/work/workdir/UnpackedTarball/cairo/src/cairo-gstate.c

Source
/* cairo - a vector graphics library with display and print output
 *
 * Copyright © 2002 University of Southern California
 * Copyright © 2005 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it either under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation
 * (the "LGPL") or, at your option, under the terms of the Mozilla
 * Public License Version 1.1 (the "MPL"). If you do not alter this
 * notice, a recipient may use your version of this file under either
 * the MPL or the LGPL.
 *
 * You should have received a copy of the LGPL along with this library
 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
 * You should have received a copy of the MPL along with this library
 * in the file COPYING-MPL-1.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
 * the specific language governing rights and limitations.
 *
 * The Original Code is the cairo graphics library.
 *
 * The Initial Developer of the Original Code is University of Southern
 * California.
 *
 * Contributor(s):
 *  Carl D. Worth <cworth@cworth.org>
 */

#include "cairoint.h"

#include "cairo-clip-inline.h"
#include "cairo-clip-private.h"
#include "cairo-error-private.h"
#include "cairo-list-inline.h"
#include "cairo-gstate-private.h"
#include "cairo-pattern-private.h"
#include "cairo-traps-private.h"

static cairo_status_t
_cairo_gstate_init_copy (cairo_gstate_t *gstate, cairo_gstate_t *other);

static cairo_status_t
_cairo_gstate_ensure_font_face (cairo_gstate_t *gstate);

static cairo_status_t
_cairo_gstate_ensure_scaled_font (cairo_gstate_t *gstate);

static void
_cairo_gstate_unset_scaled_font (cairo_gstate_t *gstate);

static void
_cairo_gstate_transform_glyphs_to_backend (cairo_gstate_t      *gstate,
                                           const cairo_glyph_t *glyphs,
                                           int                  num_glyphs,
             const cairo_text_cluster_t *clusters,
             int       num_clusters,
             cairo_text_cluster_flags_t cluster_flags,
                                           cairo_glyph_t       *transformed_glyphs,
             int      *num_transformed_glyphs,
             cairo_text_cluster_t *transformed_clusters,
             cairo_bool_t          perform_early_clip);

static void
_cairo_gstate_update_device_transform (cairo_observer_t *observer,
               void *arg)
{
    cairo_gstate_t *gstate = cairo_container_of (observer,
             cairo_gstate_t,
             device_transform_observer);

    gstate->is_identity = (_cairo_matrix_is_identity (&gstate->ctm) &&
         _cairo_matrix_is_identity (&gstate->target->device_transform));
}

cairo_status_t
_cairo_gstate_init (cairo_gstate_t  *gstate,
        cairo_surface_t *target)
{
    VG (VALGRIND_MAKE_MEM_UNDEFINED (gstate, sizeof (cairo_gstate_t)));

    gstate->next = NULL;

    gstate->op = CAIRO_GSTATE_OPERATOR_DEFAULT;
    gstate->opacity = 1.;

    gstate->tolerance = CAIRO_GSTATE_TOLERANCE_DEFAULT;
    gstate->antialias = CAIRO_ANTIALIAS_DEFAULT;

    _cairo_stroke_style_init (&gstate->stroke_style);

    gstate->fill_rule = CAIRO_GSTATE_FILL_RULE_DEFAULT;

    gstate->font_face = NULL;
    gstate->scaled_font = NULL;
    gstate->previous_scaled_font = NULL;

    cairo_matrix_init_scale (&gstate->font_matrix,
           CAIRO_GSTATE_DEFAULT_FONT_SIZE,
           CAIRO_GSTATE_DEFAULT_FONT_SIZE);

    _cairo_font_options_init_default (&gstate->font_options);

    gstate->clip = NULL;

    gstate->target = cairo_surface_reference (target);
    gstate->parent_target = NULL;
    gstate->original_target = cairo_surface_reference (target);

    gstate->device_transform_observer.callback = _cairo_gstate_update_device_transform;
    cairo_list_add (&gstate->device_transform_observer.link,
        &gstate->target->device_transform_observers);

    gstate->is_identity = _cairo_matrix_is_identity (&gstate->target->device_transform);
    cairo_matrix_init_identity (&gstate->ctm);
    gstate->ctm_inverse = gstate->ctm;
    gstate->source_ctm_inverse = gstate->ctm;

    gstate->source = (cairo_pattern_t *) &_cairo_pattern_black.base;

    /* Now that the gstate is fully initialized and ready for the eventual
     * _cairo_gstate_fini(), we can check for errors (and not worry about
     * the resource deallocation). */
    return target->status;
}

/**
 * _cairo_gstate_init_copy:
 *
 * Initialize @gstate by performing a deep copy of state fields from
 * @other. Note that gstate->next is not copied but is set to %NULL by
 * this function.
 **/
static cairo_status_t
_cairo_gstate_init_copy (cairo_gstate_t *gstate, cairo_gstate_t *other)
{
    cairo_status_t status;

    VG (VALGRIND_MAKE_MEM_UNDEFINED (gstate, sizeof (cairo_gstate_t)));

    gstate->op = other->op;
    gstate->opacity = other->opacity;

    gstate->tolerance = other->tolerance;
    gstate->antialias = other->antialias;

    status = _cairo_stroke_style_init_copy (&gstate->stroke_style,
              &other->stroke_style);
    if (unlikely (status))
  return status;

    gstate->fill_rule = other->fill_rule;

    gstate->font_face = cairo_font_face_reference (other->font_face);
    gstate->scaled_font = cairo_scaled_font_reference (other->scaled_font);
    gstate->previous_scaled_font = cairo_scaled_font_reference (other->previous_scaled_font);

    gstate->font_matrix = other->font_matrix;

    _cairo_font_options_init_copy (&gstate->font_options , &other->font_options);

    gstate->clip = _cairo_clip_copy (other->clip);

    gstate->target = cairo_surface_reference (other->target);
    /* parent_target is always set to NULL; it's only ever set by redirect_target */
    gstate->parent_target = NULL;
    gstate->original_target = cairo_surface_reference (other->original_target);

    gstate->device_transform_observer.callback = _cairo_gstate_update_device_transform;
    cairo_list_add (&gstate->device_transform_observer.link,
        &gstate->target->device_transform_observers);

    gstate->is_identity = other->is_identity;
    gstate->ctm = other->ctm;
    gstate->ctm_inverse = other->ctm_inverse;
    gstate->source_ctm_inverse = other->source_ctm_inverse;

    gstate->source = cairo_pattern_reference (other->source);

    gstate->next = NULL;

    return CAIRO_STATUS_SUCCESS;
}

void
_cairo_gstate_fini (cairo_gstate_t *gstate)
{
    _cairo_stroke_style_fini (&gstate->stroke_style);
    _cairo_font_options_fini (&gstate->font_options);

    cairo_font_face_destroy (gstate->font_face);
    gstate->font_face = NULL;

    cairo_scaled_font_destroy (gstate->previous_scaled_font);
    gstate->previous_scaled_font = NULL;

    cairo_scaled_font_destroy (gstate->scaled_font);
    gstate->scaled_font = NULL;

    _cairo_clip_destroy (gstate->clip);

    cairo_list_del (&gstate->device_transform_observer.link);

    cairo_surface_destroy (gstate->target);
    gstate->target = NULL;

    cairo_surface_destroy (gstate->parent_target);
    gstate->parent_target = NULL;

    cairo_surface_destroy (gstate->original_target);
    gstate->original_target = NULL;

    cairo_pattern_destroy (gstate->source);
    gstate->source = NULL;

    VG (VALGRIND_MAKE_MEM_UNDEFINED (gstate, sizeof (cairo_gstate_t)));
}

/**
 * _cairo_gstate_save:
 * @gstate: input/output gstate pointer
 *
 * Makes a copy of the current state of @gstate and saves it
 * to @gstate->next, then put the address of the newly allcated
 * copy into @gstate.  _cairo_gstate_restore() reverses this.
 **/
cairo_status_t
_cairo_gstate_save (cairo_gstate_t **gstate, cairo_gstate_t **freelist)
{
    cairo_gstate_t *top;
    cairo_status_t status;

    if (CAIRO_INJECT_FAULT ())
  return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    top = *freelist;
    if (top == NULL) {
  top = _cairo_calloc (sizeof (cairo_gstate_t));
  if (unlikely (top == NULL))
      return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    } else
  *freelist = top->next;

    status = _cairo_gstate_init_copy (top, *gstate);
    if (unlikely (status)) {
  top->next = *freelist;
  *freelist = top;
  return status;
    }

    top->next = *gstate;
    *gstate = top;

    return CAIRO_STATUS_SUCCESS;
}

/**
 * _cairo_gstate_restore:
 * @gstate: input/output gstate pointer
 *
 * Reverses the effects of one _cairo_gstate_save() call.
 **/
cairo_status_t
_cairo_gstate_restore (cairo_gstate_t **gstate, cairo_gstate_t **freelist)
{
    cairo_gstate_t *top;

    top = *gstate;
    if (top->next == NULL)
  return _cairo_error (CAIRO_STATUS_INVALID_RESTORE);

    *gstate = top->next;

    _cairo_gstate_fini (top);
    VG (VALGRIND_MAKE_MEM_UNDEFINED (&top->next, sizeof (cairo_gstate_t *)));
    top->next = *freelist;
    *freelist = top;

    return CAIRO_STATUS_SUCCESS;
}

/**
 * _cairo_gstate_redirect_target:
 * @gstate: a #cairo_gstate_t
 * @child: the new child target
 *
 * Redirect @gstate rendering to a "child" target. The original
 * "parent" target with which the gstate was created will not be
 * affected. See _cairo_gstate_get_target().
 **/
cairo_status_t
_cairo_gstate_redirect_target (cairo_gstate_t *gstate, cairo_surface_t *child)
{
    /* If this gstate is already redirected, this is an error; we need a
     * new gstate to be able to redirect */
    assert (gstate->parent_target == NULL);

    /* Set up our new parent_target based on our current target;
     * gstate->parent_target will take the ref that is held by gstate->target
     */
    gstate->parent_target = gstate->target;

    /* Now set up our new target; we overwrite gstate->target directly,
     * since its ref is now owned by gstate->parent_target */
    gstate->target = cairo_surface_reference (child);
    gstate->is_identity &= _cairo_matrix_is_identity (&child->device_transform);
    cairo_list_move (&gstate->device_transform_observer.link,
         &gstate->target->device_transform_observers);

    /* The clip is in surface backend coordinates for the previous target;
     * translate it into the child's backend coordinates. */
    _cairo_clip_destroy (gstate->clip);
    gstate->clip = _cairo_clip_copy_with_translation (gstate->next->clip,
                  child->device_transform.x0 - gstate->parent_target->device_transform.x0,
                  child->device_transform.y0 - gstate->parent_target->device_transform.y0);

    return CAIRO_STATUS_SUCCESS;
}

/**
 * _cairo_gstate_is_group:
 * @gstate: a #cairo_gstate_t
 *
 * Check if _cairo_gstate_redirect_target has been called on the head
 * of the stack.
 *
 * Return value: %TRUE if @gstate is redirected to a target different
 * than the previous state in the stack, %FALSE otherwise.
 **/
cairo_bool_t
_cairo_gstate_is_group (cairo_gstate_t *gstate)
{
    return gstate->parent_target != NULL;
}

/**
 * _cairo_gstate_get_target:
 * @gstate: a #cairo_gstate_t
 *
 * Return the current drawing target; if drawing is not redirected,
 * this will be the same as _cairo_gstate_get_original_target().
 *
 * Return value: the current target surface
 **/
cairo_surface_t *
_cairo_gstate_get_target (cairo_gstate_t *gstate)
{
    return gstate->target;
}

/**
 * _cairo_gstate_get_original_target:
 * @gstate: a #cairo_gstate_t
 *
 * Return the original target with which @gstate was created. This
 * function always returns the original target independent of any
 * child target that may have been set with
 * _cairo_gstate_redirect_target.
 *
 * Return value: the original target surface
 **/
cairo_surface_t *
_cairo_gstate_get_original_target (cairo_gstate_t *gstate)
{
    return gstate->original_target;
}

/**
 * _cairo_gstate_get_clip:
 * @gstate: a #cairo_gstate_t
 *
 * This space left intentionally blank.
 *
 * Return value: a pointer to the gstate's #cairo_clip_t structure.
 **/
cairo_clip_t *
_cairo_gstate_get_clip (cairo_gstate_t *gstate)
{
    return gstate->clip;
}

cairo_status_t
_cairo_gstate_set_source (cairo_gstate_t  *gstate,
        cairo_pattern_t *source)
{
    if (source->status)
  return source->status;

    source = cairo_pattern_reference (source);
    cairo_pattern_destroy (gstate->source);
    gstate->source = source;
    gstate->source_ctm_inverse = gstate->ctm_inverse;

    return CAIRO_STATUS_SUCCESS;
}

cairo_pattern_t *
_cairo_gstate_get_source (cairo_gstate_t *gstate)
{
    if (gstate->source == &_cairo_pattern_black.base) {
  /* do not expose the static object to the user */
        gstate->source = _cairo_pattern_create_solid (CAIRO_COLOR_BLACK);
    }

    return gstate->source;
}

cairo_status_t
_cairo_gstate_set_operator (cairo_gstate_t *gstate, cairo_operator_t op)
{
    gstate->op = op;

    return CAIRO_STATUS_SUCCESS;
}

cairo_operator_t
_cairo_gstate_get_operator (cairo_gstate_t *gstate)
{
    return gstate->op;
}

cairo_status_t
_cairo_gstate_set_opacity (cairo_gstate_t *gstate, double op)
{
    gstate->opacity = op;

    return CAIRO_STATUS_SUCCESS;
}

double
_cairo_gstate_get_opacity (cairo_gstate_t *gstate)
{
    return gstate->opacity;
}

cairo_status_t
_cairo_gstate_set_tolerance (cairo_gstate_t *gstate, double tolerance)
{
    gstate->tolerance = tolerance;

    return CAIRO_STATUS_SUCCESS;
}

double
_cairo_gstate_get_tolerance (cairo_gstate_t *gstate)
{
    return gstate->tolerance;
}

cairo_status_t
_cairo_gstate_set_fill_rule (cairo_gstate_t *gstate, cairo_fill_rule_t fill_rule)
{
    gstate->fill_rule = fill_rule;

    return CAIRO_STATUS_SUCCESS;
}

cairo_fill_rule_t
_cairo_gstate_get_fill_rule (cairo_gstate_t *gstate)
{
    return gstate->fill_rule;
}

cairo_status_t
_cairo_gstate_set_line_width (cairo_gstate_t *gstate, double width)
{
    if (gstate->stroke_style.is_hairline)
  gstate->stroke_style.pre_hairline_line_width = width;
  else
  gstate->stroke_style.line_width = width;

    return CAIRO_STATUS_SUCCESS;
}

double
_cairo_gstate_get_line_width (cairo_gstate_t *gstate)
{
    return gstate->stroke_style.line_width;
}

cairo_status_t
_cairo_gstate_set_hairline (cairo_gstate_t *gstate, cairo_bool_t set_hairline)
{
    if (gstate->stroke_style.is_hairline != set_hairline) {
        gstate->stroke_style.is_hairline = set_hairline;

        if (set_hairline) {
            gstate->stroke_style.pre_hairline_line_width = gstate->stroke_style.line_width;
            gstate->stroke_style.line_width = 0.0;
        } else {
            gstate->stroke_style.line_width = gstate->stroke_style.pre_hairline_line_width;
        }
    }

    return CAIRO_STATUS_SUCCESS;
}

cairo_bool_t
_cairo_gstate_get_hairline (cairo_gstate_t *gstate)
{
    return gstate->stroke_style.is_hairline;
}

cairo_status_t
_cairo_gstate_set_line_cap (cairo_gstate_t *gstate, cairo_line_cap_t line_cap)
{
    gstate->stroke_style.line_cap = line_cap;

    return CAIRO_STATUS_SUCCESS;
}

cairo_line_cap_t
_cairo_gstate_get_line_cap (cairo_gstate_t *gstate)
{
    return gstate->stroke_style.line_cap;
}

cairo_status_t
_cairo_gstate_set_line_join (cairo_gstate_t *gstate, cairo_line_join_t line_join)
{
    gstate->stroke_style.line_join = line_join;

    return CAIRO_STATUS_SUCCESS;
}

cairo_line_join_t
_cairo_gstate_get_line_join (cairo_gstate_t *gstate)
{
    return gstate->stroke_style.line_join;
}

cairo_status_t
_cairo_gstate_set_dash (cairo_gstate_t *gstate, const double *dash, int num_dashes, double offset)
{
    double dash_total, on_total, off_total;
    int i, j;

    free (gstate->stroke_style.dash);

    gstate->stroke_style.num_dashes = num_dashes;

    if (gstate->stroke_style.num_dashes == 0) {
  gstate->stroke_style.dash = NULL;
  gstate->stroke_style.dash_offset = 0.0;
  return CAIRO_STATUS_SUCCESS;
    }

    gstate->stroke_style.dash = _cairo_malloc_ab (gstate->stroke_style.num_dashes, sizeof (double));
    if (unlikely (gstate->stroke_style.dash == NULL)) {
  gstate->stroke_style.num_dashes = 0;
  return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }

    on_total = off_total = dash_total = 0.0;
    for (i = j = 0; i < num_dashes; i++) {
  if (dash[i] < 0)
      return _cairo_error (CAIRO_STATUS_INVALID_DASH);

  if (dash[i] == 0 && i > 0 && i < num_dashes - 1) {
      if (dash[++i] < 0)
    return _cairo_error (CAIRO_STATUS_INVALID_DASH);

      gstate->stroke_style.dash[j-1] += dash[i];
      gstate->stroke_style.num_dashes -= 2;
  } else
      gstate->stroke_style.dash[j++] = dash[i];

  if (dash[i]) {
      dash_total += dash[i];
      if ((i & 1) == 0)
    on_total += dash[i];
      else
    off_total += dash[i];
  }
    }

    if (dash_total == 0.0)
  return _cairo_error (CAIRO_STATUS_INVALID_DASH);

    /* An odd dash value indicate symmetric repeating, so the total
     * is twice as long. */
    if (gstate->stroke_style.num_dashes & 1) {
  dash_total *= 2;
  on_total += off_total;
    }

    if (dash_total - on_total < CAIRO_FIXED_ERROR_DOUBLE) {
  /* Degenerate dash -> solid line */
  free (gstate->stroke_style.dash);
  gstate->stroke_style.dash = NULL;
  gstate->stroke_style.num_dashes = 0;
  gstate->stroke_style.dash_offset = 0.0;
  return CAIRO_STATUS_SUCCESS;
    }

    /* The dashing code doesn't like a negative offset or a big positive
     * offset, so we compute an equivalent offset which is guaranteed to be
     * positive and less than twice the pattern length. */
    offset = fmod (offset, dash_total);
    if (offset < 0.0)
  offset += dash_total;
    if (offset <= 0.0)   /* Take care of -0 */
  offset = 0.0;
    gstate->stroke_style.dash_offset = offset;

    return CAIRO_STATUS_SUCCESS;
}

void
_cairo_gstate_get_dash (cairo_gstate_t *gstate,
      double         *dashes,
      int            *num_dashes,
      double         *offset)
{
    if (dashes) {
  memcpy (dashes,
    gstate->stroke_style.dash,
    sizeof (double) * gstate->stroke_style.num_dashes);
    }

    if (num_dashes)
  *num_dashes = gstate->stroke_style.num_dashes;

    if (offset)
  *offset = gstate->stroke_style.dash_offset;
}

cairo_status_t
_cairo_gstate_set_miter_limit (cairo_gstate_t *gstate, double limit)
{
    gstate->stroke_style.miter_limit = limit;

    return CAIRO_STATUS_SUCCESS;
}

double
_cairo_gstate_get_miter_limit (cairo_gstate_t *gstate)
{
    return gstate->stroke_style.miter_limit;
}

void
_cairo_gstate_get_matrix (cairo_gstate_t *gstate, cairo_matrix_t *matrix)
{
    *matrix = gstate->ctm;
}

cairo_status_t
_cairo_gstate_translate (cairo_gstate_t *gstate, double tx, double ty)
{
    cairo_matrix_t tmp;

    if (! ISFINITE (tx) || ! ISFINITE (ty))
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);

    _cairo_gstate_unset_scaled_font (gstate);

    cairo_matrix_init_translate (&tmp, tx, ty);
    cairo_matrix_multiply (&gstate->ctm, &tmp, &gstate->ctm);
    gstate->is_identity = FALSE;

    /* paranoid check against gradual numerical instability */
    if (! _cairo_matrix_is_invertible (&gstate->ctm))
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);

    cairo_matrix_init_translate (&tmp, -tx, -ty);
    cairo_matrix_multiply (&gstate->ctm_inverse, &gstate->ctm_inverse, &tmp);

    return CAIRO_STATUS_SUCCESS;
}

cairo_status_t
_cairo_gstate_scale (cairo_gstate_t *gstate, double sx, double sy)
{
    cairo_matrix_t tmp;

    if (sx * sy == 0.) /* either sx or sy is 0, or det == 0 due to underflow */
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);
    if (! ISFINITE (sx) || ! ISFINITE (sy))
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);

    _cairo_gstate_unset_scaled_font (gstate);

    cairo_matrix_init_scale (&tmp, sx, sy);
    cairo_matrix_multiply (&gstate->ctm, &tmp, &gstate->ctm);
    gstate->is_identity = FALSE;

    /* paranoid check against gradual numerical instability */
    if (! _cairo_matrix_is_invertible (&gstate->ctm))
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);

    cairo_matrix_init_scale (&tmp, 1/sx, 1/sy);
    cairo_matrix_multiply (&gstate->ctm_inverse, &gstate->ctm_inverse, &tmp);

    return CAIRO_STATUS_SUCCESS;
}

cairo_status_t
_cairo_gstate_rotate (cairo_gstate_t *gstate, double angle)
{
    cairo_matrix_t tmp;

    if (angle == 0.)
  return CAIRO_STATUS_SUCCESS;

    if (! ISFINITE (angle))
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);

    _cairo_gstate_unset_scaled_font (gstate);

    cairo_matrix_init_rotate (&tmp, angle);
    cairo_matrix_multiply (&gstate->ctm, &tmp, &gstate->ctm);
    gstate->is_identity = FALSE;

    /* paranoid check against gradual numerical instability */
    if (! _cairo_matrix_is_invertible (&gstate->ctm))
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);

    cairo_matrix_init_rotate (&tmp, -angle);
    cairo_matrix_multiply (&gstate->ctm_inverse, &gstate->ctm_inverse, &tmp);

    return CAIRO_STATUS_SUCCESS;
}

cairo_status_t
_cairo_gstate_transform (cairo_gstate_t       *gstate,
       const cairo_matrix_t *matrix)
{
    cairo_matrix_t tmp;
    cairo_status_t status;

    if (! _cairo_matrix_is_invertible (matrix))
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);

    if (_cairo_matrix_is_identity (matrix))
  return CAIRO_STATUS_SUCCESS;

    tmp = *matrix;
    status = cairo_matrix_invert (&tmp);
    if (unlikely (status))
  return status;

    _cairo_gstate_unset_scaled_font (gstate);

    cairo_matrix_multiply (&gstate->ctm, matrix, &gstate->ctm);
    cairo_matrix_multiply (&gstate->ctm_inverse, &gstate->ctm_inverse, &tmp);
    gstate->is_identity = FALSE;

    /* paranoid check against gradual numerical instability */
    if (! _cairo_matrix_is_invertible (&gstate->ctm))
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);

    return CAIRO_STATUS_SUCCESS;
}

cairo_status_t
_cairo_gstate_set_matrix (cairo_gstate_t       *gstate,
        const cairo_matrix_t *matrix)
{
    cairo_status_t status;

    if (memcmp (matrix, &gstate->ctm, sizeof (cairo_matrix_t)) == 0)
  return CAIRO_STATUS_SUCCESS;

    if (! _cairo_matrix_is_invertible (matrix))
  return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);

    if (_cairo_matrix_is_identity (matrix)) {
  _cairo_gstate_identity_matrix (gstate);
  return CAIRO_STATUS_SUCCESS;
    }

    _cairo_gstate_unset_scaled_font (gstate);

    gstate->ctm = *matrix;
    gstate->ctm_inverse = *matrix;
    status = cairo_matrix_invert (&gstate->ctm_inverse);
    assert (status == CAIRO_STATUS_SUCCESS);
    gstate->is_identity = FALSE;

    return CAIRO_STATUS_SUCCESS;
}

void
_cairo_gstate_identity_matrix (cairo_gstate_t *gstate)
{
    if (_cairo_matrix_is_identity (&gstate->ctm))
  return;

    _cairo_gstate_unset_scaled_font (gstate);

    cairo_matrix_init_identity (&gstate->ctm);
    cairo_matrix_init_identity (&gstate->ctm_inverse);
    gstate->is_identity = _cairo_matrix_is_identity (&gstate->target->device_transform);
}

void
_cairo_gstate_user_to_device (cairo_gstate_t *gstate, double *x, double *y)
{
    cairo_matrix_transform_point (&gstate->ctm, x, y);
}

void
_cairo_gstate_user_to_device_distance (cairo_gstate_t *gstate,
               double *dx, double *dy)
{
    cairo_matrix_transform_distance (&gstate->ctm, dx, dy);
}

void
_cairo_gstate_device_to_user (cairo_gstate_t *gstate, double *x, double *y)
{
    cairo_matrix_transform_point (&gstate->ctm_inverse, x, y);
}

void
_cairo_gstate_device_to_user_distance (cairo_gstate_t *gstate,
               double *dx, double *dy)
{
    cairo_matrix_transform_distance (&gstate->ctm_inverse, dx, dy);
}

void
_do_cairo_gstate_user_to_backend (cairo_gstate_t *gstate, double *x, double *y)
{
    cairo_matrix_transform_point (&gstate->ctm, x, y);
    cairo_matrix_transform_point (&gstate->target->device_transform, x, y);
}

void
_do_cairo_gstate_user_to_backend_distance (cairo_gstate_t *gstate, double *x, double *y)
{
    cairo_matrix_transform_distance (&gstate->ctm, x, y);
    cairo_matrix_transform_distance (&gstate->target->device_transform, x, y);
}

void
_do_cairo_gstate_backend_to_user (cairo_gstate_t *gstate, double *x, double *y)
{
    cairo_matrix_transform_point (&gstate->target->device_transform_inverse, x, y);
    cairo_matrix_transform_point (&gstate->ctm_inverse, x, y);
}

void
_do_cairo_gstate_backend_to_user_distance (cairo_gstate_t *gstate, double *x, double *y)
{
    cairo_matrix_transform_distance (&gstate->target->device_transform_inverse, x, y);
    cairo_matrix_transform_distance (&gstate->ctm_inverse, x, y);
}

void
_cairo_gstate_backend_to_user_rectangle (cairo_gstate_t *gstate,
                                         double *x1, double *y1,
                                         double *x2, double *y2,
                                         cairo_bool_t *is_tight)
{
    cairo_matrix_t matrix_inverse;

    if (! _cairo_matrix_is_identity (&gstate->target->device_transform_inverse) ||
    ! _cairo_matrix_is_identity (&gstate->ctm_inverse))
    {
  cairo_matrix_multiply (&matrix_inverse,
             &gstate->target->device_transform_inverse,
             &gstate->ctm_inverse);
  _cairo_matrix_transform_bounding_box (&matrix_inverse,
                x1, y1, x2, y2, is_tight);
    }

    else
    {
  if (is_tight)
      *is_tight = TRUE;
    }
}

/* XXX: NYI
cairo_status_t
_cairo_gstate_stroke_to_path (cairo_gstate_t *gstate)
{
    cairo_status_t status;

    _cairo_pen_init (&gstate);
    return CAIRO_STATUS_SUCCESS;
}
*/

void
_cairo_gstate_path_extents (cairo_gstate_t     *gstate,
          cairo_path_fixed_t *path,
          double *x1, double *y1,
          double *x2, double *y2)
{
    cairo_box_t box;
    double px1, py1, px2, py2;

    if (_cairo_path_fixed_extents (path, &box)) {
  px1 = _cairo_fixed_to_double (box.p1.x);
  py1 = _cairo_fixed_to_double (box.p1.y);
  px2 = _cairo_fixed_to_double (box.p2.x);
  py2 = _cairo_fixed_to_double (box.p2.y);

  _cairo_gstate_backend_to_user_rectangle (gstate,
             &px1, &py1, &px2, &py2,
             NULL);
    } else {
  px1 = 0.0;
  py1 = 0.0;
  px2 = 0.0;
  py2 = 0.0;
    }

    if (x1)
  *x1 = px1;
    if (y1)
  *y1 = py1;
    if (x2)
  *x2 = px2;
    if (y2)
  *y2 = py2;
}

static void
_cairo_gstate_copy_pattern (cairo_pattern_t *pattern,
          const cairo_pattern_t *original)
{
    /* First check if the we can replace the original with a much simpler
     * pattern. For example, gradients that are uniform or just have a single
     * stop can sometimes be replaced with a solid.
     */

    if (_cairo_pattern_is_clear (original)) {
        _cairo_pattern_init_solid ((cairo_solid_pattern_t *) pattern,
           CAIRO_COLOR_TRANSPARENT);
  return;
    }

    if (original->type == CAIRO_PATTERN_TYPE_LINEAR ||
  original->type == CAIRO_PATTERN_TYPE_RADIAL)
    {
        cairo_color_t color;
  if (_cairo_gradient_pattern_is_solid ((cairo_gradient_pattern_t *) original,
                NULL,
                &color))
  {
      _cairo_pattern_init_solid ((cairo_solid_pattern_t *) pattern,
               &color);
      return;
  }
    }

    _cairo_pattern_init_static_copy (pattern, original);
}

static void
_cairo_gstate_copy_transformed_pattern (cairo_gstate_t  *gstate,
          cairo_pattern_t *pattern,
          const cairo_pattern_t *original,
          const cairo_matrix_t  *ctm_inverse)
{
    /*
     * What calculations below do can be described in pseudo-code (so using nonexistent fields) as (using column vectors):
     * pattern->matrix = surface->device_transform *
     *       pattern->matrix *
     *       ctm_inverse *
     *       gstate->target->device_transform_inverse
     *
     * The inverse of which is:
     * pattern->matrix_inverse = gstate->target->device_transform *
     *         ctm *
     *         pattern->matrix_inverse *
     *         surface->device_transform_inverse
     */

    _cairo_gstate_copy_pattern (pattern, original);

    if (original->type == CAIRO_PATTERN_TYPE_SURFACE) {
  cairo_surface_pattern_t *surface_pattern;
  cairo_surface_t *surface;

        surface_pattern = (cairo_surface_pattern_t *) original;
        surface = surface_pattern->surface;

  if (_cairo_surface_has_device_transform (surface))
      _cairo_pattern_pretransform (pattern, &surface->device_transform);
    }

    if (! _cairo_matrix_is_identity (ctm_inverse))
  _cairo_pattern_transform (pattern, ctm_inverse);

    if (_cairo_surface_has_device_transform (gstate->target)) {
        _cairo_pattern_transform (pattern,
                                  &gstate->target->device_transform_inverse);
    }
}

static void
_cairo_gstate_copy_transformed_source (cairo_gstate_t   *gstate,
               cairo_pattern_t  *pattern)
{
    _cairo_gstate_copy_transformed_pattern (gstate, pattern,
              gstate->source,
              &gstate->source_ctm_inverse);
}

static void
_cairo_gstate_copy_transformed_mask (cairo_gstate_t   *gstate,
             cairo_pattern_t  *pattern,
             cairo_pattern_t  *mask)
{
    _cairo_gstate_copy_transformed_pattern (gstate, pattern,
              mask,
              &gstate->ctm_inverse);
}

static cairo_operator_t
_reduce_op (cairo_gstate_t *gstate)
{
    cairo_operator_t op;
    const cairo_pattern_t *pattern;

    op = gstate->op;
    if (op != CAIRO_OPERATOR_SOURCE)
  return op;

    pattern = gstate->source;
    if (pattern->type == CAIRO_PATTERN_TYPE_SOLID) {
  const cairo_solid_pattern_t *solid = (cairo_solid_pattern_t *) pattern;
  if (solid->color.alpha_short <= 0x00ff) {
      op = CAIRO_OPERATOR_CLEAR;
  } else if ((gstate->target->content & CAIRO_CONTENT_ALPHA) == 0) {
      if ((solid->color.red_short |
     solid->color.green_short |
     solid->color.blue_short) <= 0x00ff)
      {
    op = CAIRO_OPERATOR_CLEAR;
      }
  }
    } else if (pattern->type == CAIRO_PATTERN_TYPE_SURFACE) {
  const cairo_surface_pattern_t *surface = (cairo_surface_pattern_t *) pattern;
  if (surface->surface->is_clear &&
      surface->surface->content & CAIRO_CONTENT_ALPHA)
  {
      op = CAIRO_OPERATOR_CLEAR;
  }
    } else {
  const cairo_gradient_pattern_t *gradient = (cairo_gradient_pattern_t *) pattern;
  if (gradient->n_stops == 0)
      op = CAIRO_OPERATOR_CLEAR;
    }

    return op;
}

static cairo_status_t
_cairo_gstate_get_pattern_status (const cairo_pattern_t *pattern)
{
    if (unlikely (pattern->type == CAIRO_PATTERN_TYPE_MESH &&
      ((const cairo_mesh_pattern_t *) pattern)->current_patch))
    {
  /* If current patch != NULL, the pattern is under construction
   * and cannot be used as a source */
  return CAIRO_STATUS_INVALID_MESH_CONSTRUCTION;
    }

    return pattern->status;
}

cairo_status_t
_cairo_gstate_paint (cairo_gstate_t *gstate)
{
    cairo_pattern_union_t source_pattern;
    const cairo_pattern_t *pattern;
    cairo_status_t status;
    cairo_operator_t op;

    status = _cairo_gstate_get_pattern_status (gstate->source);
    if (unlikely (status))
  return status;

    if (gstate->op == CAIRO_OPERATOR_DEST)
  return CAIRO_STATUS_SUCCESS;

    if (_cairo_clip_is_all_clipped (gstate->clip))
  return CAIRO_STATUS_SUCCESS;

    op = _reduce_op (gstate);
    if (op == CAIRO_OPERATOR_CLEAR) {
  pattern = &_cairo_pattern_clear.base;
    } else {
  _cairo_gstate_copy_transformed_source (gstate, &source_pattern.base);
  pattern = &source_pattern.base;
    }

    return _cairo_surface_paint (gstate->target,
         op, pattern,
         gstate->clip);
}

cairo_status_t
_cairo_gstate_mask (cairo_gstate_t  *gstate,
        cairo_pattern_t *mask)
{
    cairo_pattern_union_t source_pattern, mask_pattern;
    const cairo_pattern_t *source;
    cairo_operator_t op;
    cairo_status_t status;

    status = _cairo_gstate_get_pattern_status (mask);
    if (unlikely (status))
  return status;

    status = _cairo_gstate_get_pattern_status (gstate->source);
    if (unlikely (status))
  return status;

    if (gstate->op == CAIRO_OPERATOR_DEST)
  return CAIRO_STATUS_SUCCESS;

    if (_cairo_clip_is_all_clipped (gstate->clip))
  return CAIRO_STATUS_SUCCESS;

    assert (gstate->opacity == 1.0);

    if (_cairo_pattern_is_opaque (mask, NULL))
  return _cairo_gstate_paint (gstate);

    if (_cairo_pattern_is_clear (mask) &&
  _cairo_operator_bounded_by_mask (gstate->op))
    {
  return CAIRO_STATUS_SUCCESS;
    }

    op = _reduce_op (gstate);
    if (op == CAIRO_OPERATOR_CLEAR) {
  source = &_cairo_pattern_clear.base;
    } else {
  _cairo_gstate_copy_transformed_source (gstate, &source_pattern.base);
  source = &source_pattern.base;
    }
    _cairo_gstate_copy_transformed_mask (gstate, &mask_pattern.base, mask);

    if (source->type == CAIRO_PATTERN_TYPE_SOLID && !source->is_foreground_marker &&
  mask_pattern.base.type == CAIRO_PATTERN_TYPE_SOLID &&
  _cairo_operator_bounded_by_source (op))
    {
  const cairo_solid_pattern_t *solid = (cairo_solid_pattern_t *) source;
  cairo_color_t combined;

  if (mask_pattern.base.has_component_alpha) {
#define M(R, A, B, c) R.c = A.c * B.c
      M(combined, solid->color, mask_pattern.solid.color, red);
      M(combined, solid->color, mask_pattern.solid.color, green);
      M(combined, solid->color, mask_pattern.solid.color, blue);
      M(combined, solid->color, mask_pattern.solid.color, alpha);
#undef M
  } else {
      combined = solid->color;
      _cairo_color_multiply_alpha (&combined, mask_pattern.solid.color.alpha);
  }

  _cairo_pattern_init_solid (&source_pattern.solid, &combined);

  status = _cairo_surface_paint (gstate->target, op,
               &source_pattern.base,
               gstate->clip);
    }
    else
    {
  status = _cairo_surface_mask (gstate->target, op,
              source,
              &mask_pattern.base,
              gstate->clip);
    }

    return status;
}

cairo_status_t
_cairo_gstate_stroke (cairo_gstate_t *gstate, cairo_path_fixed_t *path)
{
    cairo_pattern_union_t source_pattern;
    cairo_stroke_style_t style;
    double dash[2];
    cairo_status_t status;
    cairo_matrix_t aggregate_transform;
    cairo_matrix_t aggregate_transform_inverse;

    status = _cairo_gstate_get_pattern_status (gstate->source);
    if (unlikely (status))
  return status;

    if (gstate->op == CAIRO_OPERATOR_DEST)
  return CAIRO_STATUS_SUCCESS;

    if (gstate->stroke_style.line_width <= 0.0 && !gstate->stroke_style.is_hairline)
  return CAIRO_STATUS_SUCCESS;

    if (_cairo_clip_is_all_clipped (gstate->clip))
  return CAIRO_STATUS_SUCCESS;

    assert (gstate->opacity == 1.0);

    cairo_matrix_multiply (&aggregate_transform,
                           &gstate->ctm,
                           &gstate->target->device_transform);
    cairo_matrix_multiply (&aggregate_transform_inverse,
                           &gstate->target->device_transform_inverse,
                           &gstate->ctm_inverse);

    memcpy (&style, &gstate->stroke_style, sizeof (gstate->stroke_style));
    if (_cairo_stroke_style_dash_can_approximate (&gstate->stroke_style, &aggregate_transform, gstate->tolerance)) {
        style.dash = dash;
        _cairo_stroke_style_dash_approximate (&gstate->stroke_style, &gstate->ctm, gstate->tolerance,
                &style.dash_offset,
                style.dash,
                &style.num_dashes);
    }

    _cairo_gstate_copy_transformed_source (gstate, &source_pattern.base);

    return _cairo_surface_stroke (gstate->target,
          gstate->op,
          &source_pattern.base,
          path,
          &style,
          &aggregate_transform,
          &aggregate_transform_inverse,
          gstate->tolerance,
          gstate->antialias,
          gstate->clip);
}

cairo_status_t
_cairo_gstate_in_stroke (cairo_gstate_t     *gstate,
       cairo_path_fixed_t *path,
       double        x,
       double        y,
       cairo_bool_t     *inside_ret)
{
    cairo_status_t status;
    cairo_rectangle_int_t extents;
    cairo_box_t limit;
    cairo_traps_t traps;

    if (gstate->stroke_style.line_width <= 0.0) {
  *inside_ret = FALSE;
  return CAIRO_STATUS_SUCCESS;
    }

    _cairo_gstate_user_to_backend (gstate, &x, &y);

    /* Before we perform the expensive stroke analysis,
     * check whether the point is within the extents of the path.
     */
    _cairo_path_fixed_approximate_stroke_extents (path,
              &gstate->stroke_style,
              &gstate->ctm,
              gstate->target->is_vector,
              &extents);
    if (x < extents.x || x > extents.x + extents.width ||
  y < extents.y || y > extents.y + extents.height)
    {
  *inside_ret = FALSE;
  return CAIRO_STATUS_SUCCESS;
    }

    limit.p1.x = _cairo_fixed_from_double (x) - 1;
    limit.p1.y = _cairo_fixed_from_double (y) - 1;
    limit.p2.x = limit.p1.x + 2;
    limit.p2.y = limit.p1.y + 2;

    _cairo_traps_init (&traps);
    _cairo_traps_limit (&traps, &limit, 1);

    status = _cairo_path_fixed_stroke_polygon_to_traps (path,
              &gstate->stroke_style,
              &gstate->ctm,
              &gstate->ctm_inverse,
              gstate->tolerance,
              &traps);
    if (unlikely (status))
  goto BAIL;

    *inside_ret = _cairo_traps_contain (&traps, x, y);

BAIL:
    _cairo_traps_fini (&traps);

    return status;
}

cairo_status_t
_cairo_gstate_fill (cairo_gstate_t *gstate, cairo_path_fixed_t *path)
{
    cairo_status_t status;

    status = _cairo_gstate_get_pattern_status (gstate->source);
    if (unlikely (status))
  return status;

    if (gstate->op == CAIRO_OPERATOR_DEST)
  return CAIRO_STATUS_SUCCESS;

    if (_cairo_clip_is_all_clipped (gstate->clip))
  return CAIRO_STATUS_SUCCESS;

    assert (gstate->opacity == 1.0);

    if (_cairo_path_fixed_fill_is_empty (path)) {
  if (_cairo_operator_bounded_by_mask (gstate->op))
      return CAIRO_STATUS_SUCCESS;

  status = _cairo_surface_paint (gstate->target,
               CAIRO_OPERATOR_CLEAR,
               &_cairo_pattern_clear.base,
               gstate->clip);
    } else {
  cairo_pattern_union_t source_pattern;
  const cairo_pattern_t *pattern;
  cairo_operator_t op;
  cairo_rectangle_int_t extents;
  cairo_box_t box;

  op = _reduce_op (gstate);
  if (op == CAIRO_OPERATOR_CLEAR) {
      pattern = &_cairo_pattern_clear.base;
  } else {
      _cairo_gstate_copy_transformed_source (gstate, &source_pattern.base);
      pattern = &source_pattern.base;
  }

  /* Toolkits often paint the entire background with a fill */
  if (_cairo_surface_get_extents (gstate->target, &extents) &&
      _cairo_path_fixed_is_box (path, &box) &&
      box.p1.x <= _cairo_fixed_from_int (extents.x) &&
      box.p1.y <= _cairo_fixed_from_int (extents.y) &&
      box.p2.x >= _cairo_fixed_from_int (extents.x + extents.width) &&
      box.p2.y >= _cairo_fixed_from_int (extents.y + extents.height))
  {
      status = _cairo_surface_paint (gstate->target, op, pattern,
             gstate->clip);
  }
  else
  {
      status = _cairo_surface_fill (gstate->target, op, pattern,
            path,
            gstate->fill_rule,
            gstate->tolerance,
            gstate->antialias,
            gstate->clip);
  }
    }

    return status;
}

cairo_bool_t
_cairo_gstate_in_fill (cairo_gstate_t   *gstate,
           cairo_path_fixed_t *path,
           double      x,
           double      y)
{
    _cairo_gstate_user_to_backend (gstate, &x, &y);

    return _cairo_path_fixed_in_fill (path,
              gstate->fill_rule,
              gstate->tolerance,
              x, y);
}

cairo_bool_t
_cairo_gstate_in_clip (cairo_gstate_t   *gstate,
           double      x,
           double      y)
{
    cairo_clip_t *clip = gstate->clip;
    int i;

    if (_cairo_clip_is_all_clipped (clip))
  return FALSE;

    if (clip == NULL)
  return TRUE;

    _cairo_gstate_user_to_backend (gstate, &x, &y);

    if (x <  clip->extents.x ||
  x >= clip->extents.x + clip->extents.width ||
  y <  clip->extents.y ||
  y >= clip->extents.y + clip->extents.height)
    {
  return FALSE;
    }

    if (clip->num_boxes) {
  int fx, fy;

  fx = _cairo_fixed_from_double (x);
  fy = _cairo_fixed_from_double (y);
  for (i = 0; i < clip->num_boxes; i++) {
      if (fx >= clip->boxes[i].p1.x && fx <= clip->boxes[i].p2.x &&
    fy >= clip->boxes[i].p1.y && fy <= clip->boxes[i].p2.y)
    break;
  }
  if (i == clip->num_boxes)
      return FALSE;
    }

    if (clip->path) {
  cairo_clip_path_t *clip_path = clip->path;
  do {
      if (! _cairo_path_fixed_in_fill (&clip_path->path,
               clip_path->fill_rule,
               clip_path->tolerance,
               x, y))
    return FALSE;
  } while ((clip_path = clip_path->prev) != NULL);
    }

    return TRUE;
}

cairo_status_t
_cairo_gstate_copy_page (cairo_gstate_t *gstate)
{
    cairo_surface_copy_page (gstate->target);
    return cairo_surface_status (gstate->target);
}

cairo_status_t
_cairo_gstate_show_page (cairo_gstate_t *gstate)
{
    cairo_surface_show_page (gstate->target);
    return cairo_surface_status (gstate->target);
}

static void
_cairo_gstate_extents_to_user_rectangle (cairo_gstate_t   *gstate,
           const cairo_box_t *extents,
           double *x1, double *y1,
           double *x2, double *y2)
{
    double px1, py1, px2, py2;

    px1 = _cairo_fixed_to_double (extents->p1.x);
    py1 = _cairo_fixed_to_double (extents->p1.y);
    px2 = _cairo_fixed_to_double (extents->p2.x);
    py2 = _cairo_fixed_to_double (extents->p2.y);

    _cairo_gstate_backend_to_user_rectangle (gstate,
               &px1, &py1, &px2, &py2,
               NULL);
    if (x1)
  *x1 = px1;
    if (y1)
  *y1 = py1;
    if (x2)
  *x2 = px2;
    if (y2)
  *y2 = py2;
}

cairo_status_t
_cairo_gstate_stroke_extents (cairo_gstate_t   *gstate,
            cairo_path_fixed_t *path,
                              double *x1, double *y1,
            double *x2, double *y2)
{
    cairo_int_status_t status;
    cairo_box_t extents;
    cairo_bool_t empty;

    if (x1)
  *x1 = 0.0;
    if (y1)
  *y1 = 0.0;
    if (x2)
  *x2 = 0.0;
    if (y2)
  *y2 = 0.0;

    if (gstate->stroke_style.line_width <= 0.0)
  return CAIRO_STATUS_SUCCESS;

    status = CAIRO_INT_STATUS_UNSUPPORTED;
    if (_cairo_path_fixed_stroke_is_rectilinear (path)) {
  cairo_boxes_t boxes;

  _cairo_boxes_init (&boxes);
  status = _cairo_path_fixed_stroke_rectilinear_to_boxes (path,
                &gstate->stroke_style,
                &gstate->ctm,
                gstate->antialias,
                &boxes);
  empty = boxes.num_boxes == 0;
  if (! empty)
      _cairo_boxes_extents (&boxes, &extents);
  _cairo_boxes_fini (&boxes);
    }

    if (status == CAIRO_INT_STATUS_UNSUPPORTED) {
  cairo_polygon_t polygon;

  _cairo_polygon_init (&polygon, NULL, 0);
  status = _cairo_path_fixed_stroke_to_polygon (path,
                  &gstate->stroke_style,
                  &gstate->ctm,
                  &gstate->ctm_inverse,
                  gstate->tolerance,
                  &polygon);
  empty = polygon.num_edges == 0;
  if (! empty)
      extents = polygon.extents;
  _cairo_polygon_fini (&polygon);
    }
    if (! empty) {
  _cairo_gstate_extents_to_user_rectangle (gstate, &extents,
             x1, y1, x2, y2);
    }

    return status;
}

cairo_status_t
_cairo_gstate_fill_extents (cairo_gstate_t     *gstate,
          cairo_path_fixed_t *path,
                            double *x1, double *y1,
          double *x2, double *y2)
{
    cairo_status_t status;
    cairo_box_t extents;
    cairo_bool_t empty;

    if (x1)
  *x1 = 0.0;
    if (y1)
  *y1 = 0.0;
    if (x2)
  *x2 = 0.0;
    if (y2)
  *y2 = 0.0;

    if (_cairo_path_fixed_fill_is_empty (path))
  return CAIRO_STATUS_SUCCESS;

    if (_cairo_path_fixed_fill_is_rectilinear (path)) {
  cairo_boxes_t boxes;

  _cairo_boxes_init (&boxes);
  status = _cairo_path_fixed_fill_rectilinear_to_boxes (path,
                    gstate->fill_rule,
                    gstate->antialias,
                    &boxes);
  empty = boxes.num_boxes == 0;
  if (! empty)
      _cairo_boxes_extents (&boxes, &extents);

  _cairo_boxes_fini (&boxes);
    } else {
  cairo_traps_t traps;

  _cairo_traps_init (&traps);

  status = _cairo_path_fixed_fill_to_traps (path,
              gstate->fill_rule,
              gstate->tolerance,
              &traps);
  empty = traps.num_traps == 0;
  if (! empty)
      _cairo_traps_extents (&traps, &extents);

  _cairo_traps_fini (&traps);
    }

    if (! empty) {
  _cairo_gstate_extents_to_user_rectangle (gstate, &extents,
             x1, y1, x2, y2);
    }

    return status;
}

cairo_status_t
_cairo_gstate_reset_clip (cairo_gstate_t *gstate)
{
    _cairo_clip_destroy (gstate->clip);
    gstate->clip = NULL;

    return CAIRO_STATUS_SUCCESS;
}

cairo_status_t
_cairo_gstate_clip (cairo_gstate_t *gstate, cairo_path_fixed_t *path)
{
    gstate->clip =
  _cairo_clip_intersect_path (gstate->clip,
            path,
            gstate->fill_rule,
            gstate->tolerance,
            gstate->antialias);
    /* XXX */
    return CAIRO_STATUS_SUCCESS;
}

static cairo_bool_t
_cairo_gstate_int_clip_extents (cairo_gstate_t        *gstate,
        cairo_rectangle_int_t *extents)
{
    cairo_bool_t is_bounded;

    is_bounded = _cairo_surface_get_extents (gstate->target, extents);

    if (gstate->clip) {
  _cairo_rectangle_intersect (extents,
            _cairo_clip_get_extents (gstate->clip));
  is_bounded = TRUE;
    }

    return is_bounded;
}

cairo_bool_t
_cairo_gstate_clip_extents (cairo_gstate_t *gstate,
                double         *x1,
                double         *y1,
          double         *x2,
          double         *y2)
{
    cairo_rectangle_int_t extents;
    double px1, py1, px2, py2;

    if (! _cairo_gstate_int_clip_extents (gstate, &extents))
  return FALSE;

    px1 = extents.x;
    py1 = extents.y;
    px2 = extents.x + (int) extents.width;
    py2 = extents.y + (int) extents.height;

    _cairo_gstate_backend_to_user_rectangle (gstate,
               &px1, &py1, &px2, &py2,
               NULL);

    if (x1)
  *x1 = px1;
    if (y1)
  *y1 = py1;
    if (x2)
  *x2 = px2;
    if (y2)
  *y2 = py2;

    return TRUE;
}

cairo_rectangle_list_t*
_cairo_gstate_copy_clip_rectangle_list (cairo_gstate_t *gstate)
{
    cairo_rectangle_int_t extents;
    cairo_rectangle_list_t *list;
    cairo_clip_t *clip;

    if (_cairo_surface_get_extents (gstate->target, &extents))
  clip = _cairo_clip_copy_intersect_rectangle (gstate->clip, &extents);
    else
  clip = gstate->clip;

    list = _cairo_clip_copy_rectangle_list (clip, gstate);

    if (clip != gstate->clip)
  _cairo_clip_destroy (clip);

    return list;
}

cairo_status_t
_cairo_gstate_tag_begin (cairo_gstate_t *gstate,
       const char *tag_name, const char *attributes)
{
    return _cairo_surface_tag (gstate->target,
             TRUE, /* begin */
             tag_name,
             attributes ? attributes : "");
}

cairo_status_t
_cairo_gstate_tag_end (cairo_gstate_t *gstate,
           const char *tag_name)
{
    return _cairo_surface_tag (gstate->target,
             FALSE, /* begin */
             tag_name,
             NULL); /* attributes */
}

static void
_cairo_gstate_unset_scaled_font (cairo_gstate_t *gstate)
{
    if (gstate->scaled_font == NULL)
  return;

    if (gstate->previous_scaled_font != NULL)
  cairo_scaled_font_destroy (gstate->previous_scaled_font);

    gstate->previous_scaled_font = gstate->scaled_font;
    gstate->scaled_font = NULL;
}

cairo_status_t
_cairo_gstate_set_font_size (cairo_gstate_t *gstate,
           double          size)
{
    _cairo_gstate_unset_scaled_font (gstate);

    cairo_matrix_init_scale (&gstate->font_matrix, size, size);

    return CAIRO_STATUS_SUCCESS;
}

cairo_status_t
_cairo_gstate_set_font_matrix (cairo_gstate_t     *gstate,
             const cairo_matrix_t *matrix)
{
    if (memcmp (matrix, &gstate->font_matrix, sizeof (cairo_matrix_t)) == 0)
  return CAIRO_STATUS_SUCCESS;

    _cairo_gstate_unset_scaled_font (gstate);

    gstate->font_matrix = *matrix;

    return CAIRO_STATUS_SUCCESS;
}

void
_cairo_gstate_get_font_matrix (cairo_gstate_t *gstate,
             cairo_matrix_t *matrix)
{
    *matrix = gstate->font_matrix;
}

void
_cairo_gstate_set_font_options (cairo_gstate_t             *gstate,
        const cairo_font_options_t *options)
{
    if (_cairo_font_options_compare (options, &gstate->font_options))
  return;

    _cairo_gstate_unset_scaled_font (gstate);

    _cairo_font_options_fini (&gstate->font_options);
    _cairo_font_options_init_copy (&gstate->font_options, options);
}

void
_cairo_gstate_get_font_options (cairo_gstate_t       *gstate,
        cairo_font_options_t *options)
{
    _cairo_font_options_fini (options);
    _cairo_font_options_init_copy (options, &gstate->font_options);
}

cairo_status_t
_cairo_gstate_get_font_face (cairo_gstate_t     *gstate,
           cairo_font_face_t **font_face)
{
    cairo_status_t status;

    status = _cairo_gstate_ensure_font_face (gstate);
    if (unlikely (status))
  return status;

    *font_face = gstate->font_face;

    return CAIRO_STATUS_SUCCESS;
}

cairo_status_t
_cairo_gstate_get_scaled_font (cairo_gstate_t       *gstate,
             cairo_scaled_font_t **scaled_font)
{
    cairo_status_t status;

    status = _cairo_gstate_ensure_scaled_font (gstate);
    if (unlikely (status))
  return status;

    *scaled_font = gstate->scaled_font;

    return CAIRO_STATUS_SUCCESS;
}

/*
 * Like everything else in this file, fonts involve Too Many Coordinate Spaces;
 * it is easy to get confused about what's going on.
 *
 * The user's view
 * ---------------
 *
 * Users ask for things in user space. When cairo starts, a user space unit
 * is about 1/96 inch, which is similar to (but importantly different from)
 * the normal "point" units most users think in terms of. When a user
 * selects a font, its scale is set to "one user unit". The user can then
 * independently scale the user coordinate system *or* the font matrix, in
 * order to adjust the rendered size of the font.
 *
 * Metrics are returned in user space, whether they are obtained from
 * the currently selected font in a  #cairo_t or from a #cairo_scaled_font_t
 * which is a font specialized to a particular scale matrix, CTM, and target
 * surface.
 *
 * The font's view
 * ---------------
 *
 * Fonts are designed and stored (in say .ttf files) in "font space", which
 * describes an "EM Square" (a design tile) and has some abstract number
 * such as 1000, 1024, or 2048 units per "EM". This is basically an
 * uninteresting space for us, but we need to remember that it exists.
 *
 * Font resources (from libraries or operating systems) render themselves
 * to a particular device. Since they do not want to make most programmers
 * worry about the font design space, the scaling API is simplified to
 * involve just telling the font the required pixel size of the EM square
 * (that is, in device space).
 *
 *
 * Cairo's gstate view
 * -------------------
 *
 * In addition to the CTM and CTM inverse, we keep a matrix in the gstate
 * called the "font matrix" which describes the user's most recent
 * font-scaling or font-transforming request. This is kept in terms of an
 * abstract scale factor, composed with the CTM and used to set the font's
 * pixel size. So if the user asks to "scale the font by 12", the matrix
 * is:
 *
 *   [ 12.0, 0.0, 0.0, 12.0, 0.0, 0.0 ]
 *
 * It is an affine matrix, like all cairo matrices, where its tx and ty
 * components are used to "nudging" fonts around and are handled in gstate
 * and then ignored by the "scaled-font" layer.
 *
 * In order to perform any action on a font, we must build an object
 * called a #cairo_font_scale_t; this contains the central 2x2 matrix
 * resulting from "font matrix * CTM" (sans the font matrix translation
 * components as stated in the previous paragraph).
 *
 * We pass this to the font when making requests of it, which causes it to
 * reply for a particular [user request, device] combination, under the CTM
 * (to accommodate the "zoom in" == "bigger fonts" issue above).
 *
 * The other terms in our communication with the font are therefore in
 * device space. When we ask it to perform text->glyph conversion, it will
 * produce a glyph string in device space. Glyph vectors we pass to it for
 * measuring or rendering should be in device space. The metrics which we
 * get back from the font will be in device space. The contents of the
 * global glyph image cache will be in device space.
 *
 *
 * Cairo's public view
 * -------------------
 *
 * Since the values entering and leaving via public API calls are in user
 * space, the gstate functions typically need to multiply arguments by the
 * CTM (for user-input glyph vectors), and return values by the CTM inverse
 * (for font responses such as metrics or glyph vectors).
 *
 */

static cairo_status_t
_cairo_gstate_ensure_font_face (cairo_gstate_t *gstate)
{
    cairo_font_face_t *font_face;

    if (gstate->font_face != NULL)
  return gstate->font_face->status;


    font_face = cairo_toy_font_face_create (CAIRO_FONT_FAMILY_DEFAULT,
              CAIRO_FONT_SLANT_DEFAULT,
              CAIRO_FONT_WEIGHT_DEFAULT);
    if (font_face->status)
  return font_face->status;

    gstate->font_face = font_face;

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_gstate_ensure_scaled_font (cairo_gstate_t *gstate)
{
    cairo_status_t status;
    cairo_font_options_t options;
    cairo_scaled_font_t *scaled_font;
    cairo_matrix_t font_ctm;

    if (gstate->scaled_font != NULL)
  return gstate->scaled_font->status;

    status = _cairo_gstate_ensure_font_face (gstate);
    if (unlikely (status))
  return status;

    cairo_surface_get_font_options (gstate->target, &options);
    cairo_font_options_merge (&options, &gstate->font_options);

    cairo_matrix_multiply (&font_ctm,
         &gstate->ctm,
         &gstate->target->device_transform);

    scaled_font = cairo_scaled_font_create (gstate->font_face,
                    &gstate->font_matrix,
              &font_ctm,
              &options);

    _cairo_font_options_fini (&options);

    status = cairo_scaled_font_status (scaled_font);
    if (unlikely (status))
  return status;

    gstate->scaled_font = scaled_font;

    return CAIRO_STATUS_SUCCESS;
}

cairo_status_t
_cairo_gstate_get_font_extents (cairo_gstate_t *gstate,
        cairo_font_extents_t *extents)
{
    cairo_status_t status = _cairo_gstate_ensure_scaled_font (gstate);
    if (unlikely (status))
  return status;

    cairo_scaled_font_extents (gstate->scaled_font, extents);

    return cairo_scaled_font_status (gstate->scaled_font);
}

cairo_status_t
_cairo_gstate_set_font_face (cairo_gstate_t    *gstate,
           cairo_font_face_t *font_face)
{
    if (font_face && font_face->status)
  return _cairo_error (font_face->status);

    if (font_face == gstate->font_face)
  return CAIRO_STATUS_SUCCESS;

    cairo_font_face_destroy (gstate->font_face);
    gstate->font_face = cairo_font_face_reference (font_face);

    _cairo_gstate_unset_scaled_font (gstate);

    return CAIRO_STATUS_SUCCESS;
}

cairo_status_t
_cairo_gstate_glyph_extents (cairo_gstate_t *gstate,
           const cairo_glyph_t *glyphs,
           int num_glyphs,
           cairo_text_extents_t *extents)
{
    cairo_status_t status;

    status = _cairo_gstate_ensure_scaled_font (gstate);
    if (unlikely (status))
  return status;

    cairo_scaled_font_glyph_extents (gstate->scaled_font,
             glyphs, num_glyphs,
             extents);

    return cairo_scaled_font_status (gstate->scaled_font);
}

cairo_status_t
_cairo_gstate_show_text_glyphs (cairo_gstate_t       *gstate,
        const cairo_glyph_t    *glyphs,
        int         num_glyphs,
        cairo_glyph_text_info_t    *info)
{
    cairo_glyph_t stack_transformed_glyphs[CAIRO_STACK_ARRAY_LENGTH (cairo_glyph_t)];
    cairo_text_cluster_t stack_transformed_clusters[CAIRO_STACK_ARRAY_LENGTH (cairo_text_cluster_t)];
    cairo_pattern_union_t source_pattern;
    cairo_glyph_t *transformed_glyphs;
    const cairo_pattern_t *pattern;
    cairo_text_cluster_t *transformed_clusters;
    cairo_operator_t op;
    cairo_status_t status;

    status = _cairo_gstate_get_pattern_status (gstate->source);
    if (unlikely (status))
  return status;

    if (gstate->op == CAIRO_OPERATOR_DEST)
  return CAIRO_STATUS_SUCCESS;

    if (_cairo_clip_is_all_clipped (gstate->clip))
  return CAIRO_STATUS_SUCCESS;

    status = _cairo_gstate_ensure_scaled_font (gstate);
    if (unlikely (status))
  return status;

    transformed_glyphs = stack_transformed_glyphs;
    transformed_clusters = stack_transformed_clusters;

    if (num_glyphs > ARRAY_LENGTH (stack_transformed_glyphs)) {
  transformed_glyphs = cairo_glyph_allocate (num_glyphs);
  if (unlikely (transformed_glyphs == NULL))
      return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }

    if (info != NULL) {
  if (info->num_clusters > ARRAY_LENGTH (stack_transformed_clusters)) {
      transformed_clusters = cairo_text_cluster_allocate (info->num_clusters);
      if (unlikely (transformed_clusters == NULL)) {
    status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
    goto CLEANUP_GLYPHS;
      }
  }

  _cairo_gstate_transform_glyphs_to_backend (gstate,
               glyphs, num_glyphs,
               info->clusters,
               info->num_clusters,
               info->cluster_flags,
               transformed_glyphs,
               &num_glyphs,
               transformed_clusters,
               TRUE);
    } else {
  _cairo_gstate_transform_glyphs_to_backend (gstate,
               glyphs, num_glyphs,
               NULL, 0, 0,
               transformed_glyphs,
               &num_glyphs,
               NULL,
               TRUE);
    }

    if (num_glyphs == 0)
  goto CLEANUP_GLYPHS;

    op = _reduce_op (gstate);
    if (op == CAIRO_OPERATOR_CLEAR) {
  pattern = &_cairo_pattern_clear.base;
    } else {
  _cairo_gstate_copy_transformed_source (gstate, &source_pattern.base);
  pattern = &source_pattern.base;
    }

    /* For really huge font sizes, we can just do path;fill instead of
     * show_glyphs, as show_glyphs would put excess pressure on the cache,
     * and moreover, not all components below us correctly handle huge font
     * sizes.  I wanted to set the limit at 256.  But alas, seems like cairo's
     * rasterizer is something like ten times slower than freetype's for huge
     * sizes.  So, no win just yet.  For now, do it for insanely-huge sizes,
     * just to make sure we don't make anyone unhappy.  When we get a really
     * fast rasterizer in cairo, we may want to readjust this.
     *
     * Needless to say, do this only if show_text_glyphs is not available. */
    if (cairo_surface_has_show_text_glyphs (gstate->target) ||
  _cairo_scaled_font_get_max_scale (gstate->scaled_font) <= 10240)
    {

  if (info != NULL) {
      status = _cairo_surface_show_text_glyphs (gstate->target, op, pattern,
                  info->utf8, info->utf8_len,
                  transformed_glyphs, num_glyphs,
                  transformed_clusters, info->num_clusters,
                  info->cluster_flags,
                  gstate->scaled_font,
                  gstate->clip);
  } else {
      status = _cairo_surface_show_text_glyphs (gstate->target, op, pattern,
                  NULL, 0,
                  transformed_glyphs, num_glyphs,
                  NULL, 0, 0,
                  gstate->scaled_font,
                  gstate->clip);
  }
    }
    else
    {
  cairo_path_fixed_t path;

  _cairo_path_fixed_init (&path);

  status = _cairo_scaled_font_glyph_path (gstate->scaled_font,
            transformed_glyphs, num_glyphs,
            &path);

  if (status == CAIRO_STATUS_SUCCESS) {
      status = _cairo_surface_fill (gstate->target, op, pattern,
            &path,
            CAIRO_FILL_RULE_WINDING,
            gstate->tolerance,
            gstate->scaled_font->options.antialias,
            gstate->clip);
  }

  _cairo_path_fixed_fini (&path);
    }

CLEANUP_GLYPHS:
    if (transformed_glyphs != stack_transformed_glyphs)
      cairo_glyph_free (transformed_glyphs);
    if (transformed_clusters != stack_transformed_clusters)
      cairo_text_cluster_free (transformed_clusters);

    return status;
}

cairo_status_t
_cairo_gstate_glyph_path (cairo_gstate_t      *gstate,
        const cairo_glyph_t *glyphs,
        int          num_glyphs,
        cairo_path_fixed_t  *path)
{
    cairo_glyph_t stack_transformed_glyphs[CAIRO_STACK_ARRAY_LENGTH (cairo_glyph_t)];
    cairo_glyph_t *transformed_glyphs;
    cairo_status_t status;

    status = _cairo_gstate_ensure_scaled_font (gstate);
    if (unlikely (status))
  return status;

    if (num_glyphs < ARRAY_LENGTH (stack_transformed_glyphs)) {
  transformed_glyphs = stack_transformed_glyphs;
    } else {
  transformed_glyphs = cairo_glyph_allocate (num_glyphs);
  if (unlikely (transformed_glyphs == NULL))
      return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }

    _cairo_gstate_transform_glyphs_to_backend (gstate,
                 glyphs, num_glyphs,
                 NULL, 0, 0,
                 transformed_glyphs,
                 &num_glyphs, NULL, FALSE);

    status = _cairo_scaled_font_glyph_path (gstate->scaled_font,
              transformed_glyphs, num_glyphs,
              path);

    if (transformed_glyphs != stack_transformed_glyphs)
      cairo_glyph_free (transformed_glyphs);

    return status;
}

cairo_status_t
_cairo_gstate_set_antialias (cairo_gstate_t *gstate,
           cairo_antialias_t antialias)
{
    gstate->antialias = antialias;

    return CAIRO_STATUS_SUCCESS;
}

cairo_antialias_t
_cairo_gstate_get_antialias (cairo_gstate_t *gstate)
{
    return gstate->antialias;
}

/**
 * _cairo_gstate_transform_glyphs_to_backend:
 * @gstate: a #cairo_gstate_t
 * @glyphs: the array of #cairo_glyph_t objects to be transformed
 * @num_glyphs: the number of elements in @glyphs
 * @transformed_glyphs: a pre-allocated array of at least @num_glyphs
 * #cairo_glyph_t objects
 * @num_transformed_glyphs: the number of elements in @transformed_glyphs
 * after dropping out of bounds glyphs, or %NULL if glyphs shouldn't be
 * dropped
 *
 * Transform an array of glyphs to backend space by first adding the offset
 * of the font matrix, then transforming from user space to backend space.
 * The result of the transformation is placed in @transformed_glyphs.
 *
 * This also uses information from the scaled font and the surface to
 * cull/drop glyphs that will not be visible.
 **/
static void
_cairo_gstate_transform_glyphs_to_backend (cairo_gstate_t *gstate,
                                           const cairo_glyph_t  *glyphs,
                                           int       num_glyphs,
             const cairo_text_cluster_t *clusters,
             int       num_clusters,
             cairo_text_cluster_flags_t cluster_flags,
                                           cairo_glyph_t  *transformed_glyphs,
             int      *num_transformed_glyphs,
             cairo_text_cluster_t *transformed_clusters,
             cairo_bool_t         perform_early_clip)
{
    cairo_rectangle_int_t surface_extents;
    cairo_matrix_t *ctm = &gstate->ctm;
    cairo_matrix_t *font_matrix = &gstate->font_matrix;
    cairo_matrix_t *device_transform = &gstate->target->device_transform;
    cairo_bool_t drop = FALSE;
    double x1 = 0, x2 = 0, y1 = 0, y2 = 0;
    int i, j, k;

    drop = TRUE;
    if (!perform_early_clip || !_cairo_gstate_int_clip_extents (gstate, &surface_extents)) {
  drop = FALSE; /* unbounded surface */
    } else {
  double scale10 = 10 * _cairo_scaled_font_get_max_scale (gstate->scaled_font);
  if (surface_extents.width == 0 || surface_extents.height == 0) {
    /* No visible area.  Don't draw anything */
    *num_transformed_glyphs = 0;
    return;
  }
  /* XXX We currently drop any glyphs that have their position outside
   * of the surface boundaries by a safety margin depending on the
   * font scale.  This however can fail in extreme cases where the
   * font has really long swashes for example...  We can correctly
   * handle that by looking the glyph up and using its device bbox
   * to device if it's going to be visible, but I'm not inclined to
   * do that now.
   */
  x1 = surface_extents.x - scale10;
  y1 = surface_extents.y - scale10;
  x2 = surface_extents.x + (int) surface_extents.width  + scale10;
  y2 = surface_extents.y + (int) surface_extents.height + scale10;
    }

    if (!drop)
  *num_transformed_glyphs = num_glyphs;

#define KEEP_GLYPH(glyph) (x1 <= glyph.x && glyph.x <= x2 && y1 <= glyph.y && glyph.y <= y2)

    j = 0;
    if (_cairo_matrix_is_identity (ctm) &&
        _cairo_matrix_is_identity (device_transform) &&
  font_matrix->x0 == 0 && font_matrix->y0 == 0)
    {
  if (! drop) {
      memcpy (transformed_glyphs, glyphs,
        num_glyphs * sizeof (cairo_glyph_t));
      memcpy (transformed_clusters, clusters,
        num_clusters * sizeof (cairo_text_cluster_t));
      j = num_glyphs;
  } else if (num_clusters == 0) {
      for (i = 0; i < num_glyphs; i++) {
    transformed_glyphs[j].index = glyphs[i].index;
    transformed_glyphs[j].x = glyphs[i].x;
    transformed_glyphs[j].y = glyphs[i].y;
    if (KEEP_GLYPH (transformed_glyphs[j]))
        j++;
      }
  } else {
      const cairo_glyph_t *cur_glyph;

      if (cluster_flags & CAIRO_TEXT_CLUSTER_FLAG_BACKWARD)
    cur_glyph = glyphs + num_glyphs - 1;
      else
    cur_glyph = glyphs;

      for (i = 0; i < num_clusters; i++) {
    cairo_bool_t cluster_visible = FALSE;

    for (k = 0; k < clusters[i].num_glyphs; k++) {
        transformed_glyphs[j+k].index = cur_glyph->index;
        transformed_glyphs[j+k].x = cur_glyph->x;
        transformed_glyphs[j+k].y = cur_glyph->y;
        if (KEEP_GLYPH (transformed_glyphs[j+k]))
      cluster_visible = TRUE;

        if (cluster_flags & CAIRO_TEXT_CLUSTER_FLAG_BACKWARD)
      cur_glyph--;
        else
      cur_glyph++;
    }

    transformed_clusters[i] = clusters[i];
    if (cluster_visible)
        j += k;
    else
        transformed_clusters[i].num_glyphs = 0;
      }
  }
    }
    else if (_cairo_matrix_is_translation (ctm) &&
             _cairo_matrix_is_translation (device_transform))
    {
        double tx = font_matrix->x0 + ctm->x0 + device_transform->x0;
        double ty = font_matrix->y0 + ctm->y0 + device_transform->y0;

  if (! drop || num_clusters == 0) {
      for (i = 0; i < num_glyphs; i++) {
    transformed_glyphs[j].index = glyphs[i].index;
    transformed_glyphs[j].x = glyphs[i].x + tx;
    transformed_glyphs[j].y = glyphs[i].y + ty;
    if (!drop || KEEP_GLYPH (transformed_glyphs[j]))
        j++;
      }
        if (num_clusters != 0)
            memcpy (transformed_clusters, clusters,
                num_clusters * sizeof (cairo_text_cluster_t));
  } else {
      const cairo_glyph_t *cur_glyph;

      if (cluster_flags & CAIRO_TEXT_CLUSTER_FLAG_BACKWARD)
    cur_glyph = glyphs + num_glyphs - 1;
      else
    cur_glyph = glyphs;

      for (i = 0; i < num_clusters; i++) {
    cairo_bool_t cluster_visible = FALSE;

    for (k = 0; k < clusters[i].num_glyphs; k++) {
        transformed_glyphs[j+k].index = cur_glyph->index;
        transformed_glyphs[j+k].x = cur_glyph->x + tx;
        transformed_glyphs[j+k].y = cur_glyph->y + ty;
        if (KEEP_GLYPH (transformed_glyphs[j+k]))
      cluster_visible = TRUE;

        if (cluster_flags & CAIRO_TEXT_CLUSTER_FLAG_BACKWARD)
      cur_glyph--;
        else
      cur_glyph++;
    }

    transformed_clusters[i] = clusters[i];
    if (cluster_visible)
        j += k;
    else
        transformed_clusters[i].num_glyphs = 0;
      }
  }
    }
    else
    {
        cairo_matrix_t aggregate_transform;

        cairo_matrix_init_translate (&aggregate_transform,
                                     gstate->font_matrix.x0,
                                     gstate->font_matrix.y0);
        cairo_matrix_multiply (&aggregate_transform,
                               &aggregate_transform, ctm);
        cairo_matrix_multiply (&aggregate_transform,
                               &aggregate_transform, device_transform);

  if (! drop || num_clusters == 0) {
      for (i = 0; i < num_glyphs; i++) {
    transformed_glyphs[j] = glyphs[i];
    cairo_matrix_transform_point (&aggregate_transform,
                &transformed_glyphs[j].x,
                &transformed_glyphs[j].y);
    if (! drop || KEEP_GLYPH (transformed_glyphs[j]))
        j++;
      }
        if (num_clusters)
            memcpy (transformed_clusters, clusters,
                num_clusters * sizeof (cairo_text_cluster_t));
  } else {
      const cairo_glyph_t *cur_glyph;

      if (cluster_flags & CAIRO_TEXT_CLUSTER_FLAG_BACKWARD)
    cur_glyph = glyphs + num_glyphs - 1;
      else
    cur_glyph = glyphs;

      for (i = 0; i < num_clusters; i++) {
    cairo_bool_t cluster_visible = FALSE;
    for (k = 0; k < clusters[i].num_glyphs; k++) {
        transformed_glyphs[j+k] = *cur_glyph;
        cairo_matrix_transform_point (&aggregate_transform,
              &transformed_glyphs[j+k].x,
              &transformed_glyphs[j+k].y);
        if (KEEP_GLYPH (transformed_glyphs[j+k]))
      cluster_visible = TRUE;

        if (cluster_flags & CAIRO_TEXT_CLUSTER_FLAG_BACKWARD)
      cur_glyph--;
        else
      cur_glyph++;
    }

    transformed_clusters[i] = clusters[i];
    if (cluster_visible)
        j += k;
    else
        transformed_clusters[i].num_glyphs = 0;
      }
  }
    }
    *num_transformed_glyphs = j;

    if (num_clusters != 0 && cluster_flags & CAIRO_TEXT_CLUSTER_FLAG_BACKWARD) {
  for (i = 0; i < --j; i++) {
      cairo_glyph_t tmp;

      tmp = transformed_glyphs[i];
      transformed_glyphs[i] = transformed_glyphs[j];
      transformed_glyphs[j] = tmp;
  }
    }
}

Coverage Report

Created: 2025-11-16 09:57