/* * 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-cairo-utils.h" #include #include #include #include #include #include #include #ifndef MIN #define MIN(x,y) ((x) < (y) ? (x) : (y)) #endif #ifndef MAX #define MAX(x,y) ((x) > (y) ? (x) : (y)) #endif typedef struct { float r, g, b, a; } color_t; typedef struct { cairo_t *cr; hb_font_t *font; hb_font_t *unscaled_font; } paint_data_t; static inline cairo_extend_t 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:; } return CAIRO_EXTEND_PAD; } void hb_face_get_color (hb_face_t *face, unsigned int palette_index, unsigned int color_index, float alpha, float *r, float *g, float *b, float *a) { if (color_index == 0xffff) { /* foreground color */ *r = *g = *b = 0; *a = alpha; } else { hb_color_t color; unsigned int clen = 1; if (hb_ot_color_palette_get_colors (face, palette_index, color_index, &clen, &color)) { *r = hb_color_get_red (color) / 255.f; *g = hb_color_get_green (color) / 255.f; *b = hb_color_get_blue (color) / 255.f; *a = (hb_color_get_alpha (color) / 255.f) * alpha; } else { *r = *g = *b = 0; *a = alpha; } } } typedef struct { hb_blob_t *blob; unsigned int offset; } read_blob_data_t; static cairo_status_t read_blob (void *closure, unsigned char *data, unsigned int length) { read_blob_data_t *r = (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; } void hb_cairo_paint_glyph_image (cairo_t *cr, hb_font_t *font, hb_blob_t *blob, hb_tag_t format, hb_glyph_extents_t *extents) { if (format != HB_PAINT_IMAGE_FORMAT_PNG || !extents) return; read_blob_data_t r; r.blob = blob; r.offset = 0; cairo_surface_t *surface = cairo_image_surface_create_from_png_stream (read_blob, &r); int width = cairo_image_surface_get_width (surface); int height = cairo_image_surface_get_width (surface); 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); } static void 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 = y1 - 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 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 normalize_color_line (hb_color_stop_t *stops, unsigned int len, float *omin, float *omax) { float min, max; qsort (stops, len, sizeof (hb_color_stop_t), cmp_color_stop); min = max = stops[0].offset; for (unsigned int i = 0; i < len; i++) { min = MIN (min, stops[i].offset); max = 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; } void hb_cairo_paint_linear_gradient (cairo_t *cr, hb_font_t *font, hb_color_line_t *color_line, float x0, float y0, float x1, float y1, float x2, float y2) { hb_face_t *face = hb_font_get_face (font); unsigned int len; hb_color_stop_t *stops; float xx0, yy0, xx1, yy1; float xxx0, yyy0, xxx1, yyy1; float min, max; cairo_pattern_t *pattern; len = hb_color_line_get_color_stops (color_line, 0, NULL, NULL); stops = (hb_color_stop_t *) alloca (len * sizeof (hb_color_stop_t)); hb_color_line_get_color_stops (color_line, 0, &len, stops); reduce_anchors (x0, y0, x1, y1, x2, y2, &xx0, &yy0, &xx1, &yy1); normalize_color_line (stops, len, &min, &max); 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 (xxx0, yyy0, xxx1, yyy1); cairo_pattern_set_extend (pattern, cairo_extend (hb_color_line_get_extend (color_line))); for (unsigned int i = 0; i < len; i++) { float r, g, b, a; hb_face_get_color (face, 0, stops[i].color_index, stops[i].alpha, &r, &g, &b, &a); cairo_pattern_add_color_stop_rgba (pattern, stops[i].offset, r, g, b, a); } cairo_set_source (cr, pattern); cairo_paint (cr); cairo_pattern_destroy (pattern); } void hb_cairo_paint_radial_gradient (cairo_t *cr, hb_font_t *font, hb_color_line_t *color_line, float x0, float y0, float r0, float x1, float y1, float r1) { hb_face_t *face = hb_font_get_face (font); unsigned int len; hb_color_stop_t *stops; float min, max; float xx0, yy0, xx1, yy1; float rr0, rr1; cairo_pattern_t *pattern; len = hb_color_line_get_color_stops (color_line, 0, NULL, NULL); stops = (hb_color_stop_t *) alloca (len * sizeof (hb_color_stop_t)); hb_color_line_get_color_stops (color_line, 0, &len, stops); 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 (xx0, yy0, rr0, xx1, yy1, rr1); cairo_pattern_set_extend (pattern, cairo_extend (hb_color_line_get_extend (color_line))); for (unsigned int i = 0; i < len; i++) { float r, g, b, a; hb_face_get_color (face, 0, stops[i].color_index, stops[i].alpha, &r, &g, &b, &a); cairo_pattern_add_color_stop_rgba (pattern, stops[i].offset, r, g, b, a); } cairo_set_source (cr, pattern); cairo_paint (cr); cairo_pattern_destroy (pattern); } typedef struct { float x, y; } Point; static inline float interpolate (float f0, float f1, float f) { return f0 + f * (f1 - f0); } void interpolate_colors (color_t *c0, color_t *c1, float k, color_t *c) { 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); } static inline float dot (Point p, Point q) { return p.x * q.x + p.y * q.y; } static inline Point normalize (Point p) { float len = sqrt (dot (p, p)); return (Point) { p.x / len, p.y / len }; } static inline Point sum (Point p, Point q) { return (Point) { p.x + q.x, p.y + q.y }; } static inline Point difference (Point p, Point q) { return (Point) { p.x - q.x, p.y - q.y }; } static inline Point scale (Point p, float f) { return (Point) { p.x * f, p.y * f }; } typedef struct { Point center, p0, c0, c1, p1; color_t color0, color1; } Patch; static void add_patch (cairo_pattern_t *pattern, Point *center, Patch *p) { cairo_mesh_pattern_begin_patch (pattern); cairo_mesh_pattern_move_to (pattern, center->x, center->y); cairo_mesh_pattern_line_to (pattern, p->p0.x, p->p0.y); cairo_mesh_pattern_curve_to (pattern, p->c0.x, p->c0.y, p->c1.x, p->c1.y, p->p1.x, p->p1.y); cairo_mesh_pattern_line_to (pattern, center->x, center->y); cairo_mesh_pattern_set_corner_color_rgba (pattern, 0, p->color0.r, p->color0.g, p->color0.b, p->color0.a); cairo_mesh_pattern_set_corner_color_rgba (pattern, 1, p->color0.r, p->color0.g, p->color0.b, p->color0.a); cairo_mesh_pattern_set_corner_color_rgba (pattern, 2, p->color1.r, p->color1.g, p->color1.b, p->color1.a); cairo_mesh_pattern_set_corner_color_rgba (pattern, 3, p->color1.r, p->color1.g, p->color1.b, p->color1.a); cairo_mesh_pattern_end_patch (pattern); } #define MAX_ANGLE (M_PI / 8.) static void add_sweep_gradient_patches1 (float cx, float cy, float radius, float a0, color_t *c0, float a1, color_t *c1, cairo_pattern_t *pattern) { Point center = (Point) { cx, cy }; int num_splits; Point p0; color_t color0, color1; num_splits = ceilf (fabs (a1 - a0) / MAX_ANGLE); p0 = (Point) { cosf (a0), sinf (a0) }; color0 = *c0; for (int a = 0; a < num_splits; a++) { float k = (a + 1.) / num_splits; float angle1; Point p1; Point A, U; Point C0, C1; Patch patch; angle1 = interpolate (a0, a1, k); interpolate_colors (c0, c1, k, &color1); patch.color0 = color0; patch.color1 = color1; p1 = (Point) { cosf (angle1), sinf (angle1) }; patch.p0 = sum (center, scale (p0, radius)); patch.p1 = sum (center, scale (p1, radius)); A = normalize (sum (p0, p1)); U = (Point) { -A.y, A.x }; C0 = sum (A, scale (U, dot (difference (p0, A), p0) / dot (U, p0))); C1 = sum (A, scale (U, dot (difference (p1, A), p1) / dot (U, p1))); patch.c0 = sum (center, scale (sum (C0, scale (difference (C0, p0), 0.33333)), radius)); patch.c1 = sum (center, scale (sum (C1, scale (difference (C1, p1), 0.33333)), radius)); add_patch (pattern, ¢er, &patch); p0 = p1; color0 = color1; } } static void add_sweep_gradient_patches (hb_font_t *font, 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) { hb_face_t *face = hb_font_get_face (font); float *angles; color_t *colors; color_t color0, color1; if (start_angle == end_angle) { if (extend == CAIRO_EXTEND_PAD) { color_t c; if (start_angle > 0) { hb_face_get_color (face, 0, stops[0].color_index, stops[0].alpha, &c.r, &c.g, &c.b, &c.a); add_sweep_gradient_patches1 (cx, cy, radius, 0., &c, start_angle, &c, pattern); } if (end_angle < 2 * M_PI) { hb_face_get_color (face, 0, stops[n_stops-1].color_index, stops[n_stops-1].alpha, &c.r, &c.g, &c.b, &c.a); add_sweep_gradient_patches1 (cx, cy, radius, end_angle, &c, 2 * M_PI, &c, pattern); } } return; } assert (start_angle != end_angle); /* handle directions */ if (end_angle < start_angle) { float angle = end_angle; end_angle = start_angle; start_angle = angle; for (unsigned i = 0; i < n_stops - 1 - i; i++) { hb_color_stop_t stop = stops[i]; stops[i] = stops[n_stops - 1 - i]; stops[n_stops - 1 - i] = stop; } } angles = alloca (sizeof (float) * n_stops); colors = alloca (sizeof (color_t) * n_stops); for (unsigned i = 0; i < n_stops; i++) { angles[i] = start_angle + stops[i].offset * (end_angle - start_angle); hb_face_get_color (face, 0, stops[i].color_index, stops[i].alpha, &colors[i].r, &colors[i].g, &colors[i].b, &colors[i].a); } 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]); interpolate_colors (&colors[pos-1], &colors[pos], k, &color0); } break; } } if (pos == n_stops) { /* everything is below 0 */ color0 = colors[n_stops-1]; add_sweep_gradient_patches1 (cx, cy, radius, 0., &color0, 2 * M_PI, &color0, pattern); return; } 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_PI) { add_sweep_gradient_patches1 (cx, cy, radius, angles[pos - 1], &colors[pos-1], angles[pos], &colors[pos], pattern); } else { float k = (2 * M_PI - angles[pos - 1]) / (angles[pos] - angles[pos - 1]); interpolate_colors (&colors[pos - 1], &colors[pos], k, &color1); add_sweep_gradient_patches1 (cx, cy, radius, angles[pos - 1], &colors[pos - 1], 2 * M_PI, &color1, pattern); break; } } if (pos == n_stops) { /* everything is below 2*M_PI */ color0 = colors[n_stops - 1]; add_sweep_gradient_patches1 (cx, cy, radius, angles[n_stops - 1], &color0, 2 * M_PI, &color0, pattern); return; } } 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); for (unsigned l = k; 1; l++) { for (unsigned i = 1; i < n_stops; i++) { float a0, a1; 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) { color_t color; float f = (0 - a0)/(a1 - a0); interpolate_colors (c0, c1, f, &color); add_sweep_gradient_patches1 (cx, cy, radius, 0, &color, a1, c1, pattern); } else if (a1 >= 2 * M_PI) { color_t color; float f = (2 * M_PI - a0)/(a1 - a0); interpolate_colors (c0, c1, f, &color); add_sweep_gradient_patches1 (cx, cy, radius, a0, c0, 2 * M_PI, &color, pattern); goto done; } else { add_sweep_gradient_patches1 (cx, cy, radius, a0, c0, a1, c1, pattern); } } } done: ; } } void hb_cairo_paint_sweep_gradient (cairo_t *cr, hb_font_t *font, hb_color_line_t *color_line, float cx, float cy, float start_angle, float end_angle) { unsigned int len; hb_color_stop_t *stops; cairo_extend_t extend; double x1, y1, x2, y2; float max_x, max_y, radius; cairo_pattern_t *pattern; len = hb_color_line_get_color_stops (color_line, 0, NULL, NULL); stops = alloca (len * sizeof (hb_color_stop_t)); hb_color_line_get_color_stops (color_line, 0, &len, stops); qsort (stops, len, sizeof (hb_color_stop_t), cmp_color_stop); cairo_clip_extents (cr, &x1, &y1, &x2, &y2); max_x = MAX ((x1 - cx) * (x1 - cx), (x2 - cx) * (x2 - cx)); max_y = MAX ((y1 - cy) * (y1 - cy), (y2 - cy) * (y2 - cy)); radius = sqrt (max_x + max_y); extend = cairo_extend (hb_color_line_get_extend (color_line)); pattern = cairo_pattern_create_mesh (); add_sweep_gradient_patches (font, stops, len, extend, cx, cy, radius, start_angle, end_angle, pattern); cairo_set_source (cr, pattern); cairo_paint (cr); cairo_pattern_destroy (pattern); }