src/libnrtype/Layout-TNG-Output.cpp

   1 /*
   2  * Inkscape::Text::Layout - text layout engine output functions
   3  *
   4  * Authors:
   5  *   Richard Hughes <cyreve@users.sf.net>
   6  *
   7  * Copyright (C) 2005 Richard Hughes
   8  *
   9  * Released under GNU GPL, read the file 'COPYING' for more information
  10  */
  11 #include <glib/gmem.h>
  12 #include "Layout-TNG.h"
  13 #include "display/nr-arena-glyphs.h"
  14 #include "style.h"
  15 #include "print.h"
  16 #include "extension/print.h"
  17 #include "livarot/Path.h"
  18 #include "libnr/nr-matrix-fns.h"
  19 #include "libnr/nr-scale-matrix-ops.h"
  20 #include "font-instance.h"
  21 #include "svg/svg-length.h"
  22 #include "extension/internal/cairo-render-context.h"
  23 #include "display/curve.h"
  24
  25 namespace Inkscape {
  26     namespace Extension {
  27         namespace Internal {
  28             class CairoRenderContext;
  29             class CairoGlyphInfo;
  30         }
  31     }
  32 }
  33
  34 using Inkscape::Extension::Internal::CairoRenderContext;
  35 using Inkscape::Extension::Internal::CairoGlyphInfo;
  36
  37 namespace Inkscape {
  38 namespace Text {
  39
  40 void Layout::_clearOutputObjects()
  41 {
  42     _paragraphs.clear();
  43     _lines.clear();
  44     _chunks.clear();
  45     for (std::vector<Span>::iterator it_span = _spans.begin() ; it_span != _spans.end() ; it_span++)
  46         if (it_span->font) it_span->font->Unref();
  47     _spans.clear();
  48     _characters.clear();
  49     _glyphs.clear();
  50     _path_fitted = NULL;
  51 }
  52
  53 void Layout::LineHeight::max(LineHeight const &other)
  54 {
  55     if (other.ascent > ascent)  ascent  = other.ascent;
  56     if (other.descent > descent) descent = other.descent;
  57     if (other.leading > leading) leading = other.leading;
  58 }
  59
  60 void Layout::_getGlyphTransformMatrix(int glyph_index, NR::Matrix *matrix) const
  61 {
  62     Span const &span = _glyphs[glyph_index].span(this);
  63     double sin_rotation = sin(_glyphs[glyph_index].rotation);
  64     double cos_rotation = cos(_glyphs[glyph_index].rotation);
  65     (*matrix)[0] = span.font_size * cos_rotation;
  66     (*matrix)[1] = span.font_size * sin_rotation;
  67     (*matrix)[2] = span.font_size * sin_rotation;
  68     (*matrix)[3] = -span.font_size * cos_rotation;
  69     if (span.block_progression == LEFT_TO_RIGHT || span.block_progression == RIGHT_TO_LEFT) {
  70         (*matrix)[4] = _lines[_chunks[span.in_chunk].in_line].baseline_y + _glyphs[glyph_index].y;
  71         (*matrix)[5] = _chunks[span.in_chunk].left_x + _glyphs[glyph_index].x;
  72     } else {
  73         (*matrix)[4] = _chunks[span.in_chunk].left_x + _glyphs[glyph_index].x;
  74         (*matrix)[5] = _lines[_chunks[span.in_chunk].in_line].baseline_y + _glyphs[glyph_index].y;
  75     }
  76 }
  77
  78 void Layout::show(NRArenaGroup *in_arena, NRRect const *paintbox) const
  79 {
  80     int glyph_index = 0;
  81     for (unsigned span_index = 0 ; span_index < _spans.size() ; span_index++) {
  82         if (_input_stream[_spans[span_index].in_input_stream_item]->Type() != TEXT_SOURCE) continue;
  83         InputStreamTextSource const *text_source = static_cast<InputStreamTextSource const *>(_input_stream[_spans[span_index].in_input_stream_item]);
  84         NRArenaGlyphsGroup *nr_group = NRArenaGlyphsGroup::create(in_arena->arena);
  85         nr_arena_item_add_child(in_arena, nr_group, NULL);
  86         nr_arena_item_unref(nr_group);
  87
  88         nr_arena_glyphs_group_set_style(nr_group, text_source->style);
  89         while (glyph_index < (int)_glyphs.size() && _characters[_glyphs[glyph_index].in_character].in_span == span_index) {
  90             if (_characters[_glyphs[glyph_index].in_character].in_glyph != -1) {
  91                 NR::Matrix glyph_matrix;
  92                 _getGlyphTransformMatrix(glyph_index, &glyph_matrix);
  93                 nr_arena_glyphs_group_add_component(nr_group, _spans[span_index].font, _glyphs[glyph_index].glyph, &glyph_matrix);
  94             }
  95             glyph_index++;
  96         }
  97         nr_arena_glyphs_group_set_paintbox(NR_ARENA_GLYPHS_GROUP(nr_group), paintbox);
  98     }
  99     nr_arena_item_request_update(NR_ARENA_ITEM(in_arena), NR_ARENA_ITEM_STATE_ALL, FALSE);
 100 }
 101
 102 void Layout::getBoundingBox(NRRect *bounding_box, NR::Matrix const &transform, int start, int length) const
 103 {
 104     for (unsigned glyph_index = 0 ; glyph_index < _glyphs.size() ; glyph_index++) {
 105         if (_characters[_glyphs[glyph_index].in_character].in_glyph == -1) continue;
 106         if (start != -1 && (int) _glyphs[glyph_index].in_character < start) continue;
 107         if (length != -1) {
 108             if (start == -1)
 109                 start = 0;
 110             if ((int) _glyphs[glyph_index].in_character > start + length) continue;
 111         }
 112         // this could be faster
 113         NR::Matrix glyph_matrix;
 114         _getGlyphTransformMatrix(glyph_index, &glyph_matrix);
 115         NR::Matrix total_transform = glyph_matrix;
 116         total_transform *= transform;
 117         NR::Maybe<NR::Rect> glyph_rect = _glyphs[glyph_index].span(this).font->BBox(_glyphs[glyph_index].glyph);
 118         if (glyph_rect) {
 119             NR::Point bmi = glyph_rect->min(), bma = glyph_rect->max();
 120             NR::Point tlp(bmi[0],bmi[1]), trp(bma[0],bmi[1]), blp(bmi[0],bma[1]), brp(bma[0],bma[1]);
 121             tlp *= total_transform;
 122             trp *= total_transform;
 123             blp *= total_transform;
 124             brp *= total_transform;
 125             *glyph_rect = NR::Rect(tlp,trp);
 126             glyph_rect->expandTo(blp);
 127             glyph_rect->expandTo(brp);
 128             if ( (glyph_rect->min())[0] < bounding_box->x0 ) bounding_box->x0=(glyph_rect->min())[0];
 129             if ( (glyph_rect->max())[0] > bounding_box->x1 ) bounding_box->x1=(glyph_rect->max())[0];
 130             if ( (glyph_rect->min())[1] < bounding_box->y0 ) bounding_box->y0=(glyph_rect->min())[1];
 131             if ( (glyph_rect->max())[1] > bounding_box->y1 ) bounding_box->y1=(glyph_rect->max())[1];
 132         }
 133     }
 134 }
 135
 136 void Layout::print(SPPrintContext *ctx,
 137                    NRRect const *pbox, NRRect const *dbox, NRRect const *bbox,
 138                    NR::Matrix const &ctm) const
 139 {
 140     if (_input_stream.empty()) return;
 141
 142     Direction block_progression = _blockProgression();
 143     bool text_to_path = ctx->module->textToPath();
 144     for (unsigned glyph_index = 0 ; glyph_index < _glyphs.size() ; ) {
 145         if (_characters[_glyphs[glyph_index].in_character].in_glyph == -1) {
 146             // invisible glyphs
 147             unsigned same_character = _glyphs[glyph_index].in_character;
 148             while (_glyphs[glyph_index].in_character == same_character)
 149                 glyph_index++;
 150             continue;
 151         }
 152         NR::Matrix glyph_matrix;
 153         Span const &span = _spans[_characters[_glyphs[glyph_index].in_character].in_span];
 154         InputStreamTextSource const *text_source = static_cast<InputStreamTextSource const *>(_input_stream[span.in_input_stream_item]);
 155         if (text_to_path || _path_fitted) {
 156             NRBPath bpath;
 157             bpath.path = (NArtBpath*)span.font->ArtBPath(_glyphs[glyph_index].glyph);
 158             if (bpath.path) {
 159                 NRBPath abp;
 160                 _getGlyphTransformMatrix(glyph_index, &glyph_matrix);
 161                 abp.path = nr_artpath_affine(bpath.path, glyph_matrix);
 162                 if (!text_source->style->fill.isNone())
 163                     sp_print_fill(ctx, &abp, &ctm, text_source->style, pbox, dbox, bbox);
 164                 if (!text_source->style->stroke.isNone())
 165                     sp_print_stroke(ctx, &abp, &ctm, text_source->style, pbox, dbox, bbox);
 166                 g_free(abp.path);
 167             }
 168             glyph_index++;
 169         } else {
 170             NR::Point g_pos(0,0);    // all strings are output at (0,0) because we do the translation using the matrix
 171             glyph_matrix = NR::Matrix(NR::scale(1.0, -1.0) * NR::Matrix(NR::rotate(_glyphs[glyph_index].rotation)));
 172             if (block_progression == LEFT_TO_RIGHT || block_progression == RIGHT_TO_LEFT) {
 173                 glyph_matrix[4] = span.line(this).baseline_y + span.baseline_shift;
 174                 // since we're outputting character codes, not glyphs, we want the character x
 175                 glyph_matrix[5] = span.chunk(this).left_x + span.x_start + _characters[_glyphs[glyph_index].in_character].x;
 176             } else {
 177                 glyph_matrix[4] = span.chunk(this).left_x + span.x_start + _characters[_glyphs[glyph_index].in_character].x;
 178                 glyph_matrix[5] = span.line(this).baseline_y + span.baseline_shift;
 179             }
 180             Glib::ustring::const_iterator span_iter = span.input_stream_first_character;
 181             unsigned char_index = _glyphs[glyph_index].in_character;
 182             unsigned original_span = _characters[char_index].in_span;
 183             while (char_index && _characters[char_index - 1].in_span == original_span) {
 184                 char_index--;
 185                 span_iter++;
 186             }
 187
 188             // try to output as many characters as possible in one go by detecting kerning and stopping when we encounter it
 189             Glib::ustring span_string;
 190             double char_x = _characters[_glyphs[glyph_index].in_character].x;
 191             unsigned this_span_index = _characters[_glyphs[glyph_index].in_character].in_span;
 192             do {
 193                 span_string += *span_iter;
 194                 span_iter++;
 195
 196                 unsigned same_character = _glyphs[glyph_index].in_character;
 197                 while (glyph_index < _glyphs.size() && _glyphs[glyph_index].in_character == same_character) {
 198                     char_x += _glyphs[glyph_index].width;
 199                     glyph_index++;
 200                 }
 201             } while (glyph_index < _glyphs.size()
 202                      && _path_fitted == NULL
 203                      && _characters[_glyphs[glyph_index].in_character].in_span == this_span_index
 204                      && fabs(char_x - _characters[_glyphs[glyph_index].in_character].x) < 1e-5);
 205             sp_print_bind(ctx, glyph_matrix, 1.0);
 206             sp_print_text(ctx, span_string.c_str(), g_pos, text_source->style);
 207             sp_print_release(ctx);
 208         }
 209     }
 210 }
 211
 212 #ifdef HAVE_CAIRO_PDF
 213 void Layout::showGlyphs(CairoRenderContext *ctx) const
 214 {
 215     if (_input_stream.empty()) return;
 216
 217     bool clip_mode = false;//(ctx->getRenderMode() == CairoRenderContext::RENDER_MODE_CLIP);
 218     std::vector<CairoGlyphInfo> glyphtext;
 219
 220     for (unsigned glyph_index = 0 ; glyph_index < _glyphs.size() ; ) {
 221         if (_characters[_glyphs[glyph_index].in_character].in_glyph == -1) {
 222             // invisible glyphs
 223             unsigned same_character = _glyphs[glyph_index].in_character;
 224             while (_glyphs[glyph_index].in_character == same_character)
 225                 glyph_index++;
 226             continue;
 227         }
 228         Span const &span = _spans[_characters[_glyphs[glyph_index].in_character].in_span];
 229         InputStreamTextSource const *text_source = static_cast<InputStreamTextSource const *>(_input_stream[span.in_input_stream_item]);
 230
 231         NR::Matrix glyph_matrix;
 232         _getGlyphTransformMatrix(glyph_index, &glyph_matrix);
 233         if (clip_mode) {
 234             NArtBpath *bpath = (NArtBpath*)span.font->ArtBPath(_glyphs[glyph_index].glyph);
 235             if (bpath) {
 236                 NArtBpath *abp = nr_artpath_affine(bpath, glyph_matrix);
 237                 NRBPath bpath;
 238                 bpath.path = abp;
 239                 SPStyle const *style = text_source->style;
 240                 ctx->renderPath(&bpath, style, NULL);
 241                 g_free(abp);
 242             }
 243             glyph_index++;
 244             continue;
 245         }
 246
 247         NR::Matrix font_matrix;
 248         if (_path_fitted == NULL) {
 249             font_matrix = glyph_matrix;
 250             font_matrix[4] = 0;
 251             font_matrix[5] = 0;
 252         } else {
 253             font_matrix.set_identity();
 254         }
 255
 256         Glib::ustring::const_iterator span_iter = span.input_stream_first_character;
 257         unsigned char_index = _glyphs[glyph_index].in_character;
 258         unsigned original_span = _characters[char_index].in_span;
 259         while (char_index && _characters[char_index - 1].in_span == original_span) {
 260             char_index--;
 261             span_iter++;
 262         }
 263
 264         // try to output as many characters as possible in one go
 265         Glib::ustring span_string;
 266         unsigned this_span_index = _characters[_glyphs[glyph_index].in_character].in_span;
 267         unsigned int first_index = glyph_index;
 268         glyphtext.clear();
 269         do {
 270             span_string += *span_iter;
 271             span_iter++;
 272
 273             unsigned same_character = _glyphs[glyph_index].in_character;
 274             while (glyph_index < _glyphs.size() && _glyphs[glyph_index].in_character == same_character) {
 275                 if (glyph_index != first_index)
 276                     _getGlyphTransformMatrix(glyph_index, &glyph_matrix);
 277
 278                 CairoGlyphInfo info;
 279                 info.index = _glyphs[glyph_index].glyph;
 280                 if (_path_fitted == NULL) {
 281                     info.x = glyph_matrix[4];
 282                     info.y = glyph_matrix[5];
 283                 } else {
 284                     info.x = 0;
 285                     info.y = 0;
 286                 }
 287                 glyphtext.push_back(info);
 288
 289                 glyph_index++;
 290             }
 291         } while (glyph_index < _glyphs.size()
 292                  && _path_fitted == NULL
 293                  && NR::transform_equalp(font_matrix, glyph_matrix, NR_EPSILON)
 294                  && _characters[_glyphs[glyph_index].in_character].in_span == this_span_index);
 295
 296         // remove vertical flip
 297         font_matrix[3] *= -1.0;
 298
 299         SPStyle const *style = text_source->style;
 300         float opacity = SP_SCALE24_TO_FLOAT(style->opacity.value);
 301
 302         if (_path_fitted) {
 303             ctx->pushState();
 304             ctx->transform(&glyph_matrix);
 305         } else if (opacity != 1.0) {
 306             ctx->pushState();
 307             ctx->setStateForStyle(style);
 308             ctx->pushLayer();
 309         }
 310         if (glyph_index - first_index > 0)
 311             ctx->renderGlyphtext(span.font->pFont, &font_matrix, glyphtext, style);
 312         if (_path_fitted)
 313             ctx->popState();
 314         else if (opacity != 1.0) {
 315             ctx->popLayer();
 316             ctx->popState();
 317         }
 318     }
 319 }
 320 #endif
 321
 322 // these functions are for dumpAsText() only. No need to translate
 323 static char const *direction_to_text(Layout::Direction d)
 324 {
 325     switch (d) {
 326         case Layout::LEFT_TO_RIGHT: return "ltr";
 327         case Layout::RIGHT_TO_LEFT: return "rtl";
 328         case Layout::TOP_TO_BOTTOM: return "ttb";
 329         case Layout::BOTTOM_TO_TOP: return "btt";
 330     }
 331     return "???";
 332 }
 333
 334 static char const *style_to_text(PangoStyle s)
 335 {
 336     switch (s) {
 337         case PANGO_STYLE_NORMAL: return "upright";
 338         case PANGO_STYLE_ITALIC: return "italic";
 339         case PANGO_STYLE_OBLIQUE: return "oblique";
 340     }
 341     return "???";
 342 }
 343
 344 static char const *weight_to_text(PangoWeight w)
 345 {
 346     switch (w) {
 347         case PANGO_WEIGHT_ULTRALIGHT: return "ultralight";
 348         case PANGO_WEIGHT_LIGHT     : return "light";
 349         case PANGO_WEIGHT_SEMIBOLD  : return "semibold";
 350         case PANGO_WEIGHT_NORMAL    : return "normalweight";
 351         case PANGO_WEIGHT_BOLD      : return "bold";
 352         case PANGO_WEIGHT_ULTRABOLD : return "ultrabold";
 353         case PANGO_WEIGHT_HEAVY     : return "heavy";
 354     }
 355     return "???";
 356 }
 357
 358 Glib::ustring Layout::dumpAsText() const
 359 {
 360     Glib::ustring result;
 361
 362     for (unsigned span_index = 0 ; span_index < _spans.size() ; span_index++) {
 363         char line[256];
 364         snprintf(line, sizeof(line), "==== span %d\n", span_index);
 365         result += line;
 366         snprintf(line, sizeof(line), "  in para %d (direction=%s)\n", _lines[_chunks[_spans[span_index].in_chunk].in_line].in_paragraph,
 367                  direction_to_text(_paragraphs[_lines[_chunks[_spans[span_index].in_chunk].in_line].in_paragraph].base_direction));
 368         result += line;
 369         snprintf(line, sizeof(line), "  in source %d (type=%d, cookie=%p)\n", _spans[span_index].in_input_stream_item,
 370                  _input_stream[_spans[span_index].in_input_stream_item]->Type(),
 371                  _input_stream[_spans[span_index].in_input_stream_item]->source_cookie);
 372         result += line;
 373         snprintf(line, sizeof(line), "  in line %d (baseline=%f, shape=%d)\n", _chunks[_spans[span_index].in_chunk].in_line,
 374                  _lines[_chunks[_spans[span_index].in_chunk].in_line].baseline_y,
 375                  _lines[_chunks[_spans[span_index].in_chunk].in_line].in_shape);
 376         result += line;
 377         snprintf(line, sizeof(line), "  in chunk %d (x=%f, baselineshift=%f)\n", _spans[span_index].in_chunk, _chunks[_spans[span_index].in_chunk].left_x, _spans[span_index].baseline_shift);
 378         result += line;
 379         if (_spans[span_index].font) {
 380             snprintf(line, sizeof(line), "    font '%s' %f %s %s\n", pango_font_description_get_family(_spans[span_index].font->descr), _spans[span_index].font_size, style_to_text(pango_font_description_get_style(_spans[span_index].font->descr)), weight_to_text(pango_font_description_get_weight(_spans[span_index].font->descr)));
 381             result += line;
 382         }
 383         snprintf(line, sizeof(line), "    x_start = %f, x_end = %f\n", _spans[span_index].x_start, _spans[span_index].x_end);
 384         result += line;
 385         snprintf(line, sizeof(line), "    line height: ascent %f, descent %f leading %f\n", _spans[span_index].line_height.ascent, _spans[span_index].line_height.descent, _spans[span_index].line_height.leading);
 386         result += line;
 387         snprintf(line, sizeof(line), "    direction %s, block-progression %s\n", direction_to_text(_spans[span_index].direction), direction_to_text(_spans[span_index].block_progression));
 388         result += line;
 389         result += "    ** characters:\n";
 390         Glib::ustring::const_iterator iter_char = _spans[span_index].input_stream_first_character;
 391         // very inefficent code. what the hell, it's only debug stuff.
 392         for (unsigned char_index = 0 ; char_index < _characters.size() ; char_index++) {
 393             if (_characters[char_index].in_span != span_index) continue;
 394             if (_input_stream[_spans[span_index].in_input_stream_item]->Type() != TEXT_SOURCE) {
 395                 snprintf(line, sizeof(line), "      %d: control x=%f flags=%03x glyph=%d\n", char_index, _characters[char_index].x, *(unsigned*)&_characters[char_index].char_attributes, _characters[char_index].in_glyph);
 396             } else {
 397                 snprintf(line, sizeof(line), "      %d: '%c' x=%f flags=%03x glyph=%d\n", char_index, *iter_char, _characters[char_index].x, *(unsigned*)&_characters[char_index].char_attributes, _characters[char_index].in_glyph);
 398                 iter_char++;
 399             }
 400             result += line;
 401         }
 402         result += "    ** glyphs:\n";
 403         for (unsigned glyph_index = 0 ; glyph_index < _glyphs.size() ; glyph_index++) {
 404             if (_characters[_glyphs[glyph_index].in_character].in_span != span_index) continue;
 405             snprintf(line, sizeof(line), "      %d: %d (%f,%f) rot=%f cx=%f char=%d\n", glyph_index, _glyphs[glyph_index].glyph, _glyphs[glyph_index].x, _glyphs[glyph_index].y, _glyphs[glyph_index].rotation, _glyphs[glyph_index].width, _glyphs[glyph_index].in_character);
 406             result += line;
 407         }
 408         result += "\n";
 409     }
 410     result += "EOT\n";
 411     return result;
 412 }
 413
 414 void Layout::fitToPathAlign(SVGLength const &startOffset, Path const &path)
 415 {
 416     double offset = 0.0;
 417
 418     if (startOffset._set) {
 419         if (startOffset.unit == SVGLength::PERCENT)
 420             offset = startOffset.computed * const_cast<Path&>(path).Length();
 421         else
 422             offset = startOffset.computed;
 423     }
 424
 425     switch (_paragraphs.front().alignment) {
 426         case CENTER:
 427             offset -= _getChunkWidth(0) * 0.5;
 428             break;
 429         case RIGHT:
 430             offset -= _getChunkWidth(0);
 431             break;
 432         default:
 433             break;
 434     }
 435
 436     if (_characters.empty()) {
 437         int unused = 0;
 438         Path::cut_position *point_otp = const_cast<Path&>(path).CurvilignToPosition(1, &offset, unused);
 439         if (offset >= 0.0 && point_otp != NULL && point_otp[0].piece >= 0) {
 440             NR::Point point;
 441             NR::Point tangent;
 442             const_cast<Path&>(path).PointAndTangentAt(point_otp[0].piece, point_otp[0].t, point, tangent);
 443             _empty_cursor_shape.position = point;
 444             _empty_cursor_shape.rotation = atan2(tangent[NR::Y], tangent[NR::X]);
 445         }
 446     }
 447
 448     for (unsigned char_index = 0 ; char_index < _characters.size() ; ) {
 449         int next_cluster_glyph_index;
 450         unsigned next_cluster_char_index;
 451         double character_advance;
 452         Span const &span = _characters[char_index].span(this);
 453
 454         for (next_cluster_char_index = char_index + 1 ;
 455              next_cluster_char_index < _characters.size() && !_characters[next_cluster_char_index].char_attributes.is_cursor_position;
 456              next_cluster_char_index++);
 457
 458         if (next_cluster_char_index == _characters.size()) {
 459             next_cluster_glyph_index = _glyphs.size();
 460             character_advance = 0.0;   // arbitrary because we're not going to advance
 461         } else {
 462             next_cluster_glyph_index = _characters[next_cluster_char_index].in_glyph;
 463             character_advance =   (_glyphs[next_cluster_glyph_index].x + _glyphs[next_cluster_glyph_index].chunk(this).left_x)
 464                 - (_glyphs[_characters[char_index].in_glyph].x + span.chunk(this).left_x);
 465         }
 466
 467         double start_offset = offset + span.x_start + _characters[char_index].x;
 468         double cluster_width = 0.0;
 469         for (int glyph_index = _characters[char_index].in_glyph ; glyph_index < next_cluster_glyph_index ; glyph_index++)
 470             cluster_width += _glyphs[glyph_index].width;
 471         if (span.direction == RIGHT_TO_LEFT)
 472             start_offset -= cluster_width;
 473         double end_offset = start_offset + cluster_width;
 474
 475         int unused = 0;
 476         double midpoint_offset = (start_offset + end_offset) * 0.5;
 477         // as far as I know these functions are const, they're just not marked as such
 478         Path::cut_position *midpoint_otp = const_cast<Path&>(path).CurvilignToPosition(1, &midpoint_offset, unused);
 479         if (midpoint_offset >= 0.0 && midpoint_otp != NULL && midpoint_otp[0].piece >= 0) {
 480             NR::Point midpoint;
 481             NR::Point tangent;
 482
 483             const_cast<Path&>(path).PointAndTangentAt(midpoint_otp[0].piece, midpoint_otp[0].t, midpoint, tangent);
 484
 485             if (start_offset >= 0.0 && end_offset >= 0.0) {
 486                 Path::cut_position *start_otp = const_cast<Path&>(path).CurvilignToPosition(1, &start_offset, unused);
 487                 if (start_otp != NULL && start_otp[0].piece >= 0) {
 488                     Path::cut_position *end_otp = const_cast<Path&>(path).CurvilignToPosition(1, &end_offset, unused);
 489                     if (end_otp != NULL && end_otp[0].piece >= 0) {
 490                         bool on_same_subpath = true;
 491                         for (size_t i = 0 ; i < path.pts.size() ; i++) {
 492                             if (path.pts[i].piece <= start_otp[0].piece) continue;
 493                             if (path.pts[i].piece >= end_otp[0].piece) break;
 494                             if (path.pts[i].isMoveTo == polyline_moveto) {
 495                                 on_same_subpath = false;
 496                                 break;
 497                             }
 498                         }
 499                         if (on_same_subpath) {
 500                             // both points were on the same subpath (without this test the angle is very weird)
 501                             NR::Point startpoint, endpoint;
 502                             const_cast<Path&>(path).PointAt(start_otp[0].piece, start_otp[0].t, startpoint);
 503                             const_cast<Path&>(path).PointAt(end_otp[0].piece, end_otp[0].t, endpoint);
 504                             if (endpoint != startpoint) {
 505                                 tangent = endpoint - startpoint;
 506                                 tangent.normalize();
 507                             } else {
 508                                 tangent = NR::Point (0,0);
 509                             }
 510                         }
 511                         g_free(end_otp);
 512                     }
 513                     g_free(start_otp);
 514                 }
 515             }
 516
 517             double rotation = atan2(tangent[1], tangent[0]);
 518             for (int glyph_index = _characters[char_index].in_glyph ; glyph_index < next_cluster_glyph_index ; glyph_index++) {
 519                 double tangent_shift = -cluster_width * 0.5 + _glyphs[glyph_index].x - (_characters[char_index].x + span.x_start);
 520                 double normal_shift = _glyphs[glyph_index].y;
 521                 if (span.direction == RIGHT_TO_LEFT)
 522                     tangent_shift += cluster_width;
 523                 _glyphs[glyph_index].x = midpoint[0] - span.chunk(this).left_x + tangent[0] * tangent_shift - tangent[1] * normal_shift;
 524                 _glyphs[glyph_index].y = midpoint[1] - _lines.front().baseline_y + tangent[1] * tangent_shift + tangent[0] * normal_shift;
 525                 _glyphs[glyph_index].rotation += rotation;
 526             }
 527         } else {  // outside the bounds of the path: hide the glyphs
 528             _characters[char_index].in_glyph = -1;
 529         }
 530         g_free(midpoint_otp);
 531
 532         char_index = next_cluster_char_index;
 533     }
 534
 535     for (unsigned span_index = 0 ; span_index < _spans.size() ; span_index++) {
 536         _spans[span_index].x_start += offset;
 537         _spans[span_index].x_end += offset;
 538     }
 539
 540     _path_fitted = &path;
 541 }
 542
 543 SPCurve *Layout::convertToCurves(iterator const &from_glyph, iterator const &to_glyph) const
 544 {
 545     GSList *cc = NULL;
 546
 547     for (int glyph_index = from_glyph._glyph_index ; glyph_index < to_glyph._glyph_index ; glyph_index++) {
 548         NR::Matrix glyph_matrix;
 549         Span const &span = _glyphs[glyph_index].span(this);
 550         _getGlyphTransformMatrix(glyph_index, &glyph_matrix);
 551
 552         NRBPath bpath;
 553         bpath.path = (NArtBpath*)span.font->ArtBPath(_glyphs[glyph_index].glyph);
 554         if (bpath.path) {
 555             NArtBpath *abp = nr_artpath_affine(bpath.path, glyph_matrix);
 556             SPCurve *c = SPCurve::new_from_bpath(abp);
 557             if (c) cc = g_slist_prepend(cc, c);
 558         }
 559     }
 560     cc = g_slist_reverse(cc);
 561
 562     SPCurve *curve;
 563     if ( cc ) {
 564         curve = SPCurve::concat(cc);
 565     } else {
 566         curve = new SPCurve();
 567     }
 568
 569     while (cc) {
 570         /* fixme: This is dangerous, as we are mixing art_alloc and g_new */
 571         reinterpret_cast<SPCurve *>(cc->data)->unref();
 572         cc = g_slist_remove(cc, cc->data);
 573     }
 574
 575     return curve;
 576 }
 577
 578 void Layout::transform(NR::Matrix const &transform)
 579 {
 580     // this is all massively oversimplified
 581     // I can't actually think of anybody who'll want to use it at the moment, so it'll stay simple
 582     for (unsigned glyph_index = 0 ; glyph_index < _glyphs.size() ; glyph_index++) {
 583         NR::Point point(_glyphs[glyph_index].x, _glyphs[glyph_index].y);
 584         point *= transform;
 585         _glyphs[glyph_index].x = point[0];
 586         _glyphs[glyph_index].y = point[1];
 587     }
 588 }
 589
 590 }//namespace Text
 591 }//namespace Inkscape
 592
 593
 594 /*
 595   Local Variables:
 596   mode:c++
 597   c-file-style:"stroustrup"
 598   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 599   indent-tabs-mode:nil
 600   fill-column:99
 601   End:
 602 */
 603 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :