view-cairo.cc revision 5db0683a822f70c914468430cda6487cee740ae3 
1/*
2 * Copyright © 2011  Google, Inc.
3 *
4 *  This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod
25 */
26
27#include "view-cairo.hh"
28
29void
30view_cairo_t::get_surface_size (cairo_scaled_font_t *scaled_font,
31				double *w, double *h)
32{
33  cairo_font_extents_t font_extents;
34
35  cairo_scaled_font_extents (scaled_font, &font_extents);
36
37  bool vertical = HB_DIRECTION_IS_VERTICAL (direction);
38  (vertical ? *w : *h) = (int) lines->len * (font_extents.height + view_options.line_space) - view_options.line_space;
39  (vertical ? *h : *w) = 0;
40  for (unsigned int i = 0; i < lines->len; i++) {
41    helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
42    double x_advance, y_advance;
43    line.get_advance (&x_advance, &y_advance);
44    if (vertical)
45      *h =  MAX (*h, y_advance);
46    else
47      *w =  MAX (*w, x_advance);
48  }
49
50  *w += view_options.margin.l + view_options.margin.r;
51  *h += view_options.margin.t + view_options.margin.b;
52}
53
54void
55view_cairo_t::render (const font_options_t *font_opts)
56{
57  cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts, view_options.font_size);
58  double w, h;
59  get_surface_size (scaled_font, &w, &h);
60  cairo_t *cr = helper_cairo_create_context (w, h, &view_options, &output_options);
61  cairo_set_scaled_font (cr, scaled_font);
62  cairo_scaled_font_destroy (scaled_font);
63
64  draw (cr);
65
66  helper_cairo_destroy_context (cr);
67}
68
69void
70view_cairo_t::draw (cairo_t *cr)
71{
72  cairo_save (cr);
73
74  bool vertical = HB_DIRECTION_IS_VERTICAL (direction);
75  int v = vertical ? 1 : 0;
76  int h = vertical ? 0 : 1;
77  cairo_font_extents_t font_extents;
78  cairo_font_extents (cr, &font_extents);
79  cairo_translate (cr, view_options.margin.l, view_options.margin.t);
80  double descent;
81  if (vertical)
82    descent = font_extents.height * (lines->len + .5);
83  else
84    descent = font_extents.height - font_extents.ascent;
85  cairo_translate (cr, v * descent, h * -descent);
86  for (unsigned int i = 0; i < lines->len; i++)
87  {
88    helper_cairo_line_t &l = g_array_index (lines, helper_cairo_line_t, i);
89
90    if (i)
91      cairo_translate (cr, v * -view_options.line_space, h * view_options.line_space);
92
93    cairo_translate (cr, v * -font_extents.height, h * font_extents.height);
94
95    if (view_options.annotate) {
96      cairo_save (cr);
97
98      /* Draw actual glyph origins */
99      cairo_set_source_rgba (cr, 1., 0., 0., .5);
100      cairo_set_line_width (cr, 5);
101      cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
102      for (unsigned i = 0; i < l.num_glyphs; i++) {
103	cairo_move_to (cr, l.glyphs[i].x, l.glyphs[i].y);
104	cairo_rel_line_to (cr, 0, 0);
105      }
106      cairo_stroke (cr);
107
108      cairo_restore (cr);
109    }
110
111    if (0 && cairo_surface_get_type (cairo_get_target (cr)) == CAIRO_SURFACE_TYPE_IMAGE) {
112      /* cairo_show_glyphs() doesn't support subpixel positioning */
113      cairo_glyph_path (cr, l.glyphs, l.num_glyphs);
114      cairo_fill (cr);
115    } else if (l.num_clusters)
116      cairo_show_text_glyphs (cr,
117			      l.utf8, l.utf8_len,
118			      l.glyphs, l.num_glyphs,
119			      l.clusters, l.num_clusters,
120			      l.cluster_flags);
121    else
122      cairo_show_glyphs (cr, l.glyphs, l.num_glyphs);
123  }
124
125  cairo_restore (cr);
126}
127