1 files changed, 47 insertions, 33 deletions

diff --git a/src/datavisualization/utils/utils.cpp b/src/datavisualization/utils/utils.cpp
index 42a1e532..7f10bac7 100644
--- a/src/datavisualization/utils/utils.cpp
+++ b/src/datavisualization/utils/utils.cpp
@@ -21,14 +21,17 @@
 
 #include <QtGui/QPainter>
 #include <QtGui/QOpenGLContext>
-#include <QtGui/QWindow>
+#include <QtGui/QOffscreenSurface>
 
 QT_BEGIN_NAMESPACE_DATAVISUALIZATION
 
 #define NUM_IN_POWER(y, x) for (;y<x;y<<=1)
 #define MIN_POWER 2
 
-static GLint maxTextureSize = 0; // Safe, as all instances have the same texture size
+// Some values that only need to be resolved once
+static bool staticsResolved = false;
+static GLint maxTextureSize = 0;
+static bool isES = false;
 
 GLuint Utils::getNearestPowerOfTwo(GLuint value)
 {
@@ -58,10 +61,9 @@ QImage Utils::printTextToImage(const QFont &font, const QString &text, const QCo
                                const QColor &txtColor, bool labelBackground,
                                bool borders, int maxLabelWidth)
 {
-    if (maxTextureSize == 0) {
-        QOpenGLContext::currentContext()->functions()->glGetIntegerv(
-                    GL_MAX_TEXTURE_SIZE, &maxTextureSize);
-    }
+    if (!staticsResolved)
+        resolveStatics();
+
     GLuint paddingWidth = 20;
     GLuint paddingHeight = 20;
     GLuint prePadding = 20;
@@ -87,7 +89,7 @@ QImage Utils::printTextToImage(const QFont &font, const QString &text, const QCo
         // make a label with large empty space
         uint testWidth = getNearestPowerOfTwo(valueStrWidth + prePadding) >> 1;
         int diffToFit = (valueStrWidth + prePadding) - testWidth;
-        int maxSqueeze = int((valueStrWidth + prePadding) * 0.1f);
+        int maxSqueeze = int((valueStrWidth + prePadding) * 0.25f);
         if (diffToFit < maxSqueeze && maxTextureSize > GLint(testWidth))
             targetWidth = testWidth;
     }
@@ -317,39 +319,51 @@ QQuaternion Utils::calculateRotation(const QVector3D &xyzRotations)
 
 bool Utils::isOpenGLES()
 {
+    if (!staticsResolved)
+        resolveStatics();
+    return isES;
+}
+
+void Utils::resolveStatics()
+{
+    QOpenGLContext *ctx = QOpenGLContext::currentContext();
+    QOffscreenSurface *dummySurface = 0;
+    if (!ctx) {
+        QSurfaceFormat surfaceFormat;
+        dummySurface = new QOffscreenSurface();
+        dummySurface->setFormat(surfaceFormat);
+        dummySurface->create();
+        ctx = new QOpenGLContext;
+        ctx->setFormat(surfaceFormat);
+        ctx->create();
+        ctx->makeCurrent(dummySurface);
+    }
+
 #if defined(QT_OPENGL_ES_2)
-    return true;
+    isES = true;
 #elif (QT_VERSION < QT_VERSION_CHECK(5, 3, 0))
-    return false;
+    isES = false;
 #else
-    static bool resolved = false;
-    static bool isES = false;
-    if (!resolved) {
-        QOpenGLContext *ctx = QOpenGLContext::currentContext();
-        QWindow *dummySurface = 0;
-        if (!ctx) {
-            QSurfaceFormat surfaceFormat = qDefaultSurfaceFormat();
-            dummySurface = new QWindow();
-            dummySurface->setSurfaceType(QWindow::OpenGLSurface);
-            dummySurface->setFormat(surfaceFormat);
-            dummySurface->create();
-            ctx = new QOpenGLContext;
-            ctx->setFormat(surfaceFormat);
-            ctx->create();
-            ctx->makeCurrent(dummySurface);
-        }
+    isES = ctx->isOpenGLES();
+#endif
 
-        isES = ctx->isOpenGLES();
-        resolved = true;
+    ctx->functions()->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTextureSize);
 
-        if (dummySurface) {
-            ctx->doneCurrent();
-            delete ctx;
-            delete dummySurface;
-        }
+    if (dummySurface) {
+        ctx->doneCurrent();
+        delete ctx;
+        delete dummySurface;
+    }
+
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 4, 0))
+    // We support only ES2 emulation with software renderer for now
+    if (QCoreApplication::testAttribute(Qt::AA_UseSoftwareOpenGL)) {
+        qWarning("Only OpenGL ES2 emulation is available for software rendering.");
+        isES = true;
     }
-    return isES;
 #endif
+
+    staticsResolved = true;
 }
 
 QT_END_NAMESPACE_DATAVISUALIZATION