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Diffstat (limited to 'src/cairo-base85-stream.c')
| -rwxr-xr-x | src/cairo-base85-stream.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/src/cairo-base85-stream.c b/src/cairo-base85-stream.c new file mode 100755 index 000000000..f81affb49 --- /dev/null +++ b/src/cairo-base85-stream.c @@ -0,0 +1,131 @@ +/* -*- Mode: c; c-basic-offset: 4; indent-tabs-mode: t; tab-width: 8; -*- */ +/* cairo - a vector graphics library with display and print output + * + * 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., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, 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 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" +#include "cairo-error-private.h" +#include "cairo-output-stream-private.h" + +typedef struct _cairo_base85_stream { + cairo_output_stream_t base; + cairo_output_stream_t *output; + unsigned char four_tuple[4]; + int pending; +} cairo_base85_stream_t; + +static void +_expand_four_tuple_to_five (unsigned char four_tuple[4], + unsigned 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]; + if (all_zero) + *all_zero = TRUE; + for (i = 0; i < 5; i++) { + digit = value % 85; + if (digit != 0 && all_zero) + *all_zero = FALSE; + five_tuple[4-i] = digit + 33; + value = value / 85; + } +} + +static cairo_status_t +_cairo_base85_stream_write (cairo_output_stream_t *base, + const unsigned char *data, + unsigned int length) +{ + cairo_base85_stream_t *stream = (cairo_base85_stream_t *) base; + const unsigned char *ptr = data; + unsigned char five_tuple[5]; + cairo_bool_t is_zero; + + while (length) { + stream->four_tuple[stream->pending++] = *ptr++; + length--; + if (stream->pending == 4) { + _expand_four_tuple_to_five (stream->four_tuple, five_tuple, &is_zero); + if (is_zero) + _cairo_output_stream_write (stream->output, "z", 1); + else + _cairo_output_stream_write (stream->output, five_tuple, 5); + stream->pending = 0; + } + } + + return _cairo_output_stream_get_status (stream->output); +} + +static cairo_status_t +_cairo_base85_stream_close (cairo_output_stream_t *base) +{ + cairo_base85_stream_t *stream = (cairo_base85_stream_t *) base; + unsigned char five_tuple[5]; + + if (stream->pending) { + memset (stream->four_tuple + stream->pending, 0, 4 - stream->pending); + _expand_four_tuple_to_five (stream->four_tuple, five_tuple, NULL); + _cairo_output_stream_write (stream->output, five_tuple, stream->pending + 1); + } + + return _cairo_output_stream_get_status (stream->output); +} + +cairo_output_stream_t * +_cairo_base85_stream_create (cairo_output_stream_t *output) +{ + cairo_base85_stream_t *stream; + + if (output->status) + return _cairo_output_stream_create_in_error (output->status); + + stream = malloc (sizeof (cairo_base85_stream_t)); + if (unlikely (stream == NULL)) { + _cairo_error_throw (CAIRO_STATUS_NO_MEMORY); + return (cairo_output_stream_t *) &_cairo_output_stream_nil; + } + + _cairo_output_stream_init (&stream->base, + _cairo_base85_stream_write, + NULL, + _cairo_base85_stream_close); + stream->output = output; + stream->pending = 0; + + return &stream->base; +} |