Resurrect QGLWidget::renderText()

The variant taking x, y, z has been broken in all Qt 5.x releases.
This is now corrected by making the GL2 paint engine capable of applying
a Z translation.

Task-number: QTBUG-31156
Change-Id: I119566e9e9577f6cdf7e8bae56cac1e34995e622
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
index fd64a4a71f..2b49e4d2d1 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
@@ -1158,6 +1158,7 @@ bool QGL2PaintEngineExPrivate::prepareForDraw(bool srcPixelsAreOpaque)
         brushUniformsDirty = true;
         opacityUniformDirty = true;
         matrixUniformDirty = true;
+        translateZUniformDirty = true;
     }
 
     if (brushUniformsDirty && mode != ImageDrawingMode && mode != ImageArrayDrawingMode)
@@ -1174,6 +1175,12 @@ bool QGL2PaintEngineExPrivate::prepareForDraw(bool srcPixelsAreOpaque)
         matrixUniformDirty = false;
     }
 
+    if (translateZUniformDirty && shaderManager->hasComplexGeometry()) {
+        shaderManager->currentProgram()->setUniformValue(location(QGLEngineShaderManager::TranslateZ),
+                                                         translateZ);
+        translateZUniformDirty = false;
+    }
+
     return changed;
 }
 
@@ -2011,6 +2018,7 @@ bool QGL2PaintEngineEx::begin(QPaintDevice *pdev)
     d->matrixDirty = true;
     d->compositionModeDirty = true;
     d->opacityUniformDirty = true;
+    d->translateZUniformDirty = true;
     d->needsSync = true;
     d->useSystemClip = !systemClip().isEmpty();
     d->currentBrush = QBrush();
@@ -2375,6 +2383,15 @@ void QGL2PaintEngineExPrivate::systemStateChanged()
     }
 }
 
+void QGL2PaintEngineEx::setTranslateZ(GLfloat z)
+{
+    Q_D(QGL2PaintEngineEx);
+    if (d->translateZ != z) {
+        d->translateZ = z;
+        d->translateZUniformDirty = true;
+    }
+}
+
 void QGL2PaintEngineEx::setState(QPainterState *new_state)
 {
     //     qDebug("QGL2PaintEngineEx::setState()");