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
9ad1360e44
This commit is contained in:
bubnikv 2017-03-24 09:32:30 +01:00
parent 6162670bbd
commit 0dae43e4bc
3 changed files with 17 additions and 9 deletions

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@ -9,15 +9,6 @@
#include <Shiny/Shiny.h> #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 { namespace Slic3r {
#ifdef CLIPPER_UTILS_DEBUG #ifdef CLIPPER_UTILS_DEBUG

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@ -12,6 +12,16 @@ using ClipperLib::jtMiter;
using ClipperLib::jtRound; using ClipperLib::jtRound;
using ClipperLib::jtSquare; 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 { namespace Slic3r {
//----------------------------------------------------------- //-----------------------------------------------------------

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@ -983,6 +983,13 @@ MedialAxis::process_edge_neighbors(const VD::edge_type* edge, ThickPolyline* pol
bool bool
MedialAxis::validate_edge(const VD::edge_type* edge) 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 // construct the line representing this edge of the Voronoi diagram
const Line line( const Line line(
Point( edge->vertex0()->x(), edge->vertex0()->y() ), Point( edge->vertex0()->x(), edge->vertex0()->y() ),