Merge pull request 'grid: add a guide grid' (#5) from lju/adding-grid into main

Reviewed-on: #5

CMakeLists.txt

@@ -69,6 +69,7 @@ include_directories(${imgui_SOURCE_DIR} ${rlImGui_SOURCE_DIR})
 set(SRC_CXX_FILES "./src/main.cpp"
                   "./src/rules.cpp"
                   "./src/world.cpp"
+                  "./src/grid.cpp"
                   "./src/render.cpp"
                   "./src/control_menu.cpp"
                   "./src/settings_menu.cpp"
@@ -76,6 +77,7 @@ set(SRC_CXX_FILES "./src/main.cpp"
                   "./src/selection.cpp"
                   "./src/paterns_menu.cpp"
                   "./src/patern_preview.cpp"
+                  "./src/snapping.cpp"
                   "${rlImGui_SOURCE_DIR}/rlImGui.cpp"
                   "${imgui_SOURCE_DIR}/imgui.cpp"
                   "${imgui_SOURCE_DIR}/imgui_draw.cpp"

README.md

@@ -6,7 +6,7 @@ This is a simple Game Of Life editor written in C++ with raylib & dearImGUI
 
 ## How to compile the project
 
-Ensure you have g++, cmake and the thendependencies of raylib
+Ensure you have g++, cmake and the dependencies of raylib
 
 ```shell
 mkdir build

includes/grid.hpp

@@ -0,0 +1,28 @@
+/*
+* File name: grid.hpp
+* Author: lejulien
+* Date created: 01-01-1970 00:59:59
+// Date modified: 12-01-2026 21:30:10
+* ------
+*/
+
+#pragma once
+
+#include <context.hpp>
+#include <memory>
+#include <settings_menu.hpp>
+#include <world.hpp>
+
+namespace gol {
+
+class Grid {
+ public:
+  Grid(std::shared_ptr<ctx>);
+  ~Grid() = default;
+  void display();
+
+ private:
+  std::shared_ptr<ctx> context_;
+};
+
+};  // namespace gol

includes/patern_preview.hpp

@@ -10,6 +10,8 @@
 
 #include <memory>
 
+#include <raylib.h>
+
 #include <context.hpp>
 
 namespace gol {
@@ -24,6 +26,8 @@ public:
 private:
   bool is_started = false;
   std::shared_ptr<ctx> context_;
+  Vector2 mouse_pos_ = {0, 0};
+  bool is_unplacable_ = false;
 };
 
 } // namespace gol

includes/paterns_menu.hpp

@@ -30,6 +30,7 @@ private:
   std::shared_ptr<ctx> context_ = nullptr;
   std::map<std::string,std::string> paterns_paths_list_;
   std::vector<std::string> paterns_name_list_;
+public:
   int patern_width_ = 0;
   int patern_height_ = 0;
   std::vector<uint32_t> loaded_patern_;

includes/snapping.hpp

@@ -1,5 +1,5 @@
 /*
-* File name: selection.cpp
+* File name: snapping.hpp
 * Author: lejulien
 * Date created: 01-01-1970 00:59:59
 // Date modified: 12-01-2026 21:30:10
@@ -13,12 +13,6 @@
 #include <raylib.h>
 #include <cmath>
 
-Vector2 snapToGrid(Vector2 screen, int cell_size) {
-  return {static_cast<float>(round(screen.x / cell_size) * cell_size),
-          static_cast<float>(round(screen.y / cell_size) * cell_size)};
-}
+Vector2 snapToGrid(Vector2 screen, int cell_size);
 
-Vector2i screenToGrid(Vector2 screen, int cell_size) {
-  return {static_cast<int>(round(screen.x / cell_size)),
-          static_cast<int>(round(screen.y / cell_size))};
-}
+Vector2i screenToGrid(Vector2 screen, int cell_size);

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:

src/grid.cpp

@@ -0,0 +1,27 @@
+/*
+* File name: grid.cpp
+* Author: lejulien
+* Date created: 01-01-1970 00:59:59
+// Date modified: 12-01-2026 21:30:10
+* ------
+*/
+
+#include <raylib.h>
+
+#include <grid.hpp>
+
+namespace gol {
+
+Grid::Grid(std::shared_ptr<ctx> context) : context_(context) {}
+
+void Grid::display() {
+  auto cell_size = context_->settings_menu->getCellSize();
+  for (int j = 0; j < context_->world->getHeight(); j++) {
+    for (int i = 0; i < context_->world->getWidth(); i++) {
+      DrawRectangleLines(i * cell_size, j * cell_size, cell_size, cell_size,
+                         GRAY);
+    }
+  }
+}
+
+}  // namespace gol

src/main.cpp

@@ -25,6 +25,8 @@
 #include <selection_menu.hpp>
 #include <selection.hpp>
 #include <paterns_menu.hpp>
+#include <patern_preview.hpp>
+#include <grid.hpp>
 
 int main(int ac, char **av) {
   std::shared_ptr<gol::ctx> context = std::make_shared<gol::ctx>();
@@ -107,6 +109,8 @@ int main(int ac, char **av) {
   context->selection_menu = std::make_shared<gol::SelectionMenu>(context);
   context->selection = std::make_shared<gol::Selection>(context);
   context->paterns_menu = std::make_shared<gol::PaternsMenu>(context);
+  context->patern_preview = std::make_shared<gol::PaternPreview>(context);
+  gol::Grid grid(context);
 
   // Speed handling values
   float sim_speed = 1.0f;
@@ -136,6 +140,7 @@ int main(int ac, char **av) {
 
     // Selection behaviour
     context->selection->update();
+    context->patern_preview->update();
     context->selection_menu->update();
     context->settings_menu->update();
 
@@ -152,8 +157,10 @@ int main(int ac, char **av) {
     }
     BeginDrawing();
     ClearBackground(BLACK);
+    grid.display();
     context->render->display(context->world);
     context->selection->display();
+    context->patern_preview->display();
     // Start ImGui frame
     rlImGuiBegin();
     context->control_menu->display();

src/patern_preview.cpp

@@ -6,27 +6,64 @@
 * ------
 */
 
+#include <imgui.h>
+#include <raylib.h>
+#include <rlImGui.h>
+
 #include <patern_preview.hpp>
+#include <paterns_menu.hpp>
+#include <settings_menu.hpp>
+#include <snapping.hpp>
+#include <world.hpp>
 
 namespace gol {
 
-PaternPreview::PaternPreview(std::shared_ptr<ctx> context): context_(context) {}
+PaternPreview::PaternPreview(std::shared_ptr<ctx> context)
+    : context_(context) {}
 
-void PaternPreview::start() {
-  // TODO: load patern from pater menu
-  is_started = true;
-}
+void PaternPreview::start() { is_started = true; }
 
 void PaternPreview::update() {
   if (!is_started) return;
-  // gather mousePos
-  // if right click stop the preview
-  // if left click, apply patern to current world
+  mouse_pos_ = GetMousePosition();
+  if (ImGui::IsMouseClicked(1)) {
+    is_started = false;
+    return;
+  }
+  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;
+  auto cell_size = context_->settings_menu->getCellSize();
+  auto mouse_in_grid =
+      screenToGrid(mouse_pos_, context_->settings_menu->getCellSize());
+  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()));
+  for (int j = 0; j < context_->paterns_menu->patern_height_; j++) {
+    for (int i = 0; i < context_->paterns_menu->patern_width_; i++) {
+      auto cell =
+          context_->paterns_menu
+              ->loaded_patern_[i + (j * context_->paterns_menu->patern_width_)];
+      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);
+      }
+    }
+  }
 }
 
-};
+};  // namespace gol

src/paterns_menu.cpp

@@ -64,7 +64,7 @@ bool PaternsMenu::loadPatern(std::string &path) {
     }
   } catch (std::exception &e) {
     std::cerr << "Failure in loading patern : " << path << std::endl;
-    return 1;
+    return false;
   }
   return true;
 }

src/snapping.cpp

@@ -0,0 +1,19 @@
+/*
+* File name: snapping.hpp
+* Author: lejulien
+* Date created: 01-01-1970 00:59:59
+// Date modified: 12-01-2026 21:30:10
+* ------
+*/
+
+#include <snapping.hpp>
+
+Vector2 snapToGrid(Vector2 screen, int cell_size) {
+  return {static_cast<float>(round(screen.x / cell_size) * cell_size),
+          static_cast<float>(round(screen.y / cell_size) * cell_size)};
+}
+
+Vector2i screenToGrid(Vector2 screen, int cell_size) {
+  return {static_cast<int>(round(screen.x / cell_size)),
+          static_cast<int>(round(screen.y / cell_size))};
+}

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];
+    }
+  }
+}