enable widget debug outline when BWIDGETS_DEBUG is defined

meson.build

@@ -4,7 +4,6 @@ project('sdl2_basic_widgets', 'cpp',
         # 'b_lundef=false',
         # 'b_sanitize=address,undefined',
         'cpp_std=c++20',
-        'd_ndebug=if-release',
         'optimization=g',
         'warning_level=3',
     ],
@@ -12,6 +11,10 @@ project('sdl2_basic_widgets', 'cpp',
 
 add_project_arguments('-pedantic', '-Winline', language: 'cpp')
 
+if (get_option('buildtype').startswith('debug'))
+    add_project_arguments('-DBWIDGETS_DEBUG', language: 'cpp')
+endif
+
 sdl = [
     dependency('sdl2', version: '>=2.0.5'),
     dependency('SDL2_ttf')

src/w/base/widget.cpp

@@ -40,11 +40,11 @@ auto Widget::render() -> Widget*
 {
     if (_renderer == nullptr) return this;
 
-#ifndef _NDEBUG
+#ifdef BWIDGETS_DEBUG
     _renderer
       ->draw_color({
   // NOLINTNEXTLINE(readability-magic-numbers)
-        {0, 255, 0, SDL_ALPHA_TRANSPARENT}
+        {0, 255, 0, SDL_ALPHA_OPAQUE}
     })
       ->draw_rect(nullptr);
 #endif