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Diffstat (limited to 'gfx/harfbuzz/src/hb-cairo.cc')
| -rw-r--r-- | gfx/harfbuzz/src/hb-cairo.cc | 1010 |
1 files changed, 1010 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-cairo.cc b/gfx/harfbuzz/src/hb-cairo.cc new file mode 100644 index 0000000000..f005afd17e --- /dev/null +++ b/gfx/harfbuzz/src/hb-cairo.cc @@ -0,0 +1,1010 @@ +/* + * 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. + * + * Red Hat Author(s): Matthias Clasen + */ + +#include "hb.hh" + +#ifdef HAVE_CAIRO + +#include "hb-cairo.h" + +#include "hb-cairo-utils.hh" + +#include "hb-machinery.hh" +#include "hb-utf.hh" + + +/** + * SECTION:hb-cairo + * @title: hb-cairo + * @short_description: Cairo integration + * @include: hb-cairo.h + * + * Functions for using HarfBuzz with the cairo library. + * + * HarfBuzz supports using cairo for rendering. + **/ + +static void +hb_cairo_move_to (hb_draw_funcs_t *dfuncs HB_UNUSED, + void *draw_data, + hb_draw_state_t *st HB_UNUSED, + float to_x, float to_y, + void *user_data HB_UNUSED) +{ + cairo_t *cr = (cairo_t *) draw_data; + + cairo_move_to (cr, (double) to_x, (double) to_y); +} + +static void +hb_cairo_line_to (hb_draw_funcs_t *dfuncs HB_UNUSED, + void *draw_data, + hb_draw_state_t *st HB_UNUSED, + float to_x, float to_y, + void *user_data HB_UNUSED) +{ + cairo_t *cr = (cairo_t *) draw_data; + + cairo_line_to (cr, (double) to_x, (double) to_y); +} + +static void +hb_cairo_cubic_to (hb_draw_funcs_t *dfuncs HB_UNUSED, + void *draw_data, + hb_draw_state_t *st HB_UNUSED, + float control1_x, float control1_y, + float control2_x, float control2_y, + float to_x, float to_y, + void *user_data HB_UNUSED) +{ + cairo_t *cr = (cairo_t *) draw_data; + + cairo_curve_to (cr, + (double) control1_x, (double) control1_y, + (double) control2_x, (double) control2_y, + (double) to_x, (double) to_y); +} + +static void +hb_cairo_close_path (hb_draw_funcs_t *dfuncs HB_UNUSED, + void *draw_data, + hb_draw_state_t *st HB_UNUSED, + void *user_data HB_UNUSED) +{ + cairo_t *cr = (cairo_t *) draw_data; + + cairo_close_path (cr); +} + +static inline void free_static_cairo_draw_funcs (); + +static struct hb_cairo_draw_funcs_lazy_loader_t : hb_draw_funcs_lazy_loader_t<hb_cairo_draw_funcs_lazy_loader_t> +{ + static hb_draw_funcs_t *create () + { + hb_draw_funcs_t *funcs = hb_draw_funcs_create (); + + hb_draw_funcs_set_move_to_func (funcs, hb_cairo_move_to, nullptr, nullptr); + hb_draw_funcs_set_line_to_func (funcs, hb_cairo_line_to, nullptr, nullptr); + hb_draw_funcs_set_cubic_to_func (funcs, hb_cairo_cubic_to, nullptr, nullptr); + hb_draw_funcs_set_close_path_func (funcs, hb_cairo_close_path, nullptr, nullptr); + + hb_draw_funcs_make_immutable (funcs); + + hb_atexit (free_static_cairo_draw_funcs); + + return funcs; + } +} static_cairo_draw_funcs; + +static inline +void free_static_cairo_draw_funcs () +{ + static_cairo_draw_funcs.free_instance (); +} + +static hb_draw_funcs_t * +hb_cairo_draw_get_funcs () +{ + return static_cairo_draw_funcs.get_unconst (); +} + + +#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC + +static void +hb_cairo_push_transform (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + float xx, float yx, + float xy, float yy, + float dx, float dy, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + cairo_t *cr = c->cr; + + cairo_matrix_t m; + + cairo_save (cr); + cairo_matrix_init (&m, (double) xx, (double) yx, + (double) xy, (double) yy, + (double) dx, (double) dy); + cairo_transform (cr, &m); +} + +static void +hb_cairo_pop_transform (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + cairo_t *cr = c->cr; + + cairo_restore (cr); +} + +static void +hb_cairo_push_clip_glyph (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + hb_codepoint_t glyph, + hb_font_t *font, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + cairo_t *cr = c->cr; + + cairo_save (cr); + cairo_new_path (cr); + hb_font_draw_glyph (font, glyph, hb_cairo_draw_get_funcs (), cr); + cairo_close_path (cr); + cairo_clip (cr); +} + +static void +hb_cairo_push_clip_rectangle (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + float xmin, float ymin, float xmax, float ymax, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + cairo_t *cr = c->cr; + + cairo_save (cr); + cairo_rectangle (cr, + (double) xmin, (double) ymin, + (double) (xmax - xmin), (double) (ymax - ymin)); + cairo_clip (cr); +} + +static void +hb_cairo_pop_clip (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + cairo_t *cr = c->cr; + + cairo_restore (cr); +} + +static void +hb_cairo_push_group (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + cairo_t *cr = c->cr; + + cairo_save (cr); + cairo_push_group (cr); +} + +static void +hb_cairo_pop_group (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + hb_paint_composite_mode_t mode, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + cairo_t *cr = c->cr; + + cairo_pop_group_to_source (cr); + cairo_set_operator (cr, _hb_paint_composite_mode_to_cairo (mode)); + cairo_paint (cr); + + cairo_restore (cr); +} + +static void +hb_cairo_paint_color (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + hb_bool_t use_foreground, + hb_color_t color, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + cairo_t *cr = c->cr; + + if (use_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) + cairo_set_source_rgba (cr, r, g, b, a * hb_color_get_alpha (color) / 255.); + else +#endif + cairo_set_source_rgba (cr, 0, 0, 0, hb_color_get_alpha (color) / 255.); + } + else + cairo_set_source_rgba (cr, + hb_color_get_red (color) / 255., + hb_color_get_green (color) / 255., + hb_color_get_blue (color) / 255., + hb_color_get_alpha (color) / 255.); + cairo_paint (cr); +} + +static hb_bool_t +hb_cairo_paint_image (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + hb_blob_t *blob, + unsigned width, + unsigned height, + hb_tag_t format, + float slant, + hb_glyph_extents_t *extents, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + + return _hb_cairo_paint_glyph_image (c, blob, width, height, format, slant, extents); +} + +static void +hb_cairo_paint_linear_gradient (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + hb_color_line_t *color_line, + float x0, float y0, + float x1, float y1, + float x2, float y2, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + + _hb_cairo_paint_linear_gradient (c, color_line, x0, y0, x1, y1, x2, y2); +} + +static void +hb_cairo_paint_radial_gradient (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + hb_color_line_t *color_line, + float x0, float y0, float r0, + float x1, float y1, float r1, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + + _hb_cairo_paint_radial_gradient (c, color_line, x0, y0, r0, x1, y1, r1); +} + +static void +hb_cairo_paint_sweep_gradient (hb_paint_funcs_t *pfuncs HB_UNUSED, + void *paint_data, + hb_color_line_t *color_line, + float x0, float y0, + float start_angle, float end_angle, + void *user_data HB_UNUSED) +{ + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + + _hb_cairo_paint_sweep_gradient (c, color_line, x0, y0, start_angle, end_angle); +} + +static const cairo_user_data_key_t color_cache_key = {0}; + +static void +_hb_cairo_destroy_map (void *p) +{ + hb_map_destroy ((hb_map_t *) p); +} + +static hb_bool_t +hb_cairo_paint_custom_palette_color (hb_paint_funcs_t *funcs, + void *paint_data, + unsigned int color_index, + hb_color_t *color, + void *user_data HB_UNUSED) +{ +#ifdef HAVE_CAIRO_FONT_OPTIONS_GET_CUSTOM_PALETTE_COLOR + hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data; + cairo_t *cr = c->cr; + +#define HB_DEADBEEF HB_TAG(0xDE,0xAD,0xBE,0xEF) + + hb_map_t *color_cache = c->color_cache; + hb_codepoint_t *v; + if (likely (color_cache && color_cache->has (color_index, &v))) + { + if (*v == HB_DEADBEEF) + return false; + *color = *v; + return true; + } + + cairo_font_options_t *options; + double red, green, blue, alpha; + + options = cairo_font_options_create (); + cairo_get_font_options (cr, options); + if (CAIRO_STATUS_SUCCESS == + cairo_font_options_get_custom_palette_color (options, color_index, + &red, &green, &blue, &alpha)) + { + cairo_font_options_destroy (options); + *color = HB_COLOR (round (255 * blue), + round (255 * green), + round (255 * red), + round (255 * alpha)); + + if (likely (color_cache && *color != HB_DEADBEEF)) + color_cache->set (color_index, *color); + + return true; + } + cairo_font_options_destroy (options); + + if (likely (color_cache)) + color_cache->set (color_index, HB_DEADBEEF); + +#undef HB_DEADBEEF + +#endif + + return false; +} + +static inline void free_static_cairo_paint_funcs (); + +static struct hb_cairo_paint_funcs_lazy_loader_t : hb_paint_funcs_lazy_loader_t<hb_cairo_paint_funcs_lazy_loader_t> +{ + static hb_paint_funcs_t *create () + { + hb_paint_funcs_t *funcs = hb_paint_funcs_create (); + + hb_paint_funcs_set_push_transform_func (funcs, hb_cairo_push_transform, nullptr, nullptr); + hb_paint_funcs_set_pop_transform_func (funcs, hb_cairo_pop_transform, nullptr, nullptr); + hb_paint_funcs_set_push_clip_glyph_func (funcs, hb_cairo_push_clip_glyph, nullptr, nullptr); + hb_paint_funcs_set_push_clip_rectangle_func (funcs, hb_cairo_push_clip_rectangle, nullptr, nullptr); + hb_paint_funcs_set_pop_clip_func (funcs, hb_cairo_pop_clip, nullptr, nullptr); + hb_paint_funcs_set_push_group_func (funcs, hb_cairo_push_group, nullptr, nullptr); + hb_paint_funcs_set_pop_group_func (funcs, hb_cairo_pop_group, nullptr, nullptr); + hb_paint_funcs_set_color_func (funcs, hb_cairo_paint_color, nullptr, nullptr); + hb_paint_funcs_set_image_func (funcs, hb_cairo_paint_image, nullptr, nullptr); + hb_paint_funcs_set_linear_gradient_func (funcs, hb_cairo_paint_linear_gradient, nullptr, nullptr); + hb_paint_funcs_set_radial_gradient_func (funcs, hb_cairo_paint_radial_gradient, nullptr, nullptr); + hb_paint_funcs_set_sweep_gradient_func (funcs, hb_cairo_paint_sweep_gradient, nullptr, nullptr); + hb_paint_funcs_set_custom_palette_color_func (funcs, hb_cairo_paint_custom_palette_color, nullptr, nullptr); + + hb_paint_funcs_make_immutable (funcs); + + hb_atexit (free_static_cairo_paint_funcs); + + return funcs; + } +} static_cairo_paint_funcs; + +static inline +void free_static_cairo_paint_funcs () +{ + static_cairo_paint_funcs.free_instance (); +} + +static hb_paint_funcs_t * +hb_cairo_paint_get_funcs () +{ + return static_cairo_paint_funcs.get_unconst (); +} +#endif + +static const cairo_user_data_key_t hb_cairo_face_user_data_key = {0}; +static const cairo_user_data_key_t hb_cairo_font_user_data_key = {0}; +static const cairo_user_data_key_t hb_cairo_font_init_func_user_data_key = {0}; +static const cairo_user_data_key_t hb_cairo_font_init_user_data_user_data_key = {0}; +static const cairo_user_data_key_t hb_cairo_scale_factor_user_data_key = {0}; + +static void hb_cairo_face_destroy (void *p) { hb_face_destroy ((hb_face_t *) p); } +static void hb_cairo_font_destroy (void *p) { hb_font_destroy ((hb_font_t *) p); } + +static cairo_status_t +hb_cairo_init_scaled_font (cairo_scaled_font_t *scaled_font, + cairo_t *cr HB_UNUSED, + cairo_font_extents_t *extents) +{ + cairo_font_face_t *font_face = cairo_scaled_font_get_font_face (scaled_font); + + hb_font_t *font = (hb_font_t *) cairo_font_face_get_user_data (font_face, + &hb_cairo_font_user_data_key); + + if (!font) + { + hb_face_t *face = (hb_face_t *) cairo_font_face_get_user_data (font_face, + &hb_cairo_face_user_data_key); + font = hb_font_create (face); + +#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1,16,0) + cairo_font_options_t *font_options = cairo_font_options_create (); + + // Set variations + cairo_scaled_font_get_font_options (scaled_font, font_options); + const char *variations = cairo_font_options_get_variations (font_options); + hb_vector_t<hb_variation_t> vars; + const char *p = variations; + while (p && *p) + { + const char *end = strpbrk ((char *) p, ", "); + hb_variation_t var; + if (hb_variation_from_string (p, end ? end - p : -1, &var)) + vars.push (var); + p = end ? end + 1 : nullptr; + } + hb_font_set_variations (font, &vars[0], vars.length); + + cairo_font_options_destroy (font_options); +#endif + + // Set scale; Note: should NOT set slant, or we'll double-slant. + unsigned scale_factor = hb_cairo_font_face_get_scale_factor (font_face); + if (scale_factor) + { + cairo_matrix_t font_matrix; + cairo_scaled_font_get_scale_matrix (scaled_font, &font_matrix); + hb_font_set_scale (font, + round (font_matrix.xx * scale_factor), + round (font_matrix.yy * scale_factor)); + } + + auto *init_func = (hb_cairo_font_init_func_t) + cairo_font_face_get_user_data (font_face, + &hb_cairo_font_init_func_user_data_key); + if (init_func) + { + void *user_data = cairo_font_face_get_user_data (font_face, + &hb_cairo_font_init_user_data_user_data_key); + font = init_func (font, scaled_font, user_data); + } + + hb_font_make_immutable (font); + } + + cairo_scaled_font_set_user_data (scaled_font, + &hb_cairo_font_user_data_key, + (void *) hb_font_reference (font), + hb_cairo_font_destroy); + + hb_position_t x_scale, y_scale; + hb_font_get_scale (font, &x_scale, &y_scale); + + hb_font_extents_t hb_extents; + hb_font_get_h_extents (font, &hb_extents); + + extents->ascent = (double) hb_extents.ascender / y_scale; + extents->descent = (double) -hb_extents.descender / y_scale; + extents->height = extents->ascent + extents->descent; + +#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC + hb_map_t *color_cache = hb_map_create (); + if (unlikely (CAIRO_STATUS_SUCCESS != cairo_scaled_font_set_user_data (scaled_font, + &color_cache_key, + color_cache, + _hb_cairo_destroy_map))) + hb_map_destroy (color_cache); +#endif + + return CAIRO_STATUS_SUCCESS; +} + +static cairo_status_t +hb_cairo_text_to_glyphs (cairo_scaled_font_t *scaled_font, + const char *utf8, + int utf8_len, + cairo_glyph_t **glyphs, + int *num_glyphs, + cairo_text_cluster_t **clusters, + int *num_clusters, + cairo_text_cluster_flags_t *cluster_flags) +{ + hb_font_t *font = (hb_font_t *) cairo_scaled_font_get_user_data (scaled_font, + &hb_cairo_font_user_data_key); + + hb_buffer_t *buffer = hb_buffer_create (); + hb_buffer_add_utf8 (buffer, utf8, utf8_len, 0, utf8_len); + hb_buffer_guess_segment_properties (buffer); + hb_shape (font, buffer, nullptr, 0); + + hb_cairo_glyphs_from_buffer (buffer, + true, + font->x_scale, font->y_scale, + 0., 0., + utf8, utf8_len, + glyphs, (unsigned *) num_glyphs, + clusters, (unsigned *) num_clusters, + cluster_flags); + + hb_buffer_destroy (buffer); + + return CAIRO_STATUS_SUCCESS; +} + +static cairo_status_t +hb_cairo_render_glyph (cairo_scaled_font_t *scaled_font, + unsigned long glyph, + cairo_t *cr, + cairo_text_extents_t *extents) +{ + hb_font_t *font = (hb_font_t *) cairo_scaled_font_get_user_data (scaled_font, + &hb_cairo_font_user_data_key); + + hb_position_t x_scale, y_scale; + hb_font_get_scale (font, &x_scale, &y_scale); + cairo_scale (cr, +1./x_scale, -1./y_scale); + + hb_font_draw_glyph (font, glyph, hb_cairo_draw_get_funcs (), cr); + + cairo_fill (cr); + + return CAIRO_STATUS_SUCCESS; +} + +#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC + +static cairo_status_t +hb_cairo_render_color_glyph (cairo_scaled_font_t *scaled_font, + unsigned long glyph, + cairo_t *cr, + cairo_text_extents_t *extents) +{ + hb_font_t *font = (hb_font_t *) cairo_scaled_font_get_user_data (scaled_font, + &hb_cairo_font_user_data_key); + + unsigned int palette = 0; +#ifdef CAIRO_COLOR_PALETTE_DEFAULT + cairo_font_options_t *options = cairo_font_options_create (); + cairo_scaled_font_get_font_options (scaled_font, options); + palette = cairo_font_options_get_color_palette (options); + cairo_font_options_destroy (options); +#endif + + hb_color_t color = HB_COLOR (0, 0, 0, 255); + hb_position_t x_scale, y_scale; + hb_font_get_scale (font, &x_scale, &y_scale); + cairo_scale (cr, +1./x_scale, -1./y_scale); + + hb_cairo_context_t c; + c.scaled_font = scaled_font; + c.cr = cr; + c.color_cache = (hb_map_t *) cairo_scaled_font_get_user_data (scaled_font, &color_cache_key); + + hb_font_paint_glyph (font, glyph, hb_cairo_paint_get_funcs (), &c, palette, color); + + + return CAIRO_STATUS_SUCCESS; +} + +#endif + +static cairo_font_face_t * +user_font_face_create (hb_face_t *face) +{ + cairo_font_face_t *cairo_face; + + cairo_face = cairo_user_font_face_create (); + cairo_user_font_face_set_init_func (cairo_face, hb_cairo_init_scaled_font); + cairo_user_font_face_set_text_to_glyphs_func (cairo_face, hb_cairo_text_to_glyphs); + cairo_user_font_face_set_render_glyph_func (cairo_face, hb_cairo_render_glyph); +#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC + if (hb_ot_color_has_png (face) || hb_ot_color_has_layers (face) || hb_ot_color_has_paint (face)) + cairo_user_font_face_set_render_color_glyph_func (cairo_face, hb_cairo_render_color_glyph); +#endif + + if (unlikely (CAIRO_STATUS_SUCCESS != cairo_font_face_set_user_data (cairo_face, + &hb_cairo_face_user_data_key, + (void *) hb_face_reference (face), + hb_cairo_face_destroy))) + hb_face_destroy (face); + + return cairo_face; +} + +/** + * hb_cairo_font_face_create_for_font: + * @font: a #hb_font_t + * + * Creates a #cairo_font_face_t for rendering text according + * to @font. + * + * Note that the scale of @font does not affect the rendering, + * but the variations and slant that are set on @font do. + * + * Returns: (transfer full): a newly created #cairo_font_face_t + * + * Since: 7.0.0 + */ +cairo_font_face_t * +hb_cairo_font_face_create_for_font (hb_font_t *font) +{ + hb_font_make_immutable (font); + + auto *cairo_face = user_font_face_create (font->face); + + if (unlikely (CAIRO_STATUS_SUCCESS != cairo_font_face_set_user_data (cairo_face, + &hb_cairo_font_user_data_key, + (void *) hb_font_reference (font), + hb_cairo_font_destroy))) + hb_font_destroy (font); + + return cairo_face; +} + +/** + * hb_cairo_font_face_get_font: + * @font_face: a #cairo_font_face_t + * + * Gets the #hb_font_t that @font_face was created from. + * + * Returns: (nullable) (transfer none): the #hb_font_t that @font_face was created from + * + * Since: 7.0.0 + */ +hb_font_t * +hb_cairo_font_face_get_font (cairo_font_face_t *font_face) +{ + return (hb_font_t *) cairo_font_face_get_user_data (font_face, + &hb_cairo_font_user_data_key); +} + +/** + * hb_cairo_font_face_create_for_face: + * @face: a #hb_face_t + * + * Creates a #cairo_font_face_t for rendering text according + * to @face. + * + * Returns: (transfer full): a newly created #cairo_font_face_t + * + * Since: 7.0.0 + */ +cairo_font_face_t * +hb_cairo_font_face_create_for_face (hb_face_t *face) +{ + hb_face_make_immutable (face); + + return user_font_face_create (face); +} + +/** + * hb_cairo_font_face_get_face: + * @font_face: a #cairo_font_face_t + * + * Gets the #hb_face_t associated with @font_face. + * + * Returns: (nullable) (transfer none): the #hb_face_t associated with @font_face + * + * Since: 7.0.0 + */ +hb_face_t * +hb_cairo_font_face_get_face (cairo_font_face_t *font_face) +{ + return (hb_face_t *) cairo_font_face_get_user_data (font_face, + &hb_cairo_face_user_data_key); +} + +/** + * hb_cairo_font_face_set_font_init_func: + * @font_face: a #cairo_font_face_t + * @func: The virtual method to use + * @user_data: user data accompanying the method + * @destroy: function to call when @user_data is not needed anymore + * + * Set the virtual method to be called when a cairo + * face created using hb_cairo_font_face_create_for_face() + * creates an #hb_font_t for a #cairo_scaled_font_t. + * + * Since: 7.0.0 + */ +void +hb_cairo_font_face_set_font_init_func (cairo_font_face_t *font_face, + hb_cairo_font_init_func_t func, + void *user_data, + hb_destroy_func_t destroy) +{ + cairo_font_face_set_user_data (font_face, + &hb_cairo_font_init_func_user_data_key, + (void *) func, + nullptr); + if (unlikely (CAIRO_STATUS_SUCCESS != cairo_font_face_set_user_data (font_face, + &hb_cairo_font_init_user_data_user_data_key, + (void *) user_data, + destroy)) && destroy) + { + destroy (user_data); + cairo_font_face_set_user_data (font_face, + &hb_cairo_font_init_func_user_data_key, + nullptr, + nullptr); + } +} + +/** + * hb_cairo_scaled_font_get_font: + * @scaled_font: a #cairo_scaled_font_t + * + * Gets the #hb_font_t associated with @scaled_font. + * + * Returns: (nullable) (transfer none): the #hb_font_t associated with @scaled_font + * + * Since: 7.0.0 + */ +hb_font_t * +hb_cairo_scaled_font_get_font (cairo_scaled_font_t *scaled_font) +{ + return (hb_font_t *) cairo_scaled_font_get_user_data (scaled_font, &hb_cairo_font_user_data_key); +} + + +/** + * hb_cairo_font_face_set_scale_factor: + * @scale_factor: The scale factor to use. See below + * @font_face: a #cairo_font_face_t + * + * Sets the scale factor of the @font_face. Default scale + * factor is zero. + * + * When a #cairo_font_face_t is created from a #hb_face_t using + * hb_cairo_font_face_create_for_face(), such face will create + * #hb_font_t objects during scaled-font creation. The scale + * factor defines how the scale set on such #hb_font_t objects + * relates to the font-matrix (as such font size) of the cairo + * scaled-font. + * + * If the scale-factor is zero (default), then the scale of the + * #hb_font_t object will be left at default, which is the UPEM + * value of the respective #hb_face_t. + * + * If the scale-factor is set to non-zero, then the X and Y scale + * of the #hb_font_t object will be respectively set to the + * @scale_factor times the xx and yy elements of the scale-matrix + * of the cairo scaled-font being created. + * + * When using the hb_cairo_glyphs_from_buffer() API to convert the + * HarfBuzz glyph buffer that resulted from shaping with such a #hb_font_t, + * if the scale-factor was non-zero, you can pass it directly to + * that API as both X and Y scale factors. + * + * If the scale-factor was zero however, or the cairo face was + * created using the alternative constructor + * hb_cairo_font_face_create_for_font(), you need to calculate the + * correct X/Y scale-factors to pass to hb_cairo_glyphs_from_buffer() + * by dividing the #hb_font_t X/Y scale-factors by the + * cairo scaled-font's scale-matrix XX/YY components respectively + * and use those values. Or if you know that relationship offhand + * (because you set the scale of the #hb_font_t yourself), use + * the conversion rate involved. + * + * Since: 7.0.0 + */ +void +hb_cairo_font_face_set_scale_factor (cairo_font_face_t *font_face, + unsigned int scale_factor) +{ + cairo_font_face_set_user_data (font_face, + &hb_cairo_scale_factor_user_data_key, + (void *) (uintptr_t) scale_factor, + nullptr); +} + +/** + * hb_cairo_font_face_get_scale_factor: + * @font_face: a #cairo_font_face_t + * + * Gets the scale factor set on the @font_face. Defaults to zero. + * See hb_cairo_font_face_set_scale_factor() for details. + * + * Returns: the scale factor of @font_face + * + * Since: 7.0.0 + */ +unsigned int +hb_cairo_font_face_get_scale_factor (cairo_font_face_t *font_face) +{ + return (unsigned int) (uintptr_t) + cairo_font_face_get_user_data (font_face, + &hb_cairo_scale_factor_user_data_key); +} + + +/** + * hb_cairo_glyphs_from_buffer: + * @buffer: a #hb_buffer_t containing glyphs + * @utf8_clusters: `true` if @buffer clusters are in bytes, instead of characters + * @x_scale_factor: scale factor to divide #hb_position_t Y values by + * @y_scale_factor: scale factor to divide #hb_position_t X values by + * @x: X position to place first glyph + * @y: Y position to place first glyph + * @utf8: (nullable): the text that was shaped in @buffer + * @utf8_len: the length of @utf8 in bytes + * @glyphs: (out): return location for an array of #cairo_glyph_t + * @num_glyphs: (inout): return location for the length of @glyphs + * @clusters: (out) (nullable): return location for an array of cluster positions + * @num_clusters: (inout) (nullable): return location for the length of @clusters + * @cluster_flags: (out) (nullable): return location for cluster flags + * + * Extracts information from @buffer in a form that can be + * passed to cairo_show_text_glyphs() or cairo_show_glyphs(). + * This API is modeled after cairo_scaled_font_text_to_glyphs() and + * cairo_user_scaled_font_text_to_glyphs_func_t. + * + * The @num_glyphs argument should be preset to the number of glyph entries available + * in the @glyphs buffer. If the @glyphs buffer is `NULL`, the value of + * @num_glyphs must be zero. If the provided glyph array is too short for + * the conversion (or for convenience), a new glyph array may be allocated + * using cairo_glyph_allocate() and placed in @glyphs. Upon return, + * @num_glyphs should contain the number of generated glyphs. If the value + * @glyphs points at has changed after the call, the caller will free the + * allocated glyph array using cairo_glyph_free(). The caller will also free + * the original value of @glyphs, so this function shouldn't do so. + * + * If @clusters is not `NULL`, then @num_clusters and @cluster_flags + * should not be either, and @utf8 must be provided, and cluster + * mapping will be computed. The semantics of how + * cluster array allocation works is similar to the glyph array. That is, + * if @clusters initially points to a non-`NULL` value, that array may be used + * as a cluster buffer, and @num_clusters points to the number of cluster + * entries available there. If the provided cluster array is too short for + * the conversion (or for convenience), a new cluster array may be allocated + * using cairo_text_cluster_allocate() and placed in @clusters. In this case, + * the original value of @clusters will still be freed by the caller. Upon + * return, @num_clusters will contain the number of generated clusters. + * If the value @clusters points at has changed after the call, the caller + * will free the allocated cluster array using cairo_text_cluster_free(). + * + * See hb_cairo_font_face_set_scale_factor() for the details of + * the @scale_factor argument. + * + * The returned @glyphs vector actually has `@num_glyphs + 1` entries in + * it and the x,y values of the extra entry at the end add up the advance + * x,y of all the glyphs in the @buffer. + * + * Since: 7.0.0 + */ +void +hb_cairo_glyphs_from_buffer (hb_buffer_t *buffer, + hb_bool_t utf8_clusters, + double x_scale_factor, + double y_scale_factor, + double x, + double y, + const char *utf8, + int utf8_len, + cairo_glyph_t **glyphs, + unsigned int *num_glyphs, + cairo_text_cluster_t **clusters, + unsigned int *num_clusters, + cairo_text_cluster_flags_t *cluster_flags) +{ + if (utf8 && utf8_len < 0) + utf8_len = strlen (utf8); + + unsigned orig_num_glyphs = *num_glyphs; + *num_glyphs = hb_buffer_get_length (buffer); + hb_glyph_info_t *hb_glyph = hb_buffer_get_glyph_infos (buffer, nullptr); + hb_glyph_position_t *hb_position = hb_buffer_get_glyph_positions (buffer, nullptr); + if (orig_num_glyphs < *num_glyphs + 1) + *glyphs = cairo_glyph_allocate (*num_glyphs + 1); + + if (clusters && utf8) + { + unsigned orig_num_clusters = *num_clusters; + *num_clusters = *num_glyphs ? 1 : 0; + for (unsigned int i = 1; i < *num_glyphs; i++) + if (hb_glyph[i].cluster != hb_glyph[i-1].cluster) + (*num_clusters)++; + if (orig_num_clusters < *num_clusters) + *clusters = cairo_text_cluster_allocate (*num_clusters); + } + + double x_scale = x_scale_factor ? 1. / x_scale_factor : 0.; + double y_scale = y_scale_factor ? 1. / y_scale_factor : 0.; + hb_position_t hx = 0, hy = 0; + int i; + for (i = 0; i < (int) *num_glyphs; i++) + { + (*glyphs)[i].index = hb_glyph[i].codepoint; + (*glyphs)[i].x = x + (+hb_position->x_offset + hx) * x_scale; + (*glyphs)[i].y = y + (-hb_position->y_offset + hy) * y_scale; + hx += hb_position->x_advance; + hy += -hb_position->y_advance; + + hb_position++; + } + (*glyphs)[i].index = -1; + (*glyphs)[i].x = round (hx * x_scale); + (*glyphs)[i].y = round (hy * y_scale); + + if (clusters && *num_clusters && utf8) + { + memset ((void *) *clusters, 0, *num_clusters * sizeof ((*clusters)[0])); + hb_bool_t backward = HB_DIRECTION_IS_BACKWARD (hb_buffer_get_direction (buffer)); + *cluster_flags = backward ? CAIRO_TEXT_CLUSTER_FLAG_BACKWARD : (cairo_text_cluster_flags_t) 0; + unsigned int cluster = 0; + const char *start = utf8, *end; + (*clusters)[cluster].num_glyphs++; + if (backward) + { + for (i = *num_glyphs - 2; i >= 0; i--) + { + if (hb_glyph[i].cluster != hb_glyph[i+1].cluster) + { + assert (hb_glyph[i].cluster > hb_glyph[i+1].cluster); + if (utf8_clusters) + end = start + hb_glyph[i].cluster - hb_glyph[i+1].cluster; + else + end = (const char *) hb_utf_offset_to_pointer<hb_utf8_t> ((const uint8_t *) start, + (signed) (hb_glyph[i].cluster - hb_glyph[i+1].cluster)); + (*clusters)[cluster].num_bytes = end - start; + start = end; + cluster++; + } + (*clusters)[cluster].num_glyphs++; + } + (*clusters)[cluster].num_bytes = utf8 + utf8_len - start; + } + else + { + for (i = 1; i < (int) *num_glyphs; i++) + { + if (hb_glyph[i].cluster != hb_glyph[i-1].cluster) + { + assert (hb_glyph[i].cluster > hb_glyph[i-1].cluster); + if (utf8_clusters) + end = start + hb_glyph[i].cluster - hb_glyph[i-1].cluster; + else + end = (const char *) hb_utf_offset_to_pointer<hb_utf8_t> ((const uint8_t *) start, + (signed) (hb_glyph[i].cluster - hb_glyph[i-1].cluster)); + (*clusters)[cluster].num_bytes = end - start; + start = end; + cluster++; + } + (*clusters)[cluster].num_glyphs++; + } + (*clusters)[cluster].num_bytes = utf8 + utf8_len - start; + } + } + else if (num_clusters) + *num_clusters = 0; +} + +#endif |