumerate device information elements in the device information set */
+        while (SetupDiEnumDeviceInfo(devinfo, memberIndex++, &devinfoData))
+        {
+            /* get a string that identifies the device's driver key */
+            if (SetupDiGetDeviceRegistryPropertyW(devinfo,
+                        &devinfoData,
+                        SPDRP_DRIVER,
+                        nullptr,
+                        reinterpret_cast<PBYTE>(value),
+                        sizeof(value),
+                        nullptr))
+            {
+                OUString  driverKey(OUString::Concat("System\\CurrentControlSet\\Control\\Class\\") + o3tl::toU(value));
+                result = RegOpenKeyExW(HKEY_LOCAL_MACHINE, o3tl::toW(driverKey.getStr()), 0, KEY_QUERY_VALUE, &key);
+                if (result == ERROR_SUCCESS)
+                {
+                    /* we've found the driver we're looking for */
+                    dwcbData = sizeof(value);
+                    result = RegQueryValueExW(key, L"DriverVersion", nullptr, nullptr,
+                            reinterpret_cast<LPBYTE>(value), &dwcbData);
+                    if (result == ERROR_SUCCESS)
+                    {
+                        maDriverVersion = OUString(o3tl::toU(value));
+                    }
+                    else
+                    {
+                        // If the entry wasn't found, assume the worst (0.0.0.0).
+                        maDriverVersion = OUString("0.0.0.0");
+                    }
+                    dwcbData = sizeof(value);
+                    result = RegQueryValueExW(key, L"DriverDate", nullptr, nullptr,
+                            reinterpret_cast<LPBYTE>(value), &dwcbData);
+                    if (result == ERROR_SUCCESS)
+                    {
+                        maDriverDate = o3tl::toU(value);
+                    }
+                    else
+                    {
+                        // Again, assume the worst
+                        maDriverDate = OUString("01-01-1970");
+                    }
+                    RegCloseKey(key);
+                    break;
+                }
+            }
+        }
+
+        SetupDiDestroyDeviceInfoList(devinfo);
+    }
+    else
+    {
+        SAL_WARN("vcl.opengl", "invalid handle value");
+    }
+
+    appendIntegerWithPadding(maAdapterVendorID, ParseIDFromDeviceID(maDeviceID, "VEN_", 4), 4);
+    appendIntegerWithPadding(maAdapterDeviceID, ParseIDFromDeviceID(maDeviceID, "&DEV_", 4), 4);
+    appendIntegerWithPadding(maAdapterSubsysID, ParseIDFromDeviceID(maDeviceID, "&SUBSYS_", 8), 8);
+
+    // We now check for second display adapter.
+
+    // Device interface class for display adapters.
+    CLSID GUID_DISPLAY_DEVICE_ARRIVAL;
+    HRESULT hresult = CLSIDFromString(L"{1CA05180-A699-450A-9A0C-DE4FBE3DDD89}",
+            &GUID_DISPLAY_DEVICE_ARRIVAL);
+    if (hresult == NOERROR)
+    {
+        devinfo = SetupDiGetClassDevsW(&GUID_DISPLAY_DEVICE_ARRIVAL,
+                nullptr, nullptr,
+                DIGCF_PRESENT | DIGCF_INTERFACEDEVICE);
+
+        if (devinfo != INVALID_HANDLE_VALUE)
+        {
+            HKEY key;
+            LONG result;
+            WCHAR value[255];
+            DWORD dwcbData;
+            SP_DEVINFO_DATA devinfoData;
+            DWORD memberIndex = 0;
+            devinfoData.cbSize = sizeof(devinfoData);
+
+            OUString aAdapterDriver2;
+            OUString aDeviceID2;
+            OUString aDriverVersion2;
+            OUString aDriverDate2;
+            uint32_t adapterVendorID2;
+            uint32_t adapterDeviceID2;
+
+            /* enumerate device information elements in the device information set */
+            while (SetupDiEnumDeviceInfo(devinfo, memberIndex++, &devinfoData))
+            {
+                /* get a string that identifies the device's driver key */
+                if (SetupDiGetDeviceRegistryPropertyW(devinfo,
+                            &devinfoData,
+                            SPDRP_DRIVER,
+                            nullptr,
+                            reinterpret_cast<PBYTE>(value),
+                            sizeof(value),
+                            nullptr))
+                {
+                    OUString driverKey2(OUString::Concat("System\\CurrentControlSet\\Control\\Class\\") + o3tl::toU(value));
+                    result = RegOpenKeyExW(HKEY_LOCAL_MACHINE, o3tl::toW(driverKey2.getStr()), 0, KEY_QUERY_VALUE, &key);
+                    if (result == ERROR_SUCCESS)
+                    {
+                        dwcbData = sizeof(value);
+                        result = RegQueryValueExW(key, L"MatchingDeviceId", nullptr,
+                                nullptr, reinterpret_cast<LPBYTE>(value), &dwcbData);
+                        if (result != ERROR_SUCCESS)
+                        {
+                            continue;
+                        }
+                        aDeviceID2 = o3tl::toU(value);
+                        OUString aAdapterVendorID2String;
+                        OUString aAdapterDeviceID2String;
+                        adapterVendorID2 = ParseIDFromDeviceID(aDeviceID2, "VEN_", 4);
+                        appendIntegerWithPadding(aAdapterVendorID2String, adapterVendorID2, 4);
+                        adapterDeviceID2 = ParseIDFromDeviceID(aDeviceID2, "&DEV_", 4);
+                        appendIntegerWithPadding(aAdapterDeviceID2String, adapterDeviceID2, 4);
+                        if (maAdapterVendorID == aAdapterVendorID2String &&
+                                maAdapterDeviceID == aAdapterDeviceID2String)
+                        {
+                            RegCloseKey(key);
+                            continue;
+                        }
+
+                        // If this device is missing driver information, it is unlikely to
+                        // be a real display adapter.
+                        if (!GetKeyValue(o3tl::toW(driverKey2.getStr()), L"InstalledDisplayDrivers",
+                                        aAdapterDriver2, REG_MULTI_SZ))
+                        {
+                            RegCloseKey(key);
+                            continue;
+                        }
+                        dwcbData = sizeof(value);
+                        result = RegQueryValueExW(key, L"DriverVersion", nullptr, nullptr,
+                                reinterpret_cast<LPBYTE>(value), &dwcbData);
+                        if (result != ERROR_SUCCESS)
+                        {
+                            RegCloseKey(key);
+                            continue;
+                        }
+                        aDriverVersion2 = o3tl::toU(value);
+                        dwcbData = sizeof(value);
+                        result = RegQueryValueExW(key, L"DriverDate", nullptr, nullptr,
+                                reinterpret_cast<LPBYTE>(value), &dwcbData);
+                        if (result != ERROR_SUCCESS)
+                        {
+                            RegCloseKey(key);
+                            continue;
+                        }
+                        aDriverDate2 = o3tl::toU(value);
+                        dwcbData = sizeof(value);
+                        result = RegQueryValueExW(key, L"Device Description", nullptr,
+                                nullptr, reinterpret_cast<LPBYTE>(value), &dwcbData);
+                        if (result != ERROR_SUCCESS)
+                        {
+                            dwcbData = sizeof(value);
+                            result = RegQueryValueExW(key, L"DriverDesc", nullptr, nullptr,
+                                    reinterpret_cast<LPBYTE>(value), &dwcbData);
+                        }
+                        RegCloseKey(key);
+                        if (result == ERROR_SUCCESS)
+                        {
+                            mbHasDualGPU = true;
+                            maDeviceString2 = o3tl::toU(value);
+                            maDeviceID2 = aDeviceID2;
+                            maDeviceKey2 = driverKey2;
+                            maDriverVersion2 = aDriverVersion2;
+                            maDriverDate2 = aDriverDate2;
+                            appendIntegerWithPadding(maAdapterVendorID2, adapterVendorID2, 4);
+                            appendIntegerWithPadding(maAdapterDeviceID2, adapterDeviceID2, 4);
+                            appendIntegerWithPadding(maAdapterSubsysID2, ParseIDFromDeviceID(maDeviceID2, "&SUBSYS_", 8), 8);
+                            break;
+                        }
+                    }
+                }
+            }
+
+            SetupDiDestroyDeviceInfoList(devinfo);
+        }
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/opengl/win/context.cxx b/vcl/source/opengl/win/context.cxx
new file mode 100644
index 000000000..5031ec6f0
--- /dev/null
+++ b/vcl/source/opengl/win/context.cxx
@@ -0,0 +1,663 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <memory>
+#include <string_view>
+#include <thread>
+#include <vcl/opengl/OpenGLContext.hxx>
+#include <vcl/opengl/OpenGLHelper.hxx>
+#include <vcl/syschild.hxx>
+
+#include <sal/log.hxx>
+#include <comphelper/windowserrorstring.hxx>
+#include <opengl/zone.hxx>
+#include <win/wincomp.hxx>
+#include <win/saldata.hxx>
+#include <win/salframe.h>
+#include <win/salinst.h>
+#include <epoxy/wgl.h>
+#include <ControlCacheKey.hxx>
+
+static std::vector<HGLRC> g_vShareList;
+static bool g_bAnyCurrent;
+
+namespace {
+
+class GLWinWindow : public GLWindow
+{
+public:
+    HWND                    hWnd;
+    HDC                     hDC;
+    HGLRC                   hRC;
+    GLWinWindow();
+};
+
+}
+
+GLWinWindow::GLWinWindow()
+    : hWnd(nullptr)
+    , hDC(nullptr)
+    , hRC(nullptr)
+{
+}
+
+namespace {
+
+class WinOpenGLContext : public OpenGLContext
+{
+public:
+    virtual void initWindow() override;
+private:
+    GLWinWindow m_aGLWin;
+    virtual const GLWindow& getOpenGLWindow() const override { return m_aGLWin; }
+    virtual GLWindow& getModifiableOpenGLWindow() override { return m_aGLWin; }
+    virtual bool ImplInit() override;
+    virtual void makeCurrent() override;
+    virtual void destroyCurrentContext() override;
+    virtual bool isCurrent() override;
+    virtual bool isAnyCurrent() override;
+    virtual void resetCurrent() override;
+    virtual void swapBuffers() override;
+};
+
+}
+
+void WinOpenGLContext::swapBuffers()
+{
+    OpenGLZone aZone;
+
+    SwapBuffers(m_aGLWin.hDC);
+
+    BuffersSwapped();
+}
+
+void WinOpenGLContext::resetCurrent()
+{
+    clearCurrent();
+
+    OpenGLZone aZone;
+
+    wglMakeCurrent(nullptr, nullptr);
+    g_bAnyCurrent = false;
+}
+
+static void ensureDispatchTable()
+{
+    thread_local bool bEpoxyDispatchMakeCurrentCalled = false;
+    if (!bEpoxyDispatchMakeCurrentCalled)
+    {
+        epoxy_handle_external_wglMakeCurrent();
+        bEpoxyDispatchMakeCurrentCalled = true;
+    }
+}
+
+bool WinOpenGLContext::isCurrent()
+{
+    OpenGLZone aZone;
+    if (!g_bAnyCurrent || !m_aGLWin.hRC)
+        return false;
+    ensureDispatchTable();
+    return wglGetCurrentContext() == m_aGLWin.hRC && wglGetCurrentDC() == m_aGLWin.hDC;
+}
+
+bool WinOpenGLContext::isAnyCurrent()
+{
+    return g_bAnyCurrent && wglGetCurrentContext() != nullptr;
+}
+
+void WinOpenGLContext::makeCurrent()
+{
+    if (isCurrent())
+        return;
+
+    OpenGLZone aZone;
+
+    clearCurrent();
+
+    ensureDispatchTable();
+
+    if (!wglMakeCurrent(m_aGLWin.hDC, m_aGLWin.hRC))
+    {
+        g_bAnyCurrent = false;
+        DWORD nLastError = GetLastError();
+        if (nLastError != ERROR_SUCCESS)
+            SAL_WARN("vcl.opengl", "wglMakeCurrent failed: " << WindowsErrorString(nLastError));
+        return;
+    }
+
+    g_bAnyCurrent = true;
+
+    registerAsCurrent();
+}
+
+void WinOpenGLContext::initWindow()
+{
+    if( !m_pChildWindow )
+    {
+        SystemWindowData winData = generateWinData(mpWindow, false);
+        m_pChildWindow = VclPtr<SystemChildWindow>::Create(mpWindow, 0, &winData, false);
+    }
+
+    if (m_pChildWindow)
+    {
+        InitChildWindow(m_pChildWindow.get());
+        const SystemEnvData* sysData(m_pChildWindow->GetSystemData());
+        m_aGLWin.hWnd = sysData->hWnd;
+    }
+
+    m_aGLWin.hDC = GetDC(m_aGLWin.hWnd);
+}
+
+void WinOpenGLContext::destroyCurrentContext()
+{
+    if (m_aGLWin.hRC)
+    {
+        std::vector<HGLRC>::iterator itr = std::remove(g_vShareList.begin(), g_vShareList.end(), m_aGLWin.hRC);
+        if (itr != g_vShareList.end())
+            g_vShareList.erase(itr);
+
+        if (wglGetCurrentContext() != nullptr)
+        {
+            wglMakeCurrent(nullptr, nullptr);
+            g_bAnyCurrent = false;
+        }
+        wglDeleteContext( m_aGLWin.hRC );
+        ReleaseDC( m_aGLWin.hWnd, m_aGLWin.hDC );
+        m_aGLWin.hRC = nullptr;
+    }
+}
+
+static LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
+{
+    switch (message)
+    {
+    case WM_CREATE:
+        return 0;
+    case WM_CLOSE:
+        PostQuitMessage(0);
+        return 0;
+    case WM_DESTROY:
+        return 0;
+    default:
+        return DefWindowProcW(hwnd, message, wParam, lParam);
+    }
+}
+
+static bool InitTempWindow(HWND& hwnd, int width, int height, const PIXELFORMATDESCRIPTOR& inPfd, GLWinWindow& glWin)
+{
+    OpenGLZone aZone;
+
+    PIXELFORMATDESCRIPTOR  pfd = inPfd;
+    int ret;
+    WNDCLASSW wc;
+    wc.style = 0;
+    wc.lpfnWndProc = WndProc;
+    wc.cbClsExtra = wc.cbWndExtra = 0;
+    wc.hInstance = nullptr;
+    wc.hIcon = nullptr;
+    wc.hCursor = nullptr;
+    wc.hbrBackground = nullptr;
+    wc.lpszMenuName = nullptr;
+    wc.lpszClassName = L"GLRenderer";
+    RegisterClassW(&wc);
+    hwnd = CreateWindowW(wc.lpszClassName, nullptr, WS_DISABLED, 0, 0, width, height, nullptr, nullptr, wc.hInstance, nullptr);
+    glWin.hDC = GetDC(hwnd);
+
+    int nPixelFormat = ChoosePixelFormat(glWin.hDC, &pfd);
+    if (!nPixelFormat)
+    {
+        ReleaseDC(hwnd, glWin.hDC);
+        DestroyWindow(hwnd);
+        return false;
+    }
+    ret = SetPixelFormat(glWin.hDC, nPixelFormat, &pfd);
+    if(!ret)
+    {
+        ReleaseDC(hwnd, glWin.hDC);
+        DestroyWindow(hwnd);
+        return false;
+    }
+    glWin.hRC = wglCreateContext(glWin.hDC);
+    if(!(glWin.hRC))
+    {
+        ReleaseDC(hwnd, glWin.hDC);
+        DestroyWindow(hwnd);
+        return false;
+    }
+    ret = wglMakeCurrent(glWin.hDC, glWin.hRC);
+    if(!ret)
+    {
+        wglMakeCurrent(nullptr, nullptr);
+        g_bAnyCurrent = false;
+        wglDeleteContext(glWin.hRC);
+        ReleaseDC(hwnd, glWin.hDC);
+        DestroyWindow(hwnd);
+        return false;
+    }
+    g_bAnyCurrent = false;
+
+    return true;
+}
+
+static bool WGLisExtensionSupported(const char *extension)
+{
+    OpenGLZone aZone;
+
+    const size_t extlen = strlen(extension);
+    const char *supported = nullptr;
+
+    // Try to use wglGetExtensionStringARB on current DC, if possible
+    PROC wglGetExtString = wglGetProcAddress("wglGetExtensionsStringARB");
+
+    if (wglGetExtString)
+        supported = reinterpret_cast<char*(__stdcall*)(HDC)>(wglGetExtString)(wglGetCurrentDC());
+    // If that failed, try standard OpenGL extensions string
+    if (supported == nullptr)
+        supported = reinterpret_cast<char const *>(glGetString(GL_EXTENSIONS));
+    // If that failed too, must be no extensions supported
+    if (supported == nullptr)
+        return false;
+
+    // Begin examination at start of string, increment by 1 on false match
+    for (const char* p = supported; ; p++)
+    {
+        // Advance p up to the next possible match
+        p = strstr(p, extension);
+
+        if (p == nullptr)
+            return false; // No Match
+
+        // Make sure that match is at the start of the string or that
+        // the previous char is a space, or else we could accidentally
+        // match "wglFunkywglExtension" with "wglExtension"
+
+        // Also, make sure that the following character is space or null
+        // or else "wglExtensionTwo" might match "wglExtension"
+        if ((p==supported || p[-1]==' ') && (p[extlen]=='\0' || p[extlen]==' '))
+            return true; // Match
+    }
+}
+
+static bool InitMultisample(const PIXELFORMATDESCRIPTOR& pfd, int& rPixelFormat,
+        bool bUseDoubleBufferedRendering, bool bRequestVirtualDevice)
+{
+    OpenGLZone aZone;
+
+    HWND hWnd = nullptr;
+    GLWinWindow glWin;
+    // Create a temp window to check whether support multi-sample, if support, get the format
+    if (!InitTempWindow(hWnd, 32, 32, pfd, glWin))
+    {
+        SAL_WARN("vcl.opengl", "Can't create temp window to test");
+        return false;
+    }
+
+    // See if the string exists in WGL
+    if (!WGLisExtensionSupported("WGL_ARB_multisample"))
+    {
+        SAL_WARN("vcl.opengl", "Device doesn't support multisample");
+        wglMakeCurrent(nullptr, nullptr);
+        g_bAnyCurrent = false;
+        wglDeleteContext(glWin.hRC);
+        ReleaseDC(hWnd, glWin.hDC);
+        DestroyWindow(hWnd);
+        return false;
+    }
+    // Get our pixel format
+    PFNWGLCHOOSEPIXELFORMATARBPROC fn_wglChoosePixelFormatARB = reinterpret_cast<PFNWGLCHOOSEPIXELFORMATARBPROC>(wglGetProcAddress("wglChoosePixelFormatARB"));
+    if (!fn_wglChoosePixelFormatARB)
+    {
+        wglMakeCurrent(nullptr, nullptr);
+        g_bAnyCurrent = false;
+        wglDeleteContext(glWin.hRC);
+        ReleaseDC(hWnd, glWin.hDC);
+        DestroyWindow(hWnd);
+        return false;
+    }
+    // Get our current device context
+    HDC hDC = GetDC(hWnd);
+
+    int pixelFormat;
+    int valid;
+    UINT    numFormats;
+    float   fAttributes[] = {0,0};
+    // These attributes are the bits we want to test for in our sample.
+    // Everything is pretty standard, the only one we want to
+    // really focus on is the WGL_SAMPLE_BUFFERS_ARB and WGL_SAMPLES_ARB.
+    // These two are going to do the main testing for whether or not
+    // we support multisampling on this hardware.
+    int iAttributes[] =
+    {
+        WGL_DOUBLE_BUFFER_ARB,GL_TRUE,
+        WGL_DRAW_TO_WINDOW_ARB,GL_TRUE,
+        WGL_SUPPORT_OPENGL_ARB,GL_TRUE,
+        WGL_ACCELERATION_ARB,WGL_FULL_ACCELERATION_ARB,
+        WGL_COLOR_BITS_ARB,24,
+        WGL_ALPHA_BITS_ARB,8,
+        WGL_DEPTH_BITS_ARB,24,
+        WGL_STENCIL_BITS_ARB,0,
+        WGL_SAMPLE_BUFFERS_ARB,GL_TRUE,
+        WGL_SAMPLES_ARB,8,
+        0,0
+    };
+
+    if (!bUseDoubleBufferedRendering)
+    {
+        // Use asserts to make sure the iAttributes array is not changed without changing these ugly
+        // hardcode indexes into it.
+        assert(iAttributes[0] == WGL_DOUBLE_BUFFER_ARB);
+        iAttributes[1] = GL_FALSE;
+    }
+
+    if (bRequestVirtualDevice)
+    {
+        assert(iAttributes[2] == WGL_DRAW_TO_WINDOW_ARB);
+        iAttributes[2] = WGL_DRAW_TO_BITMAP_ARB;
+    }
+
+    bool bArbMultisampleSupported = false;
+
+    // First we check to see if we can get a pixel format for 8 samples
+    valid = fn_wglChoosePixelFormatARB(hDC, iAttributes, fAttributes, 1, &pixelFormat, &numFormats);
+    // If we returned true, and our format count is greater than 1
+    if (valid && numFormats >= 1)
+    {
+        bArbMultisampleSupported = true;
+        rPixelFormat = pixelFormat;
+        wglMakeCurrent(nullptr, nullptr);
+        g_bAnyCurrent = false;
+        wglDeleteContext(glWin.hRC);
+        ReleaseDC(hWnd, glWin.hDC);
+        DestroyWindow(hWnd);
+        return bArbMultisampleSupported;
+    }
+    // Our pixel format with 8 samples failed, test for 2 samples
+    assert(iAttributes[18] == WGL_SAMPLES_ARB);
+    iAttributes[19] = 2;
+    valid = fn_wglChoosePixelFormatARB(hDC, iAttributes, fAttributes, 1, &pixelFormat, &numFormats);
+    if (valid && numFormats >= 1)
+    {
+        bArbMultisampleSupported = true;
+        rPixelFormat = pixelFormat;
+        wglMakeCurrent(nullptr, nullptr);
+        g_bAnyCurrent = false;
+        wglDeleteContext(glWin.hRC);
+        ReleaseDC(hWnd, glWin.hDC);
+        DestroyWindow(hWnd);
+        return bArbMultisampleSupported;
+    }
+    // Return the valid format
+    wglMakeCurrent(nullptr, nullptr);
+    g_bAnyCurrent = false;
+    wglDeleteContext(glWin.hRC);
+    ReleaseDC(hWnd, glWin.hDC);
+    DestroyWindow(hWnd);
+
+    return bArbMultisampleSupported;
+}
+
+namespace
+{
+
+bool tryShaders(const OUString& rVertexShader, const OUString& rFragmentShader, const OUString& rGeometryShader = "", std::string_view rPreamble = "")
+{
+    GLint nId;
+
+    // Somewhat mysteriously, the OpenGLHelper::LoadShaders() API saves a compiled binary of the
+    // shader only if you give it the digest of the shaders. We have API to calculate the digest
+    // only of the combination of vertex and fragment (but not geometry) shader. So if we have a
+    // geometry shader, we should not save the binary.
+    if (rGeometryShader.isEmpty())
+    {
+        nId = OpenGLHelper::LoadShaders(rVertexShader, rFragmentShader, rPreamble, OpenGLHelper::GetDigest( rVertexShader, rFragmentShader, rPreamble));
+    }
+    else
+    {
+        assert(rPreamble.empty());
+        nId = OpenGLHelper::LoadShaders(rVertexShader, rFragmentShader, rGeometryShader);
+    }
+    if (!nId)
+        return false;
+
+    // We're interested in the error returned by glDeleteProgram().
+    glGetError();
+
+    glDeleteProgram(nId);
+    return glGetError() == GL_NO_ERROR;
+}
+
+bool compiledShaderBinariesWork()
+{
+    static bool bBeenHere = false;
+    static bool bResult;
+
+    if (bBeenHere)
+        return bResult;
+
+    bBeenHere = true;
+
+    bResult =
+        (
+#if 0 // Only look at shaders used by slideshow for now
+         // canvas
+         tryShaders("dummyVertexShader", "linearMultiColorGradientFragmentShader") &&
+         tryShaders("dummyVertexShader", "linearTwoColorGradientFragmentShader") &&
+         tryShaders("dummyVertexShader", "radialMultiColorGradientFragmentShader") &&
+         tryShaders("dummyVertexShader", "radialTwoColorGradientFragmentShader") &&
+         tryShaders("dummyVertexShader", "rectangularMultiColorGradientFragmentShader") &&
+         tryShaders("dummyVertexShader", "rectangularTwoColorGradientFragmentShader") &&
+#endif
+         // slideshow
+         tryShaders("reflectionVertexShader", "reflectionFragmentShader") &&
+         tryShaders("basicVertexShader", "basicFragmentShader") &&
+         tryShaders("vortexVertexShader", "vortexFragmentShader", "vortexGeometryShader") &&
+         tryShaders("basicVertexShader", "rippleFragmentShader") &&
+         tryShaders("glitterVertexShader", "glitterFragmentShader") &&
+         tryShaders("honeycombVertexShader", "honeycombFragmentShader", "honeycombGeometryShader"));
+
+    return bResult;
+}
+
+} // unnamed namespace
+
+bool WinOpenGLContext::ImplInit()
+{
+    static bool bFirstCall = true;
+
+    OpenGLZone aZone;
+
+    VCL_GL_INFO("OpenGLContext::ImplInit----start");
+    // PixelFormat tells Windows how we want things to be
+    PIXELFORMATDESCRIPTOR PixelFormatFront =
+    {
+        sizeof(PIXELFORMATDESCRIPTOR),
+        1,                              // Version Number
+        PFD_SUPPORT_OPENGL,
+        PFD_TYPE_RGBA,                  // Request An RGBA Format
+        BYTE(32),                       // Select Our Color Depth
+        0, 0, 0, 0, 0, 0,               // Color Bits Ignored
+        0,                              // No Alpha Buffer
+        0,                              // Shift Bit Ignored
+        0,                              // No Accumulation Buffer
+        0, 0, 0, 0,                     // Accumulation Bits Ignored
+        24,                             // 24 bit z-buffer
+        8,                              // stencil buffer
+        0,                              // No Auxiliary Buffer
+        0,                              // now ignored
+        0,                              // Reserved
+        0, 0, 0                         // Layer Masks Ignored
+    };
+
+    PixelFormatFront.dwFlags |= PFD_DOUBLEBUFFER;
+    PixelFormatFront.dwFlags |= PFD_DRAW_TO_WINDOW;
+
+    //  we must check whether can set the MSAA
+    int WindowPix = 0;
+    bool bMultiSampleSupport = false;
+
+    bMultiSampleSupport = InitMultisample(PixelFormatFront, WindowPix, /*bUseDoubleBufferedRendering*/true, false);
+
+    if (bMultiSampleSupport && WindowPix != 0)
+    {
+        m_aGLWin.bMultiSampleSupported = true;
+    }
+    else
+    {
+        WindowPix = ChoosePixelFormat(m_aGLWin.hDC, &PixelFormatFront);
+#if OSL_DEBUG_LEVEL > 0
+        PIXELFORMATDESCRIPTOR pfd;
+        DescribePixelFormat(m_aGLWin.hDC, WindowPix, sizeof(PIXELFORMATDESCRIPTOR), &pfd);
+        SAL_WARN("vcl.opengl", "Render Target: Window: " << static_cast<int>((pfd.dwFlags & PFD_DRAW_TO_WINDOW) != 0) << ", Bitmap: " << static_cast<int>((pfd.dwFlags & PFD_DRAW_TO_BITMAP) != 0));
+        SAL_WARN("vcl.opengl", "Supports OpenGL: " << static_cast<int>((pfd.dwFlags & PFD_SUPPORT_OPENGL) != 0));
+#endif
+    }
+
+    if (WindowPix == 0)
+    {
+        SAL_WARN("vcl.opengl", "Invalid pixelformat");
+        return false;
+    }
+
+    if (!SetPixelFormat(m_aGLWin.hDC, WindowPix, &PixelFormatFront))
+    {
+        SAL_WARN("vcl.opengl", "SetPixelFormat failed: " << WindowsErrorString(GetLastError()));
+        return false;
+    }
+
+    HGLRC hTempRC = wglCreateContext(m_aGLWin.hDC);
+    if (hTempRC == nullptr)
+    {
+        SAL_WARN("vcl.opengl", "wglCreateContext failed: "<< WindowsErrorString(GetLastError()));
+        return false;
+    }
+
+    if (!wglMakeCurrent(m_aGLWin.hDC, hTempRC))
+    {
+        g_bAnyCurrent = false;
+        SAL_WARN("vcl.opengl", "wglMakeCurrent failed: "<< WindowsErrorString(GetLastError()));
+        return false;
+    }
+
+    g_bAnyCurrent = true;
+
+    if (!InitGL())
+    {
+        wglMakeCurrent(nullptr, nullptr);
+        g_bAnyCurrent = false;
+        wglDeleteContext(hTempRC);
+        return false;
+    }
+
+    HGLRC hSharedCtx = nullptr;
+    if (!g_vShareList.empty())
+        hSharedCtx = g_vShareList.front();
+
+    if (!wglCreateContextAttribsARB)
+    {
+        wglMakeCurrent(nullptr, nullptr);
+        g_bAnyCurrent = false;
+        wglDeleteContext(hTempRC);
+        return false;
+    }
+
+    // now setup the shared context; this needs a temporary context already
+    // set up in order to work
+    int const attribs [] =
+    {
+#ifdef DBG_UTIL
+        WGL_CONTEXT_FLAGS_ARB, WGL_CONTEXT_DEBUG_BIT_ARB,
+#endif
+        0
+    };
+    m_aGLWin.hRC = wglCreateContextAttribsARB(m_aGLWin.hDC, hSharedCtx, attribs);
+    if (m_aGLWin.hRC == nullptr)
+    {
+        SAL_WARN("vcl.opengl", "wglCreateContextAttribsARB failed: "<< WindowsErrorString(GetLastError()));
+        wglMakeCurrent(nullptr, nullptr);
+        g_bAnyCurrent = false;
+        wglDeleteContext(hTempRC);
+        return false;
+    }
+
+    if (!compiledShaderBinariesWork())
+    {
+        wglMakeCurrent(nullptr, nullptr);
+        g_bAnyCurrent = false;
+        wglDeleteContext(hTempRC);
+        return false;
+    }
+
+    wglMakeCurrent(nullptr, nullptr);
+    g_bAnyCurrent = false;
+    wglDeleteContext(hTempRC);
+
+    if (!wglMakeCurrent(m_aGLWin.hDC, m_aGLWin.hRC))
+    {
+        g_bAnyCurrent = false;
+        SAL_WARN("vcl.opengl", "wglMakeCurrent failed: " << WindowsErrorString(GetLastError()));
+        return false;
+    }
+
+    g_bAnyCurrent = true;
+
+    if (bFirstCall)
+    {
+        // Checking texture size
+        GLint nMaxTextureSize;
+        glGetIntegerv(GL_MAX_TEXTURE_SIZE, &nMaxTextureSize);
+        if (nMaxTextureSize <= 4096)
+            SAL_WARN("vcl.opengl", "Max texture size is " << nMaxTextureSize
+                                    << ". This may not be enough for normal operation.");
+        else
+            VCL_GL_INFO("Max texture size: " << nMaxTextureSize);
+
+        // Trying to make a texture and check its size
+        for (GLint nWidthHeight = 1023; nWidthHeight < nMaxTextureSize; nWidthHeight += (nWidthHeight + 1))
+        {
+            glTexImage2D(GL_PROXY_TEXTURE_2D, 0, 4, nWidthHeight, nWidthHeight, 0, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8, nullptr);
+            CHECK_GL_ERROR();
+            if (glGetError() == GL_NO_ERROR)
+            {
+                GLint nWidth = 0;
+                GLint nHeight = 0;
+                glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &nWidth);
+                glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &nHeight);
+                VCL_GL_INFO("Created texture " << nWidthHeight << "," << nWidthHeight << " reports size: " << nWidth << ", " << nHeight);
+            }
+            else
+            {
+                SAL_WARN("vcl.opengl", "Error when creating a " << nWidthHeight << ", " << nWidthHeight << " test texture.");
+            }
+        }
+    }
+
+    InitGLDebugging();
+
+    g_vShareList.push_back(m_aGLWin.hRC);
+
+    RECT clientRect;
+    GetClientRect(WindowFromDC(m_aGLWin.hDC), &clientRect);
+    m_aGLWin.Width = clientRect.right - clientRect.left;
+    m_aGLWin.Height = clientRect.bottom - clientRect.top;
+
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+    registerAsCurrent();
+
+    bFirstCall = false;
+
+    return true;
+}
+
+OpenGLContext* WinSalInstance::CreateOpenGLContext()
+{
+    return new WinOpenGLContext;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/opengl/x11/context.cxx b/vcl/source/opengl/x11/context.cxx
new file mode 100644
index 000000000..97822b310
--- /dev/null
+++ b/vcl/source/opengl/x11/context.cxx
@@ -0,0 +1,519 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <memory>
+#include <vcl/lazydelete.hxx>
+#include <vcl/syschild.hxx>
+
+#include <svdata.hxx>
+
+#include <unx/saldisp.hxx>
+#include <unx/salframe.h>
+#include <unx/salgdi.h>
+#include <unx/salinst.h>
+#include <unx/salvd.h>
+#include <unx/x11/xlimits.hxx>
+
+#include <opengl/zone.hxx>
+
+#include <vcl/opengl/OpenGLContext.hxx>
+#include <vcl/opengl/OpenGLHelper.hxx>
+#include <sal/log.hxx>
+#include <o3tl/string_view.hxx>
+
+static std::vector<GLXContext> g_vShareList;
+static bool g_bAnyCurrent;
+
+namespace {
+
+class X11OpenGLContext : public OpenGLContext
+{
+public:
+    virtual void initWindow() override;
+private:
+    GLX11Window m_aGLWin;
+    virtual const GLWindow& getOpenGLWindow() const override { return m_aGLWin; }
+    virtual GLWindow& getModifiableOpenGLWindow() override { return m_aGLWin; }
+    virtual bool ImplInit() override;
+    void initGLWindow(Visual* pVisual);
+    virtual SystemWindowData generateWinData(vcl::Window* pParent, bool bRequestLegacyContext) override;
+    virtual void makeCurrent() override;
+    virtual void destroyCurrentContext() override;
+    virtual bool isCurrent() override;
+    virtual bool isAnyCurrent() override;
+    virtual void sync() override;
+    virtual void resetCurrent() override;
+    virtual void swapBuffers() override;
+};
+
+#ifdef DBG_UTIL
+    int unxErrorHandler(Display* dpy, XErrorEvent* event)
+    {
+        char err[256];
+        char req[256];
+        char minor[256];
+        XGetErrorText(dpy, event->error_code, err, 256);
+        XGetErrorText(dpy, event->request_code, req, 256);
+        XGetErrorText(dpy, event->minor_code, minor, 256);
+        SAL_WARN("vcl.opengl", "Error: " << err << ", Req: " << req << ", Minor: " << minor);
+        return 0;
+    }
+#endif
+
+    typedef int (*errorHandler)(Display* /*dpy*/, XErrorEvent* /*evnt*/);
+
+    class TempErrorHandler
+    {
+    private:
+        errorHandler oldErrorHandler;
+        Display* mdpy;
+
+    public:
+        TempErrorHandler(Display* dpy, errorHandler newErrorHandler)
+            : oldErrorHandler(nullptr)
+            , mdpy(dpy)
+        {
+            if (mdpy)
+            {
+                XLockDisplay(dpy);
+                XSync(dpy, false);
+                oldErrorHandler = XSetErrorHandler(newErrorHandler);
+            }
+        }
+
+        ~TempErrorHandler()
+        {
+            if (mdpy)
+            {
+                // sync so that we possibly get an XError
+                glXWaitGL();
+                XSync(mdpy, false);
+                XSetErrorHandler(oldErrorHandler);
+                XUnlockDisplay(mdpy);
+            }
+        }
+    };
+
+    bool errorTriggered;
+    int oglErrorHandler( Display* /*dpy*/, XErrorEvent* /*evnt*/ )
+    {
+        errorTriggered = true;
+
+        return 0;
+    }
+
+    GLXFBConfig* getFBConfig(Display* dpy, Window win, int& nBestFBC)
+    {
+        OpenGLZone aZone;
+
+        if( dpy == nullptr || !glXQueryExtension( dpy, nullptr, nullptr ) )
+            return nullptr;
+
+        VCL_GL_INFO("window: " << win);
+
+        XWindowAttributes xattr;
+        if( !XGetWindowAttributes( dpy, win, &xattr ) )
+        {
+            SAL_WARN("vcl.opengl", "Failed to get window attributes for fbconfig " << win);
+            xattr.screen = nullptr;
+            xattr.visual = nullptr;
+        }
+
+        int screen = XScreenNumberOfScreen( xattr.screen );
+
+        // TODO: moggi: Select colour channel depth based on visual attributes, not hardcoded */
+        static int visual_attribs[] =
+        {
+            GLX_DOUBLEBUFFER,       True,
+            GLX_X_RENDERABLE,       True,
+            GLX_RED_SIZE,           8,
+            GLX_GREEN_SIZE,         8,
+            GLX_BLUE_SIZE,          8,
+            GLX_ALPHA_SIZE,         8,
+            GLX_DEPTH_SIZE,         24,
+            GLX_X_VISUAL_TYPE,      GLX_TRUE_COLOR,
+            None
+        };
+
+        int fbCount = 0;
+        GLXFBConfig* pFBC = glXChooseFBConfig( dpy,
+                screen,
+                visual_attribs, &fbCount );
+
+        if(!pFBC)
+        {
+            SAL_WARN("vcl.opengl", "no suitable fb format found");
+            return nullptr;
+        }
+
+        int best_num_samp = -1;
+        for(int i = 0; i < fbCount; ++i)
+        {
+            XVisualInfo* pVi = glXGetVisualFromFBConfig( dpy, pFBC[i] );
+            if(pVi && (xattr.visual && pVi->visualid == xattr.visual->visualid) )
+            {
+                // pick the one with the most samples per pixel
+                int nSampleBuf = 0;
+                int nSamples = 0;
+                glXGetFBConfigAttrib( dpy, pFBC[i], GLX_SAMPLE_BUFFERS, &nSampleBuf );
+                glXGetFBConfigAttrib( dpy, pFBC[i], GLX_SAMPLES       , &nSamples  );
+
+                if ( nBestFBC < 0 || (nSampleBuf && ( nSamples > best_num_samp )) )
+                {
+                    nBestFBC = i;
+                    best_num_samp = nSamples;
+                }
+            }
+            XFree( pVi );
+        }
+
+        return pFBC;
+    }
+}
+
+void X11OpenGLContext::sync()
+{
+    OpenGLZone aZone;
+    glXWaitGL();
+    XSync(m_aGLWin.dpy, false);
+}
+
+void X11OpenGLContext::swapBuffers()
+{
+    OpenGLZone aZone;
+
+    glXSwapBuffers(m_aGLWin.dpy, m_aGLWin.win);
+
+    BuffersSwapped();
+}
+
+void X11OpenGLContext::resetCurrent()
+{
+    clearCurrent();
+
+    OpenGLZone aZone;
+
+    if (m_aGLWin.dpy)
+    {
+        glXMakeCurrent(m_aGLWin.dpy, None, nullptr);
+        g_bAnyCurrent = false;
+    }
+}
+
+bool X11OpenGLContext::isCurrent()
+{
+    OpenGLZone aZone;
+    return g_bAnyCurrent && m_aGLWin.ctx && glXGetCurrentContext() == m_aGLWin.ctx &&
+           glXGetCurrentDrawable() == m_aGLWin.win;
+}
+
+bool X11OpenGLContext::isAnyCurrent()
+{
+    return g_bAnyCurrent && glXGetCurrentContext() != None;
+}
+
+SystemWindowData X11OpenGLContext::generateWinData(vcl::Window* pParent, bool /*bRequestLegacyContext*/)
+{
+    OpenGLZone aZone;
+
+    SystemWindowData aWinData;
+    aWinData.pVisual = nullptr;
+    aWinData.bClipUsingNativeWidget = false;
+
+    const SystemEnvData* sysData(pParent->GetSystemData());
+
+    Display *dpy = static_cast<Display*>(sysData->pDisplay);
+    Window win = sysData->GetWindowHandle(pParent->ImplGetFrame());
+
+    if( dpy == nullptr || !glXQueryExtension( dpy, nullptr, nullptr ) )
+        return aWinData;
+
+    int best_fbc = -1;
+    GLXFBConfig* pFBC = getFBConfig(dpy, win, best_fbc);
+
+    if (!pFBC)
+        return aWinData;
+
+    XVisualInfo* vi = nullptr;
+    if( best_fbc != -1 )
+        vi = glXGetVisualFromFBConfig( dpy, pFBC[best_fbc] );
+
+    XFree(pFBC);
+
+    if( vi )
+    {
+        VCL_GL_INFO("using VisualID " << vi->visualid);
+        aWinData.pVisual = static_cast<void*>(vi->visual);
+    }
+
+    return aWinData;
+}
+
+bool X11OpenGLContext::ImplInit()
+{
+    if (!m_aGLWin.dpy)
+        return false;
+
+    OpenGLZone aZone;
+
+    GLXContext pSharedCtx( nullptr );
+#ifdef DBG_UTIL
+    TempErrorHandler aErrorHandler(m_aGLWin.dpy, unxErrorHandler);
+#endif
+
+    VCL_GL_INFO("OpenGLContext::ImplInit----start");
+
+    if (!g_vShareList.empty())
+        pSharedCtx = g_vShareList.front();
+
+    //tdf#112166 for, e.g. VirtualBox GL, claiming OpenGL 2.1
+    static bool hasCreateContextAttribsARB = glXGetProcAddress(reinterpret_cast<const GLubyte*>("glXCreateContextAttribsARB")) != nullptr;
+    if (hasCreateContextAttribsARB && !mbRequestLegacyContext)
+    {
+        int best_fbc = -1;
+        GLXFBConfig* pFBC = getFBConfig(m_aGLWin.dpy, m_aGLWin.win, best_fbc);
+
+        if (pFBC && best_fbc != -1)
+        {
+            int const pContextAttribs[] =
+            {
+#if 0 // defined(DBG_UTIL)
+                GLX_CONTEXT_MAJOR_VERSION_ARB, 3,
+                GLX_CONTEXT_MINOR_VERSION_ARB, 2,
+#endif
+                None
+
+            };
+            m_aGLWin.ctx = glXCreateContextAttribsARB(m_aGLWin.dpy, pFBC[best_fbc], pSharedCtx, /* direct, not via X */ GL_TRUE, pContextAttribs);
+            SAL_INFO_IF(m_aGLWin.ctx, "vcl.opengl", "created a 3.2 core context");
+        }
+        else
+            SAL_WARN("vcl.opengl", "unable to find correct FBC");
+    }
+
+    if (!m_aGLWin.ctx)
+    {
+        if (!m_aGLWin.vi)
+           return false;
+
+        SAL_WARN("vcl.opengl", "attempting to create a non-double-buffered "
+                               "visual matching the context");
+
+        m_aGLWin.ctx = glXCreateContext(m_aGLWin.dpy,
+                m_aGLWin.vi,
+                pSharedCtx,
+                GL_TRUE /* direct, not via X server */);
+    }
+
+    if( m_aGLWin.ctx )
+    {
+        g_vShareList.push_back( m_aGLWin.ctx );
+    }
+    else
+    {
+        SAL_WARN("vcl.opengl", "unable to create GLX context");
+        return false;
+    }
+
+    if( !glXMakeCurrent( m_aGLWin.dpy, m_aGLWin.win, m_aGLWin.ctx ) )
+    {
+        g_bAnyCurrent = false;
+        SAL_WARN("vcl.opengl", "unable to select current GLX context");
+        return false;
+    }
+
+    g_bAnyCurrent = true;
+
+    int glxMinor, glxMajor;
+    double nGLXVersion = 0;
+    if( glXQueryVersion( m_aGLWin.dpy, &glxMajor, &glxMinor ) )
+      nGLXVersion = glxMajor + 0.1*glxMinor;
+    SAL_INFO("vcl.opengl", "available GLX version: " << nGLXVersion);
+
+    SAL_INFO("vcl.opengl", "available GL  extensions: " << glGetString(GL_EXTENSIONS));
+
+    XWindowAttributes aWinAttr;
+    if( !XGetWindowAttributes( m_aGLWin.dpy, m_aGLWin.win, &aWinAttr ) )
+    {
+        SAL_WARN("vcl.opengl", "Failed to get window attributes on " << m_aGLWin.win);
+        m_aGLWin.Width = 0;
+        m_aGLWin.Height = 0;
+    }
+    else
+    {
+        m_aGLWin.Width = aWinAttr.width;
+        m_aGLWin.Height = aWinAttr.height;
+    }
+
+    if( m_aGLWin.HasGLXExtension("GLX_SGI_swap_control" ) )
+    {
+        // enable vsync
+        typedef GLint (*glXSwapIntervalProc)(GLint);
+        glXSwapIntervalProc glXSwapInterval = reinterpret_cast<glXSwapIntervalProc>(glXGetProcAddress( reinterpret_cast<const GLubyte*>("glXSwapIntervalSGI") ));
+        if( glXSwapInterval )
+        {
+            TempErrorHandler aLocalErrorHandler(m_aGLWin.dpy, oglErrorHandler);
+
+            errorTriggered = false;
+
+            glXSwapInterval( 1 );
+
+            if( errorTriggered )
+                SAL_WARN("vcl.opengl", "error when trying to set swap interval, NVIDIA or Mesa bug?");
+            else
+                VCL_GL_INFO("set swap interval to 1 (enable vsync)");
+        }
+    }
+
+    bool bRet = InitGL();
+    InitGLDebugging();
+
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+    registerAsCurrent();
+
+    return bRet;
+}
+
+void X11OpenGLContext::makeCurrent()
+{
+    if (isCurrent())
+        return;
+
+    OpenGLZone aZone;
+
+    clearCurrent();
+
+#ifdef DBG_UTIL
+    TempErrorHandler aErrorHandler(m_aGLWin.dpy, unxErrorHandler);
+#endif
+
+    if (m_aGLWin.dpy)
+    {
+        if (!glXMakeCurrent( m_aGLWin.dpy, m_aGLWin.win, m_aGLWin.ctx ))
+        {
+            g_bAnyCurrent = false;
+            SAL_WARN("vcl.opengl", "OpenGLContext::makeCurrent failed "
+                     "on drawable " << m_aGLWin.win);
+            return;
+        }
+        g_bAnyCurrent = true;
+    }
+
+    registerAsCurrent();
+}
+
+void X11OpenGLContext::destroyCurrentContext()
+{
+    if(!m_aGLWin.ctx)
+        return;
+
+    std::vector<GLXContext>::iterator itr = std::remove( g_vShareList.begin(), g_vShareList.end(), m_aGLWin.ctx );
+    if (itr != g_vShareList.end())
+        g_vShareList.erase(itr);
+
+    glXMakeCurrent(m_aGLWin.dpy, None, nullptr);
+    g_bAnyCurrent = false;
+    if( glGetError() != GL_NO_ERROR )
+    {
+        SAL_WARN("vcl.opengl", "glError: " << glGetError());
+    }
+    glXDestroyContext(m_aGLWin.dpy, m_aGLWin.ctx);
+    m_aGLWin.ctx = nullptr;
+}
+
+void X11OpenGLContext::initGLWindow(Visual* pVisual)
+{
+    OpenGLZone aZone;
+
+    // Get visual info
+    {
+        XVisualInfo aTemplate;
+        aTemplate.visualid = XVisualIDFromVisual( pVisual );
+        int nVisuals = 0;
+        XVisualInfo* pInfo = XGetVisualInfo( m_aGLWin.dpy, VisualIDMask, &aTemplate, &nVisuals );
+        if( nVisuals != 1 )
+            SAL_WARN( "vcl.opengl", "match count for visual id is not 1" );
+        m_aGLWin.vi = pInfo;
+    }
+
+    // Check multisample support
+    /* TODO: moggi: This is not necessarily correct in the DBG_UTIL path, as it picks
+     *      an FBConfig instead ... */
+    int nSamples = 0;
+    glXGetConfig(m_aGLWin.dpy, m_aGLWin.vi, GLX_SAMPLES, &nSamples);
+    if( nSamples > 0 )
+        m_aGLWin.bMultiSampleSupported = true;
+
+    m_aGLWin.GLXExtensions = glXQueryExtensionsString( m_aGLWin.dpy, m_aGLWin.screen );
+    SAL_INFO("vcl.opengl", "available GLX extensions: " << m_aGLWin.GLXExtensions);
+}
+
+void X11OpenGLContext::initWindow()
+{
+    const SystemEnvData* pChildSysData = nullptr;
+    SystemWindowData winData = generateWinData(mpWindow, false);
+    if( winData.pVisual )
+    {
+        if( !m_pChildWindow )
+        {
+            m_pChildWindow = VclPtr<SystemChildWindow>::Create(mpWindow, 0, &winData, false);
+        }
+        pChildSysData = m_pChildWindow->GetSystemData();
+    }
+
+    if (!m_pChildWindow || !pChildSysData)
+        return;
+
+    InitChildWindow(m_pChildWindow.get());
+
+    m_aGLWin.dpy = static_cast<Display*>(pChildSysData->pDisplay);
+    m_aGLWin.win = pChildSysData->GetWindowHandle(m_pChildWindow->ImplGetFrame());
+    m_aGLWin.screen = pChildSysData->nScreen;
+
+    Visual* pVisual = static_cast<Visual*>(pChildSysData->pVisual);
+    initGLWindow(pVisual);
+}
+
+GLX11Window::GLX11Window()
+    : dpy(nullptr)
+    , screen(0)
+    , win(0)
+    , vi(nullptr)
+    , ctx(nullptr)
+{
+}
+
+bool GLX11Window::HasGLXExtension( const char* name ) const
+{
+    for (sal_Int32 i = 0; i != -1;) {
+        if (o3tl::getToken(GLXExtensions, 0, ' ', i) == name) {
+            return true;
+        }
+    }
+    return false;
+}
+
+GLX11Window::~GLX11Window()
+{
+    XFree(vi);
+}
+
+bool GLX11Window::Synchronize(bool bOnoff) const
+{
+    XSynchronize(dpy, bOnoff);
+    return true;
+}
+
+OpenGLContext* X11SalInstance::CreateOpenGLContext()
+{
+    return new X11OpenGLContext;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */