Meter is improved but needs a few more things.

demos/meters.cpp

@@ -0,0 +1,100 @@
+#include "guecs/sfml/backend.hpp"
+#include "guecs/sfml/components.hpp"
+#include "guecs/uistack.hpp"
+#include "guecs/ui.hpp"
+#include <iostream>
+#include <chrono>
+#include <thread>
+#include <flat_map>
+#include <fmt/core.h>
+
+using namespace std::chrono_literals;
+
+struct TestMeters {
+  guecs::UI $gui{};
+
+  void init() {
+    $gui.position(0, 0, 1280, 720);
+    $gui.layout("[meter1][=meter2][meter3][meter4]");
+
+    for(auto& [name, cell] : $gui.cells()) {
+      auto gui_id = $gui.entity(name);
+
+      $gui.set<guecs::Rectangle>(gui_id, {4, {0, 255, 0, 255}});
+      $gui.set<guecs::Meter>(gui_id, {1.0f, {255, 0, 0, 255}, 4});
+      $gui.set<guecs::Effect>(gui_id, {});
+      $gui.set<guecs::Text>(gui_id, {guecs::to_wstring(name)});
+      $gui.set<guecs::Clickable>(gui_id, {
+          [&, gui_id, name](auto) {
+            auto& meter = $gui.get<guecs::Meter>(gui_id);
+            meter.percent = meter.percent - 0.1f;
+            if(meter.percent < 0.0f) {
+              meter.percent = 1.0f;
+            }
+          }
+      });
+    }
+
+    $gui.init();
+  }
+
+  void render(sf::RenderTarget& target) {
+    $gui.render(target);
+  }
+
+  bool mouse(float x, float y, guecs::Modifiers mods) {
+    return $gui.mouse(x, y, mods);
+  }
+
+  void update() {
+  }
+};
+
+int main() {
+  try {
+    sfml::Backend backend;
+    guecs::init(&backend);
+
+    sf::RenderWindow window(sf::VideoMode({1280, 720}), "Meter Tester");
+    window.setVerticalSyncEnabled(true);
+    window.setFramerateLimit(60);
+    window.setPosition({0,0});
+    TestMeters gui;
+    gui.init();
+
+    while(window.isOpen()) {
+      while (const auto event = window.pollEvent()) {
+        if(event->is<sf::Event::Closed>()) {
+          window.close();
+        }
+
+        if(const auto* mouse = event->getIf<sf::Event::MouseButtonPressed>()) {
+          if(mouse->button == sf::Mouse::Button::Left) {
+            sf::Vector2f pos = window.mapPixelToCoords(mouse->position);
+            gui.mouse(pos.x, pos.y, false);
+          }
+        } else if(const auto* key = event->getIf<sf::Event::KeyPressed>()) {
+          using KEY = sf::Keyboard::Scan;
+
+          switch(key->scancode) {
+            case KEY::Q:
+              return 0;
+            default:
+              break;
+          }
+        }
+      }
+
+      gui.update();
+      gui.render(window);
+      window.display();
+
+      std::this_thread::sleep_for(100ms);
+    }
+  } catch(const std::system_error& e) {
+    std::cout << "WARNING: On OSX you'll get this error on shutdown.\n";
+    std::cout << "Caught system_error with code "
+                 "[" << e.code() << "] meaning "
+                 "[" << e.what() << "]\n";
+  }
+}