From 82c4fe2190819dcdf19e793f496c90374357c70c Mon Sep 17 00:00:00 2001
From: Gabriel Ozouf <gabriel.ozouf@numworks.com>
Date: Mon, 19 Oct 2020 17:33:57 +0200
Subject: [PATCH] [poincare/zoom] Limit explosion detection

Do not take strong variations into account if they would erase more
interesting variations.

Change-Id: I6299a64bed449a611f90eda4234af10a183958d1
---
 poincare/src/zoom.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/poincare/src/zoom.cpp b/poincare/src/zoom.cpp
index a649ed368..b9683b6f2 100644
--- a/poincare/src/zoom.cpp
+++ b/poincare/src/zoom.cpp
@@ -152,8 +152,12 @@ bool Zoom::InterestingRangesForDisplay(ValueAtAbscissa evaluation, float * xMin,
     *yMax = NAN;
     return false;
   } else {
-    resultX[0] = std::min(resultX[0], explosion[0]);
-    resultX[1] = std::max(resultX[1], explosion[1]);
+    float xMinWithExplosion = std::min(resultX[0], explosion[0]);
+    float xMaxWithExplosion = std::max(resultX[1], explosion[1]);
+    if (xMaxWithExplosion - xMinWithExplosion < k_maxRatioBetweenPointsOfInterest * (resultX[1] - resultX[0])) {
+      resultX[0] = xMinWithExplosion;
+      resultX[1] = xMaxWithExplosion;
+    }
     /* Add breathing room around points of interest. */
     float xRange = resultX[1] - resultX[0];
     resultX[0] -= k_breathingRoom * xRange;