diff --git a/includes/patern_preview.hpp b/includes/patern_preview.hpp
index a96664c..218afb5 100644
--- a/includes/patern_preview.hpp
+++ b/includes/patern_preview.hpp
@@ -27,6 +27,7 @@ private:
   bool is_started = false;
   std::shared_ptr<ctx> context_;
   Vector2 mouse_pos_ = {0, 0};
+  bool is_unplacable_ = false;
 };
 
 } // namespace gol
diff --git a/includes/world.hpp b/includes/world.hpp
index c61e373..b21e93f 100644
--- a/includes/world.hpp
+++ b/includes/world.hpp
@@ -37,6 +37,7 @@ public:
   void setCell(int x, int y);
   void resize(int width, int height); // destructive
   std::vector<uint32_t> getSelection(Vector2i &origin, Vector2i &size);
+  void setSelection(Vector2i &origin, Vector2i &size, std::vector<uint32_t> &data);
 
   // Private members
 private:
diff --git a/src/patern_preview.cpp b/src/patern_preview.cpp
index 26a87b6..0de2d63 100644
--- a/src/patern_preview.cpp
+++ b/src/patern_preview.cpp
@@ -30,24 +30,28 @@ void PaternPreview::update() {
     is_started = false;
     return;
   }
-  // if right click stop the preview
-  // if left click, apply patern to current world
+  if (ImGui::IsMouseClicked(0) && !is_unplacable_) {
+    auto selection_pos =
+        screenToGrid(mouse_pos_, context_->settings_menu->getCellSize());
+    Vector2i size = {context_->paterns_menu->patern_width_,
+                     context_->paterns_menu->patern_height_};
+    context_->world->setSelection(selection_pos, size,
+                                  context_->paterns_menu->loaded_patern_);
+    is_started = false;
+  }
   // mouse should pass through any present windows
 }
 
 void PaternPreview::display() {
   if (!is_started) return;
-  std::cout << "preview display started " << std::endl;
   auto cell_size = context_->settings_menu->getCellSize();
   auto mouse_in_grid =
       screenToGrid(mouse_pos_, context_->settings_menu->getCellSize());
-  bool is_unplacable =
+  is_unplacable_ =
       ((mouse_in_grid.x + context_->paterns_menu->patern_width_ >
         context_->world->getWidth()) ||
        (mouse_in_grid.y + context_->paterns_menu->patern_height_ >
         context_->world->getHeight()));
-  std::cout << "mx:" << mouse_in_grid.x << ", my:" << mouse_in_grid.y
-            << ", cs:" << context_->settings_menu->getCellSize() << std::endl;
   for (int j = 0; j < context_->paterns_menu->patern_height_; j++) {
     for (int i = 0; i < context_->paterns_menu->patern_width_; i++) {
       auto cell =
@@ -56,7 +60,7 @@ void PaternPreview::display() {
       if (cell) {
         DrawRectangle((i + mouse_in_grid.x) * cell_size,
                       (j + mouse_in_grid.y) * cell_size, cell_size, cell_size,
-                      (is_unplacable) ? RED : BLUE);
+                      (is_unplacable_) ? RED : BLUE);
       }
     }
   }
diff --git a/src/world.cpp b/src/world.cpp
index ae653ba..a66dc14 100644
--- a/src/world.cpp
+++ b/src/world.cpp
@@ -143,7 +143,6 @@ void World::resize(int width, int height) {
 }
 
 std::vector<uint32_t> World::getSelection(Vector2i &origin, Vector2i &size) {
-  // We assume the selection is in the grid for now
   std::vector<uint32_t> data = {static_cast<uint32_t>(size.x),
                                 static_cast<uint32_t>(size.y)};
   for (int y = origin.y; y < origin.y + size.y; y++) {
@@ -153,3 +152,12 @@ std::vector<uint32_t> World::getSelection(Vector2i &origin, Vector2i &size) {
   }
   return data;
 }
+
+void World::setSelection(Vector2i &origin, Vector2i &size, std::vector<uint32_t> &data) {
+  
+  for (int y = 0; y < size.y; y++) {
+    for (int x = 0; x < size.x; x++) {
+      (*_data)[(x + origin.x) + (y + origin.y) * _width] = data[x + y * size.x];
+    }
+  }
+}