using System;

using System.Collections.Generic;

using System.Linq;

using System.Runtime.InteropServices;

using System.Text;

namespace GhostscriptSharp.API

{

internal class GhostScript32

{

#region Hooks into Ghostscript DLL

[DllImport("gsdll32.dll", EntryPoint = "gsapi_new_instance")]

private static extern int CreateAPIInstance(out IntPtr pinstance, IntPtr caller_handle);

[DllImport("gsdll32.dll", EntryPoint = "gsapi_init_with_args")]

private static extern int InitAPI(IntPtr instance, int argc, string[] argv);

[DllImport("gsdll32.dll", EntryPoint = "gsapi_exit")]

private static extern int ExitAPI(IntPtr instance);

[DllImport("gsdll32.dll", EntryPoint = "gsapi_delete_instance")]

private static extern void DeleteAPIInstance(IntPtr instance);

#endregion

/// <summary>

/// Calls the Ghostscript API with a collection of arguments to be passed to it

/// </summary>

public static void CallAPI(string[] args)

{

// Get a pointer to an instance of the Ghostscript API and run the API with the current arguments

IntPtr gsInstancePtr;

lock (resourceLock)

{

CreateAPIInstance(out gsInstancePtr, IntPtr.Zero);

try

{

int result = InitAPI(gsInstancePtr, args.Length, args);

if (result < 0)

{

throw new ExternalException("Ghostscript conversion error", result);

}

}

finally

{

Cleanup(gsInstancePtr);

}

}

}

/// <summary>

/// Frees up the memory used for the API arguments and clears the Ghostscript API instance

/// </summary>

private static void Cleanup(IntPtr gsInstancePtr)

{

ExitAPI(gsInstancePtr);

DeleteAPIInstance(gsInstancePtr);

}

/// <summary>

/// GS can only support a single instance, so we need to bottleneck any multi-threaded systems.

/// </summary>

private static object resourceLock = new object();

}

}