Add matching by GL_VENDOR to QOpenGLConfig

This will be essential on Linux, especially Embedded where PCI IDs are
not that useful.

Change-Id: I2fa8ca07236e8aae203e21fe629d12aab092c7fd
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>

2 files changed, 55 insertions, 11 deletions

diff --git a/src/gui/opengl/qopengl.cpp b/src/gui/opengl/qopengl.cpp
index 61d0614724..c8d33df4ba 100644
--- a/src/gui/opengl/qopengl.cpp
+++ b/src/gui/opengl/qopengl.cpp
@@ -36,6 +36,7 @@
 
 #include "qopenglcontext.h"
 #include "qopenglfunctions.h"
+#include "qoffscreensurface.h"
 
 #include <QtCore/QDebug>
 #include <QtCore/QJsonDocument>
@@ -89,8 +90,8 @@ QOpenGLExtensionMatcher::QOpenGLExtensionMatcher()
 }
 
 /* Helpers to read out the list of features matching a device from
- * a Chromium driver bug list of the format using a subset of keys
- * (namely, matching by gl_vendor RegExp is not implemented):
+ * a Chromium driver bug list. Note that not all keys are supported and
+ * some may behave differently: gl_vendor is a substring match instead of regex.
  {
   "entries": [
  {
@@ -291,14 +292,14 @@ static bool matches(const QJsonObject &object,
 
     const QJsonValue vendorV = object.value(vendorIdKey());
     if (vendorV.isString()) {
-    if (gpu.vendorId != vendorV.toString().toUInt(Q_NULLPTR, /* base */ 0))
-        return false;
+        if (gpu.vendorId != vendorV.toString().toUInt(Q_NULLPTR, /* base */ 0))
+            return false;
     } else {
         if (object.contains(glVendorKey())) {
-            qWarning().nospace() << "Id " << object.value(idKey()).toInt()
-                << ": Matching by " << glVendorKey() << " is not implemented.";
-            return false;
-       }
+            const QByteArray glVendorV = object.value(glVendorKey()).toString().toUtf8();
+            if (!gpu.glVendor.contains(glVendorV))
+                return false;
+        }
     }
 
     if (gpu.deviceId) {
@@ -447,5 +448,30 @@ QSet<QString> QOpenGLConfig::gpuFeatures(const Gpu &gpu, const QString &fileName
     return gpuFeatures(gpu, OsTypeTerm::hostOs(), OsTypeTerm::hostKernelVersion(), fileName);
 }
 
+QOpenGLConfig::Gpu QOpenGLConfig::Gpu::fromContext()
+{
+    QOpenGLContext *ctx = QOpenGLContext::currentContext();
+    QScopedPointer<QOpenGLContext> tmpContext;
+    QScopedPointer<QOffscreenSurface> tmpSurface;
+    if (!ctx) {
+        tmpContext.reset(new QOpenGLContext);
+        if (!tmpContext->create()) {
+            qWarning("QOpenGLConfig::Gpu::fromContext: Failed to create temporary context");
+            return QOpenGLConfig::Gpu();
+        }
+        tmpSurface.reset(new QOffscreenSurface);
+        tmpSurface->setFormat(tmpContext->format());
+        tmpSurface->create();
+        tmpContext->makeCurrent(tmpSurface.data());
+    }
+
+    QOpenGLConfig::Gpu gpu;
+    ctx = QOpenGLContext::currentContext();
+    const GLubyte *p = ctx->functions()->glGetString(GL_VENDOR);
+    if (p)
+        gpu.glVendor = QByteArray(reinterpret_cast<const char *>(p));
+
+    return gpu;
+}
 
 QT_END_NAMESPACE
diff --git a/src/gui/opengl/qopengl_p.h b/src/gui/opengl/qopengl_p.h
index e04ae05120..980e02aea6 100644
--- a/src/gui/opengl/qopengl_p.h
+++ b/src/gui/opengl/qopengl_p.h
@@ -74,16 +74,34 @@ private:
 class Q_GUI_EXPORT QOpenGLConfig
 {
 public:
-    struct Gpu {
+    struct Q_GUI_EXPORT Gpu {
         Gpu() : vendorId(0), deviceId(0) {}
-        bool isValid() const { return deviceId; }
+        bool isValid() const { return deviceId || !glVendor.isEmpty(); }
         bool equals(const Gpu &other) const {
-            return vendorId == other.vendorId && deviceId == other.deviceId && driverVersion == other.driverVersion;
+            return vendorId == other.vendorId && deviceId == other.deviceId && driverVersion == other.driverVersion
+                && glVendor == other.glVendor;
         }
 
         uint vendorId;
         uint deviceId;
         QVersionNumber driverVersion;
+        QByteArray glVendor;
+
+        static Gpu fromDevice(uint vendorId, uint deviceId, QVersionNumber driverVersion) {
+            Gpu gpu;
+            gpu.vendorId = vendorId;
+            gpu.deviceId = deviceId;
+            gpu.driverVersion = driverVersion;
+            return gpu;
+        }
+
+        static Gpu fromGLVendor(const QByteArray &glVendor) {
+            Gpu gpu;
+            gpu.glVendor = glVendor;
+            return gpu;
+        }
+
+        static Gpu fromContext();
     };
 
     static QSet<QString> gpuFeatures(const Gpu &gpu,