| /* -*- 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; |
| } |