1 files changed, 30 insertions, 0 deletions
diff --git a/gameplay.cpp b/gameplay.cpp
new file mode 100644
index 0000000..d80a4c9
--- /dev/null
+++ b/gameplay.cpp
@@ -0,0 +1,30 @@
+#include "gameplay.hpp"
+#include "puzzle.hpp"
+#include "FL/Fl_Group.H"
+
+static bool is_next_to_empty_box(GameParams::coordinates empty_box_pos,
+                                 GameParams::coordinates current_pos)
+{
+    return
+        (current_pos.x - spacing - puzzle_size == empty_box_pos.x &&
+         current_pos.y == empty_box_pos.y) ||
+        (current_pos.x == empty_box_pos.x &&
+         current_pos.y - spacing - puzzle_size == empty_box_pos.y) ||
+        (current_pos.x + puzzle_size + spacing == empty_box_pos.x &&
+         current_pos.y == empty_box_pos.y) ||
+        (current_pos.x == empty_box_pos.x &&
+         current_pos.y + puzzle_size + spacing == empty_box_pos.y);
+}
+
+void press_button_callback(Fl_Widget *w, void *params)
+{
+    GameParams *gp = reinterpret_cast<GameParams*>(params);
+    GameParams::coordinates current_pos = { w->x(), w->y() };
+    if(is_next_to_empty_box(gp->GetXYEmptyBox(), current_pos)) {
+        w->position(gp->GetXYEmptyBox().x, gp->GetXYEmptyBox().y);
+        gp->SetXYEmptyBox(current_pos.x, current_pos.y);
+    }
+    w->redraw();
+    w->parent()->redraw();
+}
+