From 54710608d6bcc8f5fcac66dd75abc1e6ad0a0f25 Mon Sep 17 00:00:00 2001
From: Roman Telezhynskyi <dismine@gmail.com>
Date: Thu, 26 Aug 2021 08:50:11 +0300
Subject: [PATCH] Better piece flipping.

---
 src/app/puzzle/layout/vppiece.cpp | 16 ++++++++++++++++
 src/app/puzzle/layout/vppiece.h   |  5 +++++
 src/app/puzzle/vpmainwindow.cpp   |  9 ++++++---
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/app/puzzle/layout/vppiece.cpp b/src/app/puzzle/layout/vppiece.cpp
index 2d925c461..c1147f75e 100644
--- a/src/app/puzzle/layout/vppiece.cpp
+++ b/src/app/puzzle/layout/vppiece.cpp
@@ -243,3 +243,19 @@ void VPPiece::SetPatternLabelData(const VTextManager &data)
 {
     VLayoutPiece::SetPatternLabelData(data);
 }
+
+//---------------------------------------------------------------------------------------------------------------------
+void VPPiece::Flip()
+{
+    QTransform pieceMatrix = GetMatrix();
+    QPointF center = pieceMatrix.map(DetailBoundingRect().center());
+
+    QTransform m;
+    m.translate(center.x(), 0);
+    m.scale(-1, 1);
+    m.translate(-center.x(), 0);
+
+    pieceMatrix *= m;
+    SetMatrix(pieceMatrix);
+    SetMirror(!IsMirror());
+}
diff --git a/src/app/puzzle/layout/vppiece.h b/src/app/puzzle/layout/vppiece.h
index 58768e5a8..d1825b754 100644
--- a/src/app/puzzle/layout/vppiece.h
+++ b/src/app/puzzle/layout/vppiece.h
@@ -101,6 +101,11 @@ public:
     auto GetPatternLabelData() const ->VTextManager;
     void SetPatternLabelData(const VTextManager &data);
 
+    /**
+     * @brief Flip horizontally mirror around center of bounding rect
+     */
+    void Flip();
+
 private:
     Q_DISABLE_COPY(VPPiece)
 
diff --git a/src/app/puzzle/vpmainwindow.cpp b/src/app/puzzle/vpmainwindow.cpp
index d2c4a9d75..fd9388dd2 100644
--- a/src/app/puzzle/vpmainwindow.cpp
+++ b/src/app/puzzle/vpmainwindow.cpp
@@ -570,9 +570,12 @@ void VPMainWindow::InitPropertyTabCurrentPiece()
             VPPiecePtr selectedPiece = selectedPieces.first();
             if (not selectedPiece.isNull())
             {
-                selectedPiece->SetMirror(checked);
-                LayoutWasSaved(false);
-                emit m_layout->PieceTransformationChanged(selectedPiece);
+                if (selectedPiece->IsMirror() != checked)
+                {
+                    selectedPiece->Flip();
+                    LayoutWasSaved(false);
+                    emit m_layout->PieceTransformationChanged(selectedPiece);
+                }
             }
         }
     });