From 5811a330c784c49e64c65fdaa88d01bff444da56 Mon Sep 17 00:00:00 2001
From: akaftase <168822067+akaftase@users.noreply.github.com>
Date: Sun, 7 Jul 2024 19:54:35 +0100
Subject: [PATCH] 0033615: Modeling Algorithms - Partition algorithm creates
 unexpected vertices

This problem occurs because of obtaining 2 ALines which share same vertex on the seam edge.
There should be 2 different vertices with same(or almost the same) 3d parameters, but
with different UV parameters because of periodic surface.
Current fix allows to avoid the same vertices on seam edge and also checks the next vertex.
Added consideration of predicted next point to avoid skipping tha point which is not on seam edge.
Added test case for #33702
---
 src/IntPatch/IntPatch_ALineToWLine.cxx | 20 ++++++++++++++++++++
 tests/bugs/modalg_8/bug33615           | 22 ++++++++++++++++++++++
 tests/bugs/modalg_8/bug33702           | 12 ++++++++++++
 tests/lowalgos/intss/bug29807_i1002    |  2 +-
 tests/lowalgos/intss/bug29807_i5002    |  2 +-
 5 files changed, 56 insertions(+), 2 deletions(-)
 create mode 100644 tests/bugs/modalg_8/bug33615
 create mode 100644 tests/bugs/modalg_8/bug33702

diff --git a/src/IntPatch/IntPatch_ALineToWLine.cxx b/src/IntPatch/IntPatch_ALineToWLine.cxx
index 54f8f07453..80dea14330 100644
--- a/src/IntPatch/IntPatch_ALineToWLine.cxx
+++ b/src/IntPatch/IntPatch_ALineToWLine.cxx
@@ -647,6 +647,26 @@ void IntPatch_ALineToWLine::MakeWLine(const Handle(IntPatch_ALine)& theALine,
         {// Strictly equal!!!
           break;
         }
+        else if (aParameter + aStep < theLPar)
+        {
+          // Prediction of the next point 
+          gp_Pnt aPnt3dNext;
+          gp_Vec aTg;
+          theALine->D1(aParameter + aStep, aPnt3dNext, aTg);
+          Standard_Real anU1 = 0.0, aV1 = 0.0, anU2 = 0.0, aV2 = 0.0;
+          myQuad1.Parameters(aPnt3dNext, anU1, aV1);
+          myQuad2.Parameters(aPnt3dNext, anU2, aV2);
+          IntSurf_PntOn2S aPOn2SNext;
+          aPOn2SNext.SetValue(aPnt3dNext, anU1, aV1, anU2, aV2);
+
+          if (aPOn2SNext.ValueOnSurface(0).SquareDistance(aRPT.ValueOnSurface(0)) > M_PI * M_PI ||
+            aPOn2SNext.ValueOnSurface(1).SquareDistance(aRPT.ValueOnSurface(1)) > M_PI * M_PI)
+          {
+            aPrevLPoint = aRPT;
+            aPrevParam = aParameter;
+            continue;
+          }
+        }
       }
 
       aPrePointExist = IntPatch_SPntNone;
diff --git a/tests/bugs/modalg_8/bug33615 b/tests/bugs/modalg_8/bug33615
new file mode 100644
index 0000000000..ac756f907c
--- /dev/null
+++ b/tests/bugs/modalg_8/bug33615
@@ -0,0 +1,22 @@
+puts "================================"
+puts "0033615: Modeling Algorithms - Partition algorithm creates unexpected vertices"
+puts "================================"
+puts ""
+
+plane plane -5 0 4 -1 0 0
+pcone cone plane 3 1 10 
+pcylinder cylinder 10 20 
+explode cylinder f 
+explode cone f 
+
+don cylinder_1 cone_1 
+axo;fit 
+bclearobjects
+bcleartools
+baddobjects cone_1 
+baddtools cylinder_1 
+bfillds 
+bbuild result
+
+checknbshapes result -vertex 5 -edge 8 -wire 5 -face 4
+checkview -display result -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/bugs/modalg_8/bug33702 b/tests/bugs/modalg_8/bug33702
new file mode 100644
index 0000000000..831163cc5b
--- /dev/null
+++ b/tests/bugs/modalg_8/bug33702
@@ -0,0 +1,12 @@
+puts "================================"
+puts "0033702: Modeling Algorithms - Regression: Intersection curve is not built between cone and cylinder"
+puts "================================"
+puts ""
+
+restore [locate_data_file bug33702_ext.brep] ext 
+restore [locate_data_file bug33702_rev.brep] rev 
+
+bcut result ext rev
+
+checknbshapes result -vertex 51 -edge 75 -wire 42 -face 30
+checkview -display result -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/lowalgos/intss/bug29807_i1002 b/tests/lowalgos/intss/bug29807_i1002
index 1a4df76d3d..f0c73ccba0 100644
--- a/tests/lowalgos/intss/bug29807_i1002
+++ b/tests/lowalgos/intss/bug29807_i1002
@@ -17,7 +17,7 @@ fit
 
 regexp {Tolerance Reached=+([-0-9.+eE]+)\n+([-0-9.+eE]+)} [bopcurves b1_5 b2_2 -2d] full Toler NbCurv
 
-if { ${Toler} > 0.0004} {
+if { ${Toler} > 0.002} {
    puts "Error: bad tolerance of result"
 }
 
diff --git a/tests/lowalgos/intss/bug29807_i5002 b/tests/lowalgos/intss/bug29807_i5002
index e55dec57c8..74d6d1acf0 100644
--- a/tests/lowalgos/intss/bug29807_i5002
+++ b/tests/lowalgos/intss/bug29807_i5002
@@ -55,6 +55,6 @@ fit
 checksection result -r 0
 checkmaxtol result -min_tol 2.0e-7
 
-checknbshapes result -edge 3 -vertex 3
+checknbshapes result -edge 2 -vertex 2
 
 checkview -screenshot -2d -path ${imagedir}/${test_image}.png