I'm currently coding an RPG engine in XNA. The engine executes a series of scripting commands but has to block until the next scripting command. How can I do this?
For example:
// interact with an NPC named in String 'Name'
String interactfunc = String.Format("{0}_Interact", Name);
System.Reflection.MethodInfo info = Factory.Script.GetType().GetMethod(interactfunc);
if (info != null) info.Invoke(Factory.Script, new object[]{this});
//this may run the following script command for NPC 'Bob'
public void Bob_Interact(NPC Bob)
{
Bob.Say("Well this worked.");
Bob.Say("Didnt it?");
}
//the say command looks like this
public void Say(String Text)
{
TalkGui gui = new TalkGui(this, Text);
Factory.Game.Guis.Add(gui);
Factory.FocusedGui = gui;
}
Now I need the script the wait until the first TalkGui has been dismissed before running the next script command.
What's the best way to do this? Maybe run the script functions in their own thread or something?
You don't want to use threads for this kind of thing. They're far too heavy weight.
What you really want is co-routines. You can emulate these in C# using yield and iterators.
There are some examples here and here. And perhaps my answer here is worth reading too.
C# 5.0 is introducing a much nicer way of doing asynchronous programming like this. Here's a video and here is the CTP.
Related
Installed Unity Version is 2020.2.1f1
I'm developing an online multiplayer game using Unity. I have 2 different connection types; Http and Websocket(using Websocketsharp: https://github.com/sta/websocket-sharp, I've installed it using Nuget). Http get/post, Websocket connect/send/close works totally fine but when I call function (directly or by sending events) after response, most of the time my code inside that called function is not completed on editor(works fine on builds-android,ios). I'm not sure if this problem is related to http/websocket but it's related to online connection because I've experienced the same issue when I was developing a real-time multiplayer game using Unity & Gamesparks.
I can do basic functions like print etc. until I call one of the following functions loadscene, update UI, or call another function in same/different script(only first one of these works, everything after that won't run). Console doesn't show any error and game doesn't pause or crash. It runs on same fps but that part of the code won't continue. Other scripts/updates works fine. I've searched a lot but couldn't even find a related topic.
WebSocket Client:
void OnBattleResponse(object sender, MessageEventArgs messageEventArgs) {
string message = messageEventArgs.Data;
if (messageEventArgs.Data.Equals(Constants.WEBSOCKET_ERROR))
return;
var webSocketData = JsonUtility.FromJson<BattleResponseSerializable>(message);
switch (webSocketData.type) {
case 0:
seed = webSocketData.user1.seed;
opponentSeed = webSocketData.user2.seed;
_connectionManager.BattleGetStart(seed, opponentSeed);
break;
.
.
.
}
Connection Manager:
public void BattleGetStart(int userSeed, int opponentSeed) {
_gameManager.StartWave(userSeed, opponentSeed);
}
Game Manager
public void StartWave(int userSeed, int opponentSeed)
{
UserSeed = userSeed;
OpponentSeed = opponentSeed;
UserRandom = new System.Random(UserSeed);
OpponentRandom = new System.Random(OpponentSeed);
StartWaveTimer(); // After this nothing will be run, it's not related to startWaveTimer, any function that I've mentioned causes the same issue.
print("DOESN'T WORK"); // This doesn't work on Editor but works on builds
_spawner.ActivateSpawner(true); // doesn't work
}
I've found a trick to handle this situation but I didn't like it as a proper solution and don't wanna spend resources for Update calls. When I call function (directly or by sending events) after response, inside the called function I set bool to true and in Update call I call the necessary function when the bool is true and the code works totally fine.
---The Trick---
Game Manager
bool startWave;
public void StartWave(int userSeed, int opponentSeed)
{
UserSeed = userSeed;
OpponentSeed = opponentSeed;
UserRandom = new System.Random(UserSeed);
OpponentRandom = new System.Random(OpponentSeed);
startWave = true;
}
void Update() {
if (startWave) {
startWave = false;
StartWaveTimer();
print("WORKS"); // With this trick, it works on editor too.
_spawner.ActivateSpawner(true); // works
}
}
What can be the reason of my script working on builds but not on unity editor?
Thank you!
Advice for those who will experience that kind of issue:
As I've found out Unity is not Thread safe. Unity limits us on calling their API from another Thread, which causes this issue.
So you have to call your functions/methods from main thread instead of another thread.
When using System.Threading.Thread.Sleep(n), I understand that it blocks the thread of the program, which result in the program being inaccessible; eg: Not being able to click buttons, or bring up other forms.
So what my question is, is there any other alternative that I could use that would just pause my one method, but still allow me to use buttons, and open other forms and such?
The code that I am using is messy becuase I have been using System.Threading.Thread.Sleep(1500) but here it is:
while(Reader.Read() != null)
{
ApplicationPort.WriteLine(line);
System.Threading.Thread.Sleep(1500);
}
Line is just a string that is bein updated earlier on the code, the rate that it updates is too fast for what I am trying to accomplish so I am trying to slow the program down by using Sleep. And ApplicationPort, is just a SerialPort
This code is not allowing me to use other object while it is sleeping, so is there an alternative to this where I can still use the rest of my program while the while just the while loop sleeps?
Run your method in separate thread, and you will be free to pause/resume as much as you want...
Take a look to the Thread class
You could use a while loop and Application.DoEvents Something like:
while(Reader.Read() != null)
{
ApplicationPort.WriteLine(line);
var endDate = DateTime.Now + TimeSpan.FromSeconds(1.5);
while (DateTime.Now() < endDate)
{
Application.DoEvents();
}
}
However this is "hacky" and you should be following ArsenMkrt's answer.
I'd consider adding a timer to your app and print the line when the timer hits. This would not tie up your app.
An example here Timer
So I know its a fairly big challenge but I want to write a basic movie player/converter in c# using the FFmpeg library. However, the first obstacle I need to overcome is wrapping the FFmpeg library in c#. I've downloaded ffmpeg but couldn't compile it on Windows, so I downloaded a precompiled version for me. Ok awesome. Then I started looking for C# wrappers.
I have looked around and have found a few wrappers such as SharpFFmpeg (http://sourceforge.net/projects/sharpffmpeg/) and ffmpeg-sharp (http://code.google.com/p/ffmpeg-sharp/). First of all, I wanted to use ffmpeg-sharp as its LGPL and SharpFFmpeg is GPL. However, it had quite a few compile errors. Turns out it was written for the mono compiler, I tried compiling it with mono but couldn't figure out how. I then started to manually fix the compiler errors myself, but came across a few scary ones and thought I'd better leave those alone. So I gave up on ffmpeg-sharp.
Then I looked at SharpFFmpeg and it looks like what I want, all the functions P/Invoked for me. However its GPL? Both the AVCodec.cs and AVFormat.cs files look like ports of avcodec.c and avformat.c which I reckon I could port myself? Then not have to worry about licencing.
But I want to get this right before I go ahead and start coding. Should I:
Write my own C++ library for interacting with ffmpeg, then have my C# program talk to the C++ library in order to play/convert videos etc.
OR
Port avcodec.h and avformat.h (is that all i need?) to c# by using a whole lot of DllImports and write it entirely in C#?
First of all consider that I'm not great at C++ as I rarely use it but I know enough to get around. The reason I'm thinking #1 might be the better option is that most FFmpeg tutorials are in C++ and I'd also have more control over memory management than if I was to do it in c#.
What do you think?
Also would you happen to have any useful links (perhaps a tutorial) for using FFmpeg?
The original question is now more than 5 years old. In the meantime there is now a solution for a WinRT solution from ffmpeg and an integration sample from Microsoft.
a few other managed wrappers for you to check out
FFMpeg.NET
FFMpeg-Sharp
Writing your own interop wrappers can be a time-consuming and difficult process in .NET. There are some advantages to writing a C++ library for the interop - particularly as it allows you to greatly simplify the interface that the C# code. However, if you are only needing a subset of the library, it might make your life easier to just do the interop in C#.
You can use this nuget package:
Install-Package Xabe.FFmpeg
I'm trying to make easy to use, cross-platform FFmpeg wrapper.
You can find more information about this at Xabe.FFmpeg
More info in documentation
Conversion is simple:
var conversion = await FFmpeg.Conversions.FromSnippet.ToMp4(Resources.MkvWithAudio, output);
await conversion.Start();
GPL-compiled ffmpeg can be used from non-GPL program (commercial project) only if it is invoked in the separate process as command line utility; all wrappers that are linked with ffmpeg library (including Microsoft's FFMpegInterop) can use only LGPL build of ffmpeg.
You may try my .NET wrapper for FFMpeg: Video Converter for .NET (I'm an author of this library). It embeds FFMpeg.exe into the DLL for easy deployment and doesn't break GPL rules (FFMpeg is NOT linked and wrapper invokes it in the separate process with System.Diagnostics.Process).
A solution that is viable for both Linux and Windows is to just get used to using console ffmpeg in your code. I stack up threads, write a simple thread controller class, then you can easily make use of what ever functionality of ffmpeg you want to use.
As an example, this contains sections use ffmpeg to create a thumbnail from a time that I specify.
In the thread controller you have something like
List<ThrdFfmpeg> threads = new List<ThrdFfmpeg>();
Which is the list of threads that you are running, I make use of a timer to Pole these threads, you can also set up an event if Pole'ing is not suitable for your application.
In this case thw class Thrdffmpeg contains,
public class ThrdFfmpeg
{
public FfmpegStuff ffm { get; set; }
public Thread thrd { get; set; }
}
FFmpegStuff contains the various ffmpeg functionality, thrd is obviously the thread.
A property in FfmpegStuff is the class FilesToProcess, which is used to pass information to the called process, and receive information once the thread has stopped.
public class FileToProcess
{
public int videoID { get; set; }
public string fname { get; set; }
public int durationSeconds { get; set; }
public List<string> imgFiles { get; set; }
}
VideoID (I use a database) tells the threaded process which video to use taken from the database.
fname is used in other parts of my functions that use FilesToProcess, but not used here.
durationSeconds - is filled in by the threads that just collect video duration.
imgFiles is used to return any thumbnails that were created.
I do not want to get bogged down in my code when the purpose of this is to encourage the use of ffmpeg in easily controlled threads.
Now we have our pieces we can add to our threads list, so in our controller we do something like,
AddThread()
{
ThrdFfmpeg thrd;
FileToProcess ftp;
foreach(FileToProcess ff in `dbhelper.GetFileNames(txtCategory.Text))`
{
//make a thread for each
ftp = new FileToProcess();
ftp = ff;
ftp.imgFiles = new List<string>();
thrd = new ThrdFfmpeg();
thrd.ffm = new FfmpegStuff();
thrd.ffm.filetoprocess = ftp;
thrd.thrd = new `System.Threading.Thread(thrd.ffm.CollectVideoLength);`
threads.Add(thrd);
}
if(timerNotStarted)
StartThreadTimer();
}
Now Pole'ing our threads becomes a simple task,
private void timerThreads_Tick(object sender, EventArgs e)
{
int runningCount = 0;
int finishedThreads = 0;
foreach(ThrdFfmpeg thrd in threads)
{
switch (thrd.thrd.ThreadState)
{
case System.Threading.ThreadState.Running:
++runningCount;
//Note that you can still view data progress here,
//but remember that you must use your safety checks
//here more than anywhere else in your code, make sure the data
//is readable and of the right sort, before you read it.
break;
case System.Threading.ThreadState.StopRequested:
break;
case System.Threading.ThreadState.SuspendRequested:
break;
case System.Threading.ThreadState.Background:
break;
case System.Threading.ThreadState.Unstarted:
//Any threads that have been added but not yet started, start now
thrd.thrd.Start();
++runningCount;
break;
case System.Threading.ThreadState.Stopped:
++finishedThreads;
//You can now safely read the results, in this case the
//data contained in FilesToProcess
//Such as
ThumbnailsReadyEvent( thrd.ffm );
break;
case System.Threading.ThreadState.WaitSleepJoin:
break;
case System.Threading.ThreadState.Suspended:
break;
case System.Threading.ThreadState.AbortRequested:
break;
case System.Threading.ThreadState.Aborted:
break;
default:
break;
}
}
if(flash)
{//just a simple indicator so that I can see
//that at least one thread is still running
lbThreadStatus.BackColor = Color.White;
flash = false;
}
else
{
lbThreadStatus.BackColor = this.BackColor;
flash = true;
}
if(finishedThreads >= threads.Count())
{
StopThreadTimer();
ShowSample();
MakeJoinedThumb();
}
}
Putting your own events onto into the controller class works well, but in video work, when my own code is not actually doing any of the video file processing, poling then invoking an event in the controlling class works just as well.
Using this method I have slowly built up just about every video and stills function I think I will ever use, all contained in the one class, and that class as a text file is useable on the Lunux and Windows version, with just a small number of pre-process directives.
So I know its a fairly big challenge but I want to write a basic movie player/converter in c# using the FFmpeg library. However, the first obstacle I need to overcome is wrapping the FFmpeg library in c#. I've downloaded ffmpeg but couldn't compile it on Windows, so I downloaded a precompiled version for me. Ok awesome. Then I started looking for C# wrappers.
I have looked around and have found a few wrappers such as SharpFFmpeg (http://sourceforge.net/projects/sharpffmpeg/) and ffmpeg-sharp (http://code.google.com/p/ffmpeg-sharp/). First of all, I wanted to use ffmpeg-sharp as its LGPL and SharpFFmpeg is GPL. However, it had quite a few compile errors. Turns out it was written for the mono compiler, I tried compiling it with mono but couldn't figure out how. I then started to manually fix the compiler errors myself, but came across a few scary ones and thought I'd better leave those alone. So I gave up on ffmpeg-sharp.
Then I looked at SharpFFmpeg and it looks like what I want, all the functions P/Invoked for me. However its GPL? Both the AVCodec.cs and AVFormat.cs files look like ports of avcodec.c and avformat.c which I reckon I could port myself? Then not have to worry about licencing.
But I want to get this right before I go ahead and start coding. Should I:
Write my own C++ library for interacting with ffmpeg, then have my C# program talk to the C++ library in order to play/convert videos etc.
OR
Port avcodec.h and avformat.h (is that all i need?) to c# by using a whole lot of DllImports and write it entirely in C#?
First of all consider that I'm not great at C++ as I rarely use it but I know enough to get around. The reason I'm thinking #1 might be the better option is that most FFmpeg tutorials are in C++ and I'd also have more control over memory management than if I was to do it in c#.
What do you think?
Also would you happen to have any useful links (perhaps a tutorial) for using FFmpeg?
The original question is now more than 5 years old. In the meantime there is now a solution for a WinRT solution from ffmpeg and an integration sample from Microsoft.
a few other managed wrappers for you to check out
FFMpeg.NET
FFMpeg-Sharp
Writing your own interop wrappers can be a time-consuming and difficult process in .NET. There are some advantages to writing a C++ library for the interop - particularly as it allows you to greatly simplify the interface that the C# code. However, if you are only needing a subset of the library, it might make your life easier to just do the interop in C#.
You can use this nuget package:
Install-Package Xabe.FFmpeg
I'm trying to make easy to use, cross-platform FFmpeg wrapper.
You can find more information about this at Xabe.FFmpeg
More info in documentation
Conversion is simple:
var conversion = await FFmpeg.Conversions.FromSnippet.ToMp4(Resources.MkvWithAudio, output);
await conversion.Start();
GPL-compiled ffmpeg can be used from non-GPL program (commercial project) only if it is invoked in the separate process as command line utility; all wrappers that are linked with ffmpeg library (including Microsoft's FFMpegInterop) can use only LGPL build of ffmpeg.
You may try my .NET wrapper for FFMpeg: Video Converter for .NET (I'm an author of this library). It embeds FFMpeg.exe into the DLL for easy deployment and doesn't break GPL rules (FFMpeg is NOT linked and wrapper invokes it in the separate process with System.Diagnostics.Process).
A solution that is viable for both Linux and Windows is to just get used to using console ffmpeg in your code. I stack up threads, write a simple thread controller class, then you can easily make use of what ever functionality of ffmpeg you want to use.
As an example, this contains sections use ffmpeg to create a thumbnail from a time that I specify.
In the thread controller you have something like
List<ThrdFfmpeg> threads = new List<ThrdFfmpeg>();
Which is the list of threads that you are running, I make use of a timer to Pole these threads, you can also set up an event if Pole'ing is not suitable for your application.
In this case thw class Thrdffmpeg contains,
public class ThrdFfmpeg
{
public FfmpegStuff ffm { get; set; }
public Thread thrd { get; set; }
}
FFmpegStuff contains the various ffmpeg functionality, thrd is obviously the thread.
A property in FfmpegStuff is the class FilesToProcess, which is used to pass information to the called process, and receive information once the thread has stopped.
public class FileToProcess
{
public int videoID { get; set; }
public string fname { get; set; }
public int durationSeconds { get; set; }
public List<string> imgFiles { get; set; }
}
VideoID (I use a database) tells the threaded process which video to use taken from the database.
fname is used in other parts of my functions that use FilesToProcess, but not used here.
durationSeconds - is filled in by the threads that just collect video duration.
imgFiles is used to return any thumbnails that were created.
I do not want to get bogged down in my code when the purpose of this is to encourage the use of ffmpeg in easily controlled threads.
Now we have our pieces we can add to our threads list, so in our controller we do something like,
AddThread()
{
ThrdFfmpeg thrd;
FileToProcess ftp;
foreach(FileToProcess ff in `dbhelper.GetFileNames(txtCategory.Text))`
{
//make a thread for each
ftp = new FileToProcess();
ftp = ff;
ftp.imgFiles = new List<string>();
thrd = new ThrdFfmpeg();
thrd.ffm = new FfmpegStuff();
thrd.ffm.filetoprocess = ftp;
thrd.thrd = new `System.Threading.Thread(thrd.ffm.CollectVideoLength);`
threads.Add(thrd);
}
if(timerNotStarted)
StartThreadTimer();
}
Now Pole'ing our threads becomes a simple task,
private void timerThreads_Tick(object sender, EventArgs e)
{
int runningCount = 0;
int finishedThreads = 0;
foreach(ThrdFfmpeg thrd in threads)
{
switch (thrd.thrd.ThreadState)
{
case System.Threading.ThreadState.Running:
++runningCount;
//Note that you can still view data progress here,
//but remember that you must use your safety checks
//here more than anywhere else in your code, make sure the data
//is readable and of the right sort, before you read it.
break;
case System.Threading.ThreadState.StopRequested:
break;
case System.Threading.ThreadState.SuspendRequested:
break;
case System.Threading.ThreadState.Background:
break;
case System.Threading.ThreadState.Unstarted:
//Any threads that have been added but not yet started, start now
thrd.thrd.Start();
++runningCount;
break;
case System.Threading.ThreadState.Stopped:
++finishedThreads;
//You can now safely read the results, in this case the
//data contained in FilesToProcess
//Such as
ThumbnailsReadyEvent( thrd.ffm );
break;
case System.Threading.ThreadState.WaitSleepJoin:
break;
case System.Threading.ThreadState.Suspended:
break;
case System.Threading.ThreadState.AbortRequested:
break;
case System.Threading.ThreadState.Aborted:
break;
default:
break;
}
}
if(flash)
{//just a simple indicator so that I can see
//that at least one thread is still running
lbThreadStatus.BackColor = Color.White;
flash = false;
}
else
{
lbThreadStatus.BackColor = this.BackColor;
flash = true;
}
if(finishedThreads >= threads.Count())
{
StopThreadTimer();
ShowSample();
MakeJoinedThumb();
}
}
Putting your own events onto into the controller class works well, but in video work, when my own code is not actually doing any of the video file processing, poling then invoking an event in the controlling class works just as well.
Using this method I have slowly built up just about every video and stills function I think I will ever use, all contained in the one class, and that class as a text file is useable on the Lunux and Windows version, with just a small number of pre-process directives.
I am working on a project with peek performance requirements, so we need to bulk (batch?) several operations (for example persisting the data to a database) for efficiency.
However, I want our code to maintain an easy to understand flow, like:
input = Read();
parsed = Parse(input);
if (parsed.Count > 10)
{
status = Persist(parsed);
ReportSuccess(status);
return;
}
ReportFailure();
The feature I'm looking for here is automatically have Persist() happen in bulks (and ergo asynchronously), but behave to its user as if it's synchronous (user should block until the bulk action completes). I want the implementor to be able to implement Persist(ICollection).
I looked into flow-based programming, with which I am not highly familiar. I saw one library for fbp in C# here, and played a bit with Microsoft's Workflow Foundation, but my impression is that both are overkill for what I need. What would you use to implement a bulked flow behavior?
Note that I would like to get code that is exactly like what I wrote (simple to understand & debug), so solutions that involve yield or configuration in order to connect flows to one another are inadequate for my purpose. Also, chaining
is not what I'm looking for - I don't want to first build a chain and then run it, I want code that looks as if it is a simple flow ("Do A, Do B, if C then do D").
Common problem - instead of calling Persist I usually load up commands (or smt along those lines) into a Persistor class then after the loop is finished I call Persistor.Persist to persist the batch.
Just a few pointers - If you're generating sql the commands you add to the persistor can represent your queries somehow (with built-in objects, custom objects or just query strings). If you're calling stored procedures you can use the commands to append stuff to a piece of xml tha will be passed down to the SP when you call the persist method.
hope it helps - Pretty sure there's a pattern for this but dunno the name :)
I don't know if this is what you need, because it's sqlserver based, but have you tried taking a look to SSIS and or DTS?
One simple thing that you can do is to create a MemoryBuffer where you push the messages which simply add them to a list and returns. This MemoryBuffer has a System.Timers.Timer which gets invoked periodically and do the "actual" updates.
One such implementation can be found in a Syslog Server (C#) at http://www.fantail.net.nz/wordpress/?p=5 in which the syslog messages gets logged to a SQL Server periodically in a batch.
This approach might not be good if the info being pushed to database is important, as if something goes wrong, you will lose the messages in MemoryBuffer.
How about using the BackgroundWorker class to persist each item asynchronously on a separate thread? For example:
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Threading;
class PersistenceManager
{
public void Persist(ICollection persistable)
{
// initialize a list of background workers
var backgroundWorkers = new List<BackgroundWorker>();
// launch each persistable item in a background worker on a separate thread
foreach (var persistableItem in persistable)
{
var worker = new BackgroundWorker();
worker.DoWork += new DoWorkEventHandler(worker_DoWork);
backgroundWorkers.Add(worker);
worker.RunWorkerAsync(persistableItem);
}
// wait for all the workers to finish
while (true)
{
// sleep a little bit to give the workers a chance to finish
Thread.Sleep(100);
// continue looping until all workers are done processing
if (backgroundWorkers.Exists(w => w.IsBusy)) continue;
break;
}
// dispose all the workers
foreach (var w in backgroundWorkers) w.Dispose();
}
void worker_DoWork(object sender, DoWorkEventArgs e)
{
var persistableItem = e.Argument;
// TODO: add logic here to save the persistableItem to the database
}
}