/*

 * Copyright © 2006 Keith Packard

 * Copyright © 2007 Adrian Johnson

 *

 * 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 Keith Packard

 *

 * Contributor(s):

 *      Keith Packard <keithp@keithp.com>

 *      Adrian Johnson <ajohnson@redneon.com>

 */

#include "cairoint.h"

#include "cairo-analysis-surface-private.h"

#include "cairo-box-inline.h"

#include "cairo-default-context-private.h"

#include "cairo-error-private.h"

#include "cairo-paginated-private.h"

#include "cairo-recording-surface-inline.h"

#include "cairo-surface-snapshot-inline.h"

#include "cairo-surface-subsurface-inline.h"

#include "cairo-region-private.h"

typedef struct {

    cairo_surface_t base;

    cairo_surface_t *target;

    cairo_bool_t first_op;

    cairo_bool_t has_supported;

    cairo_bool_t has_unsupported;

    cairo_region_t supported_region;

    cairo_region_t fallback_region;

    cairo_box_t page_bbox;

    cairo_bool_t has_ctm;

    cairo_matrix_t ctm;

} cairo_analysis_surface_t;

cairo_int_status_t

_cairo_analysis_surface_merge_status (cairo_int_status_t status_a,

              cairo_int_status_t status_b)

{

    /* fatal errors should be checked and propagated at source */

    assert (! _cairo_int_status_is_error (status_a));

    assert (! _cairo_int_status_is_error (status_b));

    /* return the most important status */

    if (status_a == CAIRO_INT_STATUS_UNSUPPORTED ||

  status_b == CAIRO_INT_STATUS_UNSUPPORTED)

  return CAIRO_INT_STATUS_UNSUPPORTED;

    if (status_a == CAIRO_INT_STATUS_IMAGE_FALLBACK ||

  status_b == CAIRO_INT_STATUS_IMAGE_FALLBACK)

  return CAIRO_INT_STATUS_IMAGE_FALLBACK;

    if (status_a == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN ||

  status_b == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN)

  return CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN;

    if (status_a == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY ||

  status_b == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY)

  return CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY;

    /* at this point we have checked all the valid internal codes, so... */

    assert (status_a == CAIRO_INT_STATUS_SUCCESS &&

      status_b == CAIRO_INT_STATUS_SUCCESS);

    return CAIRO_INT_STATUS_SUCCESS;

}

struct proxy {

    cairo_surface_t base;

    cairo_surface_t *target;

};

static cairo_status_t

proxy_finish (void *abstract_surface)

{

    return CAIRO_STATUS_SUCCESS;

}

static const cairo_surface_backend_t proxy_backend  = {

    CAIRO_INTERNAL_SURFACE_TYPE_NULL,

    proxy_finish,

};

static cairo_surface_t *

attach_proxy (cairo_surface_t *source,

        cairo_surface_t *target)

{

    struct proxy *proxy;

    proxy = _cairo_malloc (sizeof (*proxy));

    if (unlikely (proxy == NULL))

  return _cairo_surface_create_in_error (CAIRO_STATUS_NO_MEMORY);

    _cairo_surface_init (&proxy->base, &proxy_backend, NULL, target->content, target->is_vector);

    proxy->target = target;

    _cairo_surface_attach_snapshot (source, &proxy->base, NULL);

    return &proxy->base;

}

static void

detach_proxy (cairo_surface_t *proxy)

{

    cairo_surface_finish (proxy);

    cairo_surface_destroy (proxy);

}

static cairo_int_status_t

_add_operation (cairo_analysis_surface_t *surface,

    cairo_rectangle_int_t    *rect,

    cairo_int_status_t        backend_status)

{

    cairo_int_status_t status;

    cairo_box_t bbox;

    if (rect->width == 0 || rect->height == 0) {

  /* Even though the operation is not visible we must be careful

   * to not allow unsupported operations to be replayed to the

   * backend during CAIRO_PAGINATED_MODE_RENDER */

  if (backend_status == CAIRO_INT_STATUS_SUCCESS ||

      backend_status == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY ||

      backend_status == CAIRO_INT_STATUS_NOTHING_TO_DO)

  {

      return CAIRO_INT_STATUS_SUCCESS;

  }

  else

  {

      return CAIRO_INT_STATUS_IMAGE_FALLBACK;

  }

    }

    _cairo_box_from_rectangle (&bbox, rect);

    if (surface->has_ctm) {

  int tx, ty;

  if (_cairo_matrix_is_integer_translation (&surface->ctm, &tx, &ty)) {

      rect->x += tx;

      rect->y += ty;

      tx = _cairo_fixed_from_int (tx);

      bbox.p1.x += tx;

      bbox.p2.x += tx;

      ty = _cairo_fixed_from_int (ty);

      bbox.p1.y += ty;

      bbox.p2.y += ty;

  } else {

      _cairo_matrix_transform_bounding_box_fixed (&surface->ctm,

              &bbox, NULL);

      if (bbox.p1.x == bbox.p2.x || bbox.p1.y == bbox.p2.y) {

    /* Even though the operation is not visible we must be

     * careful to not allow unsupported operations to be

     * replayed to the backend during

     * CAIRO_PAGINATED_MODE_RENDER */

    if (backend_status == CAIRO_INT_STATUS_SUCCESS ||

        backend_status == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY ||

        backend_status == CAIRO_INT_STATUS_NOTHING_TO_DO)

    {

        return CAIRO_INT_STATUS_SUCCESS;

    }

    else

    {

        return CAIRO_INT_STATUS_IMAGE_FALLBACK;

    }

      }

      _cairo_box_round_to_rectangle (&bbox, rect);

  }

    }

    if (surface->first_op) {

  surface->first_op = FALSE;

  surface->page_bbox = bbox;

    } else

  _cairo_box_add_box(&surface->page_bbox, &bbox);

    /* If the operation is completely enclosed within the fallback

     * region there is no benefit in emitting a native operation as

     * the fallback image will be painted on top.

     */

    if (cairo_region_contains_rectangle (&surface->fallback_region, rect) == CAIRO_REGION_OVERLAP_IN)

  return CAIRO_INT_STATUS_IMAGE_FALLBACK;

    if (backend_status == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY) {

  /* A status of CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY indicates

   * that the backend only supports this operation if the

   * transparency removed. If the extents of this operation does

   * not intersect any other native operation, the operation is

   * natively supported and the backend will blend the

   * transparency into the white background.

   */

  if (cairo_region_contains_rectangle (&surface->supported_region, rect) == CAIRO_REGION_OVERLAP_OUT)

      backend_status = CAIRO_INT_STATUS_SUCCESS;

    }

    if (backend_status == CAIRO_INT_STATUS_SUCCESS) {

  /* Add the operation to the supported region. Operations in

   * this region will be emitted as native operations.

   */

  surface->has_supported = TRUE;

  return cairo_region_union_rectangle (&surface->supported_region, rect);

    }

    /* Add the operation to the unsupported region. This region will

     * be painted as an image after all native operations have been

     * emitted.

     */

    surface->has_unsupported = TRUE;

    status = cairo_region_union_rectangle (&surface->fallback_region, rect);

    /* The status CAIRO_INT_STATUS_IMAGE_FALLBACK is used to indicate

     * unsupported operations to the recording surface as using

     * CAIRO_INT_STATUS_UNSUPPORTED would cause cairo-surface to

     * invoke the cairo-surface-fallback path then return

     * CAIRO_STATUS_SUCCESS.

     */

    if (status == CAIRO_INT_STATUS_SUCCESS)

  return CAIRO_INT_STATUS_IMAGE_FALLBACK;

    else

  return status;

}

static cairo_int_status_t

_analyze_recording_surface_pattern (cairo_analysis_surface_t *surface,

            const cairo_pattern_t    *pattern,

            cairo_rectangle_int_t    *extents)

{

    const cairo_surface_pattern_t *surface_pattern;

    cairo_analysis_surface_t *tmp;

    cairo_surface_t *source, *proxy;

    cairo_matrix_t p2d;

    cairo_int_status_t status;

    cairo_int_status_t analysis_status = CAIRO_INT_STATUS_SUCCESS;

    cairo_bool_t surface_is_unbounded;

    cairo_bool_t unused;

    assert (pattern->type == CAIRO_PATTERN_TYPE_SURFACE);

    surface_pattern = (const cairo_surface_pattern_t *) pattern;

    assert (surface_pattern->surface->type == CAIRO_SURFACE_TYPE_RECORDING);

    source = surface_pattern->surface;

    proxy = _cairo_surface_has_snapshot (source, &proxy_backend);

    if (proxy != NULL) {

  /* nothing untoward found so far */

  return CAIRO_STATUS_SUCCESS;

    }

    tmp = (cairo_analysis_surface_t *)

  _cairo_analysis_surface_create (surface->target);

    if (unlikely (tmp->base.status)) {

  status =tmp->base.status;

  goto cleanup1;

    }

    proxy = attach_proxy (source, &tmp->base);

    p2d = pattern->matrix;

    status = cairo_matrix_invert (&p2d);

    assert (status == CAIRO_INT_STATUS_SUCCESS);

    _cairo_analysis_surface_set_ctm (&tmp->base, &p2d);

    source = _cairo_surface_get_source (source, NULL);

    surface_is_unbounded = (pattern->extend == CAIRO_EXTEND_REPEAT

             || pattern->extend == CAIRO_EXTEND_REFLECT);

    status = _cairo_recording_surface_replay_and_create_regions (source,

                 &pattern->matrix,

                 &tmp->base,

                 surface_is_unbounded);

    if (unlikely (status))

  goto cleanup2;

    /* black background or mime data fills entire extents */

    if (!(source->content & CAIRO_CONTENT_ALPHA) || _cairo_surface_has_mime_image (source)) {

  cairo_rectangle_int_t rect;

  if (_cairo_surface_get_extents (source, &rect)) {

      cairo_box_t bbox;

      _cairo_box_from_rectangle (&bbox, &rect);

      _cairo_matrix_transform_bounding_box_fixed (&p2d, &bbox, NULL);

      _cairo_box_round_to_rectangle (&bbox, &rect);

      status = _add_operation (tmp, &rect, CAIRO_INT_STATUS_SUCCESS);

      if (status == CAIRO_INT_STATUS_IMAGE_FALLBACK)

    status = CAIRO_INT_STATUS_SUCCESS;

      if (unlikely (status))

    goto cleanup2;

  }

    }

    if (tmp->has_supported) {

  surface->has_supported = TRUE;

  unused = cairo_region_union (&surface->supported_region, &tmp->supported_region);

    }

    if (tmp->has_unsupported) {

  surface->has_unsupported = TRUE;

  unused = cairo_region_union (&surface->fallback_region, &tmp->fallback_region);

    }

    analysis_status = tmp->has_unsupported ? CAIRO_INT_STATUS_IMAGE_FALLBACK : CAIRO_INT_STATUS_SUCCESS;

    if (pattern->extend != CAIRO_EXTEND_NONE) {

  _cairo_unbounded_rectangle_init (extents);

    } else {

  status = cairo_matrix_invert (&tmp->ctm);

  _cairo_matrix_transform_bounding_box_fixed (&tmp->ctm,

                &tmp->page_bbox, NULL);

  _cairo_box_round_to_rectangle (&tmp->page_bbox, extents);

    }

  cleanup2:

    detach_proxy (proxy);

  cleanup1:

    cairo_surface_destroy (&tmp->base);

    if (unlikely (status))

  return status;

    else

  return analysis_status;

}

static cairo_status_t

_cairo_analysis_surface_finish (void *abstract_surface)

{

    cairo_analysis_surface_t  *surface = (cairo_analysis_surface_t *) abstract_surface;

    _cairo_region_fini (&surface->supported_region);

    _cairo_region_fini (&surface->fallback_region);

    cairo_surface_destroy (surface->target);

    return CAIRO_STATUS_SUCCESS;

}

static cairo_bool_t

_cairo_analysis_surface_get_extents (void     *abstract_surface,

             cairo_rectangle_int_t  *rectangle)

{

    cairo_analysis_surface_t *surface = abstract_surface;

    return _cairo_surface_get_extents (surface->target, rectangle);

}

static void

_rectangle_intersect_clip (cairo_rectangle_int_t *extents, const cairo_clip_t *clip)

{

    if (clip != NULL)

  _cairo_rectangle_intersect (extents, _cairo_clip_get_extents (clip));

}

static void

_cairo_analysis_surface_operation_extents (cairo_analysis_surface_t *surface,

             cairo_operator_t op,

             const cairo_pattern_t *source,

             const cairo_clip_t *clip,

             cairo_rectangle_int_t *extents)

{

    cairo_bool_t is_empty;

    is_empty = _cairo_surface_get_extents (&surface->base, extents);

    if (_cairo_operator_bounded_by_source (op)) {

  cairo_rectangle_int_t source_extents;

  _cairo_pattern_get_extents (source, &source_extents, surface->target->is_vector);

  _cairo_rectangle_intersect (extents, &source_extents);

    }

    _rectangle_intersect_clip (extents, clip);

}

static cairo_int_status_t

_cairo_analysis_surface_paint (void     *abstract_surface,

             cairo_operator_t   op,

             const cairo_pattern_t  *source,

             const cairo_clip_t *clip)

{

    cairo_analysis_surface_t *surface = abstract_surface;

    cairo_int_status_t       backend_status;

    cairo_rectangle_int_t  extents;

    if (surface->target->backend->paint == NULL) {

  backend_status = CAIRO_INT_STATUS_UNSUPPORTED;

    } else {

  backend_status =

      surface->target->backend->paint (surface->target,

               op, source, clip);

  if (_cairo_int_status_is_error (backend_status))

      return backend_status;

    }

    _cairo_analysis_surface_operation_extents (surface,

                 op, source, clip,

                 &extents);

    if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN) {

  cairo_rectangle_int_t rec_extents;

  backend_status = _analyze_recording_surface_pattern (surface, source, &rec_extents);

  _cairo_rectangle_intersect (&extents, &rec_extents);

    }

    return _add_operation (surface, &extents, backend_status);

}

static cairo_int_status_t

_cairo_analysis_surface_mask (void      *abstract_surface,

            cairo_operator_t     op,

            const cairo_pattern_t *source,

            const cairo_pattern_t *mask,

            const cairo_clip_t  *clip)

{

    cairo_analysis_surface_t *surface = abstract_surface;

    cairo_int_status_t        backend_status;

    cairo_rectangle_int_t   extents;

    if (surface->target->backend->mask == NULL) {

  backend_status = CAIRO_INT_STATUS_UNSUPPORTED;

    } else {

  backend_status =

      surface->target->backend->mask (surface->target,

              op, source, mask, clip);

  if (_cairo_int_status_is_error (backend_status))

      return backend_status;

    }

    _cairo_analysis_surface_operation_extents (surface,

                 op, source, clip,

                 &extents);

    if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN) {

  cairo_int_status_t backend_source_status = CAIRO_STATUS_SUCCESS;

  cairo_int_status_t backend_mask_status = CAIRO_STATUS_SUCCESS;

  cairo_rectangle_int_t rec_extents;

  if (source->type == CAIRO_PATTERN_TYPE_SURFACE) {

      cairo_surface_t *src_surface = ((cairo_surface_pattern_t *)source)->surface;

      src_surface = _cairo_surface_get_source (src_surface, NULL);

      if (_cairo_surface_is_recording (src_surface)) {

    backend_source_status =

        _analyze_recording_surface_pattern (surface, source, &rec_extents);

    if (_cairo_int_status_is_error (backend_source_status))

        return backend_source_status;

    _cairo_rectangle_intersect (&extents, &rec_extents);

      }

  }

  if (mask->type == CAIRO_PATTERN_TYPE_SURFACE) {

      cairo_surface_t *mask_surface = ((cairo_surface_pattern_t *)mask)->surface;

      mask_surface = _cairo_surface_get_source (mask_surface, NULL);

      if (_cairo_surface_is_recording (mask_surface)) {

    backend_mask_status =

        _analyze_recording_surface_pattern (surface, mask, &rec_extents);

    if (_cairo_int_status_is_error (backend_mask_status))

        return backend_mask_status;

    _cairo_rectangle_intersect (&extents, &rec_extents);

      }

  }

  backend_status =

      _cairo_analysis_surface_merge_status (backend_source_status,

              backend_mask_status);

    }

    if (_cairo_operator_bounded_by_mask (op)) {

  cairo_rectangle_int_t mask_extents;

  _cairo_pattern_get_extents (mask, &mask_extents, surface->target->is_vector);

  _cairo_rectangle_intersect (&extents, &mask_extents);

    }

    return _add_operation (surface, &extents, backend_status);

}

static cairo_int_status_t

_cairo_analysis_surface_stroke (void         *abstract_surface,

        cairo_operator_t      op,

        const cairo_pattern_t    *source,

        const cairo_path_fixed_t   *path,

        const cairo_stroke_style_t *style,

        const cairo_matrix_t     *ctm,

        const cairo_matrix_t     *ctm_inverse,

        double          tolerance,

        cairo_antialias_t     antialias,

        const cairo_clip_t     *clip)

{

    cairo_analysis_surface_t *surface = abstract_surface;

    cairo_int_status_t       backend_status;

    cairo_rectangle_int_t    extents;

    if (surface->target->backend->stroke == NULL) {

  backend_status = CAIRO_INT_STATUS_UNSUPPORTED;

    } else {

  backend_status =

      surface->target->backend->stroke (surface->target, op,

                source, path, style,

                ctm, ctm_inverse,

                tolerance, antialias,

                clip);

  if (_cairo_int_status_is_error (backend_status))

      return backend_status;

    }

    _cairo_analysis_surface_operation_extents (surface,

                 op, source, clip,

                 &extents);

    if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN) {

  cairo_rectangle_int_t rec_extents;

  backend_status = _analyze_recording_surface_pattern (surface, source, &rec_extents);

  _cairo_rectangle_intersect (&extents, &rec_extents);

    }

    if (_cairo_operator_bounded_by_mask (op)) {

  cairo_rectangle_int_t mask_extents;

  cairo_int_status_t status;

  status = _cairo_path_fixed_stroke_extents (path, style,

               ctm, ctm_inverse,

               tolerance,

               &mask_extents);

  if (unlikely (status))

      return status;

  _cairo_rectangle_intersect (&extents, &mask_extents);

    }

    return _add_operation (surface, &extents, backend_status);

}

static cairo_int_status_t

_cairo_analysis_surface_fill (void      *abstract_surface,

            cairo_operator_t     op,

            const cairo_pattern_t *source,

            const cairo_path_fixed_t  *path,

            cairo_fill_rule_t    fill_rule,

            double       tolerance,

            cairo_antialias_t    antialias,

            const cairo_clip_t  *clip)

{

    cairo_analysis_surface_t *surface = abstract_surface;

    cairo_int_status_t       backend_status;

    cairo_rectangle_int_t    extents;

    if (surface->target->backend->fill == NULL) {

  backend_status = CAIRO_INT_STATUS_UNSUPPORTED;

    } else {

  backend_status =

      surface->target->backend->fill (surface->target, op,

              source, path, fill_rule,

              tolerance, antialias,

              clip);

  if (_cairo_int_status_is_error (backend_status))

      return backend_status;

    }

    _cairo_analysis_surface_operation_extents (surface,

                 op, source, clip,

                 &extents);

    if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN) {

  cairo_rectangle_int_t rec_extents;

  backend_status = _analyze_recording_surface_pattern (surface, source, &rec_extents);

  _cairo_rectangle_intersect (&extents, &rec_extents);

    }

    if (_cairo_operator_bounded_by_mask (op)) {

  cairo_rectangle_int_t mask_extents;

  _cairo_path_fixed_fill_extents (path, fill_rule, tolerance,

          &mask_extents);

  _cairo_rectangle_intersect (&extents, &mask_extents);

    }

    return _add_operation (surface, &extents, backend_status);

}

static cairo_int_status_t

_cairo_analysis_surface_show_glyphs (void     *abstract_surface,

             cairo_operator_t    op,

             const cairo_pattern_t *source,

             cairo_glyph_t    *glyphs,

             int       num_glyphs,

             cairo_scaled_font_t  *scaled_font,

             const cairo_clip_t         *clip)

{

    cairo_analysis_surface_t *surface = abstract_surface;

    cairo_int_status_t       status, backend_status;

    cairo_rectangle_int_t    extents, glyph_extents;

    /* Adapted from _cairo_surface_show_glyphs */

    if (surface->target->backend->show_glyphs != NULL) {

  backend_status =

      surface->target->backend->show_glyphs (surface->target, op,

               source,

               glyphs, num_glyphs,

               scaled_font,

               clip);

  if (_cairo_int_status_is_error (backend_status))

      return backend_status;

    }

    else if (surface->target->backend->show_text_glyphs != NULL)

    {

  backend_status =

      surface->target->backend->show_text_glyphs (surface->target, op,

              source,

              NULL, 0,

              glyphs, num_glyphs,

              NULL, 0,

              FALSE,

              scaled_font,

              clip);

  if (_cairo_int_status_is_error (backend_status))

      return backend_status;

    }

    else

    {

  backend_status = CAIRO_INT_STATUS_UNSUPPORTED;

    }

    _cairo_analysis_surface_operation_extents (surface,

                 op, source, clip,

                 &extents);

    if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN) {

  cairo_rectangle_int_t rec_extents;

  backend_status = _analyze_recording_surface_pattern (surface, source, &rec_extents);

  _cairo_rectangle_intersect (&extents, &rec_extents);

    }

    if (_cairo_operator_bounded_by_mask (op)) {

  status = _cairo_scaled_font_glyph_device_extents (scaled_font,

                glyphs,

                num_glyphs,

                &glyph_extents,

                NULL);

  if (unlikely (status))

      return status;

  _cairo_rectangle_intersect (&extents, &glyph_extents);

    }

    return _add_operation (surface, &extents, backend_status);

}

static cairo_bool_t

_cairo_analysis_surface_has_show_text_glyphs (void *abstract_surface)

{

    cairo_analysis_surface_t *surface = abstract_surface;

    return cairo_surface_has_show_text_glyphs (surface->target);

}

static cairo_int_status_t

_cairo_analysis_surface_show_text_glyphs (void          *abstract_surface,

            cairo_operator_t       op,

            const cairo_pattern_t     *source,

            const char        *utf8,

            int          utf8_len,

            cairo_glyph_t       *glyphs,

            int          num_glyphs,

            const cairo_text_cluster_t *clusters,

            int          num_clusters,

            cairo_text_cluster_flags_t cluster_flags,

            cairo_scaled_font_t     *scaled_font,

            const cairo_clip_t        *clip)

{

    cairo_analysis_surface_t *surface = abstract_surface;

    cairo_int_status_t       status, backend_status;

    cairo_rectangle_int_t    extents, glyph_extents;

    /* Adapted from _cairo_surface_show_glyphs */

    backend_status = CAIRO_INT_STATUS_UNSUPPORTED;

    if (surface->target->backend->show_text_glyphs != NULL) {

  backend_status =

      surface->target->backend->show_text_glyphs (surface->target, op,

              source,

              utf8, utf8_len,

              glyphs, num_glyphs,

              clusters, num_clusters,

              cluster_flags,

              scaled_font,

              clip);

  if (_cairo_int_status_is_error (backend_status))

      return backend_status;

    }

    if (backend_status == CAIRO_INT_STATUS_UNSUPPORTED &&

  surface->target->backend->show_glyphs != NULL)

    {

  backend_status =

      surface->target->backend->show_glyphs (surface->target, op,

               source,

               glyphs, num_glyphs,

               scaled_font,

               clip);

  if (_cairo_int_status_is_error (backend_status))

      return backend_status;

    }

    _cairo_analysis_surface_operation_extents (surface,

                 op, source, clip,

                 &extents);

    if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN) {

  cairo_rectangle_int_t rec_extents;

  backend_status = _analyze_recording_surface_pattern (surface, source, &rec_extents);

  _cairo_rectangle_intersect (&extents, &rec_extents);

    }

    if (_cairo_operator_bounded_by_mask (op)) {

  status = _cairo_scaled_font_glyph_device_extents (scaled_font,

                glyphs,

                num_glyphs,

                &glyph_extents,

                NULL);

  if (unlikely (status))

      return status;

  _cairo_rectangle_intersect (&extents, &glyph_extents);

    }

    return _add_operation (surface, &extents, backend_status);

}

static cairo_int_status_t

_cairo_analysis_surface_tag (void                 *abstract_surface,

           cairo_bool_t                begin,

           const char                 *tag_name,

           const char                 *attributes)

{

    cairo_analysis_surface_t *surface = abstract_surface;

    cairo_int_status_t       backend_status;

    backend_status = CAIRO_INT_STATUS_SUCCESS;

    if (surface->target->backend->tag != NULL) {

  backend_status =

      surface->target->backend->tag (surface->target,

             begin,

             tag_name,

             attributes);

        if (backend_status == CAIRO_INT_STATUS_SUCCESS)

            surface->has_supported = TRUE;

    }

    return backend_status;

}

static const cairo_surface_backend_t cairo_analysis_surface_backend = {

    CAIRO_INTERNAL_SURFACE_TYPE_ANALYSIS,

    _cairo_analysis_surface_finish,

    NULL,

    NULL, /* create_similar */

    NULL, /* create_similar_image */

    NULL, /* map_to_image */

    NULL, /* unmap */

    NULL, /* source */

    NULL, /* acquire_source_image */

    NULL, /* release_source_image */

    NULL, /* snapshot */

    NULL, /* copy_page */

    NULL, /* show_page */

    _cairo_analysis_surface_get_extents,

    NULL, /* get_font_options */

    NULL, /* flush */

    NULL, /* mark_dirty_rectangle */

    _cairo_analysis_surface_paint,

    _cairo_analysis_surface_mask,

    _cairo_analysis_surface_stroke,

    _cairo_analysis_surface_fill,

    NULL, /* fill_stroke */

    _cairo_analysis_surface_show_glyphs,

    _cairo_analysis_surface_has_show_text_glyphs,

    _cairo_analysis_surface_show_text_glyphs,

    NULL, /* get_supported_mime_types */

    _cairo_analysis_surface_tag

};

cairo_surface_t *

_cairo_analysis_surface_create (cairo_surface_t   *target)

{

    cairo_analysis_surface_t *surface;

    cairo_status_t status;

    status = target->status;

    if (unlikely (status))

  return _cairo_surface_create_in_error (status);

    surface = _cairo_malloc (sizeof (cairo_analysis_surface_t));

    if (unlikely (surface == NULL))

  return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));

    /* I believe the content type here is truly arbitrary. I'm quite

     * sure nothing will ever use this value. */

    _cairo_surface_init (&surface->base,

       &cairo_analysis_surface_backend,

       NULL, /* device */

       CAIRO_CONTENT_COLOR_ALPHA,

       target->is_vector);

    cairo_matrix_init_identity (&surface->ctm);

    surface->has_ctm = FALSE;

    surface->target = cairo_surface_reference (target);

    surface->first_op  = TRUE;

    surface->has_supported = FALSE;

    surface->has_unsupported = FALSE;

    _cairo_region_init (&surface->supported_region);

    _cairo_region_init (&surface->fallback_region);

    surface->page_bbox.p1.x = 0;

    surface->page_bbox.p1.y = 0;

    surface->page_bbox.p2.x = 0;

    surface->page_bbox.p2.y = 0;

    return &surface->base;

}

void

_cairo_analysis_surface_set_ctm (cairo_surface_t *abstract_surface,

         const cairo_matrix_t  *ctm)

{

    cairo_analysis_surface_t  *surface;

    if (abstract_surface->status)

  return;

    surface = (cairo_analysis_surface_t *) abstract_surface;

    surface->ctm = *ctm;

    surface->has_ctm = ! _cairo_matrix_is_identity (&surface->ctm);

}

void

_cairo_analysis_surface_get_ctm (cairo_surface_t *abstract_surface,

         cairo_matrix_t  *ctm)

{

    cairo_analysis_surface_t  *surface = (cairo_analysis_surface_t *) abstract_surface;

    *ctm = surface->ctm;

}

cairo_region_t *

_cairo_analysis_surface_get_supported (cairo_surface_t *abstract_surface)

{

    cairo_analysis_surface_t  *surface = (cairo_analysis_surface_t *) abstract_surface;

    return &surface->supported_region;

}

cairo_region_t *

_cairo_analysis_surface_get_unsupported (cairo_surface_t *abstract_surface)

{

    cairo_analysis_surface_t  *surface = (cairo_analysis_surface_t *) abstract_surface;

    return &surface->fallback_region;

}

cairo_bool_t

_cairo_analysis_surface_has_supported (cairo_surface_t *abstract_surface)

{

    cairo_analysis_surface_t  *surface = (cairo_analysis_surface_t *) abstract_surface;

    return surface->has_supported;

}

cairo_bool_t

_cairo_analysis_surface_has_unsupported (cairo_surface_t *abstract_surface)

{

    cairo_analysis_surface_t  *surface = (cairo_analysis_surface_t *) abstract_surface;

    return surface->has_unsupported;

}

void

_cairo_analysis_surface_get_bounding_box (cairo_surface_t *abstract_surface,

            cairo_box_t     *bbox)

{

    cairo_analysis_surface_t  *surface = (cairo_analysis_surface_t *) abstract_surface;

    *bbox = surface->page_bbox;

}

/* null surface type: a surface that does nothing (has no side effects, yay!) */

static cairo_int_status_t

_paint_return_success (void     *surface,

           cairo_operator_t    op,

           const cairo_pattern_t  *source,

           const cairo_clip_t *clip)

{

    return CAIRO_INT_STATUS_SUCCESS;

}

static cairo_int_status_t

_mask_return_success (void      *surface,

          cairo_operator_t     op,

          const cairo_pattern_t *source,

          const cairo_pattern_t *mask,

          const cairo_clip_t  *clip)