From c24985e8cf2a6a3276fceae079d5d66599b658ef Mon Sep 17 00:00:00 2001
From: jean-pierre charras <jp.charras@wanadoo.fr>
Date: Mon, 10 Jan 2022 11:31:29 +0100
Subject: [PATCH] drc_test_provider_sliver_checker.cpp: skip very small
vertices when testing. Very small vertices (length <= 2 or 3 iu) are frequent
in filled areas, and create false positive detections because one cannot
calculate a meaningful orientation of these vertices.
---
.../drc/drc_test_provider_sliver_checker.cpp | 28 +++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)
diff --git a/pcbnew/drc/drc_test_provider_sliver_checker.cpp b/pcbnew/drc/drc_test_provider_sliver_checker.cpp
index 976c9e57ca..94e7129783 100644
--- a/pcbnew/drc/drc_test_provider_sliver_checker.cpp
+++ b/pcbnew/drc/drc_test_provider_sliver_checker.cpp
@@ -132,6 +132,13 @@ bool DRC_TEST_PROVIDER_SLIVER_CHECKER::Run()
// Sharpen corners
poly.Deflate( widthTolerance / 2, ARC_LOW_DEF, SHAPE_POLY_SET::CHAMFER_ACUTE_CORNERS );
+ // Frequently, in filled areas, some points of the polygons are very near (dist is only
+ // a few internal units, like 2 or 3 units.
+ // We skip very small vertices: one cannot really compute a valid orientation of
+ // such a vertex
+ // So skip points near than min_len (in internal units).
+ const int min_len = 3;
+
for( int jj = 0; jj < poly.OutlineCount(); ++jj )
{
const std::vector<VECTOR2I>& pts = poly.Outline( jj ).CPoints();
@@ -141,10 +148,27 @@ bool DRC_TEST_PROVIDER_SLIVER_CHECKER::Run()
{
VECTOR2I pt = pts[ kk ];
VECTOR2I ptBefore = pts[ ( ptCount + kk - 1 ) % ptCount ];
- VECTOR2I ptAfter = pts[ ( kk + 1 ) % ptCount ];
-
VECTOR2I vBefore = ( ptBefore - pt );
+
+ if( std::abs( vBefore.x ) < min_len
+ && std::abs( vBefore.y ) < min_len
+ && ptCount > 5)
+ {
+ ptBefore = pts[ ( ptCount + kk - 2 ) % ptCount ];
+ vBefore = ( ptBefore - pt );
+ }
+
+ VECTOR2I ptAfter = pts[ ( kk + 1 ) % ptCount ];
VECTOR2I vAfter = ( ptAfter - pt );
+
+ if( std::abs( vAfter.x ) < min_len
+ && std::abs( vAfter.y ) < min_len
+ && ptCount > 5 )
+ {
+ ptAfter = pts[ ( kk + 2 ) % ptCount ];
+ vAfter = ( ptAfter - pt );
+ }
+
VECTOR2I vIncluded = vBefore.Resize( testLength ) - vAfter.Resize( testLength );
if( vIncluded.SquaredEuclideanNorm() < SEG::Square( widthTolerance ) )