Add common CLI Args parser for the samples (#8819)

samples/helloskinningbuffer.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include "common/arguments.h"
+
 #include <filament/Camera.h>
 #include <filament/Engine.h>
 #include <filament/IndexBuffer.h>
@@ -99,13 +101,16 @@ static void printUsage(char* name) {
             "Options:\n"
             "   --help, -h\n"
             "       Prints this message\n\n"
-            "   --api, -a\n"
-            "       Specify the backend API: opengl (default), vulkan, or metal\n\n"
+            "API_USAGE"
     );
     const std::string from("SAMPLE");
     for (size_t pos = usage.find(from); pos != std::string::npos; pos = usage.find(from, pos)) {
         usage.replace(pos, from.length(), exec_name);
     }
+    const std::string apiUsage("API_USAGE");
+    for (size_t pos = usage.find(apiUsage); pos != std::string::npos; pos = usage.find(apiUsage, pos)) {
+        usage.replace(pos, apiUsage.length(), samples::getBackendAPIArgumentsUsage());
+    }
     std::cout << usage;
 }
 
@@ -126,16 +131,7 @@ static int handleCommandLineArgments(int argc, char* argv[], Config* config) {
                 printUsage(argv[0]);
                 exit(0);
             case 'a':
-                if (arg == "opengl") {
-                    config->backend = Engine::Backend::OPENGL;
-                } else if (arg == "vulkan") {
-                    config->backend = Engine::Backend::VULKAN;
-                } else if (arg == "metal") {
-                    config->backend = Engine::Backend::METAL;
-                } else {
-                    std::cerr << "Unrecognized backend. Must be 'opengl'|'vulkan'|'metal'."
-                              << std::endl;
-                }
+                config->backend = samples::parseArgumentsForBackend(arg);
                 break;
         }
     }