Add ability to read from short integers.

IO/SegY/vtkSegYIOUtils.cxx

@@ -37,6 +37,12 @@ vtkSegYIOUtils* vtkSegYIOUtils::Instance()
 short vtkSegYIOUtils::readShortInteger(int pos, std::ifstream& in)
 {
   in.seekg(pos, in.beg);
+  return readShortInteger(in);
+}
+
+//----------------------------------------------------------------------------
+short vtkSegYIOUtils::readShortInteger(std::ifstream& in)
+{
   char buffer[2];
   in.read(buffer, sizeof(buffer));
 
@@ -54,18 +60,7 @@ short vtkSegYIOUtils::readShortInteger(int pos, std::ifstream& in)
 int vtkSegYIOUtils::readLongInteger(int pos, std::ifstream& in)
 {
   in.seekg(pos, in.beg);
-  char buffer[4];
-  in.read(buffer, sizeof(buffer));
-
-  if (!this->IsBigEndian)
-  {
-    swap(buffer, buffer + 3);
-    swap(buffer + 1, buffer + 2);
-  }
-
-  int num;
-  memcpy(&num, buffer, 4);
-  return num;
+  return readLongInteger(in);
 }
 
 //----------------------------------------------------------------------------

IO/SegY/vtkSegYIOUtils.h

@@ -24,6 +24,7 @@ class vtkSegYIOUtils
 public:
   char readChar(std::ifstream& in);
   short readShortInteger(int pos, std::ifstream& in);
+  short readShortInteger(std::ifstream& in);
   int readLongInteger(int pos, std::ifstream& in);
   int readLongInteger(std::ifstream& in);
   float readFloat(std::ifstream& in);

IO/SegY/vtkSegYTraceReader.cxx

@@ -121,6 +121,13 @@ void vtkSegYTraceReader::ReadTrace(int& startPos,
       trace->Data.push_back(value);
     }
     break;
+  case 3:
+    for (int i = 0; i < numSamples; i++)
+    {
+      value = vtkSegYIOUtils::Instance()->readShortInteger(in);
+      trace->Data.push_back(value);
+    }
+    break;
   case 5:
     for (int i = 0; i < numSamples; i++)
     {