From 482ca1036382c715bc041567bbcae58a4cdd37ad Mon Sep 17 00:00:00 2001
From: Gabriel Ozouf <gabriel.ozouf@numworks.com>
Date: Wed, 14 Oct 2020 10:24:47 +0200
Subject: [PATCH] [poincare/zoom] Improve null range

When displaying f(x) = undef, the range now defaults to an orthonormal
range, centered on the origin, with axis unit 1.

Change-Id: Ie3515be0572af4849b8ebd113449f4444755b34f
---
 poincare/src/zoom.cpp | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/poincare/src/zoom.cpp b/poincare/src/zoom.cpp
index 0744ed605..83430c660 100644
--- a/poincare/src/zoom.cpp
+++ b/poincare/src/zoom.cpp
@@ -184,11 +184,16 @@ void Zoom::RefinedYRangeForDisplay(ValueAtAbscissa evaluation, float xMin, float
    * its average order of magnitude. Then, bound is the value for the next
    * order of magnitude and is used to cut the Y range. */
 
-  float bound = (pop > 0) ? std::exp(sum / pop + 1.f) : FLT_MAX;
-  sampleYMin = std::max(sampleYMin, - bound);
-  sampleYMax = std::min(sampleYMax, bound);
-  *yMin = sampleYMin;
-  *yMax = sampleYMax;
+  if (pop == 0) {
+    *yMin = 0;
+    *yMax = 0;
+  } else {
+    float bound = std::exp(sum / pop + 1.f);
+    sampleYMin = std::max(sampleYMin, - bound);
+    sampleYMax = std::min(sampleYMax, bound);
+    *yMin = sampleYMin;
+    *yMax = sampleYMax;
+  }
   if (*yMin == *yMax) {
     RangeFromSingleValue(*yMin, yMin, yMax);
   }