Extra2D/examples/text_rendering/main.cpp

/**
 * @file main.cpp
 * @brief Extra2D 文字渲染示例
 *
 * 演示如何使用 RenderBackend 抽象接口渲染文字
 * 此示例不依赖任何特定渲染后端（如 OpenGL）
 */

#include <extra2d/extra2d.h>
#include <iostream>

using namespace extra2d;

class TextRenderingScene : public Scene {
public:
  void onEnter() override {
    // 加载字体
    // 注意：请确保有字体文件在 assets/fonts/ 目录下
    // 如果没有，可以使用系统字体路径
    if (!renderer_) {
      std::cerr << "Renderer not available!" << std::endl;
      return;
    }

    try {
      font_ = renderer_->createFontAtlas("assets/fonts/arial.ttf", 24);
    } catch (...) {
      std::cerr << "Failed to load font from assets/fonts/arial.ttf"
                << std::endl;
      // 尝试使用备用路径
      try {
        font_ = renderer_->createFontAtlas("C:/Windows/Fonts/arial.ttf", 24);
      } catch (...) {
        std::cerr << "Failed to load font from system path!" << std::endl;
        font_ = nullptr;
      }
    }

    if (font_) {
      std::cout << "Font loaded successfully!" << std::endl;
      std::cout << "  Font size: " << font_->getFontSize() << std::endl;
      std::cout << "  Line height: " << font_->getLineHeight() << std::endl;
      std::cout << "  Ascent: " << font_->getAscent() << std::endl;
      std::cout << "  Descent: " << font_->getDescent() << std::endl;
    }
  }

  void onExit() override { font_.reset(); }

  void onRender(RenderBackend &renderer) override {
    Scene::onRender(renderer);

    if (!font_) {
      return;
    }

    float y = 100.0f;
    float x = 100.0f;

    // 渲染标题（自动批处理，无需手动调用 begin/end）
    renderText(renderer, "Extra2D Text Rendering Demo", x, y,
               Color(1.0f, 0.8f, 0.2f, 1.0f));
    y += font_->getLineHeight() * 2;

    // 渲染不同颜色的文字
    renderText(renderer, "Red Text", x, y, Color(1.0f, 0.2f, 0.2f, 1.0f));
    y += font_->getLineHeight();

    renderText(renderer, "Green Text", x, y, Color(0.2f, 1.0f, 0.2f, 1.0f));
    y += font_->getLineHeight();

    renderText(renderer, "Blue Text", x, y, Color(0.2f, 0.2f, 1.0f, 1.0f));
    y += font_->getLineHeight() * 2;

    // 渲染多行文字
    renderText(renderer, "This is a multi-line text example.", x, y,
               Color(1.0f, 1.0f, 1.0f, 1.0f));
    y += font_->getLineHeight();
    renderText(renderer, "You can render text with different colors", x, y,
               Color(0.8f, 0.8f, 0.8f, 1.0f));
    y += font_->getLineHeight();
    renderText(renderer, "and styles using FontAtlas.", x, y,
               Color(0.6f, 0.6f, 0.6f, 1.0f));
    y += font_->getLineHeight() * 2;

    // 渲染半透明文字
    renderText(renderer, "Semi-transparent text (50% opacity)", x, y,
               Color(1.0f, 1.0f, 1.0f, 0.5f));
    y += font_->getLineHeight() * 2;

    // 渲染操作提示
    renderText(renderer, "Press ESC to exit", x, y,
               Color(0.5f, 0.5f, 0.5f, 1.0f));

    // 注意：无需手动调用 renderer.endSpriteBatch()，帧结束时会自动刷新
  }

  void setRenderer(RenderBackend *renderer) { renderer_ = renderer; }

private:
  void renderText(RenderBackend &renderer, const std::string &text, float x,
                  float y, const Color &color) {
    if (!font_) {
      return;
    }

    // 使用 RenderBackend 的 drawText 方法
    renderer.drawText(*font_, text, Vec2(x, y), color);
  }

  Ptr<FontAtlas> font_;
  RenderBackend *renderer_ = nullptr;
};

int main(int argc, char *argv[]) {

  Application &app = Application::get();

  // 注册模块
  app.use<WindowModule>([](auto &cfg) {
    cfg.w = 1280;
    cfg.h = 720;
    cfg.title = "Extra2D Text Rendering Demo";
    cfg.priority = 0;
    cfg.backend = "glfw";
  });

  app.use<RenderModule>([](auto &cfg) { cfg.priority = 10; });

  app.use<InputModule>([](auto &cfg) { cfg.priority = 20; });

  if (!app.init()) {
    E2D_LOG_INFO("Failed to initialize application!");
    return -1;
  }

  auto win = app.window();
  if (win) {
    E2D_LOG_INFO("Window :{} x {}", win->width(), win->height());
  }

  // 设置事件监听
  auto eventService = ServiceLocator::instance().getService<IEventService>();
  if (eventService) {
    eventService->addListener(EventType::KeyPressed, [](Event &e) {
      auto &keyEvent = std::get<KeyEvent>(e.data);
      if (keyEvent.keyCode == static_cast<int>(Key::Escape)) {
        e.handled = true;
        Application::get().quit();
      }
    });
  }

  // 获取渲染器
  RenderBackend *renderer = app.renderer();

  // 创建并配置场景
  auto scene = makeShared<TextRenderingScene>();
  scene->setRenderer(renderer);
  scene->setBackgroundColor(Color(0.1f, 0.1f, 0.15f, 1.0f));

  if (win) {
    scene->setViewportSize(static_cast<float>(win->width()),
                           static_cast<float>(win->height()));
  }

  // 配置相机
  auto cameraService = ServiceLocator::instance().getService<ICameraService>();
  if (cameraService && win) {
    ViewportConfig vpConfig;
    vpConfig.logicWidth = static_cast<float>(win->width());
    vpConfig.logicHeight = static_cast<float>(win->height());
    vpConfig.mode = ViewportMode::AspectRatio;
    cameraService->setViewportConfig(vpConfig);
    cameraService->updateViewport(win->width(), win->height());
    cameraService->applyViewportAdapter();
  }

  app.enterScene(scene);

  app.run();

  app.shutdown();
  return 0;
}