From 267907e5bac9e134184d0d62654d6bc3698aeeae Mon Sep 17 00:00:00 2001
From: tamasmeszaros <meszaros.q@gmail.com>
Date: Thu, 8 Oct 2020 10:00:39 +0200
Subject: [PATCH] SLA: Fix for crash with only 1 layer

fixes #4836
---
 src/libslic3r/SLAPrintSteps.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/libslic3r/SLAPrintSteps.cpp b/src/libslic3r/SLAPrintSteps.cpp
index d94bc682b..11c8c6f4e 100644
--- a/src/libslic3r/SLAPrintSteps.cpp
+++ b/src/libslic3r/SLAPrintSteps.cpp
@@ -93,9 +93,10 @@ void SLAPrint::Steps::apply_printer_corrections(SLAPrintObject &po, SliceOrigin
     coord_t clpr_offs = scaled(doffs);
     
     faded_lyrs = std::min(po.m_slice_index.size(), faded_lyrs);
+    size_t faded_lyrs_efc = std::max(size_t(1), faded_lyrs - 1);
     
-    auto efc = [start_efc, faded_lyrs](size_t pos) {
-        return (faded_lyrs - 1 - pos) * start_efc / (faded_lyrs - 1); 
+    auto efc = [start_efc, faded_lyrs_efc](size_t pos) {
+        return (faded_lyrs_efc - pos) * start_efc / faded_lyrs_efc;
     };
 
     std::vector<ExPolygons> &slices = o == soModel ?