Hi,
I am using scenegraph to generate a chart and so each x ms I get a new data sample from the input module. Now I regenerate the data constantly using a for loop:
QSGGeometry* geometryNewLine = mNodeNewLine->geometry();
geometryNewLine->allocate(mLoopVertices->newLineVertices.count());
QSGGeometry::ColoredPoint2D *verticesNewLine = geometryNewLine->vertexDataAsColoredPoint2D();
for (int i=0; i<mLoopVertices->newLineVertices.count(); i++)
{
color = mLoopVertices->newLineVertices.at(i).second ? colorInspiration : colorExpiration;
verticesNewLine[i].set(//adapt vertice
mLoopVertices->newLineVertices.at(i).first.x, mLoopVertices->newLineVertices.at(i).first.y,
//adapt color
color.red(), color.green(), color.blue(), color.alpha()
);
}
But this is taking quite some time and performance of course … now I do not seem to see in the documentation a method for updating this with one new sample at the time? Do I always need to copy everything?
A immediate easy update could be using a QVector in code outside of the updatePaintNode and then get the data as an array out of it and doing a memcopy or some sort (std::copy).
Still I wonder if there is not an easier way of updating part of the data through QSGGeometry instead of always copying everything,
thanks in advance,
kind regards,
Tim
[edit, code tags added, koahnig]
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