From 4847d5cab3835ed189071a0b955ebebbb13cdb5f Mon Sep 17 00:00:00 2001
From: Abdullah Tahiri <abdullah.tahiri.yo@gmail.com>
Date: Sat, 25 Sep 2021 21:58:14 +0200
Subject: [PATCH] Sketcher: Rectangular Array Snap mode

=====================================

Rectangular Array gets a snap mode every 10 degrees when pressing CTRL (for consistency with Multiline arc, which also snaps using CTRL).

Request:
https://forum.freecadweb.org/viewtopic.php?p=535691#p535691
---
 src/Mod/Sketcher/Gui/CommandSketcherTools.cpp | 30 +++++++++++++++----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/src/Mod/Sketcher/Gui/CommandSketcherTools.cpp b/src/Mod/Sketcher/Gui/CommandSketcherTools.cpp
index 7432a0e58d..e73688ccc6 100644
--- a/src/Mod/Sketcher/Gui/CommandSketcherTools.cpp
+++ b/src/Mod/Sketcher/Gui/CommandSketcherTools.cpp
@@ -1801,6 +1801,7 @@ public:
                                       int rows, int cols, bool constraintSeparation,
                                       bool equalVerticalHorizontalSpacing)
         : Mode(STATUS_SEEK_First)
+        , snapMode(SnapMode::Free)
         , geoIdList(geoidlist)
         , OriginGeoId(origingeoid)
         , OriginPos(originpos)
@@ -1821,6 +1822,11 @@ public:
         STATUS_End
     };
 
+    enum class SnapMode {
+        Free,
+        Snap10Degree
+    };
+
     virtual void activated(ViewProviderSketch *sketchgui)
     {
         setCursor(QPixmap(cursor_createrectangulararray), 7, 7);
@@ -1831,15 +1837,29 @@ public:
     virtual void mouseMove(Base::Vector2d onSketchPos)
     {
         if (Mode==STATUS_SEEK_First) {
+
+            if(QApplication::keyboardModifiers() == Qt::ControlModifier)
+                    snapMode = SnapMode::Snap10Degree;
+                else
+                    snapMode = SnapMode::Free;
+
             float length = (onSketchPos - EditCurve[0]).Length();
             float angle = (onSketchPos - EditCurve[0]).GetAngle(Base::Vector2d(1.f, 0.f));
+
+            Base::Vector2d endpoint = onSketchPos;
+
+            if (snapMode == SnapMode::Snap10Degree) {
+                angle = round(angle / (M_PI/18)) * M_PI/18;
+                endpoint = EditCurve[0] + length * Base::Vector2d(cos(angle),sin(angle));
+            }
+
             SbString text;
             text.sprintf(" (%.1f, %.1fdeg)", length, angle * 180 / M_PI);
-            setPositionText(onSketchPos, text);
+            setPositionText(endpoint, text);
 
-            EditCurve[1] = onSketchPos;
+            EditCurve[1] = endpoint;
             sketchgui->drawEdit(EditCurve);
-            if (seekAutoConstraint(sugConstr1, onSketchPos, Base::Vector2d(0.0, 0.0), AutoConstraint::VERTEX))
+            if (seekAutoConstraint(sugConstr1, endpoint, Base::Vector2d(0.0, 0.0), AutoConstraint::VERTEX))
             {
                 renderSuggestConstraintsCursor(sugConstr1);
                 return;
@@ -1849,10 +1869,9 @@ public:
         applyCursor();
     }
 
-    virtual bool pressButton(Base::Vector2d onSketchPos)
+    virtual bool pressButton(Base::Vector2d)
     {
         if (Mode == STATUS_SEEK_First) {
-            EditCurve[1] = onSketchPos;
             sketchgui->drawEdit(EditCurve);
             Mode = STATUS_End;
         }
@@ -1901,6 +1920,7 @@ public:
     }
 protected:
     SelectMode Mode;
+    SnapMode snapMode;
     string geoIdList;
     Base::Vector3d Origin;
     int OriginGeoId;