From 423f22b51c15e18ff3e56b25232f4825707f1d8f Mon Sep 17 00:00:00 2001
From: Willem Melching <willem.melching@gmail.com>
Date: Sun, 29 Jan 2023 21:57:01 +0100
Subject: [PATCH] cabana: show dots when zoomed far into a signal (#27145)

* cabana: show dots when zoomed far into a signal

* review comments
old-commit-hash: f038193f4447afc8ae7b6034dec430d08f6da331
---
 tools/cabana/chartswidget.cc | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tools/cabana/chartswidget.cc b/tools/cabana/chartswidget.cc
index 26c05cf119..9f5b4acbd1 100644
--- a/tools/cabana/chartswidget.cc
+++ b/tools/cabana/chartswidget.cc
@@ -469,6 +469,18 @@ void ChartView::updatePlot(double cur, double min, double max) {
     axis_x->setRange(min, max);
     updateAxisY();
   }
+
+  // Show points when zoomed in enough
+  for (auto &s : sigs) {
+    auto begin = std::lower_bound(s.vals.begin(), s.vals.end(), axis_x->min(), [](auto &p, double x) { return p.x() < x; });
+    auto end = std::lower_bound(s.vals.begin(), s.vals.end(), axis_x->max(), [](auto &p, double x) { return p.x() < x; });
+
+    int num_points = std::max<int>(end - begin, 1);
+    int pixels_per_point = width() / num_points;
+
+    s.series->setPointsVisible(pixels_per_point > 20);
+  }
+
   scene()->invalidate({}, QGraphicsScene::ForegroundLayer);
 }