Unified gradient for points

Made gradient image same size as the texture and similar calculation
for the pixel. Result should be more coherent for all.

Task-number: QTRD-3295
Change-Id: I666dacc6f525258ccefda288e26cac480cb385cb
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@digia.com>
Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>

3 files changed, 11 insertions, 7 deletions

diff --git a/src/datavisualization/engine/scatter3drenderer.cpp b/src/datavisualization/engine/scatter3drenderer.cpp
index 0a670fe8..ca983dac 100644
--- a/src/datavisualization/engine/scatter3drenderer.cpp
+++ b/src/datavisualization/engine/scatter3drenderer.cpp
@@ -745,7 +745,6 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
     }
 
     float rangeGradientYScaler = 0.5f / m_scaleY;
-    float rangeGradientYScalerForPoints = rangeGradientYScaler * 100.0f;
 
     foreach (SeriesRenderCache *baseCache, m_renderCacheList) {
         if (baseCache->isVisible()) {
@@ -771,6 +770,8 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                 glPointSize(itemSize * activeCamera->zoomLevel()); // Scale points based on zoom
 #endif
             QVector3D modelScaler(itemSize, itemSize, itemSize);
+            int gradientImageHeight = cache->gradientImage().height();
+            int maxGradientPositition = gradientImageHeight - 1;
 
             if (!optimizationDefault
                     && ((drawingPoints && cache->bufferPoints()->indexCount() == 0)
@@ -848,8 +849,8 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                     if (rangeGradientPoints) {
                         // Drawing points with range gradient
                         // Get color from gradient based on items y position converted to percent
-                        int position = int(item.translation().y() * rangeGradientYScalerForPoints)
-                                + 50;
+                        int position = ((item.translation().y() + m_scaleY) * rangeGradientYScaler) * gradientImageHeight;
+                        position = qMin(maxGradientPositition, position); // clamp to edge
                         dotColor = Utils::vectorFromColor(
                                     cache->gradientImage().pixel(0, position));
                     } else {
diff --git a/src/datavisualization/utils/utils.cpp b/src/datavisualization/utils/utils.cpp
index 2368d86a..d7b8dae8 100644
--- a/src/datavisualization/utils/utils.cpp
+++ b/src/datavisualization/utils/utils.cpp
@@ -139,13 +139,16 @@ QVector4D Utils::getSelection(QPoint mousepos, int height)
     return selectedColor;
 }
 
-QImage Utils::getGradientImage(const QLinearGradient &gradient)
+QImage Utils::getGradientImage(QLinearGradient &gradient)
 {
-    QImage image(QSize(1, 101), QImage::Format_RGB32);
+    QImage image(QSize(gradientTextureWidth, gradientTextureHeight), QImage::Format_RGB32);
+    gradient.setFinalStop(qreal(gradientTextureWidth), qreal(gradientTextureHeight));
+    gradient.setStart(0.0, 0.0);
+
     QPainter pmp(&image);
     pmp.setBrush(QBrush(gradient));
     pmp.setPen(Qt::NoPen);
-    pmp.drawRect(0, 0, 1, 101);
+    pmp.drawRect(0, 0, int(gradientTextureWidth), int(gradientTextureHeight));
     return image;
 }
 
diff --git a/src/datavisualization/utils/utils_p.h b/src/datavisualization/utils/utils_p.h
index d7187c16..55707fdb 100644
--- a/src/datavisualization/utils/utils_p.h
+++ b/src/datavisualization/utils/utils_p.h
@@ -57,7 +57,7 @@ public:
                                    bool borders = false,
                                    int maxLabelWidth = 0);
     static QVector4D getSelection(QPoint mousepos, int height);
-    static QImage getGradientImage(const QLinearGradient &gradient);
+    static QImage getGradientImage(QLinearGradient &gradient);
 
     static ParamType findFormatParamType(const QString &format);
     static QString formatLabel(const QByteArray &format, ParamType paramType, qreal value);