1 files changed, 166 insertions, 0 deletions
diff --git a/src/gui/opengl/platform/egl/qxlibeglintegration.cpp b/src/gui/opengl/platform/egl/qxlibeglintegration.cpp
new file mode 100644
index 0000000000..59f7024c06
--- /dev/null
+++ b/src/gui/opengl/platform/egl/qxlibeglintegration.cpp
@@ -0,0 +1,166 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/qloggingcategory.h>
+#include "qxlibeglintegration_p.h"
+
+QT_BEGIN_NAMESPACE
+
+Q_LOGGING_CATEGORY(lcXlibEglDebug, "qt.egl.xlib.debug")
+
+VisualID QXlibEglIntegration::getCompatibleVisualId(Display *display, EGLDisplay eglDisplay, EGLConfig config)
+{
+    VisualID    visualId = 0;
+    EGLint      eglValue = 0;
+
+    EGLint configRedSize = 0;
+    eglGetConfigAttrib(eglDisplay, config, EGL_RED_SIZE, &configRedSize);
+
+    EGLint configGreenSize = 0;
+    eglGetConfigAttrib(eglDisplay, config, EGL_GREEN_SIZE, &configGreenSize);
+
+    EGLint configBlueSize = 0;
+    eglGetConfigAttrib(eglDisplay, config, EGL_BLUE_SIZE, &configBlueSize);
+
+    EGLint configAlphaSize = 0;
+    eglGetConfigAttrib(eglDisplay, config, EGL_ALPHA_SIZE, &configAlphaSize);
+
+    eglGetConfigAttrib(eglDisplay, config, EGL_CONFIG_ID, &eglValue);
+    int configId = eglValue;
+
+    // See if EGL provided a valid VisualID:
+    eglGetConfigAttrib(eglDisplay, config, EGL_NATIVE_VISUAL_ID, &eglValue);
+    visualId = (VisualID)eglValue;
+    if (visualId) {
+        // EGL has suggested a visual id, so get the rest of the visual info for that id:
+        XVisualInfo visualInfoTemplate;
+        memset(&visualInfoTemplate, 0, sizeof(XVisualInfo));
+        visualInfoTemplate.visualid = visualId;
+
+        XVisualInfo *chosenVisualInfo;
+        int matchingCount = 0;
+        chosenVisualInfo = XGetVisualInfo(display, VisualIDMask, &visualInfoTemplate, &matchingCount);
+        if (chosenVisualInfo) {
+            // Skip size checks if implementation supports non-matching visual
+            // and config (QTBUG-9444).
+            if (q_hasEglExtension(eglDisplay,"EGL_NV_post_convert_rounding")) {
+                XFree(chosenVisualInfo);
+                return visualId;
+            }
+            // Skip also for i.MX6 where 565 visuals are suggested for the default 444 configs and it works just fine.
+            const char *vendor = eglQueryString(eglDisplay, EGL_VENDOR);
+            if (vendor && strstr(vendor, "Vivante")) {
+                XFree(chosenVisualInfo);
+                return visualId;
+            }
+
+            int visualRedSize = qPopulationCount(chosenVisualInfo->red_mask);
+            int visualGreenSize = qPopulationCount(chosenVisualInfo->green_mask);
+            int visualBlueSize = qPopulationCount(chosenVisualInfo->blue_mask);
+            int visualAlphaSize = chosenVisualInfo->depth - visualRedSize - visualBlueSize - visualGreenSize;
+
+            const bool visualMatchesConfig = visualRedSize >= configRedSize
+                && visualGreenSize >= configGreenSize
+                && visualBlueSize >= configBlueSize
+                && visualAlphaSize >= configAlphaSize;
+
+            // In some cases EGL tends to suggest a 24-bit visual for 8888
+            // configs. In such a case we have to fall back to XGetVisualInfo.
+            if (!visualMatchesConfig) {
+                visualId = 0;
+                qCDebug(lcXlibEglDebug,
+                        "EGL suggested using X Visual ID %d (%d %d %d %d depth %d) for EGL config %d"
+                        "(%d %d %d %d), but this is incompatible",
+                        (int)visualId, visualRedSize, visualGreenSize, visualBlueSize, visualAlphaSize, chosenVisualInfo->depth,
+                        configId, configRedSize, configGreenSize, configBlueSize, configAlphaSize);
+            }
+        } else {
+            qCDebug(lcXlibEglDebug, "EGL suggested using X Visual ID %d for EGL config %d, but that isn't a valid ID",
+                    (int)visualId, configId);
+            visualId = 0;
+        }
+        XFree(chosenVisualInfo);
+    }
+    else
+        qCDebug(lcXlibEglDebug, "EGL did not suggest a VisualID (EGL_NATIVE_VISUAL_ID was zero) for EGLConfig %d", configId);
+
+    if (visualId) {
+        qCDebug(lcXlibEglDebug, configAlphaSize > 0
+                ? "Using ARGB Visual ID %d provided by EGL for config %d"
+                : "Using Opaque Visual ID %d provided by EGL for config %d", (int)visualId, configId);
+        return visualId;
+    }
+
+    // Finally, try to use XGetVisualInfo and only use the bit depths to match on:
+    if (!visualId) {
+        XVisualInfo visualInfoTemplate;
+        memset(&visualInfoTemplate, 0, sizeof(XVisualInfo));
+        XVisualInfo *matchingVisuals;
+        int matchingCount = 0;
+
+        visualInfoTemplate.depth = configRedSize + configGreenSize + configBlueSize + configAlphaSize;
+        matchingVisuals = XGetVisualInfo(display,
+                                         VisualDepthMask,
+                                         &visualInfoTemplate,
+                                         &matchingCount);
+        if (!matchingVisuals) {
+            // Try again without taking the alpha channel into account:
+            visualInfoTemplate.depth = configRedSize + configGreenSize + configBlueSize;
+            matchingVisuals = XGetVisualInfo(display,
+                                             VisualDepthMask,
+                                             &visualInfoTemplate,
+                                             &matchingCount);
+        }
+
+        if (matchingVisuals) {
+            visualId = matchingVisuals[0].visualid;
+            XFree(matchingVisuals);
+        }
+    }
+
+    if (visualId) {
+        qCDebug(lcXlibEglDebug, "Using Visual ID %d provided by XGetVisualInfo for EGL config %d", (int)visualId, configId);
+        return visualId;
+    }
+
+    qWarning("Unable to find an X11 visual which matches EGL config %d", configId);
+    return (VisualID)0;
+}
+
+QT_END_NAMESPACE