1 files changed, 104 insertions, 0 deletions
diff --git a/gs/base/gxfmap.h b/gs/base/gxfmap.h
new file mode 100644
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+++ b/gs/base/gxfmap.h
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+/* Copyright (C) 2001-2006 Artifex Software, Inc.
+   All Rights Reserved.
+  
+   This software is provided AS-IS with no warranty, either express or
+   implied.
+
+   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.,  7 Mt. Lassen Drive - Suite A-134,
+   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
+*/
+
+/* $Id$ */
+/* Fraction map representation for Ghostscript */
+
+#ifndef gxfmap_INCLUDED
+#  define gxfmap_INCLUDED
+
+#include "gsrefct.h"
+#include "gsstype.h"
+#include "gxfrac.h"
+#include "gxtmap.h"
+
+/*
+ * Define a cached map from fracs to fracs.  Level 1 uses this only
+ * for the transfer function; level 2 also uses it for black generation
+ * and undercolor removal.  Note that reference counting macros must
+ * be used to allocate, free, and assign references to gx_transfer_maps.
+ *
+ * NOTE: proc and closure are redundant.  Eventually closure will replace
+ * proc.  For now, things are in an uneasy intermediate state where
+ * proc = 0 means use closure.
+ */
+/* log2... must not be greater than frac_bits, and must be least 8. */
+#define log2_transfer_map_size 8
+#define transfer_map_size (1 << log2_transfer_map_size)
+/*typedef struct gx_transfer_map_s gx_transfer_map; *//* in gxtmap.h */
+struct gx_transfer_map_s {
+    rc_header rc;
+    gs_mapping_proc proc;	/* typedef is in gxtmap.h */
+    gs_mapping_closure_t closure;	/* SEE ABOVE */
+    /* The id changes whenever the map or function changes. */
+    gs_id id;
+    frac values[transfer_map_size];
+};
+
+extern_st(st_transfer_map);
+#define public_st_transfer_map() /* in gscolor.c */\
+  gs_public_st_composite(st_transfer_map, gx_transfer_map, "gx_transfer_map",\
+    transfer_map_enum_ptrs, transfer_map_reloc_ptrs)
+
+/* Set a transfer map to the identity map. */
+void gx_set_identity_transfer(gx_transfer_map *);
+
+/*
+ * Map a color fraction through a transfer map.  If the map is small,
+ * we interpolate; if it is large, we don't, and save a lot of time.
+ */
+#define FRAC_MAP_INTERPOLATE (log2_transfer_map_size <= 8)
+#if FRAC_MAP_INTERPOLATE
+
+frac gx_color_frac_map(frac, const frac *);		/* in gxcmap.c */
+
+#  define gx_map_color_frac(pgs,cf,m)\
+     (pgs->m->proc == gs_identity_transfer ? cf :\
+      gx_color_frac_map(cf, &pgs->m->values[0]))
+
+#else /* !FRAC_MAP_INTERPOLATE */
+
+/* Do the lookup in-line. */
+#  define gx_map_color_frac(pgs,cf,m)\
+     (pgs->m->values[frac2bits(cf, log2_transfer_map_size)])
+
+#endif /* (!)FRAC_MAP_INTERPOLATE */
+
+/* Map a color fraction expressed as a byte through a transfer map. */
+/* (We don't use this anywhere right now.) */
+/****************
+#if log2_transfer_map_size <= 8
+#  define byte_to_tmx(b) ((b) >> (8 - log2_transfer_map_size))
+#else
+#  define byte_to_tmx(b)\
+	(((b) << (log2_transfer_map_size - 8)) +\
+	 ((b) >> (16 - log2_transfer_map_size)))
+#endif
+#define gx_map_color_frac_byte(pgs,b,m)\
+ (pgs->m->values[byte_to_tmx(b)])
+ ****************/
+
+/* Map a floating point value through a transfer map. */
+#define gx_map_color_float(pmap,v)\
+  ((pmap)->values[(int)((v) * transfer_map_size + 0.5)] / frac_1_float)
+
+/* Define a mapping procedure that just looks up the value in the cache. */
+/* (It is equivalent to gx_map_color_float with the arguments swapped.) */
+float gs_mapped_transfer(floatp, const gx_transfer_map *);
+
+/* Define an identity mapping procedure. */
+/* Don't store this directly in proc/closure.proc: */
+/* use gx_set_identity_transfer. */
+float gs_identity_transfer(floatp, const gx_transfer_map *);
+
+#endif /* gxfmap_INCLUDED */