diff options
Diffstat (limited to 'gfx/harfbuzz/src/hb-cairo-utils.cc')
| -rw-r--r-- | gfx/harfbuzz/src/hb-cairo-utils.cc | 869 |
1 files changed, 869 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-cairo-utils.cc b/gfx/harfbuzz/src/hb-cairo-utils.cc new file mode 100644 index 0000000000..1c95942309 --- /dev/null +++ b/gfx/harfbuzz/src/hb-cairo-utils.cc @@ -0,0 +1,869 @@ +/*
+ * Copyright © 2022 Red Hat, Inc
+ *
+ * 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"
+
+#include <cairo.h>
+
+#define PREALLOCATED_COLOR_STOPS 16
+
+#define _2_M_PIf (2.f * float (M_PI))
+
+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;
+
+ 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,
+ float slant,
+ 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);
+
+ /* Undo slant in the extents and apply it in the context. */
+ extents->width -= extents->height * slant;
+ extents->x_bearing -= extents->y_bearing * slant;
+ cairo_matrix_t cairo_matrix = {1., 0., (double) slant, 1., 0., 0.};
+ cairo_transform (cr, &cairo_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 ((float) M_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, ¢er, &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 < _2_M_PIf)
+ {
+ 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,
+ _2_M_PIf, &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,
+ _2_M_PIf, &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] <= _2_M_PIf)
+ {
+ _hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
+ angles[pos - 1], &colors[pos-1],
+ angles[pos], &colors[pos],
+ pattern);
+ }
+ else
+ {
+ float k = (_2_M_PIf - 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],
+ _2_M_PIf, &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,
+ _2_M_PIf, &color0,
+ pattern);
+ goto done;
+ }
+ }
+ else
+ {
+ int k;
+ float span;
+
+ span = angles[n_stops - 1] - angles[0];
+ 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 = fabs (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 >= _2_M_PIf)
+ {
+ hb_cairo_color_t color;
+ float f = (_2_M_PIf - a0)/(a1 - a0);
+ _hb_cairo_interpolate_colors (c0, c1, f, &color);
+ _hb_cairo_add_sweep_gradient_patches1 (cx, cy, radius,
+ a0, c0,
+ _2_M_PIf, &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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