eeschema: fix a readability issue for small texts.

Texts were drawn with a minimal line thickness = GetDefaultPenWidth().
The default pen width can be to large for small texts.
So the actual text thickness is now always clamped.

common/eda_text.cpp

@@ -149,15 +149,19 @@ void EDA_TEXT::SwapEffects( EDA_TEXT& aTradingPartner )
 }
 
 
-int EDA_TEXT::GetEffectiveTextPenWidth() const
+int EDA_TEXT::GetEffectiveTextPenWidth( int aDefaultWidth ) const
 {
     int width = GetTextThickness();
 
-    if( width <= 0 )
+    if( width <= 1 )
     {
+        width = aDefaultWidth;
+
         if( IsBold() )
             width = GetPenSizeForBold( GetTextWidth() );
-        else
+
+        // Avoid using a 0 width for text: it can create issues when drawing it
+        if( width <= 1 )
             width = 1;
     }
 

eeschema/sch_field.cpp

@@ -146,7 +146,7 @@ void SCH_FIELD::Print( RENDER_SETTINGS* aSettings, const wxPoint& aOffset )
     COLOR4D  color = aSettings->GetLayerColor( IsForceVisible() ? LAYER_HIDDEN : m_Layer );
     int      orient;
     wxPoint  textpos;
-    int      penWidth = std::max( GetEffectiveTextPenWidth(), aSettings->GetDefaultPenWidth() );
+    int      penWidth = GetEffectiveTextPenWidth( aSettings->GetDefaultPenWidth() );
 
     if( ( !IsVisible() && !IsForceVisible() ) || IsVoid() )
         return;
@@ -483,8 +483,8 @@ bool SCH_FIELD::HitTest( const EDA_RECT& aRect, bool aContained, int aAccuracy )
 void SCH_FIELD::Plot( PLOTTER* aPlotter )
 {
     COLOR4D color = aPlotter->RenderSettings()->GetLayerColor( GetLayer() );
-    int     penWidth = std::max( GetEffectiveTextPenWidth(),
-                                 aPlotter->RenderSettings()->GetDefaultPenWidth() );
+    int     penWidth = GetEffectiveTextPenWidth(
+                            aPlotter->RenderSettings()->GetDefaultPenWidth() );
 
     if( !IsVisible() )
         return;

eeschema/sch_painter.cpp

@@ -325,8 +325,7 @@ float SCH_PAINTER::getLineWidth( const SCH_ITEM* aItem, bool aDrawingShadows )
 
 float SCH_PAINTER::getTextThickness( const SCH_TEXT* aItem, bool aDrawingShadows )
 {
-    float width = (float) std::max( aItem->GetEffectiveTextPenWidth(),
-                                    m_schSettings.GetDefaultPenWidth() );
+    float width = (float) aItem->GetEffectiveTextPenWidth( m_schSettings.GetDefaultPenWidth() );
 
     if( aItem->IsSelected() && aDrawingShadows )
         width += getShadowWidth();
@@ -337,8 +336,7 @@ float SCH_PAINTER::getTextThickness( const SCH_TEXT* aItem, bool aDrawingShadows
 
 float SCH_PAINTER::getTextThickness( const SCH_FIELD* aItem, bool aDrawingShadows )
 {
-    float width = (float) std::max( aItem->GetEffectiveTextPenWidth(),
-                                    m_schSettings.GetDefaultPenWidth() );
+    float width = (float) aItem->GetEffectiveTextPenWidth( m_schSettings.GetDefaultPenWidth() );
 
     if( aItem->IsSelected() && aDrawingShadows )
         width += getShadowWidth();

eeschema/sch_text.cpp

@@ -592,8 +592,7 @@ void SCH_TEXT::Plot( PLOTTER* aPlotter )
 {
     static std::vector<wxPoint> Poly;
     COLOR4D color = aPlotter->RenderSettings()->GetLayerColor( GetLayer() );
-    int penWidth = std::max( GetEffectiveTextPenWidth(),
-                             aPlotter->RenderSettings()->GetDefaultPenWidth() );
+    int penWidth = GetEffectiveTextPenWidth( aPlotter->RenderSettings()->GetDefaultPenWidth() );
 
     aPlotter->SetCurrentLineWidth( penWidth );
 

include/eda_text.h

@@ -156,7 +156,12 @@ public:
      */
     void SetTextThickness( int aWidth ) { m_e.penwidth = aWidth; };
     int GetTextThickness() const { return m_e.penwidth; };
-    int GetEffectiveTextPenWidth() const;
+
+    /**
+     * The EffectiveTextPenWidth uses the text thickness if > 1 or
+     * aDefaultWidth.
+     */
+    int GetEffectiveTextPenWidth( int aDefaultWidth = 0 ) const;
 
     virtual void SetTextAngle( double aAngle )
     {