1 files changed, 55 insertions, 0 deletions
diff --git a/pcl/pcident.h b/pcl/pcident.h
new file mode 100644
index 000000000..ea0c015ae
--- /dev/null
+++ b/pcl/pcident.h
@@ -0,0 +1,55 @@
+/* Portions Copyright (C) 2001 artofcode LLC.
+   Portions Copyright (C) 1996, 2001 Artifex Software Inc.
+   Portions Copyright (C) 1988, 2000 Aladdin Enterprises.
+   This software is based in part on the work of the Independent JPEG Group.
+   All Rights Reserved.
+
+   This software is distributed under license and may not be copied, modified
+   or distributed except as expressly authorized under the terms of that
+   license.  Refer to licensing information at http://www.artifex.com/ or
+   contact Artifex Software, Inc., 101 Lucas Valley Road #110,
+   San Rafael, CA  94903, (415)492-9861, for further information. */
+/*$Id$ */
+
+/* pcident.h - object identification mechanism for PCL */
+
+#ifndef pcident_INCLUDED
+#define pcident_INCLUDED
+
+#include "gx.h"
+
+/*
+ * Various "graphic attribute" objects created by PCL are used in the graphic
+ * state: patterns, color spaces, halftones, and rendering dictionaries. Unlike
+ * PostScript, these objects also have an existence outside of the graphic state.
+ * When graphic objects are rendered, it is necessary to determine the set of
+ * attribute objects they should use, and which of these is currently installed
+ * in the graphic state.
+ *
+ * There is no way to do this directly in the graphic library, as its attribute
+ * objects do not carry any identifiers (they provide no benefit in a PostScript
+ * setting). Hence, we pair the graphic library objects with PCL objects, and
+ * assign identifiers to the latter. So long as the two objects are kept in a
+ * one-to-one relationship, the identifiers can be used as identifiers of the
+ * graphic library objects as well.
+ *
+ * Though objects of different types can in principle be assigned the same
+ * identifier, for simplicity the current code assigns unique identifiers for
+ * all objects. These identifiers are unsigned longs. They are assigned
+ * consecutively beginning from 8 at boot time. In the unlikely event that
+ * they should reach 0 once more, they will restart at 16 * 1024 * 1024; this
+ * should prevent overlap with codes that are assigned to statically allocated
+ * objects at boot time.
+ */
+
+typedef ulong   pcl_gsid_t;
+
+/* Define an opaque type for the PCL state. */
+#ifndef pcl_state_DEFINED
+#  define pcl_state_DEFINED
+typedef struct pcl_state_s pcl_state_t;
+#endif
+
+pcl_gsid_t  pcl_next_id(pcl_state_t *pcs);
+
+#endif  /* pcident_INCLUDED */