Port QXlibEglIntegration::getCompatibleVisualId to xcb

In combination with EGL_EXT_platform_xcb support, this allows xcb_egl
to be used without xlib. Without EGL_EXT_platform_xcb support, this
still reduces amount of code using xlib.

Pick-to: 6.4
Change-Id: I29e2b29f7ef8ea34320887f62697f84232b86fba
Reviewed-by: Liang Qi <liang.qi@qt.io>

2 files changed, 0 insertions, 163 deletions

diff --git a/src/gui/opengl/platform/egl/qxlibeglintegration.cpp b/src/gui/opengl/platform/egl/qxlibeglintegration.cpp
deleted file mode 100644
index cfabedc8c0..0000000000
--- a/src/gui/opengl/platform/egl/qxlibeglintegration.cpp
+++ /dev/null
@@ -1,130 +0,0 @@
-// Copyright (C) 2020 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
-
-#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
diff --git a/src/gui/opengl/platform/egl/qxlibeglintegration_p.h b/src/gui/opengl/platform/egl/qxlibeglintegration_p.h
deleted file mode 100644
index 3e0ecbc6ea..0000000000
--- a/src/gui/opengl/platform/egl/qxlibeglintegration_p.h
+++ /dev/null
@@ -1,33 +0,0 @@
-// Copyright (C) 2020 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
-
-#ifndef QXLIBEGLINTEGRATION_H
-#define QXLIBEGLINTEGRATION_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API. It exists purely as an
-// implementation detail. This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <QtGui/private/qeglconvenience_p.h>
-#include <X11/X.h>
-#include <X11/Xlib.h>
-#include <X11/Xutil.h>
-
-QT_BEGIN_NAMESPACE
-
-class Q_GUI_EXPORT QXlibEglIntegration
-{
-public:
-    static VisualID getCompatibleVisualId(Display *display, EGLDisplay eglDisplay, EGLConfig config);
-};
-
-QT_END_NAMESPACE
-
-#endif // QXLIBEGLINTEGRATION_H