Edit
kc3-lang/harfbuzz/src/hb-cairo.cc
Behdad Esfahbod
- src/hb-cairo.cc
-
/* * 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" /* TODO Error handling in cairo set_user_data calls? */ /** * 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) { cairo_t *cr = (cairo_t *) paint_data; 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) { cairo_t *cr = (cairo_t *) paint_data; 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) { cairo_t *cr = (cairo_t *) paint_data; 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) { cairo_t *cr = (cairo_t *) paint_data; 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) { cairo_t *cr = (cairo_t *) paint_data; cairo_restore (cr); } static void hb_cairo_push_group (hb_paint_funcs_t *pfuncs HB_UNUSED, void *paint_data, void *user_data HB_UNUSED) { cairo_t *cr = (cairo_t *) paint_data; 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) { cairo_t *cr = (cairo_t *) paint_data; 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) { cairo_t *cr = (cairo_t *) paint_data; 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) { cairo_t *cr = (cairo_t *) paint_data; return hb_cairo_paint_glyph_image (cr, 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) { cairo_t *cr = (cairo_t *)paint_data; hb_cairo_paint_linear_gradient (cr, 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) { cairo_t *cr = (cairo_t *)paint_data; hb_cairo_paint_radial_gradient (cr, 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) { cairo_t *cr = (cairo_t *) paint_data; hb_cairo_paint_sweep_gradient (cr, color_line, x0, y0, start_angle, end_angle); } 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_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 (); } 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); #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); 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); // 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; 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); cairo_pattern_t *pattern = cairo_get_source (cr); if (cairo_pattern_get_type (pattern) == CAIRO_PATTERN_TYPE_SOLID) { double r, g, b, a; cairo_pattern_get_rgba (pattern, &r, &g, &b, &a); color = HB_COLOR ((int)(b * 255.), (int)(g * 255.), (int) (r * 255.), (int)(a * 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_font_paint_glyph (font, glyph, hb_cairo_paint_get_funcs (), cr, 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 cairo_font_face_set_user_data (cairo_face, &hb_cairo_face_user_data_key, (void *) hb_face_reference (face), hb_cairo_face_destroy); 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: REPLACEME */ 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); cairo_font_face_set_user_data (cairo_face, &hb_cairo_font_user_data_key, (void *) hb_font_reference (font), hb_cairo_font_destroy); 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: REPLACEME */ 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: REPLACEME */ 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: REPLACEME */ 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: REPLACEME */ 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); cairo_font_face_set_user_data (font_face, &hb_cairo_font_init_user_data_user_data_key, (void *) user_data, destroy); } /** * 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: REPLACEME */ 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: REPLACEME */ 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: REPLACEME */ 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: REPLACEME */ 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