HarfBuzz text shaping engine
http://harfbuzz.github.io/
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133 lines
4.5 KiB
133 lines
4.5 KiB
/* |
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* Copyright © 2011 Google, Inc. |
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* |
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* This is part of HarfBuzz, a text shaping library. |
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* |
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* Permission is hereby granted, without written agreement and without |
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* license or royalty fees, to use, copy, modify, and distribute this |
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* software and its documentation for any purpose, provided that the |
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* above copyright notice and the following two paragraphs appear in |
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* all copies of this software. |
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* |
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR |
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES |
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN |
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH |
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* DAMAGE. |
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* |
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, |
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS |
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO |
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. |
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* |
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* Google Author(s): Behdad Esfahbod |
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*/ |
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#include "view-cairo.hh" |
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#include <assert.h> |
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void |
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view_cairo_t::render (const font_options_t *font_opts) |
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{ |
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bool vertical = HB_DIRECTION_IS_VERTICAL (direction); |
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int vert = vertical ? 1 : 0; |
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int horiz = vertical ? 0 : 1; |
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int x_sign = font_opts->font_size_x < 0 ? -1 : +1; |
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int y_sign = font_opts->font_size_y < 0 ? -1 : +1; |
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hb_font_t *font = font_opts->get_font(); |
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hb_font_extents_t extents; |
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hb_font_get_extents_for_direction (font, direction, &extents); |
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double ascent = y_sign * scalbn ((double) extents.ascender, scale_bits); |
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double descent = y_sign * -scalbn ((double) extents.descender, scale_bits); |
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double font_height = y_sign * scalbn ((double) extents.ascender - extents.descender + extents.line_gap, scale_bits); |
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double leading = font_height + view_options.line_space; |
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/* Calculate surface size. */ |
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double w = 0, h = 0; |
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(vertical ? w : h) = (int) lines->len * leading - view_options.line_space; |
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(vertical ? h : w) = 0; |
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for (unsigned int i = 0; i < lines->len; i++) { |
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helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i); |
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double x_advance, y_advance; |
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line.get_advance (&x_advance, &y_advance); |
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if (vertical) |
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h = MAX (h, y_sign * y_advance); |
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else |
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w = MAX (w, x_sign * x_advance); |
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} |
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cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts); |
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/* See if font needs color. */ |
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cairo_content_t content = CAIRO_CONTENT_ALPHA; |
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if (helper_cairo_scaled_font_has_color (scaled_font)) |
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content = CAIRO_CONTENT_COLOR; |
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/* Create surface. */ |
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cairo_t *cr = helper_cairo_create_context (w + view_options.margin.l + view_options.margin.r, |
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h + view_options.margin.t + view_options.margin.b, |
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&view_options, &output_options, content); |
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cairo_set_scaled_font (cr, scaled_font); |
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/* Setup coordinate system. */ |
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cairo_translate (cr, view_options.margin.l, view_options.margin.t); |
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if (vertical) |
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cairo_translate (cr, |
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w /* We stack lines right to left */ |
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-font_height * .5 /* "ascent" for vertical */, |
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y_sign < 0 ? h : 0); |
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else |
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{ |
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cairo_translate (cr, |
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x_sign < 0 ? w : 0, |
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y_sign < 0 ? descent : ascent); |
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} |
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/* Draw. */ |
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cairo_translate (cr, +vert * leading, -horiz * leading); |
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for (unsigned int i = 0; i < lines->len; i++) |
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{ |
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helper_cairo_line_t &l = g_array_index (lines, helper_cairo_line_t, i); |
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cairo_translate (cr, -vert * leading, +horiz * leading); |
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if (view_options.annotate) { |
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cairo_save (cr); |
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/* Draw actual glyph origins */ |
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cairo_set_source_rgba (cr, 1., 0., 0., .5); |
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cairo_set_line_width (cr, 5); |
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cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND); |
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for (unsigned i = 0; i < l.num_glyphs; i++) { |
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cairo_move_to (cr, l.glyphs[i].x, l.glyphs[i].y); |
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cairo_rel_line_to (cr, 0, 0); |
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} |
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cairo_stroke (cr); |
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cairo_restore (cr); |
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} |
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if (0 && cairo_surface_get_type (cairo_get_target (cr)) == CAIRO_SURFACE_TYPE_IMAGE) { |
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/* cairo_show_glyphs() doesn't support subpixel positioning */ |
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cairo_glyph_path (cr, l.glyphs, l.num_glyphs); |
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cairo_fill (cr); |
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} else if (l.num_clusters) |
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cairo_show_text_glyphs (cr, |
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l.utf8, l.utf8_len, |
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l.glyphs, l.num_glyphs, |
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l.clusters, l.num_clusters, |
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l.cluster_flags); |
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else |
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cairo_show_glyphs (cr, l.glyphs, l.num_glyphs); |
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} |
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/* Clean up. */ |
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helper_cairo_destroy_context (cr); |
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cairo_scaled_font_destroy (scaled_font); |
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}
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