From 7369d14b090cd816eb3a43e5db3c29b26ae26b42 Mon Sep 17 00:00:00 2001
From: Peter Hartmann <peter@edelhirsch.io>
Date: Tue, 24 Jan 2023 10:22:58 +0100
Subject: [PATCH] QskGraphic: Fix scale factors

We need to know the bounding rect of the graphic to know by how much
we can scale our shape, so we need to pass that to the scaling
methods.
E.g. when there are two shapes whose pen sizes overlap the path rect
left and right, we would calculate wrong scale factors without the
grapics' bounding rect.

Resolves #250
---
 src/graphic/QskGraphic.cpp | 38 +++++++++++++++++++++-----------------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/src/graphic/QskGraphic.cpp b/src/graphic/QskGraphic.cpp
index d2924e48..e7454038 100644
--- a/src/graphic/QskGraphic.cpp
+++ b/src/graphic/QskGraphic.cpp
@@ -257,18 +257,20 @@ namespace QskGraphicPrivate
         }
 
         inline double scaleFactorX( const QRectF& pathRect,
-            const QRectF& targetRect, bool scalePens ) const
+            const QRectF& targetRect, const QRectF& graphicBoundingRect, bool scalePens ) const
         {
             if ( pathRect.width() <= 0.0 )
                 return 0.0;
 
             const QPointF p0 = m_pointRect.center();
 
-            const qreal l = qAbs( pathRect.left() - p0.x() );
-            const qreal r = qAbs( pathRect.right() - p0.x() );
+            const auto p = pathRect.united( m_boundingRect );
+
+            const qreal l = qAbs( p.left() - p0.x() );
+            const qreal r = qAbs( p.right() - p0.x() );
 
             const double w = 2.0 * qMin( l, r ) *
-                targetRect.width() / pathRect.width();
+                targetRect.width() / graphicBoundingRect.width();
 
             double sx;
             if ( scalePens && m_scalablePen )
@@ -288,18 +290,20 @@ namespace QskGraphicPrivate
         }
 
         inline double scaleFactorY( const QRectF& pathRect,
-            const QRectF& targetRect, bool scalePens ) const
+            const QRectF& targetRect, const QRectF& graphicBoundingRect, bool scalePens ) const
         {
             if ( pathRect.height() <= 0.0 )
                 return 0.0;
 
             const QPointF p0 = m_pointRect.center();
 
-            const qreal t = qAbs( pathRect.top() - p0.y() );
-            const qreal b = qAbs( pathRect.bottom() - p0.y() );
+            const auto p = pathRect.united( m_boundingRect );
+
+            const qreal t = qAbs( p.top() - p0.y() );
+            const qreal b = qAbs( p.bottom() - p0.y() );
 
             const double h = 2.0 * qMin( t, b ) *
-                targetRect.height() / pathRect.height();
+                targetRect.height() / graphicBoundingRect.height();
 
             double sy;
             if ( scalePens && m_scalablePen )
@@ -680,14 +684,14 @@ void QskGraphic::render( QPainter* painter, const QRectF& rect,
 
     for ( const auto& info : qAsConst( m_data->pathInfos ) )
     {
-        const qreal ssx = info.scaleFactorX(
-            m_data->pointRect, rect, scalePens );
+        const qreal ssx = info.scaleFactorX( m_data->pointRect,
+            rect, m_data->boundingRect, scalePens );
 
         if ( ssx > 0.0 )
             sx = qMin( sx, ssx );
 
-        const qreal ssy = info.scaleFactorY(
-            m_data->pointRect, rect, scalePens );
+        const qreal ssy = info.scaleFactorY( m_data->pointRect,
+            rect, m_data->boundingRect, scalePens );
 
         if ( ssy > 0.0 )
             sy = qMin( sy, ssy );
@@ -702,15 +706,15 @@ void QskGraphic::render( QPainter* painter, const QRectF& rect,
         sx = sy = qMax( sx, sy );
     }
 
-    const auto& pr = m_data->pointRect;
+    const auto& br = m_data->boundingRect;
     const auto rc = rect.center();
 
     QTransform tr;
     tr.translate(
-        rc.x() - 0.5 * sx * pr.width(),
-        rc.y() - 0.5 * sy * pr.height() );
+        rc.x() - 0.5 * sx * br.width(),
+        rc.y() - 0.5 * sy * br.height() );
     tr.scale( sx, sy );
-    tr.translate( -pr.x(), -pr.y() );
+    tr.translate( -br.x(), -br.y() );
 
     const auto transform = painter->transform();
 
@@ -1079,7 +1083,7 @@ QskGraphic QskGraphic::fromGraphic(
     QPainter painter( &recoloredGraphic );
     graphic.render( &painter, colorFilter );
     painter.end();
-    
+
     return recoloredGraphic;
 }