From 38b7cbbd004ef7268a1c39114d8503906361c1f7 Mon Sep 17 00:00:00 2001
From: Tamito Kajiyama <rd6t-kjym@asahi-net.or.jp>
Date: Sun, 4 Jul 2010 23:08:37 +0000
Subject: =?UTF-8?q?Bug=20fixes=20from=20St=C3=A9phane=20Grabli,=20one=20of?=
 =?UTF-8?q?=20the=20coauthors=20of=20the=20original=20Freestyle:?=
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* Fix for making the stroke construction more robust to nearly
overlapping vertices.

* Fix for a bug in the computation of the occluded surfaces.

These changes make the visibility computation more robust and
the line quality generally higher.
---
 .../blender/freestyle/intern/stroke/Operators.cpp  | 30 +++++++++++++++++-----
 .../blender/freestyle/intern/stroke/StrokeRep.cpp  |  9 ++++++-
 .../freestyle/intern/view_map/Functions0D.cpp      | 21 +++++++--------
 .../freestyle/intern/view_map/ViewMapBuilder.cpp   |  6 ++---
 4 files changed, 42 insertions(+), 24 deletions(-)

(limited to 'source/blender/freestyle/intern')

diff --git a/source/blender/freestyle/intern/stroke/Operators.cpp b/source/blender/freestyle/intern/stroke/Operators.cpp
index ef1b2662998..ea996c67785 100755
--- a/source/blender/freestyle/intern/stroke/Operators.cpp
+++ b/source/blender/freestyle/intern/stroke/Operators.cpp
@@ -938,10 +938,18 @@ Stroke* createStroke(Interface1D& inter) {
       stroke_vertex = new StrokeVertex(cp);
     current = stroke_vertex->point2d();
     Vec3r vec_tmp(current - previous);
-    currentCurvilignAbscissa += vec_tmp.norm();
-    stroke_vertex->setCurvilinearAbscissa(currentCurvilignAbscissa);
-    stroke->push_back(stroke_vertex);
-    previous = current;
+    real vec_tmp_norm = vec_tmp.norm();
+    if((stroke->strokeVerticesSize() > 0) && (vec_tmp_norm < 1.e-06)){
+      // The point we just created is superimposed with the 
+      // previous one. We remove it to avoid having to deal
+      // with this kind of singularities in the strip creation
+      delete stroke_vertex;
+    }else{
+      currentCurvilignAbscissa += vec_tmp.norm();
+      stroke_vertex->setCurvilinearAbscissa(currentCurvilignAbscissa);
+      stroke->push_back(stroke_vertex);
+      previous = current;
+    }
     ++it;
   } while((it != itend) && (it != itfirst));
 
@@ -959,9 +967,17 @@ Stroke* createStroke(Interface1D& inter) {
       stroke_vertex = new StrokeVertex(cp);
     current = stroke_vertex->point2d();
     Vec3r vec_tmp(current - previous);
-    currentCurvilignAbscissa += vec_tmp.norm();
-    stroke_vertex->setCurvilinearAbscissa(currentCurvilignAbscissa);
-    stroke->push_back(stroke_vertex);
+    real vec_tmp_norm = vec_tmp.norm();
+    if((stroke->strokeVerticesSize() > 0) && (vec_tmp_norm < 1.e-06)){
+      // The point we just created is superimposed with the 
+      // previous one. We remove it to avoid having to deal
+      // with this kind of singularities in the strip creation
+      delete stroke_vertex;
+    }else{
+      currentCurvilignAbscissa += vec_tmp.norm();
+      stroke_vertex->setCurvilinearAbscissa(currentCurvilignAbscissa);
+      stroke->push_back(stroke_vertex);
+    }
   }
   stroke->setLength(currentCurvilignAbscissa);
   return stroke;
diff --git a/source/blender/freestyle/intern/stroke/StrokeRep.cpp b/source/blender/freestyle/intern/stroke/StrokeRep.cpp
index fbe1273bac0..6ae15c71833 100755
--- a/source/blender/freestyle/intern/stroke/StrokeRep.cpp
+++ b/source/blender/freestyle/intern/stroke/StrokeRep.cpp
@@ -254,7 +254,14 @@ Strip::createStrip (const vector<StrokeVertex*>& iStrokeVertices)
       else 
         _vertices.push_back(new StrokeVertexRep(p-thickness[0]*stripDir));
       ++i;
-		
+
+      if((stripDir+stripDirPrev).norm() <= 1.e-06){
+        // the strip is most likely doing a U-turn, we can't compute the average vector.
+        // We just continue and hope it's ok
+        vPrev = v;
+        continue;
+      }
+      
       // if the angle is obtuse, we simply average the directions to avoid the singularity
       stripDir=stripDir+stripDirPrev;
       if ((dirNorm<ZERO) || (dirPrevNorm<ZERO) || (stripDir.norm() < ZERO)) {
diff --git a/source/blender/freestyle/intern/view_map/Functions0D.cpp b/source/blender/freestyle/intern/view_map/Functions0D.cpp
index b28ac575d00..dc38ca34184 100755
--- a/source/blender/freestyle/intern/view_map/Functions0D.cpp
+++ b/source/blender/freestyle/intern/view_map/Functions0D.cpp
@@ -38,16 +38,9 @@ namespace Functions0D {
     Interface0DIterator prev = it, next = it;
     ++next;
     int count = 1;
-    while((!prev.isBegin()) && (count < 3))
-      { 
-        --prev;
-        ++count;
-      }
-    while((!next.isEnd()) && (count < 3))
-      {
-        ++next;
-        ++count;
-      } 
+    if (!it.isBegin() && !next.isEnd()) {
+      count = 3;
+    } 
     if(count < 3)
       {
         // if we only have 2 vertices
@@ -296,9 +289,13 @@ namespace Functions0D {
   int MaterialF0D::operator()(Interface0DIterator& iter) {
     FEdge *fe1, *fe2;
     getFEdges(iter,fe1,fe2);
-    
-    if(fe1 == 0)
+
+    if(fe1 == 0) {
+      // DEBUG
       getFEdges(iter, fe1, fe2);
+      return 1;
+    }
+
     if(fe1->isSmooth())
       result = ((FEdgeSmooth*)fe1)->frs_material();
     else
diff --git a/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp b/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp
index b010895a621..dbd046f050a 100755
--- a/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp
+++ b/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp
@@ -241,8 +241,7 @@ void ViewMapBuilder::ComputeRayCastingVisibility(ViewMap *ioViewMap, Grid* iGrid
 	  maxIndex = tmpQI;
 	}
       }
-      else
-	FindOccludee(fe, iGrid, epsilon, &aFace, timestamp++);
+      FindOccludee(fe, iGrid, epsilon, &aFace, timestamp++);
 
       if(aFace) { 
 	fe->setaFace(*aFace);
@@ -361,8 +360,7 @@ void ViewMapBuilder::ComputeFastRayCastingVisibility(ViewMap *ioViewMap, Grid* i
 	    maxIndex = tmpQI;
 	  }
 	}
-	else
-	  FindOccludee(fe, iGrid, epsilon, &aFace, timestamp++);
+        FindOccludee(fe, iGrid, epsilon, &aFace, timestamp++);
 
         if(aFace)
         { 
-- 
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