kc3-lang/harfbuzz/src/hb-cairo-utils.cc

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• Hash : 6f6d6e8c
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  Date : 2025-04-22T23:04:31
  

  [cairo] Remove redundant include
  

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• src/hb-cairo-utils.cc

• /*
   * Copyright © 2022  Red Hat, Inc
   * Copyright © 2021, 2022  Black Foundry
   *
   *  This is part of HarfBuzz, a text shaping library.
   *
   * Permission is hereby granted, without written agreement and without
   * license or royalty fees, to use, copy, modify, and distribute this
   * software and its documentation for any purpose, provided that the
   * above copyright notice and the following two paragraphs appear in
   * all copies of this software.
   *
   * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
   * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
   * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
   * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
   * DAMAGE.
   *
   * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
   * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
   * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
   * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
   * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
   *
   * Google Author(s): Matthias Clasen
   */
  
  #include "hb.hh"
  
  #ifdef HAVE_CAIRO
  
  #include "hb-cairo-utils.hh"
  
  /* Some routines in this file were ported from BlackRenderer by Black Foundry.
   * Used by permission to relicense to HarfBuzz license.
   *
   * https://github.com/BlackFoundryCom/black-renderer
   */
  
  #define PREALLOCATED_COLOR_STOPS 16
  
  typedef struct {
    float r, g, b, a;
  } hb_cairo_color_t;
  
  static inline cairo_extend_t
  hb_cairo_extend (hb_paint_extend_t extend)
  {
    switch (extend)
      {
      case HB_PAINT_EXTEND_PAD: return CAIRO_EXTEND_PAD;
      case HB_PAINT_EXTEND_REPEAT: return CAIRO_EXTEND_REPEAT;
      case HB_PAINT_EXTEND_REFLECT: return CAIRO_EXTEND_REFLECT;
      default: break;
      }
  
    return CAIRO_EXTEND_PAD;
  }
  
  #ifdef CAIRO_HAS_PNG_FUNCTIONS
  typedef struct
  {
    hb_blob_t *blob;
    unsigned int offset;
  } hb_cairo_read_blob_data_t;
  
  static cairo_status_t
  hb_cairo_read_blob (void *closure,
  		    unsigned char *data,
  		    unsigned int length)
  {
    hb_cairo_read_blob_data_t *r = (hb_cairo_read_blob_data_t *) closure;
    const char *d;
    unsigned int size;
  
    d = hb_blob_get_data (r->blob, &size);
  
    if (r->offset + length > size)
      return CAIRO_STATUS_READ_ERROR;
  
    hb_memcpy (data, d + r->offset, length);
    r->offset += length;
  
    return CAIRO_STATUS_SUCCESS;
  }
  #endif
  
  static const cairo_user_data_key_t *_hb_cairo_surface_blob_user_data_key = {0};
  
  static void
  _hb_cairo_destroy_blob (void *p)
  {
    hb_blob_destroy ((hb_blob_t *) p);
  }
  
  hb_bool_t
  _hb_cairo_paint_glyph_image (hb_cairo_context_t *c,
  			     hb_blob_t *blob,
  			     unsigned width,
  			     unsigned height,
  			     hb_tag_t format,
  			     HB_UNUSED float slant_deprecated,
  			     hb_glyph_extents_t *extents)
  {
    cairo_t *cr = c->cr;
  
    if (!extents) /* SVG currently. */
      return false;
  
    cairo_surface_t *surface = nullptr;
  
  #ifdef CAIRO_HAS_PNG_FUNCTIONS
    if (format == HB_PAINT_IMAGE_FORMAT_PNG)
    {
      hb_cairo_read_blob_data_t r;
      r.blob = blob;
      r.offset = 0;
      surface = cairo_image_surface_create_from_png_stream (hb_cairo_read_blob, &r);
  
      /* For PNG, width,height can be unreliable, as is the case for NotoColorEmoji :(.
       * Just pull them out of the surface. */
      width = cairo_image_surface_get_width (surface);
      height = cairo_image_surface_get_width (surface);
    }
    else
  #endif
    if (format == HB_PAINT_IMAGE_FORMAT_BGRA)
    {
      /* Byte-endian conversion. */
      unsigned data_size = hb_blob_get_length (blob);
      if (data_size < width * height * 4)
        return false;
  
      unsigned char *data;
  #ifdef __BYTE_ORDER
      if (__BYTE_ORDER == __BIG_ENDIAN)
      {
        data = (unsigned char *) hb_blob_get_data_writable (blob, nullptr);
        if (!data)
          return false;
  
        unsigned count = width * height * 4;
        for (unsigned i = 0; i < count; i += 4)
        {
          unsigned char b;
  	b = data[i];
  	data[i] = data[i+3];
  	data[i+3] = b;
  	b = data[i+1];
  	data[i+1] = data[i+2];
  	data[i+2] = b;
        }
      }
      else
  #endif
        data = (unsigned char *) hb_blob_get_data (blob, nullptr);
  
      surface = cairo_image_surface_create_for_data (data,
  						   CAIRO_FORMAT_ARGB32,
  						   width, height,
  						   width * 4);
  
      cairo_surface_set_user_data (surface,
  				 _hb_cairo_surface_blob_user_data_key,
  				 hb_blob_reference (blob),
  				 _hb_cairo_destroy_blob);
    }
  
    if (!surface)
      return false;
  
    cairo_save (cr);
    /* this clip is here to work around recording surface limitations */
    cairo_rectangle (cr,
                     extents->x_bearing,
                     extents->y_bearing,
                     extents->width,
                     extents->height);
    cairo_clip (cr);
  
    cairo_pattern_t *pattern = cairo_pattern_create_for_surface (surface);
    cairo_pattern_set_extend (pattern, CAIRO_EXTEND_PAD);
  
    cairo_matrix_t matrix = {(double) width, 0, 0, (double) height, 0, 0};
    cairo_pattern_set_matrix (pattern, &matrix);
  
    cairo_translate (cr, extents->x_bearing, extents->y_bearing);
    cairo_scale (cr, extents->width, extents->height);
    cairo_set_source (cr, pattern);
  
    cairo_paint (cr);
  
    cairo_pattern_destroy (pattern);
    cairo_surface_destroy (surface);
  
    cairo_restore (cr);
  
    return true;
  }
  
  static void
  _hb_cairo_reduce_anchors (float x0, float y0,
  			  float x1, float y1,
  			  float x2, float y2,
  			  float *xx0, float *yy0,
  			  float *xx1, float *yy1)
  {
    float q1x, q1y, q2x, q2y;
    float s;
    float k;
  
    q2x = x2 - x0;
    q2y = y2 - y0;
    q1x = x1 - x0;
    q1y = y1 - y0;
  
    s = q2x * q2x + q2y * q2y;
    if (s < 0.000001f)
      {
        *xx0 = x0; *yy0 = y0;
        *xx1 = x1; *yy1 = y1;
        return;
      }
  
    k = (q2x * q1x + q2y * q1y) / s;
    *xx0 = x0;
    *yy0 = y0;
    *xx1 = x1 - k * q2x;
    *yy1 = y1 - k * q2y;
  }
  
  static int
  _hb_cairo_cmp_color_stop (const void *p1,
  			  const void *p2)
  {
    const hb_color_stop_t *c1 = (const hb_color_stop_t *) p1;
    const hb_color_stop_t *c2 = (const hb_color_stop_t *) p2;
  
    if (c1->offset < c2->offset)
      return -1;
    else if (c1->offset > c2->offset)
      return 1;
    else
      return 0;
  }
  
  static void
  _hb_cairo_normalize_color_line (hb_color_stop_t *stops,
  				unsigned int len,
  				float *omin,
  				float *omax)
  {
    float min, max;
  
    hb_qsort (stops, len, sizeof (hb_color_stop_t), _hb_cairo_cmp_color_stop);
  
    min = max = stops[0].offset;
    for (unsigned int i = 0; i < len; i++)
      {
        min = hb_min (min, stops[i].offset);
        max = hb_max (max, stops[i].offset);
      }
  
    if (min != max)
      {
        for (unsigned int i = 0; i < len; i++)
          stops[i].offset = (stops[i].offset - min) / (max - min);
      }
  
    *omin = min;
    *omax = max;
  }
  
  static bool
  _hb_cairo_get_color_stops (hb_cairo_context_t *c,
  			   hb_color_line_t *color_line,
  			   unsigned *count,
  			   hb_color_stop_t **stops)
  {
    unsigned len = hb_color_line_get_color_stops (color_line, 0, nullptr, nullptr);
    if (len > *count)
    {
      *stops = (hb_color_stop_t *) hb_malloc (len * sizeof (hb_color_stop_t));
      if (unlikely (!stops))
        return false;
    }
    hb_color_line_get_color_stops (color_line, 0, &len, *stops);
    for (unsigned i = 0; i < len; i++)
      if ((*stops)[i].is_foreground)
      {
  #ifdef HAVE_CAIRO_USER_SCALED_FONT_GET_FOREGROUND_SOURCE
        double r, g, b, a;
        cairo_pattern_t *foreground = cairo_user_scaled_font_get_foreground_source (c->scaled_font);
        if (cairo_pattern_get_rgba (foreground, &r, &g, &b, &a) == CAIRO_STATUS_SUCCESS)
          (*stops)[i].color = HB_COLOR (round (b * 255.), round (g * 255.), round (r * 255.),
                                        round (a * hb_color_get_alpha ((*stops)[i].color)));
        else
  #endif
          (*stops)[i].color = HB_COLOR (0, 0, 0, hb_color_get_alpha ((*stops)[i].color));
      }
  
    *count = len;
    return true;
  }
  
  void
  _hb_cairo_paint_linear_gradient (hb_cairo_context_t *c,
  				 hb_color_line_t *color_line,
  				 float x0, float y0,
  				 float x1, float y1,
  				 float x2, float y2)
  {
    cairo_t *cr = c->cr;
  
    unsigned int len = PREALLOCATED_COLOR_STOPS;
    hb_color_stop_t stops_[PREALLOCATED_COLOR_STOPS];
    hb_color_stop_t *stops = stops_;
    float xx0, yy0, xx1, yy1;
    float xxx0, yyy0, xxx1, yyy1;
    float min, max;
    cairo_pattern_t *pattern;
  
    if (unlikely (!_hb_cairo_get_color_stops (c, color_line, &len, &stops)))
      return;
    _hb_cairo_normalize_color_line (stops, len, &min, &max);
  
    _hb_cairo_reduce_anchors (x0, y0, x1, y1, x2, y2, &xx0, &yy0, &xx1, &yy1);
  
    xxx0 = xx0 + min * (xx1 - xx0);
    yyy0 = yy0 + min * (yy1 - yy0);
    xxx1 = xx0 + max * (xx1 - xx0);
    yyy1 = yy0 + max * (yy1 - yy0);
  
    pattern = cairo_pattern_create_linear ((double) xxx0, (double) yyy0, (double) xxx1, (double) yyy1);
    cairo_pattern_set_extend (pattern, hb_cairo_extend (hb_color_line_get_extend (color_line)));
    for (unsigned int i = 0; i < len; i++)
      {
        double r, g, b, a;
        r = hb_color_get_red (stops[i].color) / 255.;
        g = hb_color_get_green (stops[i].color) / 255.;
        b = hb_color_get_blue (stops[i].color) / 255.;
        a = hb_color_get_alpha (stops[i].color) / 255.;
        cairo_pattern_add_color_stop_rgba (pattern, (double) stops[i].offset, r, g, b, a);
      }
  
    cairo_set_source (cr, pattern);
    cairo_paint (cr);
  
    cairo_pattern_destroy (pattern);
  
    if (stops != stops_)
      hb_free (stops);
  }
  
  void
  _hb_cairo_paint_radial_gradient (hb_cairo_context_t *c,
  				 hb_color_line_t *color_line,
  				 float x0, float y0, float r0,
  				 float x1, float y1, float r1)
  {
    cairo_t *cr = c->cr;
  
    unsigned int len = PREALLOCATED_COLOR_STOPS;
    hb_color_stop_t stops_[PREALLOCATED_COLOR_STOPS];
    hb_color_stop_t *stops = stops_;
    float min, max;
    float xx0, yy0, xx1, yy1;
    float rr0, rr1;
    cairo_pattern_t *pattern;
  
    if (unlikely (!_hb_cairo_get_color_stops (c, color_line, &len, &stops)))
      return;
    _hb_cairo_normalize_color_line (stops, len, &min, &max);
  
    xx0 = x0 + min * (x1 - x0);
    yy0 = y0 + min * (y1 - y0);
    xx1 = x0 + max * (x1 - x0);
    yy1 = y0 + max * (y1 - y0);
    rr0 = r0 + min * (r1 - r0);
    rr1 = r0 + max * (r1 - r0);
  
    pattern = cairo_pattern_create_radial ((double) xx0, (double) yy0, (double) rr0, (double) xx1, (double) yy1, (double) rr1);
    cairo_pattern_set_extend (pattern, hb_cairo_extend (hb_color_line_get_extend (color_line)));
  
    for (unsigned int i = 0; i < len; i++)
      {
        double r, g, b, a;
        r = hb_color_get_red (stops[i].color) / 255.;
        g = hb_color_get_green (stops[i].color) / 255.;
        b = hb_color_get_blue (stops[i].color) / 255.;
        a = hb_color_get_alpha (stops[i].color) / 255.;
        cairo_pattern_add_color_stop_rgba (pattern, (double) stops[i].offset, r, g, b, a);
      }
  
    cairo_set_source (cr, pattern);
    cairo_paint (cr);
  
    cairo_pattern_destroy (pattern);
  
    if (stops != stops_)
      hb_free (stops);
  }
  
  typedef struct {
    float x, y;
  } hb_cairo_point_t;
  
  static inline float
  _hb_cairo_interpolate (float f0, float f1, float f)
  {
    return f0 + f * (f1 - f0);
  }
  
  static inline void
  _hb_cairo_premultiply (hb_cairo_color_t *c)
  {
    c->r *= c->a;
    c->g *= c->a;
    c->b *= c->a;
  }
  
  static inline void
  _hb_cairo_unpremultiply (hb_cairo_color_t *c)
  {
    if (c->a != 0.f)
    {
       c->r /= c->a;
       c->g /= c->a;
       c->b /= c->a;
    }
  }
  
  static void
  _hb_cairo_interpolate_colors (hb_cairo_color_t *c0, hb_cairo_color_t *c1, float k, hb_cairo_color_t *c)
  {
    // According to the COLR specification, gradients
    // should be interpolated in premultiplied form
    _hb_cairo_premultiply (c0);
    _hb_cairo_premultiply (c1);
    c->r = c0->r + k * (c1->r - c0->r);
    c->g = c0->g + k * (c1->g - c0->g);
    c->b = c0->b + k * (c1->b - c0->b);
    c->a = c0->a + k * (c1->a - c0->a);
    _hb_cairo_unpremultiply (c);
  }
  
  static inline float
  _hb_cairo_dot (hb_cairo_point_t p, hb_cairo_point_t q)
  {
    return p.x * q.x + p.y * q.y;
  }
  
  static inline hb_cairo_point_t
  _hb_cairo_normalize (hb_cairo_point_t p)
  {
    float len = sqrtf (_hb_cairo_dot (p, p));
  
    return hb_cairo_point_t { p.x / len, p.y / len };
  }
  
  static inline hb_cairo_point_t
  _hb_cairo_sum (hb_cairo_point_t p, hb_cairo_point_t q)
  {
    return hb_cairo_point_t { p.x + q.x, p.y + q.y };
  }
  
  static inline hb_cairo_point_t
  _hb_cairo_difference (hb_cairo_point_t p, hb_cairo_point_t q)
  {
    return hb_cairo_point_t { p.x - q.x, p.y - q.y };
  }
  
  static inline hb_cairo_point_t
  _hb_cairo_scale (hb_cairo_point_t p, float f)
  {
    return hb_cairo_point_t { p.x * f, p.y * f };
  }
  
  typedef struct {
    hb_cairo_point_t center, p0, c0, c1, p1;
    hb_cairo_color_t color0, color1;
  } hb_cairo_patch_t;
  
  static void
  _hb_cairo_add_patch (cairo_pattern_t *pattern, hb_cairo_point_t *center, hb_cairo_patch_t *p)
  {
    cairo_mesh_pattern_begin_patch (pattern);
    cairo_mesh_pattern_move_to (pattern, (double) center->x, (double) center->y);
    cairo_mesh_pattern_line_to (pattern, (double) p->p0.x, (double) p->p0.y);
    cairo_mesh_pattern_curve_to (pattern,
                                 (double) p->c0.x, (double) p->c0.y,
                                 (double) p->c1.x, (double) p->c1.y,
                                 (double) p->p1.x, (double) p->p1.y);
    cairo_mesh_pattern_line_to (pattern, (double) center->x, (double) center->y);
    cairo_mesh_pattern_set_corner_color_rgba (pattern, 0,
                                              (double) p->color0.r,
                                              (double) p->color0.g,
                                              (double) p->color0.b,
                                              (double) p->color0.a);
    cairo_mesh_pattern_set_corner_color_rgba (pattern, 1,
                                              (double) p->color0.r,
                                              (double) p->color0.g,
                                              (double) p->color0.b,
                                              (double) p->color0.a);
    cairo_mesh_pattern_set_corner_color_rgba (pattern, 2,
                                              (double) p->color1.r,
                                              (double) p->color1.g,
                                              (double) p->color1.b,
                                              (double) p->color1.a);
    cairo_mesh_pattern_set_corner_color_rgba (pattern, 3,
                                              (double) p->color1.r,
                                              (double) p->color1.g,
                                              (double) p->color1.b,
                                              (double) p->color1.a);
    cairo_mesh_pattern_end_patch (pattern);
  }
  
  #define MAX_ANGLE (HB_PI / 8.f)
  
  static void
  _hb_cairo_add_sweep_gradient_patches1 (float cx, float cy, float radius,
  				       float a0, hb_cairo_color_t *c0,
  				       float a1, hb_cairo_color_t *c1,
  				       cairo_pattern_t *pattern)
  {
    hb_cairo_point_t center = hb_cairo_point_t { cx, cy };
    int num_splits;
    hb_cairo_point_t p0;
    hb_cairo_color_t color0, color1;
  
    num_splits = ceilf (fabsf (a1 - a0) / MAX_ANGLE);
    p0 = hb_cairo_point_t { cosf (a0), sinf (a0) };
    color0 = *c0;
  
    for (int a = 0; a < num_splits; a++)
      {
        float k = (a + 1.) / num_splits;
        float angle1;
        hb_cairo_point_t p1;
        hb_cairo_point_t A, U;
        hb_cairo_point_t C0, C1;
        hb_cairo_patch_t patch;
  
        angle1 = _hb_cairo_interpolate (a0, a1, k);
        _hb_cairo_interpolate_colors (c0, c1, k, &color1);
  
        patch.color0 = color0;
        patch.color1 = color1;
  
        p1 = hb_cairo_point_t { cosf (angle1), sinf (angle1) };
        patch.p0 = _hb_cairo_sum (center, _hb_cairo_scale (p0, radius));
        patch.p1 = _hb_cairo_sum (center, _hb_cairo_scale (p1, radius));
  
        A = _hb_cairo_normalize (_hb_cairo_sum (p0, p1));
        U = hb_cairo_point_t { -A.y, A.x };
        C0 = _hb_cairo_sum (A, _hb_cairo_scale (U, _hb_cairo_dot (_hb_cairo_difference (p0, A), p0) / _hb_cairo_dot (U, p0)));
        C1 = _hb_cairo_sum (A, _hb_cairo_scale (U, _hb_cairo_dot (_hb_cairo_difference (p1, A), p1) / _hb_cairo_dot (U, p1)));
  
        patch.c0 = _hb_cairo_sum (center, _hb_cairo_scale (_hb_cairo_sum (C0, _hb_cairo_scale (_hb_cairo_difference (C0, p0), 0.33333f)), radius));
        patch.c1 = _hb_cairo_sum (center, _hb_cairo_scale (_hb_cairo_sum (C1, _hb_cairo_scale (_hb_cairo_difference (C1, p1), 0.33333f)), radius));
  
        _hb_cairo_add_patch (pattern, &center, &patch);
  
        p0 = p1;
        color0 = color1;
      }
  }
  
  static void
  _hb_cairo_add_sweep_gradient_patches (hb_color_stop_t *stops,
  				      unsigned int n_stops,
  				      cairo_extend_t extend,
  				      float cx, float cy,
  				      float radius,
  				      float start_angle,
  				      float end_angle,
  				      cairo_pattern_t *pattern)
  {
    float angles_[PREALLOCATED_COLOR_STOPS];
    float *angles = angles_;
    hb_cairo_color_t colors_[PREALLOCATED_COLOR_STOPS];
    hb_cairo_color_t *colors = colors_;
    hb_cairo_color_t color0, color1;
  
    if (start_angle == end_angle)
    {
      if (extend == CAIRO_EXTEND_PAD)
      {
        hb_cairo_color_t c;
        if (start_angle > 0)
        {
  	c.r = hb_color_get_red (stops[0].color) / 255.;
  	c.g = hb_color_get_green (stops[0].color) / 255.;
  	c.b = hb_color_get_blue (stops[0].color) / 255.;
  	c.a = hb_color_get_alpha (stops[0].color) / 255.;
  	_hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  					       0.,          &c,
  					       start_angle, &c,
  					       pattern);
        }
        if (end_angle < HB_2_PI)
        {
  	c.r = hb_color_get_red (stops[n_stops - 1].color) / 255.;
  	c.g = hb_color_get_green (stops[n_stops - 1].color) / 255.;
  	c.b = hb_color_get_blue (stops[n_stops - 1].color) / 255.;
  	c.a = hb_color_get_alpha (stops[n_stops - 1].color) / 255.;
  	_hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  					       end_angle, &c,
  					       HB_2_PI,  &c,
  					       pattern);
        }
      }
      return;
    }
  
    assert (start_angle != end_angle);
  
    /* handle directions */
    if (end_angle < start_angle)
    {
      hb_swap (start_angle, end_angle);
  
      for (unsigned i = 0; i < n_stops - 1 - i; i++)
        hb_swap (stops[i], stops[n_stops - 1 - i]);
      for (unsigned i = 0; i < n_stops; i++)
        stops[i].offset = 1 - stops[i].offset;
    }
  
    if (n_stops > PREALLOCATED_COLOR_STOPS)
    {
      angles = (float *) hb_malloc (sizeof (float) * n_stops);
      colors = (hb_cairo_color_t *) hb_malloc (sizeof (hb_cairo_color_t) * n_stops);
      if (unlikely (!angles || !colors))
      {
        hb_free (angles);
        hb_free (colors);
        return;
      }
    }
  
    for (unsigned i = 0; i < n_stops; i++)
    {
      angles[i] = start_angle + stops[i].offset * (end_angle - start_angle);
      colors[i].r = hb_color_get_red (stops[i].color) / 255.;
      colors[i].g = hb_color_get_green (stops[i].color) / 255.;
      colors[i].b = hb_color_get_blue (stops[i].color) / 255.;
      colors[i].a = hb_color_get_alpha (stops[i].color) / 255.;
    }
  
    if (extend == CAIRO_EXTEND_PAD)
    {
      unsigned pos;
  
      color0 = colors[0];
      for (pos = 0; pos < n_stops; pos++)
      {
        if (angles[pos] >= 0)
        {
  	if (pos > 0)
  	{
  	  float k = (0 - angles[pos - 1]) / (angles[pos] - angles[pos - 1]);
  	  _hb_cairo_interpolate_colors (&colors[pos-1], &colors[pos], k, &color0);
  	}
  	break;
        }
      }
      if (pos == n_stops)
      {
        /* everything is below 0 */
        color0 = colors[n_stops-1];
        _hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  					     0.,       &color0,
  					     HB_2_PI, &color0,
  					     pattern);
        goto done;
      }
  
      _hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  					   0.,          &color0,
  					   angles[pos], &colors[pos],
  					   pattern);
  
      for (pos++; pos < n_stops; pos++)
      {
        if (angles[pos] <= HB_2_PI)
        {
  	_hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  					       angles[pos - 1], &colors[pos-1],
  					       angles[pos],     &colors[pos],
  					       pattern);
        }
        else
        {
  	float k = (HB_2_PI - angles[pos - 1]) / (angles[pos] - angles[pos - 1]);
  	_hb_cairo_interpolate_colors (&colors[pos - 1], &colors[pos], k, &color1);
  	_hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  					       angles[pos - 1], &colors[pos - 1],
  					       HB_2_PI,        &color1,
  					       pattern);
  	break;
        }
      }
  
      if (pos == n_stops)
      {
        /* everything is below 2*M_PI */
        color0 = colors[n_stops - 1];
        _hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  					     angles[n_stops - 1], &color0,
  					     HB_2_PI,            &color0,
  					     pattern);
        goto done;
      }
    }
    else
    {
      int k;
      float span;
  
      span = angles[n_stops - 1] - angles[0];
      if (!span)
        goto done;
  
      k = 0;
      if (angles[0] >= 0)
      {
        float ss = angles[0];
        while (ss > 0)
        {
  	if (span > 0)
  	{
  	  ss -= span;
  	  k--;
  	}
  	else
  	{
  	  ss += span;
  	  k++;
  	}
        }
      }
      else if (angles[0] < 0)
      {
        float ee = angles[n_stops - 1];
        while (ee < 0)
        {
  	if (span > 0)
  	{
  	  ee += span;
  	  k++;
  	}
  	else
  	{
  	  ee -= span;
  	  k--;
  	}
        }
      }
  
      //assert (angles[0] + k * span <= 0 && 0 < angles[n_stops - 1] + k * span);
      span = fabsf (span);
  
      for (signed l = k; l < 1000; l++)
      {
        for (unsigned i = 1; i < n_stops; i++)
        {
          float a0, a1;
  	hb_cairo_color_t *c0, *c1;
  
  	if ((l % 2 != 0) && (extend == CAIRO_EXTEND_REFLECT))
  	{
  	  a0 = angles[0] + angles[n_stops - 1] - angles[n_stops - 1 - (i-1)] + l * span;
  	  a1 = angles[0] + angles[n_stops - 1] - angles[n_stops - 1 - i] + l * span;
  	  c0 = &colors[n_stops - 1 - (i - 1)];
  	  c1 = &colors[n_stops - 1 - i];
  	}
  	else
  	{
  	  a0 = angles[i-1] + l * span;
  	  a1 = angles[i] + l * span;
  	  c0 = &colors[i-1];
  	  c1 = &colors[i];
  	}
  
  	if (a1 < 0)
  	  continue;
  	if (a0 < 0)
  	{
  	  hb_cairo_color_t color;
  	  float f = (0 - a0)/(a1 - a0);
  	  _hb_cairo_interpolate_colors (c0, c1, f, &color);
  	  _hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  						 0,  &color,
  						 a1, c1,
  						 pattern);
  	}
  	else if (a1 >= HB_2_PI)
  	{
  	  hb_cairo_color_t color;
  	  float f = (HB_2_PI - a0)/(a1 - a0);
  	  _hb_cairo_interpolate_colors (c0, c1, f, &color);
  	  _hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  						 a0,       c0,
  						 HB_2_PI, &color,
  						 pattern);
  	  goto done;
  	}
  	else
  	{
  	  _hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
  						 a0, c0,
  						 a1, c1,
  						 pattern);
  	}
        }
      }
    }
  
  done:
  
    if (angles != angles_)
      hb_free (angles);
    if (colors != colors_)
      hb_free (colors);
  }
  
  void
  _hb_cairo_paint_sweep_gradient (hb_cairo_context_t *c,
  				hb_color_line_t *color_line,
  				float cx, float cy,
  				float start_angle,
  				float end_angle)
  {
    cairo_t *cr = c->cr;
  
    unsigned int len = PREALLOCATED_COLOR_STOPS;
    hb_color_stop_t stops_[PREALLOCATED_COLOR_STOPS];
    hb_color_stop_t *stops = stops_;
    cairo_extend_t extend;
    double x1, y1, x2, y2;
    float max_x, max_y, radius;
    cairo_pattern_t *pattern;
  
    if (unlikely (!_hb_cairo_get_color_stops (c, color_line, &len, &stops)))
      return;
  
    hb_qsort (stops, len, sizeof (hb_color_stop_t), _hb_cairo_cmp_color_stop);
  
    cairo_clip_extents (cr, &x1, &y1, &x2, &y2);
    max_x = (float) hb_max ((x1 - (double) cx) * (x1 - (double) cx), (x2 - (double) cx) * (x2 - (double) cx));
    max_y = (float) hb_max ((y1 - (double) cy) * (y1 - (double) cy), (y2 - (double) cy) * (y2 - (double) cy));
    radius = sqrtf (max_x + max_y);
  
    extend = hb_cairo_extend (hb_color_line_get_extend (color_line));
    pattern = cairo_pattern_create_mesh ();
  
    _hb_cairo_add_sweep_gradient_patches (stops, len, extend, cx, cy,
  					radius, start_angle, end_angle, pattern);
  
    cairo_set_source (cr, pattern);
    cairo_paint (cr);
  
    cairo_pattern_destroy (pattern);
  
    if (stops != stops_)
      hb_free (stops);
  }
  
  #endif
  

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