Add snap to grid in selection movement.

src/settings/settings.h

@@ -21,6 +21,7 @@
 
 #include "app/color.h"
 #include "filters/tiled_mode.h"
+#include "gfx/point.h"
 #include "gfx/rect.h"
 #include "raster/pen_type.h"
 
@@ -29,6 +30,11 @@ class IPenSettings;
 
 namespace tools { class Tool; }
 
+enum SnapBehavior {
+  NormalSnap = 0,
+  SnapInRightBottom = 1
+};
+
 // Settings used in tool <-> drawing <-> editor stuff
 class ISettings
 {
@@ -59,6 +65,8 @@ public:
   virtual void setGridBounds(const gfx::Rect& rect) = 0;
   virtual void setGridColor(const Color& color) = 0;
 
+  virtual void snapToGrid(gfx::Point& point, SnapBehavior snapBehavior) const = 0;
+
   // Pixel grid
 
   virtual bool getPixelGridVisible() = 0;

src/settings/ui_settings_impl.cpp

@@ -174,6 +174,23 @@ void UISettingsImpl::setGridColor(const Color& color)
   m_gridColor = color;
 }
 
+void UISettingsImpl::snapToGrid(gfx::Point& point, SnapBehavior snapBehavior) const
+{
+  register int w = m_gridBounds.w;
+  register int h = m_gridBounds.h;
+  int adjust = (snapBehavior & SnapInRightBottom ? 1: 0);
+  div_t d, dx, dy;
+
+  dx = div(m_gridBounds.x, w);
+  dy = div(m_gridBounds.y, h);
+
+  d = div(point.x-dx.rem, w);
+  point.x = dx.rem + d.quot*w + ((d.rem > w/2)? w-adjust: 0);
+
+  d = div(point.y-dy.rem, h);
+  point.y = dy.rem + d.quot*h + ((d.rem > h/2)? h-adjust: 0);
+}
+
 //////////////////////////////////////////////////////////////////////
 // Pixel grid
 

src/settings/ui_settings_impl.h

@@ -21,6 +21,7 @@
 
 #include <map>
 #include <string>
+#include "base/compiler_specific.h"
 #include "settings/settings.h"
 
 class UISettingsImpl : public ISettings
@@ -53,6 +54,8 @@ public:
   void setGridBounds(const gfx::Rect& rect);
   void setGridColor(const Color& color);
 
+  void snapToGrid(gfx::Point& point, SnapBehavior snapBehavior) const OVERRIDE;
+
   // Pixel grid
 
   bool getPixelGridVisible();

src/tools/tool_loop_manager.cpp

@@ -197,21 +197,8 @@ void ToolLoopManager::snapToGrid(bool flexible, Point& point)
       !m_toolLoop->getContext()->getSettings()->getSnapToGrid())
     return;
 
-  Rect grid(m_toolLoop->getContext()->getSettings()->getGridBounds());
-  register int w = grid.w;
-  register int h = grid.h;
-  div_t d, dx, dy;
-
-  flexible = flexible ? 1: 0;
-
-  dx = div(grid.x, w);
-  dy = div(grid.y, h);
-
-  d = div(point.x-dx.rem, w);
-  point.x = dx.rem + d.quot*w + ((d.rem > w/2)? w-flexible: 0);
-
-  d = div(point.y-dy.rem, h);
-  point.y = dy.rem + d.quot*h + ((d.rem > h/2)? h-flexible: 0);
+  m_toolLoop->getContext()->getSettings()
+    ->snapToGrid(point, (flexible ? SnapInRightBottom: NormalSnap));
 }
 
 void ToolLoopManager::calculateDirtyArea(ToolLoop* loop, const Points& points, Rect& dirty_area)

src/widgets/editor/moving_pixels_state.cpp

@@ -189,8 +189,11 @@ bool MovingPixelsState::onMouseMove(Editor* editor, Message* msg)
 
     PixelsMovement::MoveModifier moveModifier = PixelsMovement::NormalMovement;
 
+    if (editor->getCustomizationDelegate()->isSnapToGridKeyPressed())
+      moveModifier |= PixelsMovement::SnapToGridMovement;
+
     if (editor->getCustomizationDelegate()->isAngleSnapKeyPressed())
-      moveModifier = PixelsMovement::AngleSnapMovement;
+      moveModifier |= PixelsMovement::AngleSnapMovement;
 
     // Drag the image to that position
     gfx::Rect bounds = m_pixelsMovement->moveImage(x, y, moveModifier);

src/widgets/editor/pixels_movement.cpp

@@ -29,6 +29,7 @@
 #include "raster/mask.h"
 #include "raster/rotate.h"
 #include "raster/sprite.h"
+#include "ui_context.h"
 #include "util/expand_cel_canvas.h"
 
 template<typename T>
@@ -176,6 +177,21 @@ gfx::Rect PixelsMovement::moveImage(int x, int y, MoveModifier moveModifier)
       x2 += dx;
       y2 += dy;
       updateBounds = true;
+
+      if ((moveModifier & SnapToGridMovement) == SnapToGridMovement) {
+        // Snap the x1,y1 point to the grid.
+        gfx::Point gridOffset(x1, y1);
+        UIContext::instance()->getSettings()->snapToGrid(gridOffset, NormalSnap);
+
+        // Now we calculate the difference from x1,y1 point and we can
+        // use it to adjust all coordinates (x1, y1, x2, y2).
+        gridOffset -= gfx::Point(x1, y1);
+
+        x1 += gridOffset.x;
+        y1 += gridOffset.y;
+        x2 += gridOffset.x;
+        y2 += gridOffset.y;
+      }
       break;
 
     case ScaleNWHandle:

src/widgets/editor/pixels_movement.h

@@ -89,4 +89,10 @@ private:
   Mask* m_currentMask;
 };
 
+inline PixelsMovement::MoveModifier& operator|=(PixelsMovement::MoveModifier& a,
+                                                const PixelsMovement::MoveModifier& b) {
+  a = static_cast<PixelsMovement::MoveModifier>(a | b);
+  return a;
+}
+
 #endif