Move base85 code out of cairo-output-stream.c into new cairo-base85-stream.c

1 files changed, 98 insertions, 0 deletions

diff --git a/src/cairo-base85-stream.c b/src/cairo-base85-stream.c
new file mode 100644
index 000000000..0bb6f320f
--- /dev/null
+++ b/src/cairo-base85-stream.c
@@ -0,0 +1,98 @@
+/* cairo_output_stream.c: Output stream abstraction
+ * 
+ * Copyright © 2005 Red Hat, Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ * The Original Code is cairo_output_stream.c as distributed with the
+ *   cairo graphics library.
+ *
+ * The Initial Developer of the Original Code is Red Hat, Inc.
+ *
+ * Author(s):
+ *	Kristian Høgsberg <krh@redhat.com>
+ */
+
+#include "cairoint.h"
+
+static cairo_bool_t
+_convert_four_tuple (const unsigned char *four_tuple, char five_tuple[5])
+{
+    cairo_bool_t all_zero;
+    uint32_t value;
+    int digit, i;
+    
+    value = four_tuple[0] << 24 | four_tuple[1] << 16 | four_tuple[2] << 8 | four_tuple[3];
+    all_zero = TRUE;
+    for (i = 0; i < 5; i++) {
+	digit = value % 85;
+	if (digit != 0)
+	    all_zero = FALSE;
+	five_tuple[4-i] = digit + 33;
+	value = value / 85;
+    }
+    return all_zero;
+}
+
+void
+_cairo_output_stream_write_base85_string (cairo_output_stream_t *stream,
+					  const char *data,
+					  size_t length)
+{
+    unsigned char *ptr;
+    unsigned char four_tuple[4];
+    char five_tuple[5];
+    int column;
+    
+    ptr = (unsigned char *)data;
+    column = 0;
+    while (length > 0) {
+	if (length >= 4) {
+	    if (_convert_four_tuple (ptr, five_tuple)) {
+		column += 1;
+		_cairo_output_stream_write (stream, "z", 1);
+	    } else {
+		column += 5;
+		_cairo_output_stream_write (stream, five_tuple, 5);
+	    }
+	    length -= 4;
+	    ptr += 4;
+	} else { /* length < 4 */
+	    memset (four_tuple, 0, 4);
+	    memcpy (four_tuple, ptr, length);
+	    _convert_four_tuple (four_tuple, five_tuple);
+	    column += length + 1;
+	    _cairo_output_stream_write (stream, five_tuple, length + 1);
+	    length = 0;
+	}
+	if (column >= 72) {
+	    _cairo_output_stream_write (stream, "\n", 1);
+	    column = 0;
+	}
+    }
+
+    if (column > 0) {
+	_cairo_output_stream_write (stream, "\n", 1);
+    }
+}