Optimized label texture creation

Change-Id: I2c97fb82c1ea2fa22bf603675658e53ac82e0298
Reviewed-by: Mika Salmela <mika.salmela@digia.com>

5 files changed, 66 insertions, 46 deletions

diff --git a/src/datavis3d/engine/q3dbars.cpp b/src/datavis3d/engine/q3dbars.cpp
index a9d18c73..87b67592 100644
--- a/src/datavis3d/engine/q3dbars.cpp
+++ b/src/datavis3d/engine/q3dbars.cpp
@@ -61,6 +61,12 @@
 
 #include <QDebug>
 
+#define DISPLAY_RENDER_SPEED
+
+#ifdef DISPLAY_RENDER_SPEED
+#include <QTime>
+#endif
+
 QTCOMMERCIALDATAVIS3D_BEGIN_NAMESPACE
 
 #define USE_HAX0R_SELECTION // keep this defined until the "real" method works
@@ -139,7 +145,21 @@ void Q3DBars::render()
 {
     if (!d_ptr->m_isInitialized)
         return;
-
+#ifdef DISPLAY_RENDER_SPEED
+    // For speed computation
+    static QTime lastTime = QTime::currentTime();
+    static QTime lastFrameTime = lastTime;
+    static int nbFrames = 0;
+
+    // Measure speed (as milliseconds per frame)
+    lastFrameTime = QTime::currentTime();
+    nbFrames++;
+    if (lastTime.msecsTo(lastFrameTime) >= 1000.0f) { // print only if last measurement was more than 1s ago
+        qDebug() << 1000.0f / double(nbFrames) << "ms/frame (=" << double(nbFrames) << "fps)";
+        nbFrames = 0;
+        lastTime = lastFrameTime;
+    }
+#endif
 #ifdef USE_PAINTER_TEXT
     if (d_ptr->m_paintDevice) {
         QPainter painter(d_ptr->m_paintDevice);
@@ -445,7 +465,7 @@ void Q3DBars::drawZoomScene()
     d_ptr->m_barShader->release();
 
 #ifndef USE_PAINTER_TEXT
-    // Draw labels (or values of bars)
+    // Draw bar values
     d_ptr->m_labelShader->bind();
     glDisable(GL_DEPTH_TEST);
     glEnable(GL_TEXTURE_2D);
@@ -453,33 +473,11 @@ void Q3DBars::drawZoomScene()
         glEnable(GL_BLEND);
         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
     }
+
+    // Do the actual drawing
     for (int col = 0; col < d_ptr->m_zoomSelection->d_ptr->row().size(); col++) {
         QDataItem *item = d_ptr->m_zoomSelection->d_ptr->getItem(col);
-        //
-        // TODO: Optimize! Create textures only when zoomselection changes! Store the texture id's into zoomselection
-        //
-        // ie. move this segment elsewhere...
-        // Create labels
-        // Print label into a QImage using QPainter
-        QImage label = Utils::printTextToImage(d_ptr->m_font
-                                               , item->d_ptr->valueStr()
-                                               , d_ptr->m_theme->m_textBackgroundColor
-                                               , d_ptr->m_theme->m_textColor
-                                               , d_ptr->m_labelTransparency);
-
-        // Set label size
-        item->d_ptr->setLabelSize(label.size());
-        // Insert text texture into label
-        item->d_ptr->setTextureId(d_ptr->m_textureHelper->create2DTexture(label, true, true));
-        // ...ie. move this segment elsewhere
-
         drawLabel(*item, viewMatrix, projectionMatrix, false, -45.0f);
-
-        // ie. move this segment elsewhere...
-        GLuint labelTexture = item->d_ptr->textureId();
-        glDeleteTextures(1, &labelTexture);
-        item->d_ptr->setTextureId(0);
-        // ...ie. move this segment elsewhere
     }
 
     glDisable(GL_TEXTURE_2D);
@@ -908,9 +906,16 @@ void Q3DBars::drawScene()
         d_ptr->m_zoomActivated = true;
         d_ptr->m_sceneViewPort = QRect(0, height() - height() / 5
                                        , width() / 5, height() / 5);
+
+        // Create label textures
+        for (int col = 0; col < d_ptr->m_zoomSelection->d_ptr->row().size(); col++) {
+            QDataItem *item = d_ptr->m_zoomSelection->d_ptr->getItem(col);
+            generateLabelTexture(item);
+        }
     } else {
         // Print value of selected bar
 #ifndef USE_PAINTER_TEXT
+        static QDataItem *prevItem = d_ptr->m_selectedBar;
         d_ptr->m_labelShader->bind();
         glDisable(GL_DEPTH_TEST);
         glEnable(GL_TEXTURE_2D);
@@ -918,27 +923,13 @@ void Q3DBars::drawScene()
             glEnable(GL_BLEND);
             glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
         }
-        // Create label
-        // Print label into a QImage using QPainter
-        QImage label = Utils::printTextToImage(d_ptr->m_font
-                                               , d_ptr->m_selectedBar->d_ptr->valueStr()
-                                               , d_ptr->m_theme->m_textBackgroundColor
-                                               , d_ptr->m_theme->m_textColor
-                                               , d_ptr->m_labelTransparency);
-
-        // Set label size
-        d_ptr->m_selectedBar->d_ptr->setLabelSize(label.size());
-        // Insert text texture into label
-        d_ptr->m_selectedBar->d_ptr->setTextureId(d_ptr->m_textureHelper->create2DTexture(label
-                                                                                          , true
-                                                                                          , true));
+        if (prevItem != d_ptr->m_selectedBar) {
+            generateLabelTexture(d_ptr->m_selectedBar);
+            prevItem = d_ptr->m_selectedBar;
+        }
 
         drawLabel(*d_ptr->m_selectedBar, viewMatrix, projectionMatrix, true);
 
-        GLuint labelTexture = d_ptr->m_selectedBar->d_ptr->textureId();
-        glDeleteTextures(1, &labelTexture);
-        d_ptr->m_selectedBar->d_ptr->setTextureId(0);
-
         glDisable(GL_TEXTURE_2D);
         if (d_ptr->m_labelTransparency > TransparencyNone)
             glDisable(GL_BLEND);
@@ -953,6 +944,33 @@ void Q3DBars::drawScene()
     d_ptr->m_barShader->release();
 }
 
+void Q3DBars::generateLabelTexture(QDataItem *item)
+{
+    // Delete previous texture, if there is one
+    GLuint labelTexture = item->d_ptr->textureId();
+    if (labelTexture) {
+        // We have to do this, as we can't know if data is static or not;
+        // texture doesn't change with static data
+        // (basically we could create textures for all bars when data is added, but we
+        // may not need them -> better to do it here dynamically)
+        glDeleteTextures(1, &labelTexture);
+        item->d_ptr->setTextureId(0);
+    }
+
+    // Create labels
+    // Print label into a QImage using QPainter
+    QImage label = Utils::printTextToImage(d_ptr->m_font
+                                           , item->d_ptr->valueStr()
+                                           , d_ptr->m_theme->m_textBackgroundColor
+                                           , d_ptr->m_theme->m_textColor
+                                           , d_ptr->m_labelTransparency);
+
+    // Set label size
+    item->d_ptr->setLabelSize(label.size());
+    // Insert text texture into label
+    item->d_ptr->setTextureId(d_ptr->m_textureHelper->create2DTexture(label, true, true));
+}
+
 // TODO: Move to a separate class, so that it can be used by other vis types as well (will need a lot more parameters..)
 void Q3DBars::drawLabel(const QDataItem &item, const QMatrix4x4 &viewmatrix
                         , const QMatrix4x4 &projectionmatrix, bool useDepth, qreal rotation) // TODO: Add enum? for label position (below, middle, top etc.)
diff --git a/src/datavis3d/engine/q3dbars.h b/src/datavis3d/engine/q3dbars.h
index e3936c81..0d7ef935 100644
--- a/src/datavis3d/engine/q3dbars.h
+++ b/src/datavis3d/engine/q3dbars.h
@@ -209,6 +209,7 @@ private:
     void drawLabel(const QDataItem &item, const QMatrix4x4 &viewmatrix
                    , const QMatrix4x4 &projectionmatrix, bool useDepth = false
             , qreal rotation = 0.0f);
+    void generateLabelTexture(QDataItem *item);
     QScopedPointer<Q3DBarsPrivate> d_ptr;
     Q_DISABLE_COPY(Q3DBars)
 };
diff --git a/src/datavis3d/engine/qdataitem.cpp b/src/datavis3d/engine/qdataitem.cpp
index d0a4ec74..28a96cc0 100644
--- a/src/datavis3d/engine/qdataitem.cpp
+++ b/src/datavis3d/engine/qdataitem.cpp
@@ -76,6 +76,7 @@ QDataItemPrivate::QDataItemPrivate(QDataItem *q, float value, const QString &lab
     , m_prependLabel(false)
     , m_size(QSize(0, 0))
     , m_translation(QVector3D(0, 0, 0))
+    , m_textureId(0)
 {
 }
 
diff --git a/src/datavis3d/global/qdatavis3dglobal.h b/src/datavis3d/global/qdatavis3dglobal.h
index 7bd0fea3..528180b3 100644
--- a/src/datavis3d/global/qdatavis3dglobal.h
+++ b/src/datavis3d/global/qdatavis3dglobal.h
@@ -4,7 +4,7 @@
 ** All rights reserved.
 ** For any questions to Digia, please use contact form at http://qt.digia.com
 **
-** This file is part of the Qt Commercial Charts Add-on.
+** This file is part of QtDataVis3D.
 **
 ** $QT_BEGIN_LICENSE$
 ** Licensees holding valid Qt Commercial licenses may use this file in
diff --git a/src/datavis3d/global/qdatavis3namespace.h b/src/datavis3d/global/qdatavis3namespace.h
index f19ed4d7..fd6e7919 100644
--- a/src/datavis3d/global/qdatavis3namespace.h
+++ b/src/datavis3d/global/qdatavis3namespace.h
@@ -3,7 +3,7 @@
 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
-** This file is part of the Qt3D module of the Qt Toolkit.
+** This file is part of QtDataVis3D.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial License Usage