1/*
2 * Copyright (C) Research In Motion Limited 2010-2012. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB.  If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 */
19
20#include "config.h"
21
22#if ENABLE(SVG)
23#include "SVGTextLayoutEngine.h"
24
25#include "RenderSVGInlineText.h"
26#include "RenderSVGTextPath.h"
27#include "SVGElement.h"
28#include "SVGInlineTextBox.h"
29#include "SVGLengthContext.h"
30#include "SVGTextLayoutEngineBaseline.h"
31#include "SVGTextLayoutEngineSpacing.h"
32
33// Set to a value > 0 to dump the text fragments
34#define DUMP_TEXT_FRAGMENTS 0
35
36namespace WebCore {
37
38SVGTextLayoutEngine::SVGTextLayoutEngine(Vector<SVGTextLayoutAttributes*>& layoutAttributes)
39    : m_layoutAttributes(layoutAttributes)
40    , m_layoutAttributesPosition(0)
41    , m_logicalCharacterOffset(0)
42    , m_logicalMetricsListOffset(0)
43    , m_visualCharacterOffset(0)
44    , m_visualMetricsListOffset(0)
45    , m_x(0)
46    , m_y(0)
47    , m_dx(0)
48    , m_dy(0)
49    , m_isVerticalText(false)
50    , m_inPathLayout(false)
51    , m_textPathLength(0)
52    , m_textPathCurrentOffset(0)
53    , m_textPathSpacing(0)
54    , m_textPathScaling(1)
55{
56    ASSERT(!m_layoutAttributes.isEmpty());
57}
58
59void SVGTextLayoutEngine::updateCharacerPositionIfNeeded(float& x, float& y)
60{
61    if (m_inPathLayout)
62        return;
63
64    // Replace characters x/y position, with the current text position plus any
65    // relative adjustments, if it doesn't specify an absolute position itself.
66    if (x == SVGTextLayoutAttributes::emptyValue())
67        x = m_x + m_dx;
68
69    if (y == SVGTextLayoutAttributes::emptyValue())
70        y = m_y + m_dy;
71
72    m_dx = 0;
73    m_dy = 0;
74}
75
76void SVGTextLayoutEngine::updateCurrentTextPosition(float x, float y, float glyphAdvance)
77{
78    // Update current text position after processing the character.
79    if (m_isVerticalText) {
80        m_x = x;
81        m_y = y + glyphAdvance;
82    } else {
83        m_x = x + glyphAdvance;
84        m_y = y;
85    }
86}
87
88void SVGTextLayoutEngine::updateRelativePositionAdjustmentsIfNeeded(float dx, float dy)
89{
90    // Update relative positioning information.
91    if (dx == SVGTextLayoutAttributes::emptyValue() && dy == SVGTextLayoutAttributes::emptyValue())
92        return;
93
94    if (dx == SVGTextLayoutAttributes::emptyValue())
95        dx = 0;
96    if (dy == SVGTextLayoutAttributes::emptyValue())
97        dy = 0;
98
99    if (m_inPathLayout) {
100        if (m_isVerticalText) {
101            m_dx += dx;
102            m_dy = dy;
103        } else {
104            m_dx = dx;
105            m_dy += dy;
106        }
107
108        return;
109    }
110
111    m_dx = dx;
112    m_dy = dy;
113}
114
115void SVGTextLayoutEngine::recordTextFragment(SVGInlineTextBox* textBox, Vector<SVGTextMetrics>& textMetricsValues)
116{
117    ASSERT(!m_currentTextFragment.length);
118    ASSERT(m_visualMetricsListOffset > 0);
119
120    // Figure out length of fragment.
121    m_currentTextFragment.length = m_visualCharacterOffset - m_currentTextFragment.characterOffset;
122
123    // Figure out fragment metrics.
124    SVGTextMetrics& lastCharacterMetrics = textMetricsValues.at(m_visualMetricsListOffset - 1);
125    m_currentTextFragment.width = lastCharacterMetrics.width();
126    m_currentTextFragment.height = lastCharacterMetrics.height();
127
128    if (m_currentTextFragment.length > 1) {
129        // SVGTextLayoutAttributesBuilder assures that the length of the range is equal to the sum of the individual lengths of the glyphs.
130        float length = 0;
131        if (m_isVerticalText) {
132            for (unsigned i = m_currentTextFragment.metricsListOffset; i < m_visualMetricsListOffset; ++i)
133                length += textMetricsValues.at(i).height();
134            m_currentTextFragment.height = length;
135        } else {
136            for (unsigned i = m_currentTextFragment.metricsListOffset; i < m_visualMetricsListOffset; ++i)
137                length += textMetricsValues.at(i).width();
138            m_currentTextFragment.width = length;
139        }
140    }
141
142    textBox->textFragments().append(m_currentTextFragment);
143    m_currentTextFragment = SVGTextFragment();
144}
145
146bool SVGTextLayoutEngine::parentDefinesTextLength(RenderObject* parent) const
147{
148    RenderObject* currentParent = parent;
149    while (currentParent) {
150        if (SVGTextContentElement* textContentElement = SVGTextContentElement::elementFromRenderer(currentParent)) {
151            SVGLengthContext lengthContext(textContentElement);
152            if (textContentElement->lengthAdjust() == SVGLengthAdjustSpacing && textContentElement->specifiedTextLength().value(lengthContext) > 0)
153                return true;
154        }
155
156        if (currentParent->isSVGText())
157            return false;
158
159        currentParent = currentParent->parent();
160    }
161
162    ASSERT_NOT_REACHED();
163    return false;
164}
165
166void SVGTextLayoutEngine::beginTextPathLayout(RenderObject* object, SVGTextLayoutEngine& lineLayout)
167{
168    ASSERT(object);
169
170    m_inPathLayout = true;
171    RenderSVGTextPath* textPath = toRenderSVGTextPath(object);
172
173    m_textPath = textPath->layoutPath();
174    if (m_textPath.isEmpty())
175        return;
176    m_textPathStartOffset = textPath->startOffset();
177    m_textPathLength = m_textPath.length();
178    if (m_textPathStartOffset > 0 && m_textPathStartOffset <= 1)
179        m_textPathStartOffset *= m_textPathLength;
180
181    float totalLength = 0;
182    unsigned totalCharacters = 0;
183
184    lineLayout.m_chunkLayoutBuilder.buildTextChunks(lineLayout.m_lineLayoutBoxes);
185    const Vector<SVGTextChunk>& textChunks = lineLayout.m_chunkLayoutBuilder.textChunks();
186
187    unsigned size = textChunks.size();
188    for (unsigned i = 0; i < size; ++i) {
189        const SVGTextChunk& chunk = textChunks.at(i);
190
191        float length = 0;
192        unsigned characters = 0;
193        chunk.calculateLength(length, characters);
194
195        // Handle text-anchor as additional start offset for text paths.
196        m_textPathStartOffset += chunk.calculateTextAnchorShift(length);
197
198        totalLength += length;
199        totalCharacters += characters;
200    }
201
202    m_textPathCurrentOffset = m_textPathStartOffset;
203
204    // Eventually handle textLength adjustments.
205    SVGLengthAdjustType lengthAdjust = SVGLengthAdjustUnknown;
206    float desiredTextLength = 0;
207
208    if (SVGTextContentElement* textContentElement = SVGTextContentElement::elementFromRenderer(textPath)) {
209        SVGLengthContext lengthContext(textContentElement);
210        lengthAdjust = textContentElement->lengthAdjust();
211        desiredTextLength = textContentElement->specifiedTextLength().value(lengthContext);
212    }
213
214    if (!desiredTextLength)
215        return;
216
217    if (lengthAdjust == SVGLengthAdjustSpacing)
218        m_textPathSpacing = (desiredTextLength - totalLength) / totalCharacters;
219    else
220        m_textPathScaling = desiredTextLength / totalLength;
221}
222
223void SVGTextLayoutEngine::endTextPathLayout()
224{
225    m_inPathLayout = false;
226    m_textPath = Path();
227    m_textPathLength = 0;
228    m_textPathStartOffset = 0;
229    m_textPathCurrentOffset = 0;
230    m_textPathSpacing = 0;
231    m_textPathScaling = 1;
232}
233
234void SVGTextLayoutEngine::layoutInlineTextBox(SVGInlineTextBox* textBox)
235{
236    ASSERT(textBox);
237
238    RenderSVGInlineText* text = toRenderSVGInlineText(textBox->textRenderer());
239    ASSERT(text);
240    ASSERT(text->parent());
241    ASSERT(text->parent()->node());
242    ASSERT(text->parent()->node()->isSVGElement());
243
244    const RenderStyle* style = text->style();
245    ASSERT(style);
246
247    textBox->clearTextFragments();
248    m_isVerticalText = style->svgStyle()->isVerticalWritingMode();
249    layoutTextOnLineOrPath(textBox, text, style);
250
251    if (m_inPathLayout) {
252        m_pathLayoutBoxes.append(textBox);
253        return;
254    }
255
256    m_lineLayoutBoxes.append(textBox);
257}
258
259#if DUMP_TEXT_FRAGMENTS > 0
260static inline void dumpTextBoxes(Vector<SVGInlineTextBox*>& boxes)
261{
262    unsigned boxCount = boxes.size();
263    fprintf(stderr, "Dumping all text fragments in text sub tree, %i boxes\n", boxCount);
264
265    for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
266        SVGInlineTextBox* textBox = boxes.at(boxPosition);
267        Vector<SVGTextFragment>& fragments = textBox->textFragments();
268        fprintf(stderr, "-> Box %i: Dumping text fragments for SVGInlineTextBox, textBox=%p, textRenderer=%p\n", boxPosition, textBox, textBox->textRenderer());
269        fprintf(stderr, "        textBox properties, start=%i, len=%i, box direction=%i\n", textBox->start(), textBox->len(), textBox->direction());
270        fprintf(stderr, "   textRenderer properties, textLength=%i\n", textBox->textRenderer()->textLength());
271
272        const UChar* characters = textBox->textRenderer()->characters();
273
274        unsigned fragmentCount = fragments.size();
275        for (unsigned i = 0; i < fragmentCount; ++i) {
276            SVGTextFragment& fragment = fragments.at(i);
277            String fragmentString(characters + fragment.characterOffset, fragment.length);
278            fprintf(stderr, "    -> Fragment %i, x=%lf, y=%lf, width=%lf, height=%lf, characterOffset=%i, length=%i, characters='%s'\n"
279                          , i, fragment.x, fragment.y, fragment.width, fragment.height, fragment.characterOffset, fragment.length, fragmentString.utf8().data());
280        }
281    }
282}
283#endif
284
285void SVGTextLayoutEngine::finalizeTransformMatrices(Vector<SVGInlineTextBox*>& boxes)
286{
287    unsigned boxCount = boxes.size();
288    if (!boxCount)
289        return;
290
291    AffineTransform textBoxTransformation;
292    for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
293        SVGInlineTextBox* textBox = boxes.at(boxPosition);
294        Vector<SVGTextFragment>& fragments = textBox->textFragments();
295
296        unsigned fragmentCount = fragments.size();
297        for (unsigned i = 0; i < fragmentCount; ++i) {
298            m_chunkLayoutBuilder.transformationForTextBox(textBox, textBoxTransformation);
299            if (textBoxTransformation.isIdentity())
300                continue;
301            ASSERT(fragments[i].lengthAdjustTransform.isIdentity());
302            fragments[i].lengthAdjustTransform = textBoxTransformation;
303        }
304    }
305
306    boxes.clear();
307}
308
309void SVGTextLayoutEngine::finishLayout()
310{
311    // After all text fragments are stored in their correpsonding SVGInlineTextBoxes, we can layout individual text chunks.
312    // Chunk layouting is only performed for line layout boxes, not for path layout, where it has already been done.
313    m_chunkLayoutBuilder.layoutTextChunks(m_lineLayoutBoxes);
314
315    // Finalize transform matrices, after the chunk layout corrections have been applied, and all fragment x/y positions are finalized.
316    if (!m_lineLayoutBoxes.isEmpty()) {
317#if DUMP_TEXT_FRAGMENTS > 0
318        fprintf(stderr, "Line layout: ");
319        dumpTextBoxes(m_lineLayoutBoxes);
320#endif
321
322        finalizeTransformMatrices(m_lineLayoutBoxes);
323    }
324
325    if (!m_pathLayoutBoxes.isEmpty()) {
326#if DUMP_TEXT_FRAGMENTS > 0
327        fprintf(stderr, "Path layout: ");
328        dumpTextBoxes(m_pathLayoutBoxes);
329#endif
330
331        finalizeTransformMatrices(m_pathLayoutBoxes);
332    }
333}
334
335bool SVGTextLayoutEngine::currentLogicalCharacterAttributes(SVGTextLayoutAttributes*& logicalAttributes)
336{
337    if (m_layoutAttributesPosition == m_layoutAttributes.size())
338        return false;
339
340    logicalAttributes = m_layoutAttributes[m_layoutAttributesPosition];
341    ASSERT(logicalAttributes);
342
343    if (m_logicalCharacterOffset != logicalAttributes->context()->textLength())
344        return true;
345
346    ++m_layoutAttributesPosition;
347    if (m_layoutAttributesPosition == m_layoutAttributes.size())
348        return false;
349
350    logicalAttributes = m_layoutAttributes[m_layoutAttributesPosition];
351    m_logicalMetricsListOffset = 0;
352    m_logicalCharacterOffset = 0;
353    return true;
354}
355
356bool SVGTextLayoutEngine::currentLogicalCharacterMetrics(SVGTextLayoutAttributes*& logicalAttributes, SVGTextMetrics& logicalMetrics)
357{
358    Vector<SVGTextMetrics>* textMetricsValues = &logicalAttributes->textMetricsValues();
359    unsigned textMetricsSize = textMetricsValues->size();
360    while (true) {
361        if (m_logicalMetricsListOffset == textMetricsSize) {
362            if (!currentLogicalCharacterAttributes(logicalAttributes))
363                return false;
364
365            textMetricsValues = &logicalAttributes->textMetricsValues();
366            textMetricsSize = textMetricsValues->size();
367            continue;
368        }
369
370        ASSERT(textMetricsSize);
371        ASSERT(m_logicalMetricsListOffset < textMetricsSize);
372        logicalMetrics = textMetricsValues->at(m_logicalMetricsListOffset);
373        if (logicalMetrics.isEmpty() || (!logicalMetrics.width() && !logicalMetrics.height())) {
374            advanceToNextLogicalCharacter(logicalMetrics);
375            continue;
376        }
377
378        // Stop if we found the next valid logical text metrics object.
379        return true;
380    }
381
382    ASSERT_NOT_REACHED();
383    return true;
384}
385
386bool SVGTextLayoutEngine::currentVisualCharacterMetrics(SVGInlineTextBox* textBox, Vector<SVGTextMetrics>& visualMetricsValues, SVGTextMetrics& visualMetrics)
387{
388    ASSERT(!visualMetricsValues.isEmpty());
389    unsigned textMetricsSize = visualMetricsValues.size();
390    unsigned boxStart = textBox->start();
391    unsigned boxLength = textBox->len();
392
393    if (m_visualMetricsListOffset == textMetricsSize)
394        return false;
395
396    while (m_visualMetricsListOffset < textMetricsSize) {
397        // Advance to text box start location.
398        if (m_visualCharacterOffset < boxStart) {
399            advanceToNextVisualCharacter(visualMetricsValues[m_visualMetricsListOffset]);
400            continue;
401        }
402
403        // Stop if we've finished processing this text box.
404        if (m_visualCharacterOffset >= boxStart + boxLength)
405            return false;
406
407        visualMetrics = visualMetricsValues[m_visualMetricsListOffset];
408        return true;
409    }
410
411    return false;
412}
413
414void SVGTextLayoutEngine::advanceToNextLogicalCharacter(const SVGTextMetrics& logicalMetrics)
415{
416    ++m_logicalMetricsListOffset;
417    m_logicalCharacterOffset += logicalMetrics.length();
418}
419
420void SVGTextLayoutEngine::advanceToNextVisualCharacter(const SVGTextMetrics& visualMetrics)
421{
422    ++m_visualMetricsListOffset;
423    m_visualCharacterOffset += visualMetrics.length();
424}
425
426void SVGTextLayoutEngine::layoutTextOnLineOrPath(SVGInlineTextBox* textBox, RenderSVGInlineText* text, const RenderStyle* style)
427{
428    if (m_inPathLayout && m_textPath.isEmpty())
429        return;
430
431    SVGElement* lengthContext = toSVGElement(text->parent()->node());
432
433    RenderObject* textParent = text->parent();
434    bool definesTextLength = textParent ? parentDefinesTextLength(textParent) : false;
435
436    const SVGRenderStyle* svgStyle = style->svgStyle();
437    ASSERT(svgStyle);
438
439    m_visualMetricsListOffset = 0;
440    m_visualCharacterOffset = 0;
441
442    Vector<SVGTextMetrics>& visualMetricsValues = text->layoutAttributes()->textMetricsValues();
443    ASSERT(!visualMetricsValues.isEmpty());
444
445    const UChar* characters = text->characters();
446    const Font& font = style->font();
447
448    SVGTextLayoutEngineSpacing spacingLayout(font);
449    SVGTextLayoutEngineBaseline baselineLayout(font);
450
451    bool didStartTextFragment = false;
452    bool applySpacingToNextCharacter = false;
453
454    float lastAngle = 0;
455    float baselineShift = baselineLayout.calculateBaselineShift(svgStyle, lengthContext);
456    baselineShift -= baselineLayout.calculateAlignmentBaselineShift(m_isVerticalText, text);
457
458    // Main layout algorithm.
459    while (true) {
460        // Find the start of the current text box in this list, respecting ligatures.
461        SVGTextMetrics visualMetrics(SVGTextMetrics::SkippedSpaceMetrics);
462        if (!currentVisualCharacterMetrics(textBox, visualMetricsValues, visualMetrics))
463            break;
464
465        if (visualMetrics.isEmpty()) {
466            advanceToNextVisualCharacter(visualMetrics);
467            continue;
468        }
469
470        SVGTextLayoutAttributes* logicalAttributes = 0;
471        if (!currentLogicalCharacterAttributes(logicalAttributes))
472            break;
473
474        ASSERT(logicalAttributes);
475        SVGTextMetrics logicalMetrics(SVGTextMetrics::SkippedSpaceMetrics);
476        if (!currentLogicalCharacterMetrics(logicalAttributes, logicalMetrics))
477            break;
478
479        SVGCharacterDataMap& characterDataMap = logicalAttributes->characterDataMap();
480        SVGCharacterData data;
481        SVGCharacterDataMap::iterator it = characterDataMap.find(m_logicalCharacterOffset + 1);
482        if (it != characterDataMap.end())
483            data = it->value;
484
485        float x = data.x;
486        float y = data.y;
487
488        // When we've advanced to the box start offset, determine using the original x/y values,
489        // whether this character starts a new text chunk, before doing any further processing.
490        if (m_visualCharacterOffset == textBox->start())
491            textBox->setStartsNewTextChunk(logicalAttributes->context()->characterStartsNewTextChunk(m_logicalCharacterOffset));
492
493        float angle = data.rotate == SVGTextLayoutAttributes::emptyValue() ? 0 : data.rotate;
494
495        // Calculate glyph orientation angle.
496        const UChar* currentCharacter = characters + m_visualCharacterOffset;
497        float orientationAngle = baselineLayout.calculateGlyphOrientationAngle(m_isVerticalText, svgStyle, *currentCharacter);
498
499        // Calculate glyph advance & x/y orientation shifts.
500        float xOrientationShift = 0;
501        float yOrientationShift = 0;
502        float glyphAdvance = baselineLayout.calculateGlyphAdvanceAndOrientation(m_isVerticalText, visualMetrics, orientationAngle, xOrientationShift, yOrientationShift);
503
504        // Assign current text position to x/y values, if needed.
505        updateCharacerPositionIfNeeded(x, y);
506
507        // Apply dx/dy value adjustments to current text position, if needed.
508        updateRelativePositionAdjustmentsIfNeeded(data.dx, data.dy);
509
510        // Calculate SVG Fonts kerning, if needed.
511        float kerning = spacingLayout.calculateSVGKerning(m_isVerticalText, visualMetrics.glyph());
512
513        // Calculate CSS 'kerning', 'letter-spacing' and 'word-spacing' for next character, if needed.
514        float spacing = spacingLayout.calculateCSSKerningAndSpacing(svgStyle, lengthContext, currentCharacter);
515
516        float textPathOffset = 0;
517        if (m_inPathLayout) {
518            float scaledGlyphAdvance = glyphAdvance * m_textPathScaling;
519            if (m_isVerticalText) {
520                // If there's an absolute y position available, it marks the beginning of a new position along the path.
521                if (y != SVGTextLayoutAttributes::emptyValue())
522                    m_textPathCurrentOffset = y + m_textPathStartOffset;
523
524                m_textPathCurrentOffset += m_dy - kerning;
525                m_dy = 0;
526
527                // Apply dx/dy correction and setup translations that move to the glyph midpoint.
528                xOrientationShift += m_dx + baselineShift;
529                yOrientationShift -= scaledGlyphAdvance / 2;
530            } else {
531                // If there's an absolute x position available, it marks the beginning of a new position along the path.
532                if (x != SVGTextLayoutAttributes::emptyValue())
533                    m_textPathCurrentOffset = x + m_textPathStartOffset;
534
535                m_textPathCurrentOffset += m_dx - kerning;
536                m_dx = 0;
537
538                // Apply dx/dy correction and setup translations that move to the glyph midpoint.
539                xOrientationShift -= scaledGlyphAdvance / 2;
540                yOrientationShift += m_dy - baselineShift;
541            }
542
543            // Calculate current offset along path.
544            textPathOffset = m_textPathCurrentOffset + scaledGlyphAdvance / 2;
545
546            // Move to next character.
547            m_textPathCurrentOffset += scaledGlyphAdvance + m_textPathSpacing + spacing * m_textPathScaling;
548
549            // Skip character, if we're before the path.
550            if (textPathOffset < 0) {
551                advanceToNextLogicalCharacter(logicalMetrics);
552                advanceToNextVisualCharacter(visualMetrics);
553                continue;
554            }
555
556            // Stop processing, if the next character lies behind the path.
557            if (textPathOffset > m_textPathLength)
558                break;
559
560            bool ok = false;
561            FloatPoint point = m_textPath.pointAtLength(textPathOffset, ok);
562            ASSERT(ok);
563
564            x = point.x();
565            y = point.y();
566            angle = m_textPath.normalAngleAtLength(textPathOffset, ok);
567            ASSERT(ok);
568
569            // For vertical text on path, the actual angle has to be rotated 90 degrees anti-clockwise, not the orientation angle!
570            if (m_isVerticalText)
571                angle -= 90;
572        } else {
573            // Apply all previously calculated shift values.
574            if (m_isVerticalText) {
575                x += baselineShift;
576                y -= kerning;
577            } else {
578                x -= kerning;
579                y -= baselineShift;
580            }
581
582            x += m_dx;
583            y += m_dy;
584        }
585
586        // Determine whether we have to start a new fragment.
587        bool shouldStartNewFragment = m_dx || m_dy || m_isVerticalText || m_inPathLayout || angle || angle != lastAngle
588            || orientationAngle || kerning || applySpacingToNextCharacter || definesTextLength;
589
590        // If we already started a fragment, close it now.
591        if (didStartTextFragment && shouldStartNewFragment) {
592            applySpacingToNextCharacter = false;
593            recordTextFragment(textBox, visualMetricsValues);
594        }
595
596        // Eventually start a new fragment, if not yet done.
597        if (!didStartTextFragment || shouldStartNewFragment) {
598            ASSERT(!m_currentTextFragment.characterOffset);
599            ASSERT(!m_currentTextFragment.length);
600
601            didStartTextFragment = true;
602            m_currentTextFragment.characterOffset = m_visualCharacterOffset;
603            m_currentTextFragment.metricsListOffset = m_visualMetricsListOffset;
604            m_currentTextFragment.x = x;
605            m_currentTextFragment.y = y;
606
607            // Build fragment transformation.
608            if (angle)
609                m_currentTextFragment.transform.rotate(angle);
610
611            if (xOrientationShift || yOrientationShift)
612                m_currentTextFragment.transform.translate(xOrientationShift, yOrientationShift);
613
614            if (orientationAngle)
615                m_currentTextFragment.transform.rotate(orientationAngle);
616
617            m_currentTextFragment.isTextOnPath = m_inPathLayout && m_textPathScaling != 1;
618            if (m_currentTextFragment.isTextOnPath) {
619                if (m_isVerticalText)
620                    m_currentTextFragment.lengthAdjustTransform.scaleNonUniform(1, m_textPathScaling);
621                else
622                    m_currentTextFragment.lengthAdjustTransform.scaleNonUniform(m_textPathScaling, 1);
623            }
624        }
625
626        // Update current text position, after processing of the current character finished.
627        if (m_inPathLayout)
628            updateCurrentTextPosition(x, y, glyphAdvance);
629        else {
630            // Apply CSS 'kerning', 'letter-spacing' and 'word-spacing' to next character, if needed.
631            if (spacing)
632                applySpacingToNextCharacter = true;
633
634            float xNew = x - m_dx;
635            float yNew = y - m_dy;
636
637            if (m_isVerticalText)
638                xNew -= baselineShift;
639            else
640                yNew += baselineShift;
641
642            updateCurrentTextPosition(xNew, yNew, glyphAdvance + spacing);
643        }
644
645        advanceToNextLogicalCharacter(logicalMetrics);
646        advanceToNextVisualCharacter(visualMetrics);
647        lastAngle = angle;
648    }
649
650    if (!didStartTextFragment)
651        return;
652
653    // Close last open fragment, if needed.
654    recordTextFragment(textBox, visualMetricsValues);
655}
656
657}
658
659#endif // ENABLE(SVG)
660