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/*
* Copyright © 2011 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 VIEW_CAIRO_HH
#define VIEW_CAIRO_HH
#include "view-options.hh"
#include "output-options.hh"
#include "helper-cairo.hh"
struct view_cairo_t : view_options_t, output_options_t<>
{
~view_cairo_t ()
{
cairo_debug_reset_static_data ();
}
void add_options (option_parser_t *parser)
{
parser->set_summary ("View text with given font.");
view_options_t::add_options (parser);
output_options_t::add_options (parser, helper_cairo_supported_formats);
}
void init (hb_buffer_t *buffer, const font_options_t *font_opts)
{
lines = g_array_new (false, false, sizeof (helper_cairo_line_t));
subpixel_bits = font_opts->subpixel_bits;
}
void new_line () {}
void consume_text (hb_buffer_t *buffer,
const char *text,
unsigned int text_len,
hb_bool_t utf8_clusters) {}
void error (const char *message)
{ g_printerr ("%s: %s\n", g_get_prgname (), message); }
void consume_glyphs (hb_buffer_t *buffer,
const char *text,
unsigned int text_len,
hb_bool_t utf8_clusters)
{
direction = hb_buffer_get_direction (buffer);
helper_cairo_line_t l (text, text_len, buffer, utf8_clusters, subpixel_bits);
g_array_append_val (lines, l);
}
void finish (hb_buffer_t *buffer, const font_options_t *font_opts)
{
render (font_opts);
for (unsigned int i = 0; i < lines->len; i++) {
helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
line.finish ();
}
#if GLIB_CHECK_VERSION (2, 22, 0)
g_array_unref (lines);
#else
g_array_free (lines, TRUE);
#endif
}
protected:
void render (const font_options_t *font_opts);
hb_direction_t direction = HB_DIRECTION_INVALID; // Remove this, make segment_properties accessible
GArray *lines = nullptr;
unsigned subpixel_bits = 0;
};
inline void
view_cairo_t::render (const font_options_t *font_opts)
{
bool vertical = HB_DIRECTION_IS_VERTICAL (direction);
int vert = vertical ? 1 : 0;
int horiz = vertical ? 0 : 1;
int x_sign = font_opts->font_size_x < 0 ? -1 : +1;
int y_sign = font_opts->font_size_y < 0 ? -1 : +1;
hb_font_t *font = font_opts->font;
if (!have_font_extents)
{
hb_font_extents_t hb_extents;
hb_font_get_extents_for_direction (font, direction, &hb_extents);
font_extents.ascent = scalbn ((double) hb_extents.ascender, - (int) subpixel_bits);
font_extents.descent = -scalbn ((double) hb_extents.descender, - (int) subpixel_bits);
font_extents.line_gap = scalbn ((double) hb_extents.line_gap, - (int) subpixel_bits);
have_font_extents = true;
}
double ascent = y_sign * font_extents.ascent;
double descent = y_sign * font_extents.descent;
double line_gap = y_sign * font_extents.line_gap + line_space;
double leading = ascent + descent + line_gap;
/* Calculate surface size. */
double w = 0, h = 0;
(vertical ? w : h) = (int) lines->len * leading - (font_extents.line_gap + line_space);
(vertical ? h : w) = 0;
for (unsigned int i = 0; i < lines->len; i++) {
helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
double x_advance, y_advance;
line.get_advance (&x_advance, &y_advance);
if (vertical)
h = MAX (h, y_sign * y_advance);
else
w = MAX (w, x_sign * x_advance);
}
cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts,
this);
/* See if font needs color. */
cairo_content_t content = CAIRO_CONTENT_ALPHA;
if (helper_cairo_scaled_font_has_color (scaled_font))
content = CAIRO_CONTENT_COLOR;
/* Create surface. */
cairo_t *cr = helper_cairo_create_context (w + margin.l + margin.r,
h + margin.t + margin.b,
this,
this,
content);
cairo_set_scaled_font (cr, scaled_font);
/* Setup coordinate system. */
cairo_translate (cr, margin.l, margin.t);
if (vertical)
cairo_translate (cr,
w - ascent, /* We currently always stack lines right to left */
y_sign < 0 ? h : 0);
else
{
cairo_translate (cr,
x_sign < 0 ? w : 0,
y_sign < 0 ? descent : ascent);
}
/* Draw. */
cairo_translate (cr, +vert * leading, -horiz * leading);
for (unsigned int i = 0; i < lines->len; i++)
{
helper_cairo_line_t &l = g_array_index (lines, helper_cairo_line_t, i);
cairo_translate (cr, -vert * leading, +horiz * leading);
if (show_extents)
{
cairo_save (cr);
cairo_set_source_rgba (cr, 1., 0., 0., .5);
cairo_set_line_width (cr, 10);
cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
for (unsigned i = 0; i < l.num_glyphs; i++) {
cairo_move_to (cr, l.glyphs[i].x, l.glyphs[i].y);
cairo_rel_line_to (cr, 0, 0);
}
cairo_stroke (cr);
cairo_restore (cr);
cairo_save (cr);
cairo_set_source_rgba (cr, 1., 0., 1., .5);
cairo_set_line_width (cr, 3);
for (unsigned i = 0; i < l.num_glyphs; i++)
{
hb_glyph_extents_t hb_extents;
hb_font_get_glyph_extents (font, l.glyphs[i].index, &hb_extents);
double x1 = scalbn ((double) hb_extents.x_bearing, - (int) subpixel_bits);
double y1 = -scalbn ((double) hb_extents.y_bearing, - (int) subpixel_bits);
double width = scalbn ((double) hb_extents.width, - (int) subpixel_bits);
double height = -scalbn ((double) hb_extents.height, - (int) subpixel_bits);
cairo_rectangle (cr, l.glyphs[i].x + x1, l.glyphs[i].y + y1, width, height);
}
cairo_stroke (cr);
cairo_restore (cr);
}
// https://github.com/harfbuzz/harfbuzz/issues/4378
#if CAIRO_VERSION >= 11705
if (l.num_clusters)
cairo_show_text_glyphs (cr,
l.utf8, l.utf8_len,
l.glyphs, l.num_glyphs,
l.clusters, l.num_clusters,
l.cluster_flags);
else
#endif
cairo_show_glyphs (cr, l.glyphs, l.num_glyphs);
}
/* Clean up. */
helper_cairo_destroy_context (cr);
cairo_scaled_font_destroy (scaled_font);
}
#endif
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