jankae/LibreVNA
1
0
Fork 0
mirror of https://github.com/jankae/LibreVNA.git synced 2026-04-07 23:43:42 +00:00
Code Issues Projects Releases Packages Wiki Activity

improve XY-plot rendering, especially for logarithmic Y-axes

Browse source
This commit is contained in:
Jan Käberich 2024-04-16 21:13:23 +02:00
parent cdfe95af17
commit 994b536bc6
3 changed files with 89 additions and 36 deletions
Download patch file Download diff file Expand all files Collapse all files

89
Software/PC_Application/LibreVNA-GUI/Traces/tracexyplot.cpp
View file

@ -478,7 +478,11 @@ void TraceXYPlot::draw(QPainter &p)
step = max / 1000;
}
int significantDigits = floor(log10(max)) - floor(log10(step)) + 1;
if(yAxis[i].getLog() && yAxis[i].getRangeMax()/yAxis[i].getRangeMin() >= 100) {
significantDigits = floor(log10(max)) + 1;
}
int lastTickLabelEnd = std::numeric_limits<int>::max();
for(unsigned int j = 0; j < yAxis[i].getTicks().size(); j++) {
auto yCoord = yAxis[i].transform(yAxis[i].getTicks()[j], w.height() - xAxisSpace, plotAreaTop);
p.setPen(QPen(pref.Graphs.Color.axis, 1));
@ -486,17 +490,23 @@ void TraceXYPlot::draw(QPainter &p)
auto tickStart = i == 0 ? plotAreaLeft : plotAreaLeft + plotAreaWidth;
auto tickLen = i == 0 ? -2 : 2;
p.drawLine(tickStart, yCoord, tickStart + tickLen, yCoord);
QString unit = "";
QString prefix = " ";
if(pref.Graphs.showUnits) {
unit = yAxis[i].Unit();
prefix = yAxis[i].Prefixes();
}
auto tickValue = Unit::ToString(yAxis[i].getTicks()[j], unit, prefix, significantDigits);
if(i == 0) {
p.drawText(QRectF(0, yCoord - pref.Graphs.fontSizeAxis/2 - 2, tickStart + 2 * tickLen, pref.Graphs.fontSizeAxis*1.5), Qt::AlignRight, tickValue);
if(yCoord + pref.Graphs.fontSizeAxis >= lastTickLabelEnd) {
// would overlap previous tick label, skip
} else {
p.drawText(QRectF(tickStart + 2 * tickLen + 2, yCoord - pref.Graphs.fontSizeAxis/2 - 2, yAxisSpace, pref.Graphs.fontSizeAxis*1.5), Qt::AlignLeft, tickValue);
QString unit = "";
QString prefix = " ";
if(pref.Graphs.showUnits) {
unit = yAxis[i].Unit();
prefix = yAxis[i].Prefixes();
}
auto tickValue = Unit::ToString(yAxis[i].getTicks()[j], unit, prefix, significantDigits);
QRect bounding;
if(i == 0) {
p.drawText(QRect(0, yCoord - pref.Graphs.fontSizeAxis/2 - 2, tickStart + 2 * tickLen, pref.Graphs.fontSizeAxis*1.5), Qt::AlignRight, tickValue, &bounding);
} else {
p.drawText(QRect(tickStart + 2 * tickLen + 2, yCoord - pref.Graphs.fontSizeAxis/2 - 2, yAxisSpace, pref.Graphs.fontSizeAxis*1.5), Qt::AlignLeft, tickValue, &bounding);
}
lastTickLabelEnd = bounding.y();
}
// tick lines
@ -509,8 +519,8 @@ void TraceXYPlot::draw(QPainter &p)
if (pref.Graphs.Color.Ticks.Background.enabled) {
if (j%2)
{
int yCoordTop = yAxis[i].transform(yAxis[i].getTicks()[j], plotAreaTop, w.height() - xAxisSpace);
int yCoordBot = yAxis[i].transform(yAxis[i].getTicks()[j-1], plotAreaTop, w.height() - xAxisSpace);
int yCoordTop = yCoord;
int yCoordBot = yAxis[i].transform(yAxis[i].getTicks()[j-1], w.height() - xAxisSpace, plotAreaTop);
if(yCoordTop > yCoordBot) {
auto buf = yCoordBot;
yCoordBot = yCoordTop;
@ -925,26 +935,51 @@ void TraceXYPlot::updateAxisTicks()
}
if(max >= min) {
auto range = max - min;
if(range == 0.0) {
// this could happen if all values in a trace are identical (e.g. imported ideal touchstone files)
if(max == 0.0) {
// simply use +/-1 range
max = 1.0;
min = -1.0;
} else {
// +/-5% around value
max += abs(max * 0.05);
min -= abs(max * 0.05);
if(yAxis[i].getLog()){
// log axis
double maxLog10 = log10(abs(max));
// prevent zero-crossing
if(min <= 0.0 && max > 0) {
min = pow(10, maxLog10 - 3); // just show 3 decades by default
} else if(min >= 0.0 && max < 0) {
// same thing if negative
min = -pow(10, maxLog10 - 3);
}
// add 5% visible range
double ratio = log10(max/min);
max *= pow(10, ratio * 0.05);
min /= pow(10, ratio * 0.05);
} else {
// add 5% of range at both ends
min -= range * 0.05;
max += range * 0.05;
// linear axis
if(range == 0.0) {
// this could happen if all values in a trace are identical (e.g. imported ideal touchstone files)
if(max == 0.0) {
// simply use +/-1 range
max = 1.0;
min = -1.0;
} else {
// +/-5% around value
max += abs(max * 0.05);
min -= abs(max * 0.05);
}
} else {
// add 5% of range at both ends
min -= range * 0.05;
max += range * 0.05;
}
}
} else {
// max/min still at default values, no valid samples are available for this axis, use default range
max = 1.0;
min = -1.0;
if(!yAxis[i].getLog()) {
// linear axis
max = 1.0;
min = -1.0;
} else {
// log axis
max = 100.0;
min = 0.1;
}
}
yAxis[i].set(yAxis[i].getType(), yAxis[i].getLog(), true, min, max, 0);
}