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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
*/
#include "view-cairo.hh"
#include <assert.h>
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->get_font();
hb_font_extents_t extents;
hb_font_get_extents_for_direction (font, direction, &extents);
double ascent = y_sign * scalbn ((double) extents.ascender, scale_bits);
double descent = y_sign * -scalbn ((double) extents.descender, scale_bits);
double font_height = y_sign * scalbn ((double) extents.ascender - extents.descender + extents.line_gap, scale_bits);
double leading = font_height + view_options.line_space;
/* Calculate surface size. */
double w = 0, h = 0;
(vertical ? w : h) = (int) lines->len * leading - view_options.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);
/* 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 + view_options.margin.l + view_options.margin.r,
h + view_options.margin.t + view_options.margin.b,
&view_options, &output_options, content);
cairo_set_scaled_font (cr, scaled_font);
/* Setup coordinate system. */
cairo_translate (cr, view_options.margin.l, view_options.margin.t);
if (vertical)
cairo_translate (cr,
w /* We stack lines right to left */
-font_height * .5 /* "ascent" for vertical */,
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 (view_options.annotate) {
cairo_save (cr);
/* Draw actual glyph origins */
cairo_set_source_rgba (cr, 1., 0., 0., .5);
cairo_set_line_width (cr, 5);
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);
}
if (0 && cairo_surface_get_type (cairo_get_target (cr)) == CAIRO_SURFACE_TYPE_IMAGE) {
/* cairo_show_glyphs() doesn't support subpixel positioning */
cairo_glyph_path (cr, l.glyphs, l.num_glyphs);
cairo_fill (cr);
} else 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
cairo_show_glyphs (cr, l.glyphs, l.num_glyphs);
}
/* Clean up. */
helper_cairo_destroy_context (cr);
cairo_scaled_font_destroy (scaled_font);
}
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