Fix: Nans at surfacedata row/column 0 render fail

If the first or last column or row of the data
given to surfacedataproxy contains NaN values,
the surfacedataproxy might fail to find the
limit values for the axis. Changed limitValues
function in surfacedataproxy so that if it
doesn't find min/max values from the first/last
column/row it continues from the next column/row.
Added a test to verify that the limit values are
found when first/last row contains NaN values.

Change-Id: Ica3eebb1c6072656f59394814c3fa5e334f12c54
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>
(cherry picked from commit a9ccf1c7a1ccc7499e9a0d6178e9555caa364901)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 54 insertions, 26 deletions

diff --git a/src/datavisualization/data/qsurfacedataproxy.cpp b/src/datavisualization/data/qsurfacedataproxy.cpp
index 7601d021..c9c6425d 100644
--- a/src/datavisualization/data/qsurfacedataproxy.cpp
+++ b/src/datavisualization/data/qsurfacedataproxy.cpp
@@ -552,9 +552,11 @@ void QSurfaceDataProxyPrivate::limitValues(QVector3D &minValues, QVector3D &maxV
                 float itemValue = m_dataArray->at(i)->at(j).y();
                 if (qIsNaN(itemValue) || qIsInf(itemValue))
                     continue;
-                if (min > itemValue && isValidValue(itemValue, axisY))
+                if ((min > itemValue || (qIsNaN(min) || qIsInf(min)))
+                        && isValidValue(itemValue, axisY)) {
                     min = itemValue;
-                if (max < itemValue)
+                }
+                if (max < itemValue  || (qIsNaN(max) || qIsInf(max)))
                     max = itemValue;
             }
         }
@@ -569,33 +571,59 @@ void QSurfaceDataProxyPrivate::limitValues(QVector3D &minValues, QVector3D &maxV
         float xHigh = m_dataArray->at(0)->last().x();
         float zLow = m_dataArray->at(0)->at(0).z();
         float zHigh = m_dataArray->last()->at(0).z();
-        for (int i = 0; i < columns; i++) {
-            float zItemValue = m_dataArray->at(0)->at(i).z();
-            if (qIsNaN(zItemValue) || qIsInf(zItemValue))
-                continue;
-            else if (isValidValue(zItemValue, axisZ))
-                zLow = qMin(zLow,zItemValue);
+        for (int i = 0; i < rows; i++) {
+            for (int j = 0; j < columns; j++) {
+                float zItemValue = m_dataArray->at(i)->at(j).z();
+                if (qIsNaN(zItemValue) || qIsInf(zItemValue))
+                    continue;
+                else if (isValidValue(zItemValue, axisZ))
+                    zLow = qMin(zLow,zItemValue);
+            }
+            if (!qIsNaN(zLow) && !qIsInf(zLow))
+                break;
         }
-        for (int i = 0; i < columns; i++) {
-            float zItemValue = m_dataArray->last()->at(i).z();
-            if (qIsNaN(zItemValue) || qIsInf(zItemValue))
-                continue;
-            else if (isValidValue(zItemValue, axisZ))
-                zHigh = qMax(zHigh, zItemValue);
+        for (int i = rows - 1; i >= 0; i--) {
+            for (int j = 0; j < columns; j++) {
+                float zItemValue = m_dataArray->at(i)->at(j).z();
+                if (qIsNaN(zItemValue) || qIsInf(zItemValue))
+                    continue;
+                else if (isValidValue(zItemValue, axisZ))
+                {
+                    if (!qIsNaN(zHigh) && !qIsInf(zHigh))
+                        zHigh = qMax(zHigh, zItemValue);
+                    else
+                        zHigh = zItemValue;
+                }
+            }
+            if (!qIsNaN(zHigh) && !qIsInf(zHigh))
+                break;
         }
-        for (int i = 0; i < rows; i++) {
-            float xItemValue = m_dataArray->at(i)->at(0).x();
-            if (qIsNaN(xItemValue) || qIsInf(xItemValue))
-                continue;
-            else if (isValidValue(xItemValue, axisX))
-                xLow = qMin(xLow, xItemValue);
+        for (int j = 0; j<columns; j++){
+            for (int i = 0; i < rows; i++) {
+                float xItemValue = m_dataArray->at(i)->at(j).x();
+                if (qIsNaN(xItemValue) || qIsInf(xItemValue))
+                    continue;
+                else if (isValidValue(xItemValue, axisX))
+                    xLow = qMin(xLow, xItemValue);
+            }
+            if (!qIsNaN(xLow) && !qIsInf(xLow))
+                break;
         }
-        for (int i = 0; i < rows; i++) {
-            float xItemValue = m_dataArray->at(i)->last().x();
-            if (qIsNaN(xItemValue) || qIsInf(xItemValue))
-                continue;
-            else if (isValidValue(xItemValue, axisX))
-                xHigh = qMax(xHigh, xItemValue);
+        for (int j = columns-1; j >= 0; j--){
+            for (int i = 0; i < rows; i++) {
+                float xItemValue = m_dataArray->at(i)->at(j).x();
+                if (qIsNaN(xItemValue) || qIsInf(xItemValue))
+                    continue;
+                else if (isValidValue(xItemValue, axisX))
+                {
+                    if (!qIsNaN(xHigh) && !qIsInf(xHigh))
+                        xHigh = qMax(xHigh, xItemValue);
+                    else
+                        xHigh = xItemValue;
+                }
+            }
+            if (!qIsNaN(xHigh) && !qIsInf(xHigh))
+                break;
         }
         minValues.setX(xLow);
         minValues.setZ(zLow);