Enhance examples (#17)

* enhance examples

* doc enhancement

* mv pool to stack

* missing ; and doc update

fix readme example image link

examples/simple/CMakeLists.txt

@@ -1,5 +1,5 @@
 set(SRC
-  ${CMAKE_CURRENT_SOURCE_DIR}/main.cpp)
+  ${CMAKE_CURRENT_SOURCE_DIR}/simple.cpp)
 
 set(SIMPLE_NAME "${PROJECT_NAME}_SIMPLE")
 

examples/simple/main.cpp

@@ -1,26 +0,0 @@
-#include <memory>
-
-#include "DefaultApp.hpp"
-#include "resources/resource.hpp"
-#include "utilities/ILog.hpp"
-#include "utilities/SpdLogger.hpp"
-
-int main(int argc, char** argv)
-{
-    using namespace pixelarium;
-    using namespace std;
-    unique_ptr<utils::log::ILog> logger;
-#ifdef _WIN32
-    logger = make_unique<utils::log::SpdLogger>(string(getenv("APPDATA")) + "/pixelarium/logfile.log", "default");
-#else
-    logger = make_unique<utils::log::SpdLogger>(std::string(getenv("HOME")) + "/.cache/pixelarium/log.log", "default");
-#endif
-    logger->Info(std::format("{}: Starting Application {}", __FUNCTION__, "Pixelarium"));
-
-    logger->ChangeLevel(utils::log::LogLevel::kDebug);
-    auto image_pool{std::make_unique<resources::ImageResourcePool>()};
-
-    application::DefaultApp app = application::DefaultApp(*logger, *image_pool);
-
-    app.Start();
-}

examples/simple/simple.cpp

@@ -0,0 +1,34 @@
+#include <memory>
+
+#include "DefaultApp.hpp"
+#include "resources/resource.hpp"
+#include "utilities/ILog.hpp"
+#include "utilities/SpdLogger.hpp"
+
+using namespace pixelarium;
+using namespace std;
+using Log = utils::log::ILog;
+using Pool = resources::ImageResourcePool;
+
+// setup a logger
+#ifdef _WIN32
+unique_ptr<Log> logger{
+    make_unique<utils::log::SpdLogger>(string(getenv("APPDATA")) + "/pixelarium/simple_app.log", "default")};
+#else
+unique_ptr<Log> logger{
+    make_unique<utils::log::SpdLogger>(string(getenv("HOME")) + "/.cache/pixelarium/simple_app.log", "default")};
+#endif
+
+int main()
+{
+    // some initial log message and default log level setting
+    logger->Info(format("{}: Starting Application {}", __FUNCTION__, "Pixelarium"));
+    logger->ChangeLevel(utils::log::LogLevel::kDebug);
+
+    // instantiate an image pool for the application
+    resources::ImageResourcePool image_pool;
+
+    // create an application, inject its dependencies and start it
+    auto app{application::DefaultApp(*logger, image_pool)};
+    app.Start();
+}