From 0dae43e4bc68fb3fce2a5c6d41ba7030c7d542a5 Mon Sep 17 00:00:00 2001
From: bubnikv <bubnikv@gmail.com>
Date: Fri, 24 Mar 2017 09:32:30 +0100
Subject: [PATCH] Bugfix: when the Voronoi diagram contained very large
coordinates we need to check whether they are greater than our allowed range
and consider the Voronoi edges infinite in those cases, in order to prevent
overflows. https://github.com/alexrj/Slic3r/issues/3776
https://github.com/alexrj/Slic3r/commit/9ad1360e445cd3043c4dc30ccad64b82b914f952
---
xs/src/libslic3r/ClipperUtils.cpp | 9 ---------
xs/src/libslic3r/ClipperUtils.hpp | 10 ++++++++++
xs/src/libslic3r/Geometry.cpp | 7 +++++++
3 files changed, 17 insertions(+), 9 deletions(-)
diff --git a/xs/src/libslic3r/ClipperUtils.cpp b/xs/src/libslic3r/ClipperUtils.cpp
index 660b687e0..8aa72cae4 100644
--- a/xs/src/libslic3r/ClipperUtils.cpp
+++ b/xs/src/libslic3r/ClipperUtils.cpp
@@ -9,15 +9,6 @@
#include <Shiny/Shiny.h>
-// Factor to convert from coord_t (which is int32) to an int64 type used by the Clipper library
-// for general offsetting (the offset(), offset2(), offset_ex() functions) and for the safety offset,
-// which is optionally executed by other functions (union, intersection, diff).
-// By the way, is the scalling for offset needed at all?
-#define CLIPPER_OFFSET_POWER_OF_2 17
-// 2^17=131072
-#define CLIPPER_OFFSET_SCALE (1 << CLIPPER_OFFSET_POWER_OF_2)
-#define CLIPPER_OFFSET_SCALE_ROUNDING_DELTA ((1 << (CLIPPER_OFFSET_POWER_OF_2 - 1)) - 1)
-
namespace Slic3r {
#ifdef CLIPPER_UTILS_DEBUG
diff --git a/xs/src/libslic3r/ClipperUtils.hpp b/xs/src/libslic3r/ClipperUtils.hpp
index d6060386a..b14232d90 100644
--- a/xs/src/libslic3r/ClipperUtils.hpp
+++ b/xs/src/libslic3r/ClipperUtils.hpp
@@ -12,6 +12,16 @@ using ClipperLib::jtMiter;
using ClipperLib::jtRound;
using ClipperLib::jtSquare;
+// Factor to convert from coord_t (which is int32) to an int64 type used by the Clipper library
+// for general offsetting (the offset(), offset2(), offset_ex() functions) and for the safety offset,
+// which is optionally executed by other functions (union, intersection, diff).
+// By the way, is the scalling for offset needed at all?
+#define CLIPPER_OFFSET_POWER_OF_2 17
+// 2^17=131072
+#define CLIPPER_OFFSET_SCALE (1 << CLIPPER_OFFSET_POWER_OF_2)
+#define CLIPPER_OFFSET_SCALE_ROUNDING_DELTA ((1 << (CLIPPER_OFFSET_POWER_OF_2 - 1)) - 1)
+#define CLIPPER_MAX_COORD_UNSCALED (ClipperLib::hiRange / CLIPPER_OFFSET_SCALE)
+
namespace Slic3r {
//-----------------------------------------------------------
diff --git a/xs/src/libslic3r/Geometry.cpp b/xs/src/libslic3r/Geometry.cpp
index 314990734..96613549a 100644
--- a/xs/src/libslic3r/Geometry.cpp
+++ b/xs/src/libslic3r/Geometry.cpp
@@ -983,6 +983,13 @@ MedialAxis::process_edge_neighbors(const VD::edge_type* edge, ThickPolyline* pol
bool
MedialAxis::validate_edge(const VD::edge_type* edge)
{
+ // prevent overflows and detect almost-infinite edges
+ if (std::abs(edge->vertex0()->x()) > double(CLIPPER_MAX_COORD_UNSCALED) ||
+ std::abs(edge->vertex0()->y()) > double(CLIPPER_MAX_COORD_UNSCALED) ||
+ std::abs(edge->vertex1()->x()) > double(CLIPPER_MAX_COORD_UNSCALED) ||
+ std::abs(edge->vertex1()->y()) > double(CLIPPER_MAX_COORD_UNSCALED))
+ return false;
+
// construct the line representing this edge of the Voronoi diagram
const Line line(
Point( edge->vertex0()->x(), edge->vertex0()->y() ),