add comment to ExampleAppLog and mini refactoring

src/doompanning.cc

@@ -199,7 +199,7 @@ int doom_controller_loop(ControllerContext &ctx)
     return 0;
 }
 
-void log_to_context(log_Event *ev)
+void log_to_imgui(log_Event *ev)
 {
     auto ctx = reinterpret_cast<ControllerContext *>(ev->udata);
     ctx->appLog.AddLog(ev->fmt, ev->ap);
@@ -258,7 +258,7 @@ int main(int argc, char *argv[])
         {},
     };
 
-    log_add_callback(log_to_context, &ctx, LOG_TRACE);
+    log_add_callback(log_to_imgui, &ctx, LOG_TRACE);
 
     int ret = doom_controller_loop(ctx);
 

src/dp_util.hpp

@@ -31,6 +31,9 @@ template<size_t Size>
     return buf.data();
 }
 
+// Copied from the ImGui demo code. Added the AddLog() overload taking a
+// va_list.
+
 // Usage:
 //  static ExampleAppLog my_log;
 //  my_log.AddLog("Hello %d world\n", 123);