Added argument for selecting the app to run.

private/sdl_gpu_test/SModule

@@ -23,6 +23,7 @@ prog_app = env.UnityProgram(
     target = env['BIN_DIR'] + '/sdl_gpu_test',
     source = src_files,
     dependencies = {
+        'argparse': {},
         'glm': {},
         'mijin': {},
         'SDL': {

private/sdl_gpu_test/main.cpp

@@ -1,35 +1,89 @@
 
+#include <argparse/argparse.hpp>
+#include <mijin/debug/stacktrace.hpp>
+
 #include "./0_clear_swapchain/app.hpp"
 #include "./1_green_triangle/app.hpp"
 #include "./2_triangle_with_texcoords/app.hpp"
 #include "./3_textured_quad/app.hpp"
 #include "./4_textured_cube/app.hpp"
+#include "./util/spdlog_wrapper.hpp"
 
-#include <mijin/debug/stacktrace.hpp>
+namespace
-#include <spdlog/spdlog.h>
+{
-#include <mijin/util/winundef.hpp>
+inline constexpr int APP_ERROR = 1;
+inline constexpr int USER_ERROR = 2;
+
+struct AppListEntry
+{
+    std::string name;
+    std::function<std::unique_ptr<sdl_gpu_test::Application>()> factoryFn;
+};
+
+template<typename TApp>
+AppListEntry makeAppHelper(std::string name) noexcept
+{
+    return {
+        .name = std::move(name),
+        .factoryFn = []() { return std::make_unique<TApp>(); }
+    };
+}
+
+const std::array APPS = {
+    makeAppHelper<sdl_gpu_test::ClearSwapchainApp>("clear_swapchain"),
+    makeAppHelper<sdl_gpu_test::GreenTriangleApp>("green_triangle"),
+    makeAppHelper<sdl_gpu_test::TriangleWithTexcoordsApp>("triangle_with_texcoords"),
+    makeAppHelper<sdl_gpu_test::TexturedQuadApp>("textured_quad"),
+    makeAppHelper<sdl_gpu_test::TexturedCubeApp>("textured_cube")
+};
+}
 
 int main(int argc, char* argv[])
 {
     if (argc < 1)
     {
-        return 1;
+        return APP_ERROR;
     }
 
     if (SDL_Init(0) != SDL_TRUE)
     {
         spdlog::error("Error initializing SDL.");
-        return 1;
+        return APP_ERROR;
+    }
+
+    std::string appString = APPS.back().name;
+    argparse::ArgumentParser parser("sdl_gpu_test");
+    argparse::Argument& appArg = parser.add_argument("--app")
+        .help("Application to run")
+        .store_into(appString);
+    for (const AppListEntry& appHelper : APPS)
+    {
+        appArg.add_choice(appHelper.name);
+    }
+
+    // now parse
+    try
+    {
+        parser.parse_args(argc, argv);
+    }
+    catch (std::runtime_error& error)
+    {
+        spdlog::error("{}.", error.what());
+        return USER_ERROR;
     }
 
     try
     {
-        // make sure app is destructed before shutting down SDL
+        std::unique_ptr<sdl_gpu_test::Application> app;
-        // std::unique_ptr<sdl_gpu_test::Application> app = std::make_unique<sdl_gpu_test::ClearSwapchainApp>();
+        for (const AppListEntry& appHelper : APPS)
-        // std::unique_ptr<sdl_gpu_test::Application> app = std::make_unique<sdl_gpu_test::GreenTriangleApp>();
+        {
-        // std::unique_ptr<sdl_gpu_test::Application> app = std::make_unique<sdl_gpu_test::TriangleWithTexcoordsApp>();
+            if (appHelper.name == appString)
-        // std::unique_ptr<sdl_gpu_test::Application> app = std::make_unique<sdl_gpu_test::TexturedQuadApp>();
+            {
-        std::unique_ptr<sdl_gpu_test::Application> app = std::make_unique<sdl_gpu_test::TexturedCubeApp>();
+                app = appHelper.factoryFn();
+                break;
+            }
+        }
+        MIJIN_ASSERT_FATAL(app != nullptr, "Error creating app.");
         app->run(std::span(const_cast<const char**>(argv), argc));
     }
     catch (std::exception& exception)

private/sdl_gpu_test/util/spdlog_wrapper.hpp

@@ -0,0 +1,11 @@
+
+#pragma once
+
+#if !defined(SDL_GPU_TEST_PRIVATE_SDL_GPU_TEST_UTIL_SPDLOG_WRAPPER_HPP_INCLUDED)
+#define SDL_GPU_TEST_PRIVATE_SDL_GPU_TEST_UTIL_SPDLOG_WRAPPER_HPP_INCLUDED 1
+
+// spdlog includes windows.h ...
+#include <spdlog/spdlog.h>
+#include <mijin/util/winundef.hpp>
+
+#endif // !defined(SDL_GPU_TEST_PRIVATE_SDL_GPU_TEST_UTIL_SPDLOG_WRAPPER_HPP_INCLUDED)