fixed incompatibility problem with 'gsapi_set_arg_encoding' function in Ghostscript releases prior to 9.10. (this function was introduced in 9.10 release)

fixed older versions incompatibility problem with '-dMaxBitmap=1g' switch bugfix which in some cases turns on text antialiasing for Ghostscript 9.14

Author: jhabjan

Ghostscript.NET/GhostscriptLibrary.cs

@@ -42,6 +42,7 @@ public class GhostscriptLibrary : IDisposable
         private DynamicNativeLibrary _library;
         private GhostscriptVersionInfo _version;
         private bool _loadedFromMemory = false;
+        private int _revision;
 
         #endregion
 
@@ -224,6 +225,12 @@ private void Initialize()
             if (this.gsapi_revision == null)
                 throw new GhostscriptException(string.Format(symbolMappingError, "gsapi_revision"));
 
+            gsapi_revision_s rev = new gsapi_revision_s();
+            if (this.gsapi_revision(ref rev, System.Runtime.InteropServices.Marshal.SizeOf(rev)) == 0)
+            {
+                _revision = rev.revision;
+            }
+
             this.gsapi_new_instance = _library.GetDelegateForFunction<gsapi_new_instance>("gsapi_new_instance");
 
             if (this.gsapi_new_instance == null)
@@ -249,10 +256,13 @@ private void Initialize()
             if (this.gsapi_set_display_callback == null)
                 throw new GhostscriptException(string.Format(symbolMappingError, "gsapi_set_display_callback"));
 
-            this.gsapi_set_arg_encoding = _library.GetDelegateForFunction<gsapi_set_arg_encoding>("gsapi_set_arg_encoding");
+            if (is_gsapi_set_arg_encoding_supported)
+            {
+                this.gsapi_set_arg_encoding = _library.GetDelegateForFunction<gsapi_set_arg_encoding>("gsapi_set_arg_encoding");
 
-            if (this.gsapi_set_arg_encoding == null)
-                throw new GhostscriptException(string.Format(symbolMappingError, "gsapi_set_arg_encoding"));
+                if (this.gsapi_set_arg_encoding == null)
+                    throw new GhostscriptException(string.Format(symbolMappingError, "gsapi_set_arg_encoding"));
+            }
 
             this.gsapi_init_with_args = _library.GetDelegateForFunction<gsapi_init_with_args>("gsapi_init_with_args");
 
@@ -314,5 +324,33 @@ private void ThrowIncompatibileNativeGhostscriptLibraryException()
 
         #endregion
 
+        #region Revision
+
+        public int Revision
+        {
+            get { return _revision; }
+        }
+
+        #endregion
+
+        #region is_gsapi_set_arg_encoding
+
+        public bool is_gsapi_set_arg_encoding_supported
+        {
+            get
+            {
+                if (_revision >= 910)
+                {
+                    return true;
+                }
+                else
+                {
+                    return false;
+                }
+            }
+        }
+
+        #endregion
+
     }
 }

Ghostscript.NET/Interpreter/GhostscriptInterpreter.cs

@@ -277,8 +277,11 @@ public void Setup(GhostscriptStdIO stdIO, GhostscriptDisplayDeviceHandler displa
         /// </summary>
         public void InitArgs(string[] args)
         {
-            // set the encoding to UTF8
-            int rc_enc = _gs.gsapi_set_arg_encoding(_gs_instance, GS_ARG_ENCODING.UTF8);
+            if (_gs.is_gsapi_set_arg_encoding_supported)
+            {
+                // set the encoding to UTF8
+                int rc_enc = _gs.gsapi_set_arg_encoding(_gs_instance, GS_ARG_ENCODING.UTF8);
+            }
 
             // GSAPI: initialize the interpreter
             int rc_init = _gs.gsapi_init_with_args(_gs_instance, args.Length, args);
@@ -381,5 +384,14 @@ public void RunFile(string path)
 
         #endregion
 
+        #region LibraryRevision
+
+        public int LibraryRevision
+        {
+            get { return _gs.Revision; }
+        }
+
+        #endregion
+
     }
 }

Ghostscript.NET/Processor/GhostscriptProcessor.cs

@@ -276,7 +276,10 @@ public void StartProcessing(string[] args, GhostscriptStdIO stdIO_callback)
 
                 _stopProcessing = false;
 
-                int rc_enc = _gs.gsapi_set_arg_encoding(instance, GS_ARG_ENCODING.UTF8);
+                if (_gs.is_gsapi_set_arg_encoding_supported)
+                {
+                    int rc_enc = _gs.gsapi_set_arg_encoding(instance, GS_ARG_ENCODING.UTF8);
+                }
 
                 int rc_init = _gs.gsapi_init_with_args(instance, args.Length, args);
 

Ghostscript.NET/Viewer/GhostscriptViewer.cs

@@ -376,7 +376,11 @@ private void Open()
 
             args.Add("-dDOINTERPOLATE");
 
-            args.Add("-dMaxBitmap=1g");
+            // fixes bug: http://bugs.ghostscript.com/show_bug.cgi?id=695180
+            if (_interpreter.LibraryRevision > 910)
+            {
+                args.Add("-dMaxBitmap=1g");
+            }
 
             _interpreter.InitArgs(args.ToArray());
 

Ghostscript.NET/gs/iapi.h.cs

@@ -37,10 +37,10 @@ namespace Ghostscript.NET
     [StructLayout(LayoutKind.Sequential)]
     public struct gsapi_revision_s
     {
-        public string product;
-        public string copyright;
-        public Int32 revision;
-        public Int32 revisiondate;
+        public IntPtr product;
+        public IntPtr copyright;
+        public int revision;
+        public int revisiondate;
     }
 
     #endregion
@@ -60,7 +60,7 @@ public struct gsapi_revision_s
     /// <param name="len"></param>
     /// <returns></returns>
     [UnmanagedFunctionPointer(CallingConvention.Winapi)]
-    public delegate int gsapi_revision(out gsapi_revision_s pr, Int32 len);
+    public delegate int gsapi_revision(ref gsapi_revision_s pr, Int32 len);
 
     /// <summary>
     /// Create a new instance of Ghostscript.