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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /gfx/harfbuzz/src/hb-cairo-utils.cc | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gfx/harfbuzz/src/hb-cairo-utils.cc')
-rw-r--r-- | gfx/harfbuzz/src/hb-cairo-utils.cc | 874 |
1 files changed, 874 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..ec1499e861 --- /dev/null +++ b/gfx/harfbuzz/src/hb-cairo-utils.cc @@ -0,0 +1,874 @@ +/* + * 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" + +#include <cairo.h> + +/* 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, + 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 (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, ¢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 < 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]; + 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 |