Enable transparency for walls

When alpha value for wall is below 1.0, enable blending for walls.
Rearrange code so that solid objects are drawn first and then possible
tranparent objects.

Task-number: QTBUG-59140
Change-Id: I5087a664a59ecdb4516b17e8fac1f8ff48ad1c16
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>

1 files changed, 65 insertions, 38 deletions

diff --git a/src/datavisualization/engine/surface3drenderer.cpp b/src/datavisualization/engine/surface3drenderer.cpp
index 848dc0f7..9cfa0edc 100644
--- a/src/datavisualization/engine/surface3drenderer.cpp
+++ b/src/datavisualization/engine/surface3drenderer.cpp
@@ -760,17 +760,19 @@ void Surface3DRenderer::render(GLuint defaultFboHandle)
     if (m_cachedIsSlicingActivated)
         drawSlicedScene();
 
-    // Render selection ball
+    // Render selection label
     if (m_selectionActive
             && m_cachedSelectionMode.testFlag(QAbstract3DGraph::SelectionItem)) {
-        foreach (SeriesRenderCache *baseCache, m_renderCacheList) {
-            SurfaceSeriesRenderCache *cache = static_cast<SurfaceSeriesRenderCache *>(baseCache);
+        for (SeriesRenderCache *baseCache: m_renderCacheList) {
+            const SurfaceSeriesRenderCache *cache = static_cast<SurfaceSeriesRenderCache *>(baseCache);
             if (cache->slicePointerActive() && cache->renderable() &&
                     m_cachedIsSlicingActivated ) {
-                cache->sliceSelectionPointer()->render(defaultFboHandle);
+                cache->sliceSelectionPointer()->renderSelectionLabel(defaultFboHandle);
+            }
+            if (cache->mainPointerActive() && cache->renderable()) {
+                cache->mainSelectionPointer()->renderSelectionLabel(defaultFboHandle,
+                                                                    m_useOrthoProjection);
             }
-            if (cache->mainPointerActive() && cache->renderable())
-                cache->mainSelectionPointer()->render(defaultFboHandle, m_useOrthoProjection);
         }
     }
 }
@@ -1328,6 +1330,38 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
                    m_primarySubViewport.height());
     }
 
+    // Selection handling
+    if (m_selectionDirty || m_selectionLabelDirty) {
+        QPoint visiblePoint = Surface3DController::invalidSelectionPosition();
+        if (m_selectedSeries) {
+            SurfaceSeriesRenderCache *cache =
+                    static_cast<SurfaceSeriesRenderCache *>(
+                        m_renderCacheList.value(const_cast<QSurface3DSeries *>(m_selectedSeries)));
+            if (cache && m_selectedPoint != Surface3DController::invalidSelectionPosition()) {
+                const QRect &sampleSpace = cache->sampleSpace();
+                int x = m_selectedPoint.x() - sampleSpace.y();
+                int y = m_selectedPoint.y() - sampleSpace.x();
+                if (x >= 0 && y >= 0 && x < sampleSpace.height() && y < sampleSpace.width()
+                        && cache->dataArray().size()) {
+                    visiblePoint = QPoint(x, y);
+                }
+            }
+        }
+
+        if (m_cachedSelectionMode == QAbstract3DGraph::SelectionNone
+                || visiblePoint == Surface3DController::invalidSelectionPosition()) {
+            m_selectionActive = false;
+        } else {
+            if (m_cachedIsSlicingActivated)
+                updateSliceDataModel(visiblePoint);
+            if (m_cachedSelectionMode.testFlag(QAbstract3DGraph::SelectionItem))
+                surfacePointSelected(visiblePoint);
+            m_selectionActive = true;
+        }
+
+        m_selectionDirty = false;
+    }
+
     // Draw the surface
     if (!m_renderCacheList.isEmpty()) {
         // For surface we can see glimpses from underneath
@@ -1452,6 +1486,22 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
         }
     }
 
+    // Render selection ball
+    if (m_selectionActive
+            && m_cachedSelectionMode.testFlag(QAbstract3DGraph::SelectionItem)) {
+        for (SeriesRenderCache *baseCache: m_renderCacheList) {
+            const SurfaceSeriesRenderCache *cache = static_cast<SurfaceSeriesRenderCache *>(baseCache);
+            if (cache->slicePointerActive() && cache->renderable() &&
+                    m_cachedIsSlicingActivated ) {
+                cache->sliceSelectionPointer()->renderSelectionPointer(defaultFboHandle);
+            }
+            if (cache->mainPointerActive() && cache->renderable()) {
+                cache->mainSelectionPointer()->renderSelectionPointer(defaultFboHandle,
+                                                                      m_useOrthoProjection);
+            }
+        }
+    }
+
     // Bind background shader
     m_backgroundShader->bind();
     glCullFace(GL_BACK);
@@ -1481,7 +1531,13 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
         MVPMatrix = projectionViewMatrix * modelMatrix;
 #endif
 
+        bool blendEnabled = false;
         QVector4D backgroundColor = Utils::vectorFromColor(m_cachedTheme->backgroundColor());
+        if (backgroundColor.w() < 1.0f) {
+            blendEnabled = true;
+            glEnable(GL_BLEND);
+            glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+        }
 
         // Set shader bindings
         m_backgroundShader->setUniformValue(m_backgroundShader->lightP(), lightPos);
@@ -1516,6 +1572,9 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
             // Draw the object
             m_drawer->drawObject(m_backgroundShader, m_backgroundObj);
         }
+
+        if (blendEnabled)
+            glDisable(GL_BLEND);
     }
 
     // Draw grid lines
@@ -1865,38 +1924,6 @@ void Surface3DRenderer::drawScene(GLuint defaultFboHandle)
 
     // Release shader
     glUseProgram(0);
-
-    // Selection handling
-    if (m_selectionDirty || m_selectionLabelDirty) {
-        QPoint visiblePoint = Surface3DController::invalidSelectionPosition();
-        if (m_selectedSeries) {
-            SurfaceSeriesRenderCache *cache =
-                    static_cast<SurfaceSeriesRenderCache *>(
-                        m_renderCacheList.value(const_cast<QSurface3DSeries *>(m_selectedSeries)));
-            if (cache && m_selectedPoint != Surface3DController::invalidSelectionPosition()) {
-                const QRect &sampleSpace = cache->sampleSpace();
-                int x = m_selectedPoint.x() - sampleSpace.y();
-                int y = m_selectedPoint.y() - sampleSpace.x();
-                if (x >= 0 && y >= 0 && x < sampleSpace.height() && y < sampleSpace.width()
-                        && cache->dataArray().size()) {
-                    visiblePoint = QPoint(x, y);
-                }
-            }
-        }
-
-        if (m_cachedSelectionMode == QAbstract3DGraph::SelectionNone
-                || visiblePoint == Surface3DController::invalidSelectionPosition()) {
-            m_selectionActive = false;
-        } else {
-            if (m_cachedIsSlicingActivated)
-                updateSliceDataModel(visiblePoint);
-            if (m_cachedSelectionMode.testFlag(QAbstract3DGraph::SelectionItem))
-                surfacePointSelected(visiblePoint);
-            m_selectionActive = true;
-        }
-
-        m_selectionDirty = false;
-    }
 }
 
 void Surface3DRenderer::drawLabels(bool drawSelection, const Q3DCamera *activeCamera,