From 7b9dc1b9f0003900a0f7271b9207919e67090f29 Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Wed, 22 Jun 2022 16:44:35 -0700
Subject: [PATCH] Fix Eeschema Arc plotting

The start/end point plotting is not reliable for eeschema.  We need to
preconvert to angles to get the correct winding as the default plotter
conversion in the PLOTTER class makes pcbnew-based assumptions

Fixes https://gitlab.com/kicad/code/kicad/issues/11885
---
 common/plotters/plotter.cpp | 39 -------------------------------------
 eeschema/lib_shape.cpp      |  8 +++++++-
 eeschema/sch_shape.cpp      | 19 +++++++++++++++---
 3 files changed, 23 insertions(+), 43 deletions(-)

diff --git a/common/plotters/plotter.cpp b/common/plotters/plotter.cpp
index 658cd27581..b51236dbaa 100644
--- a/common/plotters/plotter.cpp
+++ b/common/plotters/plotter.cpp
@@ -154,44 +154,6 @@ void PLOTTER::Arc( const VECTOR2I& aCenter, const VECTOR2I& aStart, const VECTOR
     EDA_ANGLE endAngle( aEnd - aCenter );
     int       radius = ( aStart - aCenter ).EuclideanNorm();
 
-    #if 0
-    // Approximate arc by segments:
-    int       numSegs = GetArcToSegmentCount( radius, aMaxError, FULL_CIRCLE );
-    EDA_ANGLE delta = ANGLE_360 / std::max( 8, numSegs );
-    VECTOR2I  start( aStart );
-    VECTOR2I  end( aEnd );
-    VECTOR2I  pt;
-
-    if( startAngle > endAngle )
-    {
-        if( endAngle < ANGLE_0 )
-            endAngle.Normalize();
-        else
-            startAngle = startAngle.Normalize() - ANGLE_360;
-    }
-
-    SetCurrentLineWidth( aWidth );
-    MoveTo( start );
-
-    for( EDA_ANGLE ii = delta; startAngle + ii < endAngle; ii += delta )
-    {
-        pt = start;
-        RotatePoint( pt, aCenter, -ii );
-
-        LineTo( pt );
-    }
-
-    if( aFill == FILL_T::NO_FILL )
-    {
-        FinishTo( end );
-    }
-    else
-    {
-        LineTo( end );
-        FinishTo( aCenter );
-    }
-
-    #else
     if( startAngle > endAngle )
     {
         if( endAngle < ANGLE_0 )
@@ -208,7 +170,6 @@ void PLOTTER::Arc( const VECTOR2I& aCenter, const VECTOR2I& aStart, const VECTOR
     }
 
     Arc( aCenter, startAngle, endAngle, radius, aFill, aWidth );
-    #endif
 }
 
 
diff --git a/eeschema/lib_shape.cpp b/eeschema/lib_shape.cpp
index e12f536e7e..d43f873d5e 100644
--- a/eeschema/lib_shape.cpp
+++ b/eeschema/lib_shape.cpp
@@ -224,7 +224,13 @@ void LIB_SHAPE::Plot( PLOTTER* aPlotter, bool aBackground, const VECTOR2I& aOffs
     switch( GetShape() )
     {
     case SHAPE_T::ARC:
-        aPlotter->Arc( center, start, end, fill, penWidth, ARC_HIGH_DEF );
+    {
+        EDA_ANGLE t1, t2;
+
+        CalcArcAngles( t1, t2 );
+        aTransform.MapAngles( &t1, &t2 );
+        aPlotter->Arc( center, -t2, -t1, GetRadius(), fill, penWidth );
+    }
         break;
 
     case SHAPE_T::CIRCLE:
diff --git a/eeschema/sch_shape.cpp b/eeschema/sch_shape.cpp
index c1a729cf7f..c818acffdd 100644
--- a/eeschema/sch_shape.cpp
+++ b/eeschema/sch_shape.cpp
@@ -137,7 +137,14 @@ void SCH_SHAPE::Plot( PLOTTER* aPlotter, bool aBackground ) const
             switch( GetShape() )
             {
             case SHAPE_T::ARC:
-                aPlotter->Arc( getCenter(), GetStart(), GetEnd(), m_fill, 0, ARC_HIGH_DEF );
+            {
+                EDA_ANGLE start;
+                EDA_ANGLE end;
+                CalcArcAngles( start, end );
+
+                aPlotter->Arc( getCenter(), -end, -start, GetRadius(), m_fill, 0 );
+            }
+
                 break;
 
             case SHAPE_T::CIRCLE:
@@ -174,8 +181,14 @@ void SCH_SHAPE::Plot( PLOTTER* aPlotter, bool aBackground ) const
         switch( GetShape() )
         {
         case SHAPE_T::ARC:
-            aPlotter->Arc( getCenter(), GetStart(), GetEnd(), FILL_T::NO_FILL, pen_size,
-                           ARC_HIGH_DEF );
+        {
+            EDA_ANGLE start;
+            EDA_ANGLE end;
+            CalcArcAngles( start, end );
+
+            aPlotter->Arc( getCenter(), -end, -start, GetRadius(), FILL_T::NO_FILL, pen_size );
+        }
+
             break;
 
         case SHAPE_T::CIRCLE: