harfbuzz/util/helper-cairo-user.hh

420 lines
12 KiB
C++

/*
* Copyright © 2022 Google, 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): Behdad Esfahbod
*/
#ifndef HELPER_CAIRO_USER_HH
#define HELPER_CAIRO_USER_HH
#include "config.h"
#include "font-options.hh"
#include <cairo.h>
#include <hb.h>
#include "hb-blob.hh"
#include "hb-cairo-utils.h"
static const cairo_user_data_key_t _hb_font_cairo_user_data_key = {0};
static void
move_to (hb_draw_funcs_t *dfuncs,
cairo_t *cr,
hb_draw_state_t *st,
float to_x, float to_y,
void *)
{
cairo_move_to (cr,
(double) to_x, (double) to_y);
}
static void
line_to (hb_draw_funcs_t *dfuncs,
cairo_t *cr,
hb_draw_state_t *st,
float to_x, float to_y,
void *)
{
cairo_line_to (cr,
(double) to_x, (double) to_y);
}
static void
cubic_to (hb_draw_funcs_t *dfuncs,
cairo_t *cr,
hb_draw_state_t *st,
float control1_x, float control1_y,
float control2_x, float control2_y,
float to_x, float to_y,
void *)
{
cairo_curve_to (cr,
(double) control1_x, (double) control1_y,
(double) control2_x, (double) control2_y,
(double) to_x, (double) to_y);
}
static void
close_path (hb_draw_funcs_t *dfuncs,
cairo_t *cr,
hb_draw_state_t *st,
void *)
{
cairo_close_path (cr);
}
static hb_draw_funcs_t *
get_cairo_draw_funcs (void)
{
static hb_draw_funcs_t *funcs;
if (!funcs)
{
funcs = hb_draw_funcs_create ();
hb_draw_funcs_set_move_to_func (funcs, (hb_draw_move_to_func_t) move_to, nullptr, nullptr);
hb_draw_funcs_set_line_to_func (funcs, (hb_draw_line_to_func_t) line_to, nullptr, nullptr);
hb_draw_funcs_set_cubic_to_func (funcs, (hb_draw_cubic_to_func_t) cubic_to, nullptr, nullptr);
hb_draw_funcs_set_close_path_func (funcs, (hb_draw_close_path_func_t) close_path, nullptr, nullptr);
}
return funcs;
}
#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC
typedef struct {
cairo_t *cr;
hb_font_t *font;
hb_font_t *unscaled_font;
} paint_data_t;
static void
push_transform (hb_paint_funcs_t *funcs,
void *paint_data,
float xx, float yx,
float xy, float yy,
float dx, float dy,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
cairo_matrix_t m;
cairo_save (cr);
cairo_matrix_init (&m, xx, yx, xy, yy, dx, dy);
cairo_transform (data->cr, &m);
}
static void
pop_transform (hb_paint_funcs_t *funcs,
void *paint_data,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
cairo_restore (cr);
}
static void
push_clip_glyph (hb_paint_funcs_t *funcs,
void *paint_data,
hb_codepoint_t glyph,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
cairo_save (cr);
cairo_new_path (cr);
hb_font_get_glyph_shape (data->unscaled_font, glyph, get_cairo_draw_funcs (), cr);
cairo_close_path (cr);
cairo_clip (cr);
}
static void
push_clip_rectangle (hb_paint_funcs_t *funcs,
void *paint_data,
float xmin, float ymin, float xmax, float ymax,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
cairo_save (cr);
cairo_rectangle (cr, xmin, ymin, xmax - xmin, ymax - ymin);
cairo_clip (cr);
}
static void
pop_clip (hb_paint_funcs_t *funcs,
void *paint_data,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
cairo_restore (cr);
}
static void
push_group (hb_paint_funcs_t *funcs,
void *paint_data,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
cairo_save (cr);
cairo_push_group (cr);
}
static void
pop_group (hb_paint_funcs_t *funcs,
void *paint_data,
hb_paint_composite_mode_t mode,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->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
paint_color (hb_paint_funcs_t *funcs,
void *paint_data,
unsigned int color_index,
float alpha,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
hb_face_t *face = hb_font_get_face (data->font);
cairo_t *cr = data->cr;
float r, g, b, a;
hb_face_get_color (face, 0, color_index, alpha, &r, &g, &b, &a);
cairo_set_source_rgba (cr, r, g, b, a);
cairo_paint (cr);
}
static void
paint_image (hb_paint_funcs_t *funcs,
void *paint_data,
hb_blob_t *blob,
hb_tag_t format,
hb_glyph_extents_t *extents,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
hb_font_t *font = data->font;
if (format != HB_PAINT_IMAGE_FORMAT_PNG || !extents)
return;
hb_cairo_paint_glyph_image (cr, font, blob, format, extents);
}
static void
paint_linear_gradient (hb_paint_funcs_t *funcs,
void *paint_data,
hb_color_line_t *color_line,
float x0, float y0,
float x1, float y1,
float x2, float y2,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
hb_font_t *font = data->font;
hb_cairo_paint_linear_gradient (cr, font, color_line, x0, y0, x1, y1, x2, y2);
}
static void
paint_radial_gradient (hb_paint_funcs_t *funcs,
void *paint_data,
hb_color_line_t *color_line,
float x0, float y0, float r0,
float x1, float y1, float r1,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
hb_font_t *font = data->font;
hb_cairo_paint_radial_gradient (cr, font, color_line, x0, y0, r0, x1, y1, r1);
}
static void
paint_sweep_gradient (hb_paint_funcs_t *funcs,
void *paint_data,
hb_color_line_t *color_line,
float x0, float y0,
float start_angle, float end_angle,
void *user_data)
{
paint_data_t *data = (paint_data_t *) paint_data;
cairo_t *cr = data->cr;
hb_font_t *font = data->font;
hb_cairo_paint_sweep_gradient (cr, font, color_line, x0, y0, start_angle, end_angle);
}
static hb_paint_funcs_t *
get_cairo_paint_funcs (void)
{
static hb_paint_funcs_t *funcs;
if (!funcs)
{
funcs = hb_paint_funcs_create ();
hb_paint_funcs_set_push_transform_func (funcs, push_transform, nullptr, nullptr);
hb_paint_funcs_set_pop_transform_func (funcs, pop_transform, nullptr, nullptr);
hb_paint_funcs_set_push_clip_glyph_func (funcs, push_clip_glyph, nullptr, nullptr);
hb_paint_funcs_set_push_clip_rectangle_func (funcs, push_clip_rectangle, nullptr, nullptr);
hb_paint_funcs_set_pop_clip_func (funcs, pop_clip, nullptr, nullptr);
hb_paint_funcs_set_push_group_func (funcs, push_group, nullptr, nullptr);
hb_paint_funcs_set_pop_group_func (funcs, pop_group, nullptr, nullptr);
hb_paint_funcs_set_color_func (funcs, paint_color, nullptr, nullptr);
hb_paint_funcs_set_image_func (funcs, paint_image, nullptr, nullptr);
hb_paint_funcs_set_linear_gradient_func (funcs, paint_linear_gradient, nullptr, nullptr);
hb_paint_funcs_set_radial_gradient_func (funcs, paint_radial_gradient, nullptr, nullptr);
hb_paint_funcs_set_sweep_gradient_func (funcs, paint_sweep_gradient, nullptr, nullptr);
}
return funcs;
}
#endif
static cairo_status_t
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_font_face_get_user_data (cairo_scaled_font_get_font_face (scaled_font),
&_hb_font_cairo_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_get_glyph_shape (font, glyph, get_cairo_draw_funcs (), cr);
cairo_fill (cr);
return CAIRO_STATUS_SUCCESS;
}
#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC
static cairo_status_t
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_font_face_get_user_data (cairo_scaled_font_get_font_face (scaled_font),
&_hb_font_cairo_user_data_key));
paint_data_t paint_data;
paint_data.cr = cr;
paint_data.font = font;
hb_face_t *face = hb_font_get_face (font);
paint_data.unscaled_font = hb_font_create (face);
unsigned int upem = hb_face_get_upem (face);
hb_font_set_scale (paint_data.unscaled_font, upem, upem);
hb_font_set_synthetic_slant (paint_data.unscaled_font, 0.);
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, get_cairo_paint_funcs (), (void *)&paint_data);
hb_glyph_extents_t hb_extents;
hb_font_get_glyph_extents (font, glyph, &hb_extents);
extents->x_bearing = (double) hb_extents.x_bearing / x_scale;
extents->y_bearing = (double) hb_extents.y_bearing / y_scale;
extents->width = (double) hb_extents.width / x_scale;
extents->height = (double) hb_extents.height / y_scale;
hb_font_destroy (paint_data.unscaled_font);
return CAIRO_STATUS_SUCCESS;
}
#endif
static inline cairo_font_face_t *
helper_cairo_create_user_font_face (const font_options_t *font_opts)
{
cairo_font_face_t *cairo_face = cairo_user_font_face_create ();
cairo_font_face_set_user_data (cairo_face,
&_hb_font_cairo_user_data_key,
hb_font_reference (font_opts->font),
(cairo_destroy_func_t) hb_font_destroy);
cairo_user_font_face_set_render_glyph_func (cairo_face, render_glyph);
#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC
hb_face_t *face = hb_font_get_face (font_opts->font);
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, render_color_glyph);
}
#endif
return cairo_face;
}
static inline bool
helper_cairo_user_font_face_has_data (cairo_font_face_t *font_face)
{
return cairo_font_face_get_user_data (font_face, &_hb_font_cairo_user_data_key);
}
static inline bool
helper_cairo_user_scaled_font_has_color (cairo_scaled_font_t *scaled_font)
{
/* Ignoring SVG for now, since we cannot render it. */
hb_font_t *font = (hb_font_t *) (cairo_font_face_get_user_data (cairo_scaled_font_get_font_face (scaled_font),
&_hb_font_cairo_user_data_key));
hb_face_t *face = hb_font_get_face (font);
return hb_ot_color_has_png (face) || hb_ot_color_has_layers (face) || hb_ot_color_has_paint (face);
}
#endif