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 29 #include <assert.h> 30 31 32 void 33 view_cairo_t::render (const font_options_t *font_opts) 34 { 35 bool vertical = HB_DIRECTION_IS_VERTICAL (direction); 36 int vert = vertical ? 1 : 0; 37 int horiz = vertical ? 0 : 1; 38 39 int x_sign = font_opts->font_size_x < 0 ? -1 : +1; 40 int y_sign = font_opts->font_size_y < 0 ? -1 : +1; 41 42 hb_font_t *font = font_opts->get_font(); 43 hb_font_extents_t extents; 44 hb_font_get_extents_for_direction (font, direction, &extents); 45 46 double ascent = y_sign * scalbn ((double) extents.ascender, scale_bits); 47 double descent = y_sign * -scalbn ((double) extents.descender, scale_bits); 48 double font_height = y_sign * scalbn ((double) extents.ascender - extents.descender + extents.line_gap, scale_bits); 49 double leading = font_height + view_options.line_space; 50 51 /* Calculate surface size. */ 52 double w, h; 53 (vertical ? w : h) = (int) lines->len * leading - view_options.line_space; 54 (vertical ? h : w) = 0; 55 for (unsigned int i = 0; i < lines->len; i++) { 56 helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i); 57 double x_advance, y_advance; 58 line.get_advance (&x_advance, &y_advance); 59 if (vertical) 60 h = MAX (h, y_sign * y_advance); 61 else 62 w = MAX (w, x_sign * x_advance); 63 } 64 65 cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts); 66 67 /* See if font needs color. */ 68 cairo_content_t content = CAIRO_CONTENT_ALPHA; 69 if (helper_cairo_scaled_font_has_color (scaled_font)) 70 content = CAIRO_CONTENT_COLOR; 71 72 /* Create surface. */ 73 cairo_t *cr = helper_cairo_create_context (w + view_options.margin.l + view_options.margin.r, 74 h + view_options.margin.t + view_options.margin.b, 75 &view_options, &output_options, content); 76 cairo_set_scaled_font (cr, scaled_font); 77 78 /* Setup coordinate system. */ 79 cairo_translate (cr, view_options.margin.l, view_options.margin.t); 80 if (vertical) 81 cairo_translate (cr, 82 w /* We stack lines right to left */ 83 -font_height * .5 /* "ascent" for vertical */, 84 y_sign < 0 ? h : 0); 85 else 86 { 87 cairo_translate (cr, 88 x_sign < 0 ? w : 0, 89 y_sign < 0 ? descent : ascent); 90 } 91 92 /* Draw. */ 93 cairo_translate (cr, +vert * leading, -horiz * leading); 94 for (unsigned int i = 0; i < lines->len; i++) 95 { 96 helper_cairo_line_t &l = g_array_index (lines, helper_cairo_line_t, i); 97 98 cairo_translate (cr, -vert * leading, +horiz * leading); 99 100 if (view_options.annotate) { 101 cairo_save (cr); 102 103 /* Draw actual glyph origins */ 104 cairo_set_source_rgba (cr, 1., 0., 0., .5); 105 cairo_set_line_width (cr, 5); 106 cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND); 107 for (unsigned i = 0; i < l.num_glyphs; i++) { 108 cairo_move_to (cr, l.glyphs[i].x, l.glyphs[i].y); 109 cairo_rel_line_to (cr, 0, 0); 110 } 111 cairo_stroke (cr); 112 113 cairo_restore (cr); 114 } 115 116 if (0 && cairo_surface_get_type (cairo_get_target (cr)) == CAIRO_SURFACE_TYPE_IMAGE) { 117 /* cairo_show_glyphs() doesn't support subpixel positioning */ 118 cairo_glyph_path (cr, l.glyphs, l.num_glyphs); 119 cairo_fill (cr); 120 } else if (l.num_clusters) 121 cairo_show_text_glyphs (cr, 122 l.utf8, l.utf8_len, 123 l.glyphs, l.num_glyphs, 124 l.clusters, l.num_clusters, 125 l.cluster_flags); 126 else 127 cairo_show_glyphs (cr, l.glyphs, l.num_glyphs); 128 } 129 130 /* Clean up. */ 131 helper_cairo_destroy_context (cr); 132 cairo_scaled_font_destroy (scaled_font); 133 } 134
