private void RenderDataSignal(Plottables.Signal signal)
{
// use the signal processing class to convert dense data to pixel column fills
PixelColumn[] pxCols = SignalToPixelConverter(signal, settings);
Pen linePen = new Pen(signal.style.lineColor);
Brush brushPen = new SolidBrush(signal.style.lineColor);
// disable anti-aliasing so art looks better
var originalSmoothMode = gfxData.SmoothingMode;
gfxData.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighSpeed;
// for zoomed-in data, only individual points will be plotted
var points = new List <Point>();
// plot one column at a time
int skippedColumns = 0;
for (int i = 0; i < pxCols.Length; i++)
{
if (pxCols[i] == null)
{
// this column contains no data
skippedColumns += 1;
}
else if (pxCols[i].min == pxCols[i].max)
{
// this column contains a single pixel of data
gfxData.FillRectangle(brushPen, i, pxCols[i].min, 1, 1);
}
else
{
// this column contains a span of data
Point pt1 = new Point(i, pxCols[i].min);
Point pt2 = new Point(i, pxCols[i].max);
gfxData.DrawLine(linePen, pt1, pt2);
}
// if this is a new data point, remember it
if (i > 0 && pxCols[i] != null && pxCols[i - 1] != null && pxCols[i].iLeft > pxCols[i - 1].iLeft)
{
points.Add(new Point(i, pxCols[i].min));
}
}
// draw markers at each individual point if zoomed-in6
if ((points.Count() + skippedColumns) < settings.dataPlotWidth / 3)
{
int ptSize = 2;
foreach (var point in points)
{
gfxData.FillEllipse(brushPen, point.X - ptSize, point.Y - ptSize, 2 * ptSize, 2 * ptSize);
}
//gfxData.DrawLines(linePen, points.ToArray());
}
// revert to how things were
gfxData.SmoothingMode = originalSmoothMode;
}
private PixelColumn[] SignalToPixelConverter(Plottables.Signal signal, Settings settings)
{
PixelColumn[] pxCols = new PixelColumn[settings.dataPlotWidth];
// theoretical minimum pixel if X1 were drawn
int dataMinPx = (int)(settings.axisX.pxPerUnit * (-settings.axisX.x1));
// step column by column left to right
for (int i = 0; i < settings.dataPlotWidth; i++)
{
// determine what index values of the signal correspond to this pixel column
int iLeft = (int)(settings.axisX.unitsPerPx * signal.sampleRateHz * (i - dataMinPx));
int iRight = (int)(iLeft + settings.axisX.unitsPerPx * signal.sampleRateHz);
// ensure indexes are valid and skip columns without data
iLeft = Math.Max(iLeft, 0);
iRight = Math.Min(signal.ys.Length - 1, iRight);
iRight = Math.Max(iRight, 0);
if (iRight == 0)
{
continue;
}
if (iRight < 0 || iLeft > iRight)
{
continue;
}
// pull iLeft of this column to the same iRight as the last
if (i > 0 && pxCols[i - 1] != null)
{
iLeft = pxCols[i - 1].iRight - 1;
}
// determine vertical span of this range
double valMin = ArraySubMin(signal.ys, iLeft, iRight);
double valMax = ArraySubMax(signal.ys, iLeft, iRight);
// TODO: make indexes perfect - they don't always match-up exactly
//Console.WriteLine($"Index [{iLeft}:{iRight}] min/max = {valMin}/{valMax}");
// convert this value to a pixel location on screen
int pxMin = (int)((settings.axisY.x2 - valMin) * settings.axisY.pxPerUnit) + 1;
int pxMax = (int)((settings.axisY.x2 - valMax) * settings.axisY.pxPerUnit) + 1;
// populate the object
pxCols[i] = new PixelColumn(pxMin, pxMax, iLeft, iRight);
}
return(pxCols);
}
