Quelle  cairo-svg-surface.c   Sprache: C

/* vim: set sw=4 sts=4: -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
/* cairo - a vector graphics library with display and print output
 *
 * Copyright © 2004 Red Hat, Inc
 * Copyright © 2005-2007 Emmanuel Pacaud <emmanuel.pacaud@free.fr>
 * Copyright © 2006 Red Hat, Inc
 * Copyright © 2020-2021 Anton Danilkin <afdw@yandex.ru>
 *
 * 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 University of Southern
 * California.
 *
 * Contributor(s):
 * Kristian Høgsberg <krh@redhat.com>
 * Emmanuel Pacaud <emmanuel.pacaud@free.fr>
 * Carl Worth <cworth@cworth.org>
 * Anton Danilkin <afdw@yandex.ru>
 */

#include "cairoint.h"

#include "cairo-svg.h"

#include "cairo-array-private.h"
#include "cairo-default-context-private.h"
#include "cairo-error-private.h"
#include "cairo-image-info-private.h"
#include "cairo-image-surface-private.h"
#include "cairo-recording-surface-inline.h"
#include "cairo-output-stream-private.h"
#include "cairo-paginated-private.h"
#include "cairo-scaled-font-subsets-private.h"
#include "cairo-surface-clipper-private.h"
#include "cairo-surface-snapshot-inline.h"
#include "cairo-svg-surface-private.h"

/**
 * SECTION:cairo-svg
 * @Title: SVG Surfaces
 * @Short_Description: Rendering SVG documents
 * @See_Also: #cairo_surface_t
 *
 * The SVG surface is used to render cairo graphics to
 * SVG files and is a multi-page vector surface backend.
 **/

typedef struct _cairo_svg_source_surface {
    cairo_hash_entry_t base;
    unsigned int id;
    unsigned char *unique_id;
    unsigned long unique_id_length;
    cairo_bool_t transitive_paint_used;
} cairo_svg_source_surface_t;

/*
 * _cairo_svg_paint_element and _cairo_svg_paint are used to implement paints in transformed recording patterns.
 */

typedef struct _cairo_svg_paint_element {
    unsigned int source_id;
    cairo_matrix_t matrix;
} cairo_svg_paint_element_t;

typedef struct _cairo_svg_paint {
    cairo_hash_entry_t base;
    unsigned int source_id;
    cairo_array_t paint_elements;
    cairo_box_double_t box;
} cairo_svg_paint_t;

static void
_cairo_svg_source_surface_init_key (cairo_svg_source_surface_t *source_surface)
{
    if (source_surface->unique_id && source_surface->unique_id_length > 0) {
 source_surface->base.hash = _cairo_hash_bytes (_CAIRO_HASH_INIT_VALUE,
             source_surface->unique_id,
             source_surface->unique_id_length);
    } else {
 source_surface->base.hash = source_surface->id;
    }
}

static cairo_bool_t
_cairo_svg_source_surface_equal (const void *key_a, const void *key_b)
{
    const cairo_svg_source_surface_t *a = key_a;
    const cairo_svg_source_surface_t *b = key_b;

    if (a->unique_id && b->unique_id && a->unique_id_length == b->unique_id_length) {
 return memcmp (a->unique_id, b->unique_id, a->unique_id_length) == 0;
    }

    return a->id == b->id;
}

static void
_cairo_svg_source_surface_pluck (void *entry, void *closure)
{
    cairo_svg_source_surface_t *source_surface = entry;
    cairo_hash_table_t *patterns = closure;

    _cairo_hash_table_remove (patterns, &source_surface->base);
    free (source_surface->unique_id);
    free (source_surface);
}

static void
_cairo_svg_paint_init_key (cairo_svg_paint_t *paint)
{
    paint->base.hash = paint->source_id;
}

static cairo_bool_t
_cairo_svg_paint_equal (const void *key_a, const void *key_b)
{
    const cairo_svg_paint_t *a = key_a;
    const cairo_svg_paint_t *b = key_b;

    return a->source_id == b->source_id;
}

static void
_cairo_svg_paint_pluck (void *entry, void *closure)
{
    cairo_svg_paint_t *paint = entry;
    cairo_hash_table_t *patterns = closure;

    _cairo_hash_table_remove (patterns, &paint->base);
    _cairo_array_fini (&paint->paint_elements);
    free (paint);
}

static void
_cairo_svg_paint_box_add_padding (cairo_box_double_t *box)
{
    double width = box->p2.x - box->p1.x;
    double height = box->p2.y - box->p1.y;

    box->p1.x -= width / 10.0;
    box->p1.y -= height / 10.0;
    box->p2.x += width / 10.0;
    box->p2.y += height / 10.0;
}

enum cairo_svg_stream_element_type {
    CAIRO_SVG_STREAM_ELEMENT_TYPE_TEXT,
    CAIRO_SVG_STREAM_ELEMENT_TYPE_PAINT_DEPENDENT,
};

enum cairo_svg_stream_paint_dependent_element_type {
    CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE,
    CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE_AT_ORIGIN,
    CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_TRANSLATION,
    CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_INVERSE_TRANSLATION,
};

typedef struct _cairo_svg_stream_element {
    enum cairo_svg_stream_element_type type;
    union {
        struct {
     cairo_output_stream_t *output_stream;
 } text;
        struct {
     unsigned int source_id;
     enum cairo_svg_stream_paint_dependent_element_type type;
        } paint_dependent;
    };
} cairo_svg_stream_element_t;

typedef struct _cairo_svg_stream {
    cairo_status_t status;
    cairo_array_t elements;
} cairo_svg_stream_t;

static cairo_svg_stream_t
_cairo_svg_stream_create ()
{
    cairo_svg_stream_t svg_stream;
    svg_stream.status = CAIRO_STATUS_SUCCESS;
    _cairo_array_init (&svg_stream.elements, sizeof (cairo_svg_stream_element_t));
    return svg_stream;
}

static void
_cairo_svg_stream_write (cairo_svg_stream_t *svg_stream,
    const void *data,
    size_t length)
{
    cairo_status_t status;

    cairo_svg_stream_element_t *last_element = NULL;
    if (svg_stream->elements.num_elements > 0) {
 last_element = _cairo_array_index (&svg_stream->elements,
        svg_stream->elements.num_elements - 1);
    }

    if (last_element == NULL || last_element->type != CAIRO_SVG_STREAM_ELEMENT_TYPE_TEXT) {
 cairo_svg_stream_element_t element;
 element.type = CAIRO_SVG_STREAM_ELEMENT_TYPE_TEXT;
 element.text.output_stream = _cairo_memory_stream_create();
 status = _cairo_array_append (&svg_stream->elements, &element);
 if (unlikely (status)) {
     if (svg_stream->status == CAIRO_STATUS_SUCCESS) {
  svg_stream->status = status;
     }
     return;
 }
 last_element = _cairo_array_index (&svg_stream->elements,
        svg_stream->elements.num_elements - 1);
    }

    _cairo_output_stream_write (last_element->text.output_stream, data, length);
}

static void CAIRO_PRINTF_FORMAT (2, 0)
_cairo_svg_stream_printf (cairo_svg_stream_t *svg_stream,
     const char *fmt,
     ...)
{
    cairo_status_t status;

    cairo_svg_stream_element_t *last_element = NULL;
    if (svg_stream->elements.num_elements > 0) {
 last_element = _cairo_array_index (&svg_stream->elements,
        svg_stream->elements.num_elements - 1);
    }

    if (last_element == NULL || last_element->type != CAIRO_SVG_STREAM_ELEMENT_TYPE_TEXT) {
        cairo_svg_stream_element_t element;
 element.type = CAIRO_SVG_STREAM_ELEMENT_TYPE_TEXT;
 element.text.output_stream = _cairo_memory_stream_create();
 status = _cairo_array_append (&svg_stream->elements, &element);
 if (unlikely (status)) {
     if (svg_stream->status == CAIRO_STATUS_SUCCESS) {
  svg_stream->status = status;
     }
     return;
 }
 last_element = _cairo_array_index (&svg_stream->elements,
        svg_stream->elements.num_elements - 1);
    }

    va_list ap;
    va_start (ap, fmt);
    _cairo_output_stream_vprintf (last_element->text.output_stream, fmt, ap);
    va_end (ap);
}

static void
_cairo_svg_stream_append_paint_dependent (cairo_svg_stream_t *svg_stream,
       unsigned int source_id,
       enum cairo_svg_stream_paint_dependent_element_type type)
{
    cairo_status_t status;

    cairo_svg_stream_element_t element;
    element.type = CAIRO_SVG_STREAM_ELEMENT_TYPE_PAINT_DEPENDENT;
    element.paint_dependent.source_id = source_id;
    element.paint_dependent.type = type;
    status = _cairo_array_append (&svg_stream->elements, &element);
    if (svg_stream->status == CAIRO_STATUS_SUCCESS) {
 svg_stream->status = status;
    }
}

static void
_cairo_svg_stream_copy (cairo_svg_stream_t *from,
   cairo_svg_stream_t *to)
{
    cairo_status_t status;

    if (unlikely (from->status)) {
 if (to->status == CAIRO_STATUS_SUCCESS) {
     to->status = from->status;
 }
 return;
    }

    for (unsigned int i = 0; i < from->elements.num_elements; i++) {
 cairo_svg_stream_element_t *element = _cairo_array_index (&from->elements, i);
 cairo_svg_stream_element_t element_copy = *element;
 if (element->type == CAIRO_SVG_STREAM_ELEMENT_TYPE_TEXT) {
     element_copy.text.output_stream = _cairo_memory_stream_create ();
     _cairo_memory_stream_copy (element->text.output_stream, element_copy.text.output_stream);
     if (to->status == CAIRO_STATUS_SUCCESS) {
  to->status = element->text.output_stream->status;
     }
 }
 status = _cairo_array_append (&to->elements, &element_copy);
 if (unlikely (status)) {
     if (to->status == CAIRO_STATUS_SUCCESS) {
  to->status = status;
     }
     return;
 }
    }
}

static void
_cairo_svg_stream_copy_to_output_stream (cairo_svg_stream_t *from,
      cairo_output_stream_t *to,
      cairo_hash_table_t *paints)
{
    if (unlikely (from->status)) {
 if (to->status == CAIRO_STATUS_SUCCESS) {
     to->status = from->status;
 }
 return;
    }

    for (unsigned int i = 0; i < from->elements.num_elements; i++) {
 cairo_svg_stream_element_t *element = _cairo_array_index (&from->elements, i);
 if (element->type == CAIRO_SVG_STREAM_ELEMENT_TYPE_TEXT) {
     _cairo_memory_stream_copy (element->text.output_stream, to);
 }
 if (element->type == CAIRO_SVG_STREAM_ELEMENT_TYPE_PAINT_DEPENDENT) {
     cairo_svg_paint_t paint_key;
     paint_key.source_id = element->paint_dependent.source_id;
     _cairo_svg_paint_init_key (&paint_key);

     cairo_svg_paint_t *found_paint_entry = _cairo_hash_table_lookup (paints,
              &paint_key.base);
     assert (found_paint_entry);

     switch (element->paint_dependent.type) {
     case CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE:
  _cairo_output_stream_printf (to,
          " x=\"%f\" y=\"%f\" width=\"%f\" height=\"%f\"",
          found_paint_entry->box.p1.x,
          found_paint_entry->box.p1.y,
          found_paint_entry->box.p2.x - found_paint_entry->box.p1.x,
          found_paint_entry->box.p2.y - found_paint_entry->box.p1.y);
  break;
     case CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE_AT_ORIGIN:
  _cairo_output_stream_printf (to,
          " x=\"0\" y=\"0\" width=\"%f\" height=\"%f\"",
          found_paint_entry->box.p2.x - found_paint_entry->box.p1.x,
          found_paint_entry->box.p2.y - found_paint_entry->box.p1.y);
  break;
     case CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_TRANSLATION:
  _cairo_output_stream_printf (to,
          " transform=\"translate(%f, %f)\"",
          found_paint_entry->box.p1.x,
          found_paint_entry->box.p1.y);
  break;
     case CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_INVERSE_TRANSLATION:
  _cairo_output_stream_printf (to,
          " transform=\"translate(%f, %f)\"",
          -found_paint_entry->box.p1.x,
          -found_paint_entry->box.p1.y);
  break;
     }
 }
    }
}

static cairo_status_t
_cairo_svg_stream_destroy (cairo_svg_stream_t *svg_stream)
{
    cairo_status_t status = svg_stream->status;
    for (unsigned int i = 0; i < svg_stream->elements.num_elements; i++) {
 cairo_svg_stream_element_t *element = _cairo_array_index (&svg_stream->elements, i);
 if (element->type == CAIRO_SVG_STREAM_ELEMENT_TYPE_TEXT) {
     cairo_status_t element_status = _cairo_output_stream_destroy (element->text.output_stream);
     if (status == CAIRO_STATUS_SUCCESS) {
  status = element_status;
     }
 }
    }
    _cairo_array_fini (&svg_stream->elements);
    return status;
}

/**
 * CAIRO_HAS_SVG_SURFACE:
 *
 * Defined if the SVG surface backend is available.
 * This macro can be used to conditionally compile backend-specific code.
 *
 * Since: 1.2
 **/

static const unsigned int invalid_pattern_id = -1;

static const cairo_svg_version_t _cairo_svg_versions[] =
{
    CAIRO_SVG_VERSION_1_1,
    CAIRO_SVG_VERSION_1_2
};

#define CAIRO_SVG_VERSION_LAST ARRAY_LENGTH (_cairo_svg_versions)

static const char *_cairo_svg_supported_mime_types[] =
{
    CAIRO_MIME_TYPE_JPEG,
    CAIRO_MIME_TYPE_PNG,
    CAIRO_MIME_TYPE_UNIQUE_ID,
    CAIRO_MIME_TYPE_URI,
    NULL
};

static void
_cairo_svg_surface_emit_path (cairo_svg_stream_t *output,
         const cairo_path_fixed_t *path,
         const cairo_matrix_t *ctm_inverse);

static const char * _cairo_svg_version_strings[CAIRO_SVG_VERSION_LAST] =
{
    "SVG 1.1",
    "SVG 1.2"
};

static const char * _cairo_svg_unit_strings[] =
{
    "",
    "em",
    "ex",
    "px",
    "in",
    "cm",
    "mm",
    "pt",
    "pc",
    "%"
};

enum cairo_svg_filter {
    CAIRO_SVG_FILTER_REMOVE_COLOR,
    CAIRO_SVG_FILTER_REMOVE_COLOR_AND_INVERT_ALPHA,
    CAIRO_SVG_FILTER_COLOR_TO_ALPHA,
    CAIRO_SVG_FILTER_LAST_STATIC_FILTER,
    CAIRO_SVG_FILTER_OVER,
    CAIRO_SVG_FILTER_IN,
    CAIRO_SVG_FILTER_OUT,
    CAIRO_SVG_FILTER_ATOP,
    CAIRO_SVG_FILTER_XOR,
    CAIRO_SVG_FILTER_ADD,
    CAIRO_SVG_FILTER_MULTIPLY,
    CAIRO_SVG_FILTER_SCREEN,
    CAIRO_SVG_FILTER_OVERLAY,
    CAIRO_SVG_FILTER_DARKEN,
    CAIRO_SVG_FILTER_LIGHTEN,
    CAIRO_SVG_FILTER_COLOR_DODGE,
    CAIRO_SVG_FILTER_COLOR_BURN,
    CAIRO_SVG_FILTER_HARD_LIGHT,
    CAIRO_SVG_FILTER_SOFT_LIGHT,
    CAIRO_SVG_FILTER_DIFFERENCE,
    CAIRO_SVG_FILTER_EXCLUSION,
    CAIRO_SVG_FILTER_HUE,
    CAIRO_SVG_FILTER_SATURATION,
    CAIRO_SVG_FILTER_COLOR,
    CAIRO_SVG_FILTER_LUMINOSITY,
};

typedef struct _cairo_svg_page {
    cairo_svg_stream_t xml_node;
} cairo_svg_page_t;

typedef struct _cairo_svg_document {
    cairo_output_stream_t *output_stream;
    unsigned long refcount;
    cairo_surface_t *owner;
    cairo_bool_t finished;

    double width;
    double height;
    cairo_svg_unit_t unit;

    cairo_svg_stream_t xml_node_defs;
    cairo_svg_stream_t xml_node_glyphs;
    cairo_svg_stream_t xml_node_filters;

    unsigned int linear_pattern_id;
    unsigned int radial_pattern_id;
    unsigned int pattern_id;
    unsigned int clip_id;
    unsigned int mask_id;
    unsigned int compositing_group_id;
    unsigned int filter_id;

    cairo_bool_t filters_emitted[CAIRO_SVG_FILTER_LAST_STATIC_FILTER];

    cairo_svg_version_t svg_version;

    cairo_scaled_font_subsets_t *font_subsets;

    cairo_hash_table_t *paints;
} cairo_svg_document_t;

// Must be compatible with the struct _cairo_svg_surface_start.
typedef struct _cairo_svg_surface {
    cairo_surface_t base;

    cairo_bool_t force_fallbacks;

    unsigned int source_id;
    unsigned int depth;

    double width;
    double height;
    cairo_bool_t surface_bounded;

    cairo_svg_document_t *document;

    cairo_svg_stream_t xml_node;
    cairo_array_t page_set;

    cairo_hash_table_t *source_surfaces;

    cairo_surface_clipper_t clipper;
    cairo_svg_stream_t *current_clipper_stream;
    unsigned int clip_level;

    cairo_bool_t transitive_paint_used;

    cairo_paginated_mode_t paginated_mode;
} cairo_svg_surface_t;

static cairo_status_t
_cairo_svg_document_create (cairo_output_stream_t *stream,
       double width,
       double height,
       cairo_svg_version_t version,
       cairo_svg_document_t **document_out);

static cairo_status_t
_cairo_svg_document_destroy (cairo_svg_document_t *document);

static cairo_status_t
_cairo_svg_document_finish (cairo_svg_document_t *document);

static cairo_svg_document_t *
_cairo_svg_document_reference (cairo_svg_document_t *document);

static cairo_surface_t *
_cairo_svg_surface_create_for_document (cairo_svg_document_t *document,
     cairo_content_t content,
     double width,
     double height,
     cairo_bool_t bounded);

static cairo_surface_t *
_cairo_svg_surface_create_for_stream_internal (cairo_output_stream_t *stream,
            double width,
            double height,
            cairo_svg_version_t version);

static cairo_status_t
_cairo_svg_surface_emit_composite_pattern (cairo_svg_stream_t *output,
        cairo_svg_surface_t *surface,
        cairo_surface_pattern_t *pattern,
        unsigned int pattern_id,
        const cairo_matrix_t *parent_matrix);

static cairo_status_t
_cairo_svg_surface_emit_paint (cairo_svg_stream_t *output,
          cairo_svg_surface_t *surface,
          const cairo_pattern_t *source,
          cairo_bool_t at_origin);

static const cairo_surface_backend_t cairo_svg_surface_backend;
static const cairo_paginated_surface_backend_t cairo_svg_surface_paginated_backend;

/**
 * cairo_svg_surface_create_for_stream:
 * @write_func: a #cairo_write_func_t to accept the output data, may be %NULL
 *              to indicate a no-op @write_func. With a no-op @write_func,
 *              the surface may be queried or used as a source without
 *              generating any temporary files.
 * @closure: the closure argument for @write_func
 * @width_in_points: width of the surface, in points (1 point == 1/72.0 inch)
 * @height_in_points: height of the surface, in points (1 point == 1/72.0 inch)
 *
 * Creates a SVG surface of the specified size in points to be written
 * incrementally to the stream represented by @write_func and @closure.
 *
 * Return value: a pointer to the newly created surface. The caller
 * owns the surface and should call cairo_surface_destroy() when done
 * with it.
 *
 * This function always returns a valid pointer, but it will return a
 * pointer to a "nil" surface if an error such as out of memory
 * occurs. You can use cairo_surface_status() to check for this.
 *
 * Since: 1.2
 **/
cairo_surface_t *
cairo_svg_surface_create_for_stream (cairo_write_func_t   write_func,
         void   *closure,
         double    width,
         double    height)
{
    cairo_output_stream_t *stream;

    stream = _cairo_output_stream_create (write_func, NULL, closure);
    if (_cairo_output_stream_get_status (stream))
 return _cairo_surface_create_in_error (_cairo_output_stream_destroy (stream));

    return _cairo_svg_surface_create_for_stream_internal (stream, width, height, CAIRO_SVG_VERSION_1_1);
}

/**
 * cairo_svg_surface_create:
 * @filename: a filename for the SVG output (must be writable), %NULL may be
 *            used to specify no output. This will generate a SVG surface that
 *            may be queried and used as a source, without generating a
 *            temporary file.
 * @width_in_points: width of the surface, in points (1 point == 1/72.0 inch)
 * @height_in_points: height of the surface, in points (1 point == 1/72.0 inch)
 *
 * Creates a SVG surface of the specified size in points to be written
 * to @filename.
 *
 * The SVG surface backend recognizes the following MIME types for the
 * data attached to a surface (see cairo_surface_set_mime_data()) when
 * it is used as a source pattern for drawing on this surface:
 * %CAIRO_MIME_TYPE_JPEG, %CAIRO_MIME_TYPE_PNG,
 * %CAIRO_MIME_TYPE_URI. If any of them is specified, the SVG backend
 * emits a href with the content of MIME data instead of a surface
 * snapshot (PNG, Base64-encoded) in the corresponding image tag.
 *
 * The unofficial MIME type %CAIRO_MIME_TYPE_URI is examined
 * first. If present, the URI is emitted as is: assuring the
 * correctness of URI is left to the client code.
 *
 * If %CAIRO_MIME_TYPE_URI is not present, but %CAIRO_MIME_TYPE_JPEG
 * or %CAIRO_MIME_TYPE_PNG is specified, the corresponding data is
 * Base64-encoded and emitted.
 *
 * If %CAIRO_MIME_TYPE_UNIQUE_ID is present, all surfaces with the same
 * unique identifier will only be embedded once.
 *
 * Return value: a pointer to the newly created surface. The caller
 * owns the surface and should call cairo_surface_destroy() when done
 * with it.
 *
 * This function always returns a valid pointer, but it will return a
 * pointer to a "nil" surface if an error such as out of memory
 * occurs. You can use cairo_surface_status() to check for this.
 *
 * Since: 1.2
 **/
cairo_surface_t *
cairo_svg_surface_create (const char *filename,
     double  width,
     double  height)
{
    cairo_output_stream_t *stream;

    stream = _cairo_output_stream_create_for_filename (filename);
    if (_cairo_output_stream_get_status (stream))
 return _cairo_surface_create_in_error (_cairo_output_stream_destroy (stream));

    return _cairo_svg_surface_create_for_stream_internal (stream, width, height, CAIRO_SVG_VERSION_1_1);
}

static cairo_bool_t
_cairo_surface_is_svg (cairo_surface_t *surface)
{
    return surface->backend == &cairo_svg_surface_backend;
}

/* If the abstract_surface is a paginated surface, and that paginated
 * surface's target is a svg_surface, then set svg_surface to that
 * target. Otherwise return FALSE.
 */
static cairo_bool_t
_extract_svg_surface (cairo_surface_t *surface,
        cairo_svg_surface_t **svg_surface)
{
    cairo_surface_t *target;

    if (surface->status)
 return FALSE;
    if (surface->finished) {
 (void) _cairo_surface_set_error (surface, _cairo_error (CAIRO_STATUS_SURFACE_FINISHED));
 return FALSE;
    }

    if (!_cairo_surface_is_paginated (surface)) {
 (void) _cairo_surface_set_error (surface, _cairo_error (CAIRO_STATUS_SURFACE_TYPE_MISMATCH));
 return FALSE;
    }

    target = _cairo_paginated_surface_get_target (surface);
    if (target->status) {
 (void) _cairo_surface_set_error (surface, target->status);
 return FALSE;
    }
    if (target->finished) {
 (void) _cairo_surface_set_error (surface, _cairo_error (CAIRO_STATUS_SURFACE_FINISHED));
 return FALSE;
    }

    if (!_cairo_surface_is_svg (target)) {
 (void) _cairo_surface_set_error (surface, _cairo_error (CAIRO_STATUS_SURFACE_TYPE_MISMATCH));
 return FALSE;
    }

    *svg_surface = (cairo_svg_surface_t *) target;
    return TRUE;
}

/**
 * cairo_svg_surface_restrict_to_version:
 * @surface: a SVG #cairo_surface_t
 * @version: SVG version
 *
 * Restricts the generated SVG file to @version. See cairo_svg_get_versions()
 * for a list of available version values that can be used here.
 *
 * This function should only be called before any drawing operations
 * have been performed on the given surface. The simplest way to do
 * this is to call this function immediately after creating the
 * surface.
 *
 * Since: 1.2
 **/
void
cairo_svg_surface_restrict_to_version (cairo_surface_t  *abstract_surface,
           cairo_svg_version_t  version)
{
    cairo_svg_surface_t *surface;

    if (! _extract_svg_surface (abstract_surface, &surface))
 return;

    if (version < CAIRO_SVG_VERSION_LAST)
 surface->document->svg_version = version;
}

/**
 * cairo_svg_get_versions:
 * @versions: supported version list
 * @num_versions: list length
 *
 * Used to retrieve the list of supported versions. See
 * cairo_svg_surface_restrict_to_version().
 *
 * Since: 1.2
 **/
void
cairo_svg_get_versions (cairo_svg_version_t const **versions,
                        int     *num_versions)
{
    if (versions != NULL)
 *versions = _cairo_svg_versions;

    if (num_versions != NULL)
 *num_versions = CAIRO_SVG_VERSION_LAST;
}

/**
 * cairo_svg_version_to_string:
 * @version: a version id
 *
 * Get the string representation of the given @version id. This function
 * will return %NULL if @version isn't valid. See cairo_svg_get_versions()
 * for a way to get the list of valid version ids.
 *
 * Return value: the string associated to given version.
 *
 * Since: 1.2
 **/
const char *
cairo_svg_version_to_string (cairo_svg_version_t version)
{
    if (version >= CAIRO_SVG_VERSION_LAST)
 return NULL;

    return _cairo_svg_version_strings[version];
}

/**
 * cairo_svg_surface_set_document_unit:
 * @surface: a SVG #cairo_surface_t
 * @unit: SVG unit
 *
 * Use the specified unit for the width and height of the generated SVG file.
 * See #cairo_svg_unit_t for a list of available unit values that can be used
 * here.
 *
 * This function can be called at any time before generating the SVG file.
 *
 * However to minimize the risk of ambiguities it's recommended to call it
 * before any drawing operations have been performed on the given surface, to
 * make it clearer what the unit used in the drawing operations is.
 *
 * The simplest way to do this is to call this function immediately after
 * creating the SVG surface.
 *
 * Note if this function is never called, the default unit for SVG documents
 * generated by cairo will be user unit.
 *
 * Since: 1.16
 **/
void
cairo_svg_surface_set_document_unit (cairo_surface_t *abstract_surface,
         cairo_svg_unit_t  unit)
{
    cairo_svg_surface_t *surface;

    if (! _extract_svg_surface (abstract_surface, &surface))
 return;

    if (unit <= CAIRO_SVG_UNIT_PERCENT)
 surface->document->unit = unit;
}

/**
 * cairo_svg_surface_get_document_unit:
 * @surface: a SVG #cairo_surface_t
 *
 * Get the unit of the SVG surface.
 *
 * If the surface passed as an argument is not a SVG surface, the function
 * sets the error status to CAIRO_STATUS_SURFACE_TYPE_MISMATCH and returns
 * CAIRO_SVG_UNIT_USER.
 *
 * Return value: the SVG unit of the SVG surface.
 *
 * Since: 1.16
 **/
cairo_svg_unit_t
cairo_svg_surface_get_document_unit (cairo_surface_t *abstract_surface)
{
    cairo_svg_surface_t *surface;

    if (! _extract_svg_surface (abstract_surface, &surface)) {
 _cairo_error_throw (CAIRO_STATUS_SURFACE_TYPE_MISMATCH);
 return CAIRO_SVG_UNIT_USER;
    }

    return surface->document->unit;
}

static void
_cairo_svg_paint_compute (cairo_svg_document_t *document, cairo_svg_paint_t *paint) {
    for (unsigned int i = 0; i < paint->paint_elements.num_elements; i++) {
 cairo_svg_paint_element_t *paint_element = _cairo_array_index (&paint->paint_elements, i);

 cairo_svg_paint_t paint_key;
 paint_key.source_id = paint_element->source_id;
 _cairo_svg_paint_init_key (&paint_key);

 cairo_svg_paint_t *found_paint_entry = _cairo_hash_table_lookup (document->paints,
          &paint_key.base);
 assert (found_paint_entry);

 _cairo_svg_paint_compute (document, found_paint_entry);

 cairo_box_double_t box = found_paint_entry->box;
 _cairo_matrix_transform_bounding_box (&paint_element->matrix,
           &box.p1.x, &box.p1.y,
           &box.p2.x, &box.p2.y,
           NULL);
 _cairo_svg_paint_box_add_padding (&box);

 if (i == 0) {
     paint->box = box;
 } else {
     paint->box.p1.x = MIN (paint->box.p1.x, box.p1.x);
     paint->box.p1.y = MIN (paint->box.p1.y, box.p1.y);
     paint->box.p2.x = MAX (paint->box.p2.x, box.p2.x);
     paint->box.p2.y = MAX (paint->box.p2.y, box.p2.y);
 }
    }
    _cairo_array_truncate (&paint->paint_elements, 0);
}

static void
_cairo_svg_paint_compute_func (void *entry, void *closure)
{
    cairo_svg_paint_t *paint = entry;
    cairo_svg_document_t *document = closure;

    _cairo_svg_paint_compute (document, paint);
}

static cairo_status_t
_cairo_svg_surface_add_source_surface (cairo_svg_surface_t *surface,
           cairo_surface_t *source_surface,
           cairo_bool_t *is_new,
           cairo_svg_source_surface_t **result_source_surface)
{
    cairo_status_t status;

    cairo_svg_source_surface_t source_surface_key;
    source_surface_key.id = source_surface->unique_id;
    cairo_surface_get_mime_data (source_surface,
     CAIRO_MIME_TYPE_UNIQUE_ID,
     (const unsigned char **) &source_surface_key.unique_id,
     &source_surface_key.unique_id_length);
    _cairo_svg_source_surface_init_key (&source_surface_key);

    cairo_svg_source_surface_t *found_source_surface_entry = _cairo_hash_table_lookup (surface->source_surfaces,
                 &source_surface_key.base);
    if (found_source_surface_entry) {
 *is_new = FALSE;
 *result_source_surface = found_source_surface_entry;
 return CAIRO_STATUS_SUCCESS;
    }

    unsigned char *unique_id = NULL;
    unsigned long unique_id_length = 0;
    if (source_surface_key.unique_id && source_surface_key.unique_id_length > 0) {
 unique_id = _cairo_malloc (source_surface_key.unique_id_length);
 if (unique_id == NULL) {
     return _cairo_error (CAIRO_STATUS_NO_MEMORY);
 }

 unique_id_length = source_surface_key.unique_id_length;
 memcpy (unique_id, source_surface_key.unique_id, unique_id_length);
    } else {
 unique_id = NULL;
 unique_id_length = 0;
    }

    cairo_svg_source_surface_t *source_surface_entry = malloc (sizeof (cairo_svg_source_surface_t));
    if (source_surface_entry == NULL) {
 status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
 goto fail;
    }
    source_surface_entry->id = source_surface_key.id;
    source_surface_entry->unique_id_length = unique_id_length;
    source_surface_entry->unique_id = unique_id;
    _cairo_svg_source_surface_init_key (source_surface_entry);
    status = _cairo_hash_table_insert (surface->source_surfaces, &source_surface_entry->base);
    if (unlikely (status)) {
 goto fail;
    }

    *is_new = TRUE;
    *result_source_surface = source_surface_entry;
    return CAIRO_STATUS_SUCCESS;

    fail:
    free (unique_id);
    free (source_surface_entry);
    return status;
}

static cairo_bool_t
_cairo_svg_surface_cliprect_covers_surface (cairo_svg_surface_t *surface,
         cairo_path_fixed_t *path)
{
    cairo_box_t box;

    return surface->surface_bounded &&
    _cairo_path_fixed_is_box (path, &box) &&
    box.p1.x <= 0 &&
    box.p1.y <= 0 &&
    _cairo_fixed_to_double (box.p2.x) >= surface->width &&
    _cairo_fixed_to_double (box.p2.y) >= surface->height;
}

static cairo_status_t
_cairo_svg_surface_clipper_intersect_clip_path (cairo_surface_clipper_t *clipper,
      cairo_path_fixed_t *path,
      cairo_fill_rule_t fill_rule,
      double tolerance,
      cairo_antialias_t antialias)
{
    cairo_svg_surface_t *surface = cairo_container_of (clipper,
             cairo_svg_surface_t,
             clipper);
    cairo_svg_document_t *document = surface->document;

    if (path == NULL) {
 for (unsigned int i = 0; i < surface->clip_level; i++) {
     _cairo_svg_stream_printf (surface->current_clipper_stream, "\n");
 }
 surface->clip_level = 0;
 return CAIRO_STATUS_SUCCESS;
    }

    /* skip trivial whole-page clips */
    if (_cairo_svg_surface_cliprect_covers_surface (surface, path)) {
 return CAIRO_STATUS_SUCCESS;
    }

    _cairo_svg_stream_printf (&document->xml_node_defs,
         "clip-%d\">\n",
         document->clip_id);

    _cairo_svg_stream_printf (&document->xml_node_defs,
         "%s\"",
         fill_rule == CAIRO_FILL_RULE_EVEN_ODD ? "evenodd" : "nonzero");
    _cairo_svg_surface_emit_path (&document->xml_node_defs, path, NULL);
    _cairo_svg_stream_printf (&document->xml_node_defs, "/>\n");

    _cairo_svg_stream_printf (&document->xml_node_defs, "\n");

    _cairo_svg_stream_printf (surface->current_clipper_stream,
         "url(#clip-%d)\">\n",
         document->clip_id);

    document->clip_id++;
    surface->clip_level++;

    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_svg_surface_reset_clip (cairo_svg_surface_t *surface)
{
    _cairo_surface_clipper_reset (&surface->clipper);
    if (surface->current_clipper_stream != NULL) {
 for (unsigned int i = 0; i < surface->clip_level; i++) {
     _cairo_svg_stream_printf (surface->current_clipper_stream, "\n");
 }
    }
    surface->clip_level = 0;
}

static cairo_status_t
_cairo_svg_surface_set_clip (cairo_svg_surface_t *surface,
        cairo_svg_stream_t *clipper_stream,
        const cairo_clip_t *clip)
{
    if (surface->current_clipper_stream != clipper_stream) {
 _cairo_svg_surface_reset_clip (surface);
 surface->current_clipper_stream = clipper_stream;
    }
    return _cairo_surface_clipper_set_clip (&surface->clipper, clip);
}

static cairo_surface_t *
_cairo_svg_surface_create_for_document (cairo_svg_document_t *document,
     cairo_content_t content,
     double width,
     double height,
     cairo_bool_t bounded)
{
    cairo_svg_surface_t *surface;
    cairo_surface_t *paginated;
    cairo_status_t status;

    surface = _cairo_malloc (sizeof (cairo_svg_surface_t));
    if (unlikely (surface == NULL)) {
 return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
    }

    _cairo_surface_init (&surface->base,
    &cairo_svg_surface_backend,
    NULL, /* device */
    content,
    TRUE); /* is_vector */

    surface->source_id = surface->base.unique_id;
    surface->depth = 0;

    surface->width = width;
    surface->height = height;
    surface->surface_bounded = bounded;

    surface->document = _cairo_svg_document_reference (document);

    surface->xml_node = _cairo_svg_stream_create ();
    _cairo_array_init (&surface->page_set, sizeof (cairo_svg_page_t));

    surface->source_surfaces = _cairo_hash_table_create (_cairo_svg_source_surface_equal);
    if (unlikely (surface->source_surfaces == NULL)) {
 status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
 goto CLEANUP;
    }

    _cairo_surface_clipper_init (&surface->clipper, _cairo_svg_surface_clipper_intersect_clip_path);
    surface->current_clipper_stream = NULL;
    surface->clip_level = 0;
    surface->transitive_paint_used = FALSE;

    surface->paginated_mode = CAIRO_PAGINATED_MODE_ANALYZE;

    surface->force_fallbacks = FALSE;


    paginated = _cairo_paginated_surface_create (&surface->base,
       surface->base.content,
       &cairo_svg_surface_paginated_backend);
    status = paginated->status;
    if (status == CAIRO_STATUS_SUCCESS) {
 /* paginated keeps the only reference to surface now, drop ours */
 cairo_surface_destroy (&surface->base);
 return paginated;
    }

    /* ignore status as we are on the error path */
    CLEANUP:
    (void) _cairo_svg_stream_destroy (&surface->xml_node);
    (void) _cairo_svg_document_destroy (document);

    free (surface);

    return _cairo_surface_create_in_error (status);
}

static cairo_surface_t *
_cairo_svg_surface_create_for_stream_internal (cairo_output_stream_t *stream,
            double    width,
            double    height,
            cairo_svg_version_t  version)
{
    cairo_svg_document_t *document;
    cairo_surface_t *surface;
    cairo_status_t status;

    status = _cairo_svg_document_create (stream,
                                  width, height, version,
      &document);
    if (unlikely (status)) {
 surface =  _cairo_surface_create_in_error (status);
 /* consume the output stream on behalf of caller */
 status = _cairo_output_stream_destroy (stream);
 return surface;
    }

    surface = _cairo_svg_surface_create_for_document (document, CAIRO_CONTENT_COLOR_ALPHA,
            width, height, TRUE);
    if (surface->status) {
 return surface;
    }

    document->owner = surface;
    status = _cairo_svg_document_destroy (document);
    /* the ref count should be 2 at this point */
    assert (status == CAIRO_STATUS_SUCCESS);

    return surface;
}

static cairo_svg_page_t *
_cairo_svg_surface_store_page (cairo_svg_surface_t *surface)
{
    _cairo_svg_surface_reset_clip (surface);
    cairo_svg_page_t page;
    page.xml_node = surface->xml_node;
    if (_cairo_array_append (&surface->page_set, &page)) {
 return NULL;
    }
    surface->xml_node = _cairo_svg_stream_create ();
    return _cairo_array_index (&surface->page_set,
          surface->page_set.num_elements - 1);
}

static cairo_int_status_t
_cairo_svg_surface_copy_page (void *abstract_surface)
{
    cairo_svg_surface_t *surface = abstract_surface;

    cairo_svg_page_t *page = _cairo_svg_surface_store_page (surface);
    if (unlikely (page == NULL)) {
 return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }

    _cairo_svg_stream_copy (&page->xml_node, &surface->xml_node);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_svg_surface_show_page (void *abstract_surface)
{
    cairo_svg_surface_t *surface = abstract_surface;

    cairo_svg_page_t *page = _cairo_svg_surface_store_page (surface);
    if (unlikely (page == NULL)) {
 return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }

    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_svg_surface_emit_transform (cairo_svg_stream_t *output,
       char const *attribute_name,
       const cairo_matrix_t *object_matrix,
       const cairo_matrix_t *parent_matrix)
{
    cairo_matrix_t matrix = *object_matrix;

    if (parent_matrix != NULL) {
 cairo_matrix_multiply (&matrix, &matrix, parent_matrix);
    }

    if (!_cairo_matrix_is_identity (&matrix)) {
 _cairo_svg_stream_printf (output,
      " %s=\"matrix(%f, %f, %f, %f, %f, %f)\"",
      attribute_name,
      matrix.xx, matrix.yx,
      matrix.xy, matrix.yy,
      matrix.x0, matrix.y0);
    }
}

typedef struct {
    cairo_svg_stream_t *output;
    const cairo_matrix_t *ctm_inverse;
} svg_path_info_t;

static cairo_status_t
_cairo_svg_path_move_to (void *closure,
    const cairo_point_t *point)
{
    svg_path_info_t *info = closure;
    double x = _cairo_fixed_to_double (point->x);
    double y = _cairo_fixed_to_double (point->y);

    if (info->ctm_inverse)
 cairo_matrix_transform_point (info->ctm_inverse, &x, &y);

    _cairo_svg_stream_printf (info->output, "M %f %f ", x, y);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_svg_path_line_to (void *closure,
    const cairo_point_t *point)
{
    svg_path_info_t *info = closure;
    double x = _cairo_fixed_to_double (point->x);
    double y = _cairo_fixed_to_double (point->y);

    if (info->ctm_inverse)
 cairo_matrix_transform_point (info->ctm_inverse, &x, &y);

    _cairo_svg_stream_printf (info->output, "L %f %f ", x, y);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_svg_path_curve_to (void          *closure,
     const cairo_point_t *b,
     const cairo_point_t *c,
     const cairo_point_t *d)
{
    svg_path_info_t *info = closure;
    double bx = _cairo_fixed_to_double (b->x);
    double by = _cairo_fixed_to_double (b->y);
    double cx = _cairo_fixed_to_double (c->x);
    double cy = _cairo_fixed_to_double (c->y);
    double dx = _cairo_fixed_to_double (d->x);
    double dy = _cairo_fixed_to_double (d->y);

    if (info->ctm_inverse) {
 cairo_matrix_transform_point (info->ctm_inverse, &bx, &by);
 cairo_matrix_transform_point (info->ctm_inverse, &cx, &cy);
 cairo_matrix_transform_point (info->ctm_inverse, &dx, &dy);
    }

    _cairo_svg_stream_printf (info->output,
         "C %f %f %f %f %f %f ",
         bx, by, cx, cy, dx, dy);

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_svg_path_close_path (void *closure)
{
    svg_path_info_t *info = closure;

    _cairo_svg_stream_printf (info->output, "Z ");

    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_svg_surface_emit_path (cairo_svg_stream_t *output,
         const cairo_path_fixed_t *path,
         const cairo_matrix_t *ctm_inverse)
{
    cairo_status_t status;
    svg_path_info_t info;

    _cairo_svg_stream_printf (output, " d=\"");

    info.output = output;
    info.ctm_inverse = ctm_inverse;
    status = _cairo_path_fixed_interpret (path,
       _cairo_svg_path_move_to,
       _cairo_svg_path_line_to,
       _cairo_svg_path_curve_to,
       _cairo_svg_path_close_path,
       &info);
    assert (status == CAIRO_STATUS_SUCCESS);

    _cairo_svg_stream_printf (output, "\"");
}

static cairo_int_status_t
_cairo_svg_document_emit_outline_glyph_data (cairo_svg_document_t *document,
          cairo_scaled_font_t *scaled_font,
          unsigned long glyph_index)
{
    cairo_scaled_glyph_t *scaled_glyph;
    cairo_int_status_t status;

    status = _cairo_scaled_glyph_lookup (scaled_font,
      glyph_index,
      CAIRO_SCALED_GLYPH_INFO_METRICS | CAIRO_SCALED_GLYPH_INFO_PATH,
      NULL, /* foreground color */
      &scaled_glyph);
    if (unlikely (status)) {
 return status;
    }

    if (_cairo_path_fixed_size (scaled_glyph->path) != 0) {
 _cairo_svg_stream_printf (&document->xml_node_glyphs,
      ");

 _cairo_svg_surface_emit_path (&document->xml_node_glyphs,
          scaled_glyph->path,
          NULL);

 _cairo_svg_stream_printf (&document->xml_node_glyphs,
      "/>\n");
    }

    return status;
}

static cairo_int_status_t
_cairo_svg_document_emit_bitmap_glyph_data (cairo_svg_document_t *document,
         cairo_scaled_font_t *scaled_font,
         unsigned long glyph_index)
{
    cairo_status_t status;

    cairo_scaled_glyph_t *scaled_glyph;
    status = _cairo_scaled_glyph_lookup (scaled_font,
      glyph_index,
      CAIRO_SCALED_GLYPH_INFO_METRICS | CAIRO_SCALED_GLYPH_INFO_SURFACE,
      NULL, /* foreground color */
      &scaled_glyph);
    if (unlikely (status)) {
 return status;
    }

    cairo_bool_t use_recording_surface = (scaled_glyph->has_info & CAIRO_SCALED_GLYPH_INFO_RECORDING_SURFACE) != 0;
    cairo_matrix_t glyph_matrix = scaled_glyph->surface->base.device_transform_inverse;
    cairo_image_surface_t *glyph_image_surface = scaled_glyph->surface;

    // Attempt to recognize a common pattern for a bitmap font and extract the original glyph image from it
    cairo_surface_t *extracted_surface;
    cairo_image_surface_t *extracted_image = NULL;
    void *extracted_image_extra;
    if (use_recording_surface) {
 cairo_recording_surface_t *recording_surface = (cairo_recording_surface_t *) scaled_glyph->recording_surface;
 if (recording_surface->commands.num_elements == 1) {
     cairo_command_t *command = *((cairo_command_t **) _cairo_array_index (&recording_surface->commands, 0));
     if (command->header.type == CAIRO_COMMAND_MASK &&
  command->header.op == CAIRO_OPERATOR_OVER &&
  command->header.clip == NULL &&
  command->mask.source.base.type == CAIRO_PATTERN_TYPE_SOLID &&
  _cairo_color_equal (&command->mask.source.solid.color, _cairo_stock_color (CAIRO_STOCK_BLACK)) &&
  command->mask.mask.base.extend == CAIRO_EXTEND_NONE &&
  command->mask.mask.base.type == CAIRO_PATTERN_TYPE_SURFACE &&
  command->mask.mask.surface.surface->type == CAIRO_SURFACE_TYPE_IMAGE) {
  extracted_surface = command->mask.mask.surface.surface;
  if (_cairo_surface_acquire_source_image (extracted_surface,
        &extracted_image,
        &extracted_image_extra) == CAIRO_STATUS_SUCCESS) {
      if (extracted_image->format == CAIRO_FORMAT_A1 || extracted_image->format == CAIRO_FORMAT_A8) {
   use_recording_surface = FALSE;
   glyph_image_surface = extracted_image;
   glyph_matrix = command->mask.mask.base.matrix;
   status = cairo_matrix_invert (&glyph_matrix);
   assert (status == CAIRO_STATUS_SUCCESS);
      }
  }
     }
 }
    }

    cairo_surface_t *paginated_surface = _cairo_svg_surface_create_for_document (document,
           CAIRO_CONTENT_COLOR_ALPHA,
           0,
           0,
           FALSE);
    cairo_svg_surface_t *svg_surface = (cairo_svg_surface_t *) _cairo_paginated_surface_get_target (paginated_surface);
    status = paginated_surface->status;
    if (unlikely (status)) {
 goto cleanup;
    }

    unsigned int source_id = svg_surface->base.unique_id;

    cairo_surface_set_fallback_resolution (paginated_surface,
        document->owner->x_fallback_resolution,
        document->owner->y_fallback_resolution);

    cairo_svg_stream_t temporary_stream = _cairo_svg_stream_create ();

    unsigned int mask_id = document->mask_id++;

    _cairo_svg_stream_printf (&temporary_stream,
         "mask-%d\">\n",
         mask_id);

    cairo_pattern_t *pattern = cairo_pattern_create_for_surface (use_recording_surface ? scaled_glyph->recording_surface
                 : &glyph_image_surface->base);
    _cairo_svg_surface_emit_composite_pattern (&temporary_stream,
            svg_surface,
            (cairo_surface_pattern_t *) pattern,
            invalid_pattern_id,
            NULL);
    cairo_pattern_destroy (pattern);

    _cairo_svg_stream_printf (&temporary_stream, "\n");

    _cairo_svg_stream_copy (&temporary_stream, &document->xml_node_defs);

    status = _cairo_svg_stream_destroy (&temporary_stream);
    if (unlikely (status)) {
 goto cleanup;
    }

    svg_surface->transitive_paint_used = TRUE;

    _cairo_svg_stream_printf (&document->xml_node_glyphs, ");
    _cairo_svg_stream_append_paint_dependent (&document->xml_node_glyphs,
           source_id,
           CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE);
    _cairo_svg_stream_printf (&document->xml_node_glyphs,
         " mask=\"url(#mask-%d)\"",
         mask_id);
    if (!use_recording_surface) {
 _cairo_svg_surface_emit_transform (&document->xml_node_glyphs,
        "transform",
        &glyph_matrix,
        NULL);
    }
    _cairo_svg_stream_printf (&document->xml_node_glyphs, "/>\n");

    cairo_svg_paint_t *paint_entry = malloc (sizeof (cairo_svg_paint_t));
    if (paint_entry == NULL) {
 status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
 goto cleanup;
    }
    paint_entry->source_id = source_id;
    paint_entry->box.p1.x = 0;
    paint_entry->box.p1.y = 0;
    paint_entry->box.p2.x = glyph_image_surface->width;
    paint_entry->box.p2.y = glyph_image_surface->height;
    if (use_recording_surface) {
 _cairo_matrix_transform_bounding_box (&glyph_matrix,
           &paint_entry->box.p1.x, &paint_entry->box.p1.y,
           &paint_entry->box.p2.x, &paint_entry->box.p2.y,
           NULL);
    }
    _cairo_svg_paint_box_add_padding (&paint_entry->box);
    _cairo_array_init (&paint_entry->paint_elements, sizeof (cairo_svg_paint_element_t));
    _cairo_svg_paint_init_key (paint_entry);
    status = _cairo_hash_table_insert (document->paints, &paint_entry->base);
    if (unlikely (status)) {
 goto cleanup;
    }

    cleanup:
    if (status == CAIRO_STATUS_SUCCESS) {
 status = cairo_surface_status (paginated_surface);
    }
    cairo_surface_destroy (paginated_surface);

    if (extracted_image != NULL) {
 _cairo_surface_release_source_image (extracted_surface, extracted_image, extracted_image_extra);
    }

    return status;
}

static cairo_int_status_t
_cairo_svg_document_emit_glyph (cairo_svg_document_t *document,
    cairo_scaled_font_t *scaled_font,
    unsigned long   scaled_font_glyph_index,
    unsigned int   font_id,
    unsigned int   subset_glyph_index)
{
    cairo_int_status_t      status;

    _cairo_svg_stream_printf (&document->xml_node_glyphs,
         "glyph-%d-%d\">\n",
         font_id,
         subset_glyph_index);

    status = _cairo_svg_document_emit_outline_glyph_data (document,
         scaled_font,
         scaled_font_glyph_index);
    if (status == CAIRO_INT_STATUS_UNSUPPORTED)
 status = _cairo_svg_document_emit_bitmap_glyph_data (document,
            scaled_font,
            scaled_font_glyph_index);
    if (unlikely (status))
 return status;

    _cairo_svg_stream_printf (&document->xml_node_glyphs, "\n");

    return CAIRO_INT_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_svg_document_emit_font_subset (cairo_scaled_font_subset_t *font_subset,
          void    *closure)
{
    cairo_svg_document_t *document = closure;
    cairo_int_status_t status = CAIRO_INT_STATUS_SUCCESS;
    unsigned int i;

    _cairo_scaled_font_freeze_cache (font_subset->scaled_font);
    for (i = 0; i < font_subset->num_glyphs; i++) {
 status = _cairo_svg_document_emit_glyph (document,
              font_subset->scaled_font,
              font_subset->glyphs[i],
              font_subset->font_id, i);
 if (unlikely (status))
     break;
    }
    _cairo_scaled_font_thaw_cache (font_subset->scaled_font);

    return status;
}

static cairo_status_t
_cairo_svg_document_emit_font_subsets (cairo_svg_document_t *document)
{
    cairo_status_t status;

    status = _cairo_scaled_font_subsets_foreach_scaled (document->font_subsets,
                                                        _cairo_svg_document_emit_font_subset,
                                                        document);
    _cairo_scaled_font_subsets_destroy (document->font_subsets);
    document->font_subsets = NULL;

    return status;
}

static cairo_bool_t
_cairo_svg_surface_are_operation_and_pattern_supported (cairo_svg_surface_t *surface,
       cairo_operator_t op,
       const cairo_pattern_t *pattern)
{
    if (surface->force_fallbacks) {
 return FALSE;
    }

    if (op == CAIRO_OPERATOR_SATURATE) {
        return FALSE;
    }

    /* SVG 1.1 does not support these operators. We already have code for them for SVG 2
     * that can be enabled when SVG 2 becomes widespread.  */
    if (op == CAIRO_OPERATOR_OVERLAY ||
 op == CAIRO_OPERATOR_COLOR_DODGE ||
 op == CAIRO_OPERATOR_COLOR_BURN ||
 op == CAIRO_OPERATOR_HARD_LIGHT ||
 op == CAIRO_OPERATOR_SOFT_LIGHT ||
 op == CAIRO_OPERATOR_DIFFERENCE ||
 op == CAIRO_OPERATOR_EXCLUSION ||
 op == CAIRO_OPERATOR_HSL_HUE ||
 op == CAIRO_OPERATOR_HSL_SATURATION ||
 op == CAIRO_OPERATOR_HSL_COLOR ||
 op == CAIRO_OPERATOR_HSL_LUMINOSITY) {
 return FALSE;
    }

    if (pattern->type == CAIRO_PATTERN_TYPE_SURFACE) {
        /* Do not cause stack overflow because of too deep or infinite recording surfaces. */
 if (((cairo_surface_pattern_t *) pattern)->surface->type == CAIRO_SURFACE_TYPE_RECORDING &&
     surface->depth > 1000) {
     return FALSE;
 }
 /* SVG doesn't support extends reflect and pad for surface pattern. */
        if (pattern->extend != CAIRO_EXTEND_NONE && pattern->extend != CAIRO_EXTEND_REPEAT) {
     return FALSE;
 }
    }

    /* SVG 1.1 does not support the focal point (fx, fy) that is outside of the circle defined by (cx, cy) and r. */
    if (pattern->type == CAIRO_PATTERN_TYPE_RADIAL) {
 cairo_radial_pattern_t *radial_pattern = (cairo_radial_pattern_t *) pattern;
 double max_radius;
 if (radial_pattern->cd1.radius > radial_pattern->cd2.radius) {
     max_radius = radial_pattern->cd1.radius;
 } else {
     max_radius = radial_pattern->cd2.radius;
 }
 cairo_point_double_t c1 = radial_pattern->cd1.center;
 cairo_point_double_t c2 = radial_pattern->cd2.center;
 if ((c1.x - c2.x) * (c1.x - c2.x) + (c1.y - c2.y) * (c1.y - c2.y) >= max_radius * max_radius) {
     return FALSE;
 }
    }

    if (pattern->type == CAIRO_PATTERN_TYPE_MESH) {
 return FALSE;
    }

    if (pattern->type == CAIRO_PATTERN_TYPE_RASTER_SOURCE) {
 return FALSE;
    }

    return TRUE;
}

static cairo_status_t
_cairo_svg_surface_finish (void *abstract_surface)
{
    cairo_status_t status, final_status;
    cairo_svg_surface_t *surface = abstract_surface;

    if (_cairo_paginated_surface_get_target (surface->document->owner) == &surface->base) {
 final_status = _cairo_svg_document_finish (surface->document);
    } else {
 final_status = CAIRO_STATUS_SUCCESS;
    }

    status = _cairo_svg_stream_destroy (&surface->xml_node);
    if (final_status == CAIRO_STATUS_SUCCESS) {
 final_status = status;
    }

    for (unsigned int i = 0; i < surface->page_set.num_elements; i++) {
 cairo_svg_page_t *page = _cairo_array_index (&surface->page_set, i);
 status = _cairo_svg_stream_destroy (&page->xml_node);
 if (final_status == CAIRO_STATUS_SUCCESS) {
     final_status = status;
 }
    }
    _cairo_array_fini (&surface->page_set);

    _cairo_surface_clipper_reset (&surface->clipper);

    _cairo_hash_table_foreach (surface->source_surfaces, _cairo_svg_source_surface_pluck, surface->source_surfaces);
    _cairo_hash_table_destroy (surface->source_surfaces);

    status = _cairo_svg_document_destroy (surface->document);
    if (final_status == CAIRO_STATUS_SUCCESS) {
 final_status = status;
    }

    return final_status;
}

static const char *
_cairo_svg_surface_emit_static_filter (cairo_svg_document_t *document, enum cairo_svg_filter filter)
{
    if (!document->filters_emitted[filter]) {
 document->filters_emitted[filter] = TRUE;
 if (filter == CAIRO_SVG_FILTER_REMOVE_COLOR) {
     // (r, g, b, a) -> (1, 1, 1, a)
     _cairo_svg_stream_printf (&document->xml_node_filters,
          "filter-remove-color\" "
          "x=\"0%%\" y=\"0%%\" width=\"100%%\" height=\"100%%\">\n"
          "sRGB\" "
                               "values=\"0 0 0 0 1 "
          /*    */ "0 0 0 0 1 "
          /*    */ "0 0 0 0 1 "
          /*    */ "0 0 0 1 0\" />\n"
          "\n");
 } else if (filter == CAIRO_SVG_FILTER_REMOVE_COLOR_AND_INVERT_ALPHA) {
     // (r, g, b, a) -> (1, 1, 1, 1 - a)
     _cairo_svg_stream_printf (&document->xml_node_filters,
          "filter-remove-color-and-invert-alpha\" "
          "x=\"0%%\" y=\"0%%\" width=\"100%%\" height=\"100%%\">\n"
          "sRGB\" "
          "values=\"0 0 0 0 1 "
          /*    */ "0 0 0 0 1 "
          /*    */ "0 0 0 0 1 "
          /*    */ "0 0 0 -1 1\"/>\n"
          "\n");
 } else if (filter ==  CAIRO_SVG_FILTER_COLOR_TO_ALPHA) {
     // (r, g, b, a) -> (1, 1, 1, 0.2126 * r + 0.7152 * g + 0.0722 * b)
     _cairo_svg_stream_printf (&document->xml_node_filters,
          "filter-color-to-alpha\" "
          "x=\"0%%\" y=\"0%%\" width=\"100%%\" height=\"100%%\">\n"
          "sRGB\" "
          "values=\"0 0 0 0 1 "
          /*    */ "0 0 0 0 1 "
          /*    */ "0 0 0 0 1 "
          /*    */ "0.2126 0.7152 0.0722 0 0\"/>\n"
          "\n");
 }
    }

    if (filter == CAIRO_SVG_FILTER_REMOVE_COLOR) {
 return "remove-color";
    } else if (filter == CAIRO_SVG_FILTER_REMOVE_COLOR_AND_INVERT_ALPHA) {
 return "remove-color-and-invert-alpha";
    } else if (filter ==  CAIRO_SVG_FILTER_COLOR_TO_ALPHA) {
 return "color-to-alpha";
    } else {
 ASSERT_NOT_REACHED;
    }
    return FALSE; /* squelch warning */
}

#define _CAIRO_SVG_SURFACE_OUTPUT_FE_COMPOSITE_FILTER(operation) \
    _cairo_svg_stream_printf (&surface->document->xml_node_filters, \
                              "filter-%d\" " \
                              "x=\"0%%\" y=\"0%%\" width=\"100%%\" height=\"100%%\">\n" \
                              "#compositing-group-%d\" result=\"source\"", \
                              filter_id, \
                              source_compositing_group_id); \
    _cairo_svg_stream_append_paint_dependent (&surface->document->xml_node_filters, \
                                              surface->source_id, \
                                              CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE_AT_ORIGIN); \
    _cairo_svg_stream_printf (&surface->document->xml_node_filters, \
                              "/>\n" \
                              "#compositing-group-%d\" result=\"destination\"", \
                              destination_compositing_group_id); \
    _cairo_svg_stream_append_paint_dependent (&surface->document->xml_node_filters, \
                                              surface->source_id, \
                                              CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE_AT_ORIGIN); \
    _cairo_svg_stream_printf (&surface->document->xml_node_filters, \
                              "/>\n" \
                              "source\" in2=\"destination\" " \
                              "operator=\"" operation "\" " \
                              "color-interpolation-filters=\"sRGB\"/>\n" \
                              "\n", \
                              filter_id, \
                              source_compositing_group_id, \
                              destination_compositing_group_id);

#define _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER(mode) \
    _cairo_svg_stream_printf (&surface->document->xml_node_filters, \
                              "filter-%d\" " \
                              "x=\"0%%\" y=\"0%%\" width=\"100%%\" height=\"100%%\">\n" \
                              "#compositing-group-%d\" result=\"source\"", \
                              filter_id, \
                              source_compositing_group_id); \
    _cairo_svg_stream_append_paint_dependent (&surface->document->xml_node_filters, \
                                              surface->source_id, \
                                              CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE_AT_ORIGIN); \
    _cairo_svg_stream_printf (&surface->document->xml_node_filters, \
                              "/>\n" \
                              "#compositing-group-%d\" result=\"destination\"", \
                              destination_compositing_group_id); \
    _cairo_svg_stream_append_paint_dependent (&surface->document->xml_node_filters, \
                                              surface->source_id, \
                                              CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE_AT_ORIGIN); \
    _cairo_svg_stream_printf (&surface->document->xml_node_filters, \
                              "/>\n" \
                              "source\" in2=\"destination\" " \
                              "mode=\"" mode "\" " \
                              "color-interpolation-filters=\"sRGB\"/>\n" \
                              "\n", \
                              filter_id, \
                              source_compositing_group_id, \
                              destination_compositing_group_id);

static unsigned int
_cairo_svg_surface_emit_parametric_filter (cairo_svg_surface_t *surface,
        enum cairo_svg_filter filter,
        unsigned int source_compositing_group_id,
        unsigned int destination_compositing_group_id)
{
    unsigned int filter_id = surface->document->filter_id++;
    switch (filter) {
    case CAIRO_SVG_FILTER_OVER:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_COMPOSITE_FILTER ("over")
 break;
    case CAIRO_SVG_FILTER_IN:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_COMPOSITE_FILTER ("in")
 break;
    case CAIRO_SVG_FILTER_OUT:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_COMPOSITE_FILTER ("out")
 break;
    case CAIRO_SVG_FILTER_ATOP:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_COMPOSITE_FILTER ("atop")
 break;
    case CAIRO_SVG_FILTER_XOR:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_COMPOSITE_FILTER ("xor")
 break;
    case CAIRO_SVG_FILTER_ADD:
 // This can also be done with <feComposite operator="lighter"/>, but it is not in SVG 1.1
 _cairo_svg_stream_printf (&surface->document->xml_node_filters,
      "filter-%d\" "
      "x=\"0%%\" y=\"0%%\" width=\"100%%\" height=\"100%%\">\n"
      "#compositing-group-%d\" result=\"source\"",
      filter_id,
      source_compositing_group_id);
 _cairo_svg_stream_append_paint_dependent (&surface->document->xml_node_filters,
        surface->source_id,
        CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE_AT_ORIGIN);
 _cairo_svg_stream_printf (&surface->document->xml_node_filters,
      "/>\n"
      "#compositing-group-%d\" result=\"destination\"",
      destination_compositing_group_id);
 _cairo_svg_stream_append_paint_dependent (&surface->document->xml_node_filters,
        surface->source_id,
        CAIRO_SVG_STREAM_PAINT_DEPENDENT_ELEMENT_TYPE_RECTANGLE_AT_ORIGIN);
 _cairo_svg_stream_printf (&surface->document->xml_node_filters,
      "/>\n"
      "source\" in2=\"destination\" "
      "operator=\"arithmetic\" k1=\"0\" k2=\"1\" k3=\"1\" k4=\"0\" "
      "color-interpolation-filters=\"sRGB\"/>\n"
      "\n");
 break;
    case CAIRO_SVG_FILTER_MULTIPLY:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("multiply")
 break;
    case CAIRO_SVG_FILTER_SCREEN:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("screen")
 break;
    case CAIRO_SVG_FILTER_OVERLAY:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("overlay")
 break;
    case CAIRO_SVG_FILTER_DARKEN:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("darken")
 break;
    case CAIRO_SVG_FILTER_LIGHTEN:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("lighten")
 break;
    case CAIRO_SVG_FILTER_COLOR_DODGE:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("color-dodge")
 break;
    case CAIRO_SVG_FILTER_COLOR_BURN:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("color-burn")
 break;
    case CAIRO_SVG_FILTER_HARD_LIGHT:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("hard-light")
 break;
    case CAIRO_SVG_FILTER_SOFT_LIGHT:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("soft-light")
 break;
    case CAIRO_SVG_FILTER_DIFFERENCE:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("difference")
 break;
    case CAIRO_SVG_FILTER_EXCLUSION:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("exclusion")
 break;
    case CAIRO_SVG_FILTER_HUE:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("hue")
 break;
    case CAIRO_SVG_FILTER_SATURATION:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("saturation")
 break;
    case CAIRO_SVG_FILTER_COLOR:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("color")
 break;
    case CAIRO_SVG_FILTER_LUMINOSITY:
 _CAIRO_SVG_SURFACE_OUTPUT_FE_BLEND_FILTER ("luminosity")
 break;
    case CAIRO_SVG_FILTER_REMOVE_COLOR:
    case CAIRO_SVG_FILTER_REMOVE_COLOR_AND_INVERT_ALPHA:
    case CAIRO_SVG_FILTER_COLOR_TO_ALPHA:
    case CAIRO_SVG_FILTER_LAST_STATIC_FILTER:
    default:
 ASSERT_NOT_REACHED;
    }
    return filter_id;
}

typedef struct {
    cairo_svg_stream_t *output;
    unsigned int in_mem;
    unsigned int trailing;
    unsigned char src[3];
} base64_write_closure_t;

static char const base64_table[64] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

static cairo_status_t
base64_write_func (void *closure,
     const unsigned char *data,
     unsigned int length)
{
    base64_write_closure_t *info = (base64_write_closure_t *) closure;
    unsigned int i;
    unsigned char *src;

    src = info->src;

    if (info->in_mem + length < 3) {
 for (i = 0; i < length; i++) {
     src[i + info->in_mem] = *data++;
 }
 info->in_mem += length;
 return CAIRO_STATUS_SUCCESS;
    }

    do {
 unsigned char dst[4];

 for (i = info->in_mem; i < 3; i++) {
     src[i] = *data++;
     length--;
 }
 info->in_mem = 0;

 dst[0] = base64_table[src[0] >> 2];
 dst[1] = base64_table[(src[0] & 0x03) << 4 | src[1] >> 4];
 dst[2] = base64_table[(src[1] & 0x0f) << 2 | src[2] >> 6];
 dst[3] = base64_table[src[2] & 0xfc >> 2];
 /* Special case for the last missing bits */
 switch (info->trailing) {
     case 2:
  dst[2] = '=';
  /* fall through */
     case 1:
  dst[3] = '=';
     default:
  break;
 }
 _cairo_svg_stream_write (info->output, dst, 4);
    } while (length >= 3);

    for (i = 0; i < length; i++) {
 src[i] = *data++;
    }
    info->in_mem = length;

    return info->output->status;
}

static cairo_int_status_t
_cairo_surface_base64_encode_jpeg (cairo_surface_t       *surface,
       cairo_svg_stream_t *output)
{
    const unsigned char *mime_data;
    unsigned long mime_data_length;
    cairo_image_info_t image_info;
    base64_write_closure_t info;
    cairo_status_t status;

    cairo_surface_get_mime_data (surface, CAIRO_MIME_TYPE_JPEG,
     &mime_data, &mime_data_length);
    if (mime_data == NULL)
 return CAIRO_INT_STATUS_UNSUPPORTED;

    status = _cairo_image_info_get_jpeg_info (&image_info, mime_data, mime_data_length);
    if (unlikely (status))
 return status;

    if (image_info.num_components == 4)
 return CAIRO_INT_STATUS_UNSUPPORTED;

    _cairo_svg_stream_printf (output, "data:image/jpeg;base64,");

    info.output = output;
    info.in_mem = 0;
    info.trailing = 0;

    status = base64_write_func (&info, mime_data, mime_data_length);
    if (unlikely (status))
 return status;

    if (info.in_mem > 0) {
 memset (info.src + info.in_mem, 0, 3 - info.in_mem);
 info.trailing = 3 - info.in_mem;
 info.in_mem = 3;
 status = base64_write_func (&info, NULL, 0);
    }

    return status;
}

static cairo_int_status_t
_cairo_surface_base64_encode_png (cairo_surface_t       *surface,
      cairo_svg_stream_t *output)
{
    const unsigned char *mime_data;
    unsigned long mime_data_length;
    base64_write_closure_t info;
    cairo_status_t status;

    cairo_surface_get_mime_data (surface, CAIRO_MIME_TYPE_PNG,
     &mime_data, &mime_data_length);
    if (unlikely (surface->status))
 return surface->status;
    if (mime_data == NULL)
 return CAIRO_INT_STATUS_UNSUPPORTED;

    _cairo_svg_stream_printf (output, "data:image/png;base64,");

    info.output = output;
    info.in_mem = 0;
    info.trailing = 0;

    status = base64_write_func (&info, mime_data, mime_data_length);
    if (unlikely (status))
 return status;

    if (info.in_mem > 0) {
 memset (info.src + info.in_mem, 0, 3 - info.in_mem);
 info.trailing = 3 - info.in_mem;
 info.in_mem = 3;
 status = base64_write_func (&info, NULL, 0);
    }

    return status;
}

static cairo_int_status_t
_cairo_surface_base64_encode (cairo_surface_t       *surface,
         cairo_svg_stream_t *output)
{
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