Use GL_LINES for ES2 grid lines

Task-number: QTRD-2527

Change-Id: I08b9c740f6dfaf8107601cfc1e7e53db13bf8268
Note: Not to be merged until 1.0 is released
Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>

8 files changed, 211 insertions, 70 deletions

diff --git a/src/datavisualization/engine/bars3drenderer.cpp b/src/datavisualization/engine/bars3drenderer.cpp
index a7f9e2b3..ead825e4 100644
--- a/src/datavisualization/engine/bars3drenderer.cpp
+++ b/src/datavisualization/engine/bars3drenderer.cpp
@@ -338,7 +338,11 @@ void Bars3DRenderer::drawSlicedScene()
     // Draw grid lines
     if (m_cachedTheme->isGridEnabled()) {
         glDisable(GL_DEPTH_TEST);
+#if !(defined QT_OPENGL_ES_2)
         ShaderHelper *lineShader = m_backgroundShader;
+#else
+        ShaderHelper *lineShader = m_selectionShader; // Plain color shader for GL_LINES
+#endif
         // Bind line shader
         lineShader->bind();
 
@@ -378,7 +382,11 @@ void Bars3DRenderer::drawSlicedScene()
                 lineShader->setUniformValue(lineShader->MVP(), MVPMatrix);
 
                 // Draw the object
+#if !(defined QT_OPENGL_ES_2)
                 m_drawer->drawObject(lineShader, m_gridLineObj);
+#else
+                m_drawer->drawLine(lineShader);
+#endif
 
                 // Check if we have a line at zero position already
                 if (gridPos == (barPosYAdjustment + zeroPosAdjustment))
@@ -386,6 +394,7 @@ void Bars3DRenderer::drawSlicedScene()
 
                 gridPos += gridStep;
             }
+
             // Draw a line at zero, if none exists
             if (!m_noZeroInRange && noZero) {
                 QMatrix4x4 modelMatrix;
@@ -400,10 +409,14 @@ void Bars3DRenderer::drawSlicedScene()
                                             itModelMatrix.inverted().transposed());
                 lineShader->setUniformValue(lineShader->MVP(), MVPMatrix);
                 lineShader->setUniformValue(lineShader->color(),
-                                            Utils::vectorFromColor(m_cachedTheme->backgroundColor()));
+                                            Utils::vectorFromColor(m_cachedTheme->labelTextColor()));
 
                 // Draw the object
+#if !(defined QT_OPENGL_ES_2)
                 m_drawer->drawObject(lineShader, m_gridLineObj);
+#else
+                m_drawer->drawLine(lineShader);
+#endif
             }
         }
 
@@ -633,7 +646,7 @@ void Bars3DRenderer::drawSlicedScene()
                 // Create label texture if we need it
                 if (item.sliceLabel().isNull() || m_updateLabels) {
                     item.setSliceLabel(generateValueLabel(m_axisCacheY.labelFormat(),
-                                                           item.value()));
+                                                          item.value()));
                     m_drawer->generateLabelItem(item.sliceLabelItem(), item.sliceLabel());
                     m_updateLabels = false;
                 }
@@ -658,7 +671,7 @@ void Bars3DRenderer::drawSlicedScene()
                 // Create label texture if we need it
                 if (item.sliceLabel().isNull() || m_updateLabels) {
                     item.setSliceLabel(generateValueLabel(m_axisCacheY.labelFormat(),
-                                                           item.value()));
+                                                          item.value()));
                     m_drawer->generateLabelItem(item.sliceLabelItem(), item.sliceLabel());
                     m_updateLabels = false;
                 }
@@ -1073,7 +1086,6 @@ void Bars3DRenderer::drawScene(GLuint defaultFboHandle)
     }
 
     // Draw bars
-
     GLfloat adjustedLightStrength = m_cachedTheme->lightStrength() / 10.0f;
     GLfloat adjustedHighlightStrength = m_cachedTheme->highlightLightStrength() / 10.0f;
 
@@ -1419,7 +1431,11 @@ void Bars3DRenderer::drawScene(GLuint defaultFboHandle)
 
     // Draw grid lines
     if (m_cachedTheme->isGridEnabled() && m_heightNormalizer) {
+#if !(defined QT_OPENGL_ES_2)
         ShaderHelper *lineShader = m_backgroundShader;
+#else
+        ShaderHelper *lineShader = m_selectionShader; // Plain color shader for GL_LINES
+#endif
         QQuaternion lineRotation;
 
         // Bind bar shader
@@ -1446,11 +1462,9 @@ void Bars3DRenderer::drawScene(GLuint defaultFboHandle)
                                         m_cachedTheme->lightStrength() / 2.5f);
         }
 
-        GLfloat yFloorLinePosition = 0.0f;
+        GLfloat yFloorLinePosition = gridLineOffset;
         if (m_yFlipped)
-            yFloorLinePosition -= gridLineOffset;
-        else
-            yFloorLinePosition += gridLineOffset;
+            yFloorLinePosition = -yFloorLinePosition;
 
         QVector3D gridLineScaler(rowScaleFactor, gridLineWidth, gridLineWidth);
 
@@ -1488,15 +1502,19 @@ void Bars3DRenderer::drawScene(GLuint defaultFboHandle)
                 lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                 // Draw the object
                 m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-            } else
-#endif
-            {
+            } else {
                 // Draw the object
                 m_drawer->drawObject(lineShader, m_gridLineObj);
             }
+#else
+            m_drawer->drawLine(lineShader);
+#endif
         }
 
         // Floor lines: columns
+#if defined(QT_OPENGL_ES_2)
+        lineRotation = QQuaternion::fromAxisAndAngle(0.0f, 1.0f, 0.0f, 90.0f);
+#endif
         gridLineScaler = QVector3D(gridLineWidth, gridLineWidth, columnScaleFactor);
         for (GLfloat bar = 0.0f; bar <= m_cachedColumnCount; bar++) {
             QMatrix4x4 modelMatrix;
@@ -1526,12 +1544,13 @@ void Bars3DRenderer::drawScene(GLuint defaultFboHandle)
                 lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                 // Draw the object
                 m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-            } else
-#endif
-            {
+            } else {
                 // Draw the object
                 m_drawer->drawObject(lineShader, m_gridLineObj);
             }
+#else
+            m_drawer->drawLine(lineShader);
+#endif
         }
 
         if (m_axisCacheY.segmentCount() > 0) {
@@ -1583,12 +1602,13 @@ void Bars3DRenderer::drawScene(GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 lineHeight += heightStep;
             }
 
@@ -1632,12 +1652,13 @@ void Bars3DRenderer::drawScene(GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 lineHeight += heightStep;
             }
         }
diff --git a/src/datavisualization/engine/drawer.cpp b/src/datavisualization/engine/drawer.cpp
index 55a2c2a5..38c15a58 100644
--- a/src/datavisualization/engine/drawer.cpp
+++ b/src/datavisualization/engine/drawer.cpp
@@ -45,18 +45,27 @@ QT_BEGIN_NAMESPACE_DATAVISUALIZATION
 // Vertex array buffer for point
 const GLfloat point_data[] = {0.0f, 0.0f, 0.0f};
 
+// Vertex array buffer for line
+const GLfloat line_data[] = {
+    -1.0f, 0.0f, 0.0f,
+    1.0f, 0.0f, 0.0f,
+};
+
 Drawer::Drawer(Q3DTheme *theme)
     : m_theme(theme),
       m_textureHelper(0),
-      m_pointbuffer(0)
+      m_pointbuffer(0),
+      m_linebuffer(0)
 {
 }
 
 Drawer::~Drawer()
 {
     delete m_textureHelper;
-    if (QOpenGLContext::currentContext())
+    if (QOpenGLContext::currentContext()) {
         glDeleteBuffers(1, &m_pointbuffer);
+        glDeleteBuffers(1, &m_linebuffer);
+    }
 }
 
 void Drawer::initializeOpenGL()
@@ -162,6 +171,8 @@ void Drawer::drawSurfaceGrid(ShaderHelper *shader, SurfaceObject *object)
 
 void Drawer::drawPoint(ShaderHelper *shader)
 {
+    // Draw a single point
+
     // Generate vertex buffer for point if it does not exist
     if (!m_pointbuffer) {
         glGenBuffers(1, &m_pointbuffer);
@@ -183,6 +194,31 @@ void Drawer::drawPoint(ShaderHelper *shader)
     glDisableVertexAttribArray(shader->posAtt());
 }
 
+void Drawer::drawLine(ShaderHelper *shader)
+{
+    // Draw a single line
+
+    // Generate vertex buffer for line if it does not exist
+    if (!m_linebuffer) {
+        glGenBuffers(1, &m_linebuffer);
+        glBindBuffer(GL_ARRAY_BUFFER, m_linebuffer);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(line_data), line_data, GL_STATIC_DRAW);
+    }
+
+    // 1st attribute buffer : vertices
+    glEnableVertexAttribArray(shader->posAtt());
+    glBindBuffer(GL_ARRAY_BUFFER, m_linebuffer);
+    glVertexAttribPointer(shader->posAtt(), 3, GL_FLOAT, GL_FALSE, 0, (void*)0);
+
+    // Draw the line
+    glDrawArrays(GL_LINES, 0, 2);
+
+    // Free buffers
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+    glDisableVertexAttribArray(shader->posAtt());
+}
+
 void Drawer::drawLabel(const AbstractRenderItem &item, const LabelItem &labelItem,
                        const QMatrix4x4 &viewmatrix, const QMatrix4x4 &projectionmatrix,
                        const QVector3D &positionComp, const QVector3D &rotation,
diff --git a/src/datavisualization/engine/drawer_p.h b/src/datavisualization/engine/drawer_p.h
index 8e98aa3a..5d10018e 100644
--- a/src/datavisualization/engine/drawer_p.h
+++ b/src/datavisualization/engine/drawer_p.h
@@ -76,6 +76,7 @@ public:
                     GLuint depthTextureId = 0);
     void drawSurfaceGrid(ShaderHelper *shader, SurfaceObject *object);
     void drawPoint(ShaderHelper *shader);
+    void drawLine(ShaderHelper *shader);
     void drawLabel(const AbstractRenderItem &item, const LabelItem &labelItem,
                    const QMatrix4x4 &viewmatrix, const QMatrix4x4 &projectionmatrix,
                    const QVector3D &positionComp, const QVector3D &rotation, GLfloat itemHeight,
@@ -94,6 +95,7 @@ private:
     Q3DTheme *m_theme;
     TextureHelper *m_textureHelper;
     GLuint m_pointbuffer;
+    GLuint m_linebuffer;
 };
 
 QT_END_NAMESPACE_DATAVISUALIZATION
diff --git a/src/datavisualization/engine/meshes/backgroundNegatives.obj b/src/datavisualization/engine/meshes/backgroundNegatives.obj
index 76c7c1d8..d314e1fc 100644
--- a/src/datavisualization/engine/meshes/backgroundNegatives.obj
+++ b/src/datavisualization/engine/meshes/backgroundNegatives.obj
@@ -1,18 +1,18 @@
 # Blender v2.66 (sub 0) OBJ File: 'backgroudNegativesWall.blend'
 # www.blender.org
 o Cube
-v 0.999999 1.000000 1.000001
+v 1.000000 1.000000 1.000000
 v -1.000000 1.000000 1.000000
 v -1.000000 1.000000 -1.000000
 v 1.000000 -3.000000 1.000000
 v -1.000000 -3.000000 1.000000
 v -1.000000 -3.000000 -1.000000
-vt 0.000100 0.000100
-vt 0.500000 0.000100
-vt 0.500000 0.999900
-vt 0.999900 0.000100
-vt 0.999900 0.999900
-vt 0.000100 0.999900
+vt 0.000000 0.000000
+vt 0.500000 0.000000
+vt 0.500000 1.000000
+vt 1.000000 0.000000
+vt 1.000000 1.000000
+vt 0.000000 1.000000
 vn 0.000000 -0.000000 -1.000000
 vn 1.000000 0.000000 0.000000
 s off
diff --git a/src/datavisualization/engine/scatter3drenderer.cpp b/src/datavisualization/engine/scatter3drenderer.cpp
index de1a769a..38e48cc2 100644
--- a/src/datavisualization/engine/scatter3drenderer.cpp
+++ b/src/datavisualization/engine/scatter3drenderer.cpp
@@ -69,7 +69,9 @@ Scatter3DRenderer::Scatter3DRenderer(Scatter3DController *controller)
       m_backgroundShader(0),
       m_labelShader(0),
       m_backgroundObj(0),
+      #if !defined(QT_OPENGL_ES_2)
       m_gridLineObj(0),
+      #endif
       m_labelObj(0),
       m_bgrTexture(0),
       m_depthTexture(0),
@@ -112,7 +114,9 @@ Scatter3DRenderer::~Scatter3DRenderer()
     delete m_backgroundShader;
     delete m_labelShader;
     delete m_backgroundObj;
+#if !defined(QT_OPENGL_ES_2)
     delete m_gridLineObj;
+#endif
     delete m_labelObj;
 }
 
@@ -135,8 +139,10 @@ void Scatter3DRenderer::initializeOpenGL()
     // Init selection shader
     initSelectionShader();
 
+#if !defined(QT_OPENGL_ES_2)
     // Load grid line mesh
     loadGridLineMesh();
+#endif
 
     // Load label mesh
     loadLabelMesh();
@@ -848,7 +854,11 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
 #endif
 
     if (m_cachedTheme->isGridEnabled() && m_heightNormalizer) {
+#if !(defined QT_OPENGL_ES_2)
         ShaderHelper *lineShader = m_backgroundShader;
+#else
+        ShaderHelper *lineShader = m_selectionShader; // Plain color shader for GL_LINES
+#endif
 
         // Bind line shader
         lineShader->bind();
@@ -942,12 +952,13 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos -= lineStep;
             }
 
@@ -976,8 +987,13 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                 modelMatrix.scale(gridLineScaler);
                 itModelMatrix.scale(gridLineScaler);
 
+#if !defined(QT_OPENGL_ES_2)
                 modelMatrix.rotate(lineYRotation);
                 itModelMatrix.rotate(lineYRotation);
+#else
+                modelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+                itModelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+#endif
 
                 MVPMatrix = projectionViewMatrix * modelMatrix;
 
@@ -994,18 +1010,22 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos -= lineStep;
             }
         }
 
         // Columns (= X)
         if (m_axisCacheX.segmentCount() > 0) {
+#if defined(QT_OPENGL_ES_2)
+            lineXRotation = QQuaternion::fromAxisAndAngle(0.0f, 1.0f, 0.0f, 90.0f);
+#endif
             // Floor lines
 #ifndef USE_UNIFORM_SCALING
             GLfloat lineStep = aspectRatio * m_axisCacheX.subSegmentStep();
@@ -1051,12 +1071,13 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos += lineStep;
             }
 
@@ -1086,10 +1107,15 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                 modelMatrix.scale(gridLineScaler);
                 itModelMatrix.scale(gridLineScaler);
 
+#if !defined(QT_OPENGL_ES_2)
                 if (m_zFlipped) {
                     modelMatrix.rotate(180.0f, 1.0f, 0.0f, 0.0f);
                     itModelMatrix.rotate(180.0f, 1.0f, 0.0f, 0.0f);
                 }
+#else
+                modelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+                itModelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+#endif
 
                 MVPMatrix = projectionViewMatrix * modelMatrix;
 
@@ -1106,12 +1132,13 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos += lineStep;
             }
         }
@@ -1170,12 +1197,13 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos += lineStep;
             }
 
@@ -1228,12 +1256,13 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos += lineStep;
             }
         }
@@ -1604,6 +1633,7 @@ void Scatter3DRenderer::loadBackgroundMesh()
     m_backgroundObj->load();
 }
 
+#if !(defined QT_OPENGL_ES_2)
 void Scatter3DRenderer::loadGridLineMesh()
 {
     if (m_gridLineObj)
@@ -1611,6 +1641,7 @@ void Scatter3DRenderer::loadGridLineMesh()
     m_gridLineObj = new ObjectHelper(QStringLiteral(":/defaultMeshes/plane"));
     m_gridLineObj->load();
 }
+#endif
 
 void Scatter3DRenderer::loadLabelMesh()
 {
diff --git a/src/datavisualization/engine/scatter3drenderer_p.h b/src/datavisualization/engine/scatter3drenderer_p.h
index 5591a362..b82ff4ae 100644
--- a/src/datavisualization/engine/scatter3drenderer_p.h
+++ b/src/datavisualization/engine/scatter3drenderer_p.h
@@ -68,7 +68,9 @@ private:
     ShaderHelper *m_backgroundShader;
     ShaderHelper *m_labelShader;
     ObjectHelper *m_backgroundObj;
+#if !(defined QT_OPENGL_ES_2)
     ObjectHelper *m_gridLineObj;
+#endif
     ObjectHelper *m_labelObj;
     GLuint m_bgrTexture;
     GLuint m_depthTexture;
@@ -121,13 +123,13 @@ private:
     void drawScene(GLuint defaultFboHandle);
 
     void loadBackgroundMesh();
-    void loadGridLineMesh();
     void loadLabelMesh();
     void initSelectionShader();
     void initBackgroundShaders(const QString &vertexShader, const QString &fragmentShader);
     void initLabelShaders(const QString &vertexShader, const QString &fragmentShader);
     void initSelectionBuffer();
 #if !defined(QT_OPENGL_ES_2)
+    void loadGridLineMesh();
     void initDepthShader();
     void updateDepthBuffer();
 #else
diff --git a/src/datavisualization/engine/surface3drenderer.cpp b/src/datavisualization/engine/surface3drenderer.cpp
index 41415393..243c27de 100644
--- a/src/datavisualization/engine/surface3drenderer.cpp
+++ b/src/datavisualization/engine/surface3drenderer.cpp
@@ -72,7 +72,9 @@ Surface3DRenderer::Surface3DRenderer(Surface3DController *controller)
       m_visibleColumnRange(0.0f),
       m_visibleRowRange(0.0f),
       m_backgroundObj(0),
+      #if !defined(QT_OPENGL_ES_2)
       m_gridLineObj(0),
+      #endif
       m_labelObj(0),
       m_depthTexture(0),
       m_depthModelTexture(0),
@@ -133,7 +135,9 @@ Surface3DRenderer::~Surface3DRenderer()
     delete m_labelShader;
 
     delete m_backgroundObj;
+#if !defined(QT_OPENGL_ES_2)
     delete m_gridLineObj;
+#endif
     delete m_labelObj;
 
     foreach (SurfaceSeriesRenderCache *cache, m_renderCacheList) {
@@ -160,8 +164,10 @@ void Surface3DRenderer::initializeOpenGL()
     // Init selection shader
     initSelectionShaders();
 
+#if !(defined QT_OPENGL_ES_2)
     // Load grid line mesh
     loadGridLineMesh();
+#endif
 
     // Load label mesh
     loadLabelMesh();
@@ -415,7 +421,7 @@ void Surface3DRenderer::updateSliceDataModel(const QPoint &point)
     if (m_cachedSelectionMode.testFlag(QAbstract3DGraph::SelectionMultiSeries)) {
         // Find axis coordinates for the selected point
         SurfaceSeriesRenderCache *selectedCache =
-            m_renderCacheList.value(const_cast<QSurface3DSeries *>(m_selectedSeries));
+                m_renderCacheList.value(const_cast<QSurface3DSeries *>(m_selectedSeries));
         QSurfaceDataArray &dataArray = selectedCache->dataArray();
         QSurfaceDataItem item = dataArray.at(point.x())->at(point.y());
         QPointF coords(item.x(), item.z());
@@ -536,7 +542,7 @@ void Surface3DRenderer::updateSliceObject(SurfaceSeriesRenderCache *cache, const
     int row = point.x();
 
     if ((m_cachedSelectionMode.testFlag(QAbstract3DGraph::SelectionRow) && row == -1) ||
-        (m_cachedSelectionMode.testFlag(QAbstract3DGraph::SelectionColumn) && column == -1)) {
+            (m_cachedSelectionMode.testFlag(QAbstract3DGraph::SelectionColumn) && column == -1)) {
         cache->sliceSurfaceObject()->clear();
         return;
     }
@@ -847,7 +853,11 @@ void Surface3DRenderer::drawSlicedScene()
 
     // Grid lines
     if (m_cachedTheme->isGridEnabled() && m_heightNormalizer) {
+#if !(defined QT_OPENGL_ES_2)
         ShaderHelper *lineShader = m_backgroundShader;
+#else
+        ShaderHelper *lineShader = m_selectionShader; // Plain color shader for GL_LINES
+#endif
         // Bind line shader
         lineShader->bind();
 
@@ -888,7 +898,11 @@ void Surface3DRenderer::drawSlicedScene()
                 lineShader->setUniformValue(lineShader->MVP(), MVPMatrix);
 
                 // Draw the object
+#if !(defined QT_OPENGL_ES_2)
                 m_drawer->drawObject(lineShader, m_gridLineObj);
+#else
+                m_drawer->drawLine(lineShader);
+#endif
 
                 linePos += lineStep;
             }
@@ -918,6 +932,10 @@ void Surface3DRenderer::drawSlicedScene()
             modelMatrix.translate(linePos, 0.0f, -sliceZScale);
             modelMatrix.scale(gridLineScaleY);
             itModelMatrix.scale(gridLineScaleY);
+#if (defined QT_OPENGL_ES_2)
+            modelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+            itModelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+#endif
 
             MVPMatrix = projectionViewMatrix * modelMatrix;
 
@@ -928,7 +946,11 @@ void Surface3DRenderer::drawSlicedScene()
             lineShader->setUniformValue(lineShader->MVP(), MVPMatrix);
 
             // Draw the object
+#if !(defined QT_OPENGL_ES_2)
             m_drawer->drawObject(lineShader, m_gridLineObj);
+#else
+            m_drawer->drawLine(lineShader);
+#endif
 
             linePos += lineStep;
         }
@@ -1436,7 +1458,11 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
     QVector3D gridLineScaleY(gridLineWidth, backgroundMargin, gridLineWidth);
 
     if (m_cachedTheme->isGridEnabled() && m_heightNormalizer) {
+#if !(defined QT_OPENGL_ES_2)
         ShaderHelper *lineShader = m_backgroundShader;
+#else
+        ShaderHelper *lineShader = m_selectionShader; // Plain color shader for GL_LINES
+#endif
 
         // Bind line shader
         lineShader->bind();
@@ -1514,12 +1540,13 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos -= lineStep;
             }
 
@@ -1540,8 +1567,13 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
                 modelMatrix.scale(gridLineScaleY);
                 itModelMatrix.scale(gridLineScaleY);
 
+#if !defined(QT_OPENGL_ES_2)
                 modelMatrix.rotate(lineYRotation);
                 itModelMatrix.rotate(lineYRotation);
+#else
+                modelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+                itModelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+#endif
 
                 MVPMatrix = projectionViewMatrix * modelMatrix;
 
@@ -1558,18 +1590,22 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos -= lineStep;
             }
         }
 
         // Columns (= X)
         if (m_axisCacheX.segmentCount() > 0) {
+#if defined(QT_OPENGL_ES_2)
+            lineXRotation = QQuaternion::fromAxisAndAngle(0.0f, 1.0f, 0.0f, 90.0f);
+#endif
             // Floor lines
             GLfloat lineStep = -2.0f * aspectRatio * m_axisCacheX.subSegmentStep() / m_scaleFactor;
             GLfloat linePos = m_scaleX;
@@ -1603,12 +1639,13 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos += lineStep;
             }
 
@@ -1629,10 +1666,15 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
                 modelMatrix.scale(gridLineScaleY);
                 itModelMatrix.scale(gridLineScaleY);
 
+#if !defined(QT_OPENGL_ES_2)
                 if (m_zFlipped) {
                     modelMatrix.rotate(180.0f, 1.0f, 0.0f, 0.0f);
                     itModelMatrix.rotate(180.0f, 1.0f, 0.0f, 0.0f);
                 }
+#else
+                modelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+                itModelMatrix.rotate(90.0f, 0.0f, 0.0f, 1.0f);
+#endif
 
                 MVPMatrix = projectionViewMatrix * modelMatrix;
 
@@ -1649,12 +1691,13 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos += lineStep;
             }
         }
@@ -1701,12 +1744,13 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos += lineStep;
             }
 
@@ -1746,12 +1790,13 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
                     lineShader->setUniformValue(lineShader->depth(), depthMVPMatrix);
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj, 0, m_depthTexture);
-                } else
-#endif
-                {
+                } else {
                     // Draw the object
                     m_drawer->drawObject(lineShader, m_gridLineObj);
                 }
+#else
+                m_drawer->drawLine(lineShader);
+#endif
                 linePos += lineStep;
             }
         }
@@ -2129,6 +2174,7 @@ void Surface3DRenderer::loadBackgroundMesh()
     m_backgroundObj->load();
 }
 
+#if !(defined QT_OPENGL_ES_2)
 void Surface3DRenderer::loadGridLineMesh()
 {
     if (m_gridLineObj)
@@ -2136,6 +2182,7 @@ void Surface3DRenderer::loadGridLineMesh()
     m_gridLineObj = new ObjectHelper(QStringLiteral(":/defaultMeshes/plane"));
     m_gridLineObj->load();
 }
+#endif
 
 void Surface3DRenderer::surfacePointSelected(const QPoint &point)
 {
@@ -2147,7 +2194,7 @@ void Surface3DRenderer::surfacePointSelected(const QPoint &point)
     if (m_cachedSelectionMode.testFlag(QAbstract3DGraph::SelectionMultiSeries)) {
         // Find axis coordinates for the selected point
         SurfaceSeriesRenderCache *selectedCache =
-            m_renderCacheList.value(const_cast<QSurface3DSeries *>(m_selectedSeries));
+                m_renderCacheList.value(const_cast<QSurface3DSeries *>(m_selectedSeries));
         QSurfaceDataArray &dataArray = selectedCache->dataArray();
         QSurfaceDataItem item = dataArray.at(point.x())->at(point.y());
         QPointF coords(item.x(), item.z());
diff --git a/src/datavisualization/engine/surface3drenderer_p.h b/src/datavisualization/engine/surface3drenderer_p.h
index 2c55d902..5d93ee4a 100644
--- a/src/datavisualization/engine/surface3drenderer_p.h
+++ b/src/datavisualization/engine/surface3drenderer_p.h
@@ -74,7 +74,9 @@ private:
     GLfloat m_visibleColumnRange;
     GLfloat m_visibleRowRange;
     ObjectHelper *m_backgroundObj;
+#if !(defined QT_OPENGL_ES_2)
     ObjectHelper *m_gridLineObj;
+#endif
     ObjectHelper *m_labelObj;
     GLuint m_depthTexture;
     GLuint m_depthModelTexture;
@@ -138,7 +140,6 @@ private:
     void initShaders(const QString &vertexShader, const QString &fragmentShader);
     QRect calculateSampleRect(SurfaceSeriesRenderCache *cache, const QSurfaceDataArray &array);
     void loadBackgroundMesh();
-    void loadGridLineMesh();
     void loadLabelMesh();
     void drawScene(GLuint defaultFboHandle);
     void calculateSceneScalingFactors();
@@ -157,6 +158,7 @@ private:
     QPoint selectionIdToSurfacePoint(uint id);
     QString createSelectionLabel(SurfaceSeriesRenderCache *cache, float value, int column, int row);
 #if !defined(QT_OPENGL_ES_2)
+    void loadGridLineMesh();
     void updateDepthBuffer();
 #endif
     void emitSelectedPointChanged(QPoint position);