+ assert(scale > 0);
+ assert(_data);
+ assert(right >= left);
+
+ paint_axis(p, y, left, right);
+
+ const deque< shared_ptr<pv::data::AnalogSnapshot> > &snapshots =
+ _data->get_snapshots();
+ if (snapshots.empty())
+ return;
+
+ const shared_ptr<pv::data::AnalogSnapshot> &snapshot =
+ snapshots.front();
+
+ const double pixels_offset = offset / scale;
+ const double samplerate = _data->get_samplerate();
+ const double start_time = _data->get_start_time();
+ const int64_t last_sample = snapshot->get_sample_count() - 1;
+ const double samples_per_pixel = samplerate * scale;
+ const double start = samplerate * (offset - start_time);
+ const double end = start + samples_per_pixel * (right - left);
+
+ const int64_t start_sample = min(max((int64_t)floor(start),
+ (int64_t)0), last_sample);
+ const int64_t end_sample = min(max((int64_t)ceil(end) + 1,
+ (int64_t)0), last_sample);
+
+ if (samples_per_pixel < EnvelopeThreshold)
+ paint_trace(p, snapshot, y, left,
+ start_sample, end_sample,
+ pixels_offset, samples_per_pixel);
+ else
+ paint_envelope(p, snapshot, y, left,
+ start_sample, end_sample,
+ pixels_offset, samples_per_pixel);
+}
+
+void AnalogSignal::paint_trace(QPainter &p,
+ const shared_ptr<pv::data::AnalogSnapshot> &snapshot,
+ int y, int left, const int64_t start, const int64_t end,
+ const double pixels_offset, const double samples_per_pixel)
+{
+ const int64_t sample_count = end - start;
+
+ const float *const samples = snapshot->get_samples(start, end);
+ assert(samples);
+
+ p.setPen(_colour);
+
+ QPointF *points = new QPointF[sample_count];
+ QPointF *point = points;
+
+ for (int64_t sample = start; sample != end; sample++) {
+ const float x = (sample / samples_per_pixel -
+ pixels_offset) + left;
+ *point++ = QPointF(x,
+ y - samples[sample - start] * _scale);
+ }
+
+ p.drawPolyline(points, point - points);
+
+ delete[] samples;
+ delete[] points;