Refactor retrieving the X11 visual for EGL

We need this in qwindowsurface_gl.cpp.

This patch was modified slightly by Tom, who stole it from another
branch. :-)

Reviewed-by: Gunnar

1 files changed, 84 insertions, 74 deletions

diff --git a/src/opengl/qgl_x11egl.cpp b/src/opengl/qgl_x11egl.cpp
index d4bf4da..d802bdd 100644
--- a/src/opengl/qgl_x11egl.cpp
+++ b/src/opengl/qgl_x11egl.cpp
@@ -140,85 +140,36 @@ void QGLWidget::updateOverlayGL()
     //handle overlay
 }
 
-void QGLWidget::setContext(QGLContext *context, const QGLContext* shareContext, bool deleteOldContext)
+bool qt_egl_setup_x11_visual(XVisualInfo &vi, EGLDisplay display, EGLConfig config, const QX11Info &x11Info, bool useArgbVisual)
 {
-    Q_D(QGLWidget);
-    if (context == 0) {
-        qWarning("QGLWidget::setContext: Cannot set null context");
-        return;
-    }
-    if (!context->deviceIsPixmap() && context->device() != this) {
-        qWarning("QGLWidget::setContext: Context must refer to this widget");
-        return;
-    }
-
-    if (d->glcx)
-        d->glcx->doneCurrent();
-    QGLContext* oldcx = d->glcx;
-    d->glcx = context;
-
-    if (parentWidget()) {
-        // force creation of delay-created widgets
-        parentWidget()->winId();
-        if (parentWidget()->x11Info().screen() != x11Info().screen())
-            d_func()->xinfo = parentWidget()->d_func()->xinfo;
-    }
-
-    // If the application has set WA_TranslucentBackground and not explicitly set
-    // the alpha buffer size to zero, modify the format so it have an alpha channel
-    QGLFormat& fmt = d->glcx->d_func()->glFormat;
-    const bool useArgbVisual = testAttribute(Qt::WA_TranslucentBackground);
-    if (useArgbVisual && fmt.alphaBufferSize() == -1)
-        fmt.setAlphaBufferSize(1);
-
-    bool createFailed = false;
-    if (!d->glcx->isValid()) {
-        if (!d->glcx->create(shareContext ? shareContext : oldcx))
-            createFailed = true;
-    }
-    if (createFailed) {
-        if (deleteOldContext)
-            delete oldcx;
-        return;
-    }
-
-    if (d->glcx->windowCreated() || d->glcx->deviceIsPixmap()) {
-        if (deleteOldContext)
-            delete oldcx;
-        return;
-    }
+    bool foundVisualIsArgb = useArgbVisual;
 
-    bool visible = isVisible();
-    if (visible)
-        hide();
-
-    XVisualInfo vi;
     memset(&vi, 0, sizeof(XVisualInfo));
 
     // Check to see if EGL is suggesting an appropriate visual id:
     EGLint nativeVisualId;
-    QEglContext* qeglCtx = d->glcx->d_func()->eglContext;
-    qeglCtx->configAttrib(EGL_NATIVE_VISUAL_ID, &nativeVisualId);
+    eglGetConfigAttrib(display, config, EGL_NATIVE_VISUAL_ID, &nativeVisualId);
     vi.visualid = nativeVisualId;
 
     if (vi.visualid) {
         // EGL has suggested a visual id, so get the rest of the visual info for that id:
         XVisualInfo *chosenVisualInfo;
         int matchingCount = 0;
-        chosenVisualInfo = XGetVisualInfo(x11Info().display(), VisualIDMask, &vi, &matchingCount);
+        chosenVisualInfo = XGetVisualInfo(x11Info.display(), VisualIDMask, &vi, &matchingCount);
         if (chosenVisualInfo) {
 #if !defined(QT_NO_XRENDER)
             if (useArgbVisual) {
                 // Check to make sure the visual provided by EGL is ARGB
                 XRenderPictFormat *format;
-                format = XRenderFindVisualFormat(x11Info().display(), chosenVisualInfo->visual);
+                format = XRenderFindVisualFormat(x11Info.display(), chosenVisualInfo->visual);
                 if (format->type == PictTypeDirect && format->direct.alphaMask) {
-//                    qDebug("Using opaque X Visual ID (%d) provided by EGL", (int)vi.visualid);
+//                    qDebug("Using ARGB X Visual ID (%d) provided by EGL", (int)vi.visualid);
+                    foundVisualIsArgb = true;
                     vi = *chosenVisualInfo;
                 }
                 else {
                     qWarning("Warning: EGL suggested using X visual ID %d for config %d, but this is not ARGB",
-                             nativeVisualId, (int)qeglCtx->config());
+                             nativeVisualId, (int)config);
                     vi.visualid = 0;
                 }
             } else
@@ -231,32 +182,32 @@ void QGLWidget::setContext(QGLContext *context, const QGLContext* shareContext,
         }
         else {
             qWarning("Warning: EGL suggested using X visual ID %d for config %d, but this seems to be invalid!",
-                     nativeVisualId, (int)qeglCtx->config());
+                     nativeVisualId, (int)config);
             vi.visualid = 0;
         }
     }
 
     // If EGL does not know the visual ID, so try to select an appropriate one ourselves, first
     // using XRender if we're supposed to have an alpha, then falling back to XGetVisualInfo
-
-    bool useArgb = context->format().alpha() && !context->deviceIsPixmap();
+          
 #if !defined(QT_NO_XRENDER)
-    if (vi.visualid == 0 && useArgb) {
+    if (vi.visualid == 0 && useArgbVisual) {
         // Try to use XRender to find an ARGB visual we can use
-        vi.screen  = x11Info().screen();
-        vi.depth   = 32;
+        vi.screen  = x11Info.screen();
+        vi.depth   = 32; //### We might at some point (soon) get ARGB4444
         vi.c_class = TrueColor;
         XVisualInfo *matchingVisuals;
         int matchingCount = 0;
-        matchingVisuals = XGetVisualInfo(x11Info().display(),
+        matchingVisuals = XGetVisualInfo(x11Info.display(),
                                          VisualScreenMask|VisualDepthMask|VisualClassMask,
                                          &vi, &matchingCount);
 
         for (int i = 0; i < matchingCount; ++i) {
             XRenderPictFormat *format;
-            format = XRenderFindVisualFormat(x11Info().display(), matchingVisuals[i].visual);
+            format = XRenderFindVisualFormat(x11Info.display(), matchingVisuals[i].visual);
             if (format->type == PictTypeDirect && format->direct.alphaMask) {
                 vi = matchingVisuals[i];
+                foundVisualIsArgb = true;
 //                qDebug("Using X Visual ID (%d) for ARGB visual as provided by XRender", (int)vi.visualid);
                 break;
             }
@@ -267,17 +218,17 @@ void QGLWidget::setContext(QGLContext *context, const QGLContext* shareContext,
 
     if (vi.visualid == 0) {
         EGLint depth;
-        qeglCtx->configAttrib(EGL_BUFFER_SIZE, &depth);
+        eglGetConfigAttrib(display, config, EGL_BUFFER_SIZE, &depth);
         int err;
-        err = XMatchVisualInfo(x11Info().display(), x11Info().screen(), depth, TrueColor, &vi);
+        err = XMatchVisualInfo(x11Info.display(), x11Info.screen(), depth, TrueColor, &vi);
         if (err == 0) {
             qWarning("Warning: Can't find an X visual which matches the EGL config(%d)'s depth (%d)!",
-                     (int)qeglCtx->config(), depth);
-            depth = x11Info().depth();
-            err = XMatchVisualInfo(x11Info().display(), x11Info().screen(), depth, TrueColor, &vi);
+                     (int)config, depth);
+            depth = x11Info.depth();
+            err = XMatchVisualInfo(x11Info.display(), x11Info.screen(), depth, TrueColor, &vi);
             if (err == 0) {
                 qWarning("Error: Couldn't get any matching X visual!");
-                return;
+                return false;
             } else
                 qWarning("         - Falling back to X11 suggested depth (%d)", depth);
         }
@@ -285,8 +236,8 @@ void QGLWidget::setContext(QGLContext *context, const QGLContext* shareContext,
 //            qDebug("Using X Visual ID (%d) for EGL provided depth (%d)", (int)vi.visualid, depth);
 
         // Don't try to use ARGB now unless the visual is 32-bit - even then it might stil fail :-(
-        if (useArgb)
-            useArgb = vi.depth == 32;
+        if (useArgbVisual)
+            foundVisualIsArgb = vi.depth == 32; //### We might at some point (soon) get ARGB4444
     }
 
 //    qDebug("Visual Info:");
@@ -299,6 +250,65 @@ void QGLWidget::setContext(QGLContext *context, const QGLContext* shareContext,
 //    qDebug("   depth=%d", vi.depth);
 //    qDebug("   screen=%d", vi.screen);
 //    qDebug("   visualid=%d", vi.visualid);
+    return foundVisualIsArgb;
+}
+
+void QGLWidget::setContext(QGLContext *context, const QGLContext* shareContext, bool deleteOldContext)
+{
+    Q_D(QGLWidget);
+    if (context == 0) {
+        qWarning("QGLWidget::setContext: Cannot set null context");
+        return;
+    }
+    if (!context->deviceIsPixmap() && context->device() != this) {
+        qWarning("QGLWidget::setContext: Context must refer to this widget");
+        return;
+    }
+
+    if (d->glcx)
+        d->glcx->doneCurrent();
+    QGLContext* oldcx = d->glcx;
+    d->glcx = context;
+
+    if (parentWidget()) {
+        // force creation of delay-created widgets
+        parentWidget()->winId();
+        if (parentWidget()->x11Info().screen() != x11Info().screen())
+            d_func()->xinfo = parentWidget()->d_func()->xinfo;
+    }
+
+    // If the application has set WA_TranslucentBackground and not explicitly set
+    // the alpha buffer size to zero, modify the format so it have an alpha channel
+    QGLFormat& fmt = d->glcx->d_func()->glFormat;
+    const bool tryArgbVisual = testAttribute(Qt::WA_TranslucentBackground);
+    if (tryArgbVisual && fmt.alphaBufferSize() == -1)
+        fmt.setAlphaBufferSize(1);
+
+    bool createFailed = false;
+    if (!d->glcx->isValid()) {
+        if (!d->glcx->create(shareContext ? shareContext : oldcx))
+            createFailed = true;
+    }
+    if (createFailed) {
+        if (deleteOldContext)
+            delete oldcx;
+        return;
+    }
+
+    if (d->glcx->windowCreated() || d->glcx->deviceIsPixmap()) {
+        if (deleteOldContext)
+            delete oldcx;
+        return;
+    }
+
+    bool visible = isVisible();
+    if (visible)
+        hide();
+
+    XVisualInfo vi;
+    QEglContext *eglContext = d->glcx->d_func()->eglContext;
+    bool usingArgbVisual = qt_egl_setup_x11_visual(vi, eglContext->display(), eglContext->config(),
+                                                   x11Info(), tryArgbVisual);
 
     XSetWindowAttributes a;
 
@@ -311,7 +321,7 @@ void QGLWidget::setContext(QGLContext *context, const QGLContext* shareContext,
     a.border_pixel = colmap.pixel(Qt::black);
 
     unsigned int valueMask = CWBackPixel|CWBorderPixel;
-    if(useArgb) {
+    if (usingArgbVisual) {
         a.colormap = XCreateColormap(x11Info().display(), p, vi.visual, AllocNone);
         valueMask |= CWColormap;
     }