C++ SkPaint::getTextAlign方法代码示例

void drawTestCase(SkCanvas* canvas, const char* text, SkScalar y, const SkPaint& paint) {
        SkScalar widths[kMaxStringLength];
        SkScalar posX[kMaxStringLength];
        SkPoint pos[kMaxStringLength];
        int length = SkToInt(strlen(text));
        SkASSERT(length <= kMaxStringLength);

        paint.getTextWidths(text, length, widths);

        float originX;
        switch (paint.getTextAlign()) {
            case SkPaint::kRight_Align: originX = 1; break;
            case SkPaint::kCenter_Align: originX = 0.5f; break;
            case SkPaint::kLeft_Align: originX = 0; break;
            default: SkFAIL("Invalid paint origin"); return;
        }

        float x = kTextHeight;
        for (int i = 0; i < length; ++i) {
            posX[i] = x + originX * widths[i];
            pos[i].set(posX[i], i ? pos[i - 1].y() + 3 : y + kTextHeight);
            x += widths[i];
        }

        canvas->drawPosTextH(text, length, posX, y, paint);
        canvas->drawPosText(text, length, pos, paint);
}

void SkSVGDevice::AutoElement::addTextAttributes(const SkPaint& paint) {
    this->addAttribute("font-size", paint.getTextSize());

    if (const char* textAlign = svg_text_align(paint.getTextAlign())) {
        this->addAttribute("text-anchor", textAlign);
    }

    SkString familyName;
    SkTHashSet<SkString> familySet;
    SkAutoTUnref<const SkTypeface> tface(paint.getTypeface() ?
        SkRef(paint.getTypeface()) : SkTypeface::RefDefault());

    SkASSERT(tface);
    SkTypeface::Style style = tface->style();
    if (style & SkTypeface::kItalic) {
        this->addAttribute("font-style", "italic");
    }
    if (style & SkTypeface::kBold) {
        this->addAttribute("font-weight", "bold");
    }

    SkAutoTUnref<SkTypeface::LocalizedStrings> familyNameIter(tface->createFamilyNameIterator());
    SkTypeface::LocalizedString familyString;
    while (familyNameIter->next(&familyString)) {
        if (familySet.contains(familyString.fString)) {
            continue;
        }
        familySet.add(familyString.fString);
        familyName.appendf((familyName.isEmpty() ? "%s" : ", %s"), familyString.fString.c_str());
    }

    if (!familyName.isEmpty()) {
        this->addAttribute("font-family", familyName);
    }
}

void SkBBoxRecord::onDrawText(const void* text, size_t byteLength, SkScalar x, SkScalar y,
                              const SkPaint& paint) {
    SkRect bbox;
    paint.measureText(text, byteLength, &bbox);
    SkPaint::FontMetrics metrics;
    paint.getFontMetrics(&metrics);

    // Vertical and aligned text need to be offset
    if (paint.isVerticalText()) {
        SkScalar h = bbox.fBottom - bbox.fTop;
        if (paint.getTextAlign() == SkPaint::kCenter_Align) {
            bbox.fTop    -= h / 2;
            bbox.fBottom -= h / 2;
        }
        // Pad top and bottom with max extents from FontMetrics
        bbox.fBottom += metrics.fBottom;
        bbox.fTop += metrics.fTop;
    } else {
        SkScalar w = bbox.fRight - bbox.fLeft;
        if (paint.getTextAlign() == SkPaint::kCenter_Align) {
            bbox.fLeft  -= w / 2;
            bbox.fRight -= w / 2;
        } else if (paint.getTextAlign() == SkPaint::kRight_Align) {
            bbox.fLeft  -= w;
            bbox.fRight -= w;
        }
        // Set vertical bounds to max extents from font metrics
        bbox.fTop = metrics.fTop;
        bbox.fBottom = metrics.fBottom;
    }

    // Pad horizontal bounds on each side by half of max vertical extents (this is sort of
    // arbitrary, but seems to produce reasonable results, if there were a way of getting max
    // glyph X-extents to pad by, that may be better here, but FontMetrics fXMin and fXMax seem
    // incorrect on most platforms (too small in Linux, never even set in Windows).
    SkScalar pad = (metrics.fBottom - metrics.fTop) / 2;
    bbox.fLeft  -= pad;
    bbox.fRight += pad;

    bbox.fLeft += x;
    bbox.fRight += x;
    bbox.fTop += y;
    bbox.fBottom += y;
    if (this->transformBounds(bbox, &paint)) {
        INHERITED::onDrawText(text, byteLength, x, y, paint);
    }
}

void SkBaseDevice::drawTextOnPath(const SkDraw& draw, const void* text, size_t byteLength,
                                  const SkPath& follow, const SkMatrix* matrix,
                                  const SkPaint& paint) {
    SkASSERT(byteLength == 0 || text != nullptr);

    // nothing to draw
    if (text == nullptr || byteLength == 0 || draw.fRC->isEmpty()) {
        return;
    }

    SkTextToPathIter    iter((const char*)text, byteLength, paint, true);
    SkPathMeasure       meas(follow, false);
    SkScalar            hOffset = 0;

    // need to measure first
    if (paint.getTextAlign() != SkPaint::kLeft_Align) {
        SkScalar pathLen = meas.getLength();
        if (paint.getTextAlign() == SkPaint::kCenter_Align) {
            pathLen = SkScalarHalf(pathLen);
        }
        hOffset += pathLen;
    }

    const SkPath*   iterPath;
    SkScalar        xpos;
    SkMatrix        scaledMatrix;
    SkScalar        scale = iter.getPathScale();

    scaledMatrix.setScale(scale, scale);

    while (iter.next(&iterPath, &xpos)) {
        if (iterPath) {
            SkPath      tmp;
            SkMatrix    m(scaledMatrix);

            tmp.setIsVolatile(true);
            m.postTranslate(xpos + hOffset, 0);
            if (matrix) {
                m.postConcat(*matrix);
            }
            morphpath(&tmp, *iterPath, meas, m);
            this->drawPath(draw, tmp, iter.getPaint(), nullptr, true);
        }
    }
}

void SkOverdrawCanvas::onDrawText(const void* text, size_t byteLength, SkScalar x, SkScalar y,
                                  const SkPaint& paint) {
    ProcessOneGlyphBounds processBounds(this);
    SkSurfaceProps props(0, kUnknown_SkPixelGeometry);
    this->getProps(&props);
    auto cache = SkStrikeCache::FindOrCreateStrikeExclusive(
            paint, &props, SkScalerContextFlags::kNone, &this->getTotalMatrix());
    SkFindAndPlaceGlyph::ProcessText(paint.getTextEncoding(), (const char*) text, byteLength,
                                     SkPoint::Make(x, y), SkMatrix(), paint.getTextAlign(),
                                     cache.get(), processBounds);
}

void SkSVGDevice::drawTextOnPath(const SkDraw&, const void* text, size_t len, const SkPath& path,
                                 const SkMatrix* matrix, const SkPaint& paint) {
    SkString pathID = fResourceBucket->addPath();

    {
        AutoElement defs("defs", fWriter);
        AutoElement pathElement("path", fWriter);
        pathElement.addAttribute("id", pathID);
        pathElement.addPathAttributes(path);

    }

    {
        AutoElement textElement("text", fWriter);
        textElement.addTextAttributes(paint);

        if (matrix && !matrix->isIdentity()) {
            textElement.addAttribute("transform", svg_transform(*matrix));
        }

        {
            AutoElement textPathElement("textPath", fWriter);
            textPathElement.addAttribute("xlink:href", SkStringPrintf("#%s", pathID.c_str()));

            if (paint.getTextAlign() != SkPaint::kLeft_Align) {
                SkASSERT(paint.getTextAlign() == SkPaint::kCenter_Align ||
                         paint.getTextAlign() == SkPaint::kRight_Align);
                textPathElement.addAttribute("startOffset",
                    paint.getTextAlign() == SkPaint::kCenter_Align ? "50%" : "100%");
            }

            SVGTextBuilder builder(text, len, paint, SkPoint::Make(0, 0), 0);
            textPathElement.addText(builder.text());
        }
    }
}

static void apply_paint_textalign(const SkPaint& paint, Json::Value* target) {
    SkPaint::Align textAlign = paint.getTextAlign();
    if (textAlign != SkPaint::kLeft_Align) {
        switch (textAlign) {
            case SkPaint::kCenter_Align: {
                (*target)[SKJSONCANVAS_ATTRIBUTE_TEXTALIGN] = SKJSONCANVAS_ALIGN_CENTER;
                break;
            }
            case SkPaint::kRight_Align: {
                (*target)[SKJSONCANVAS_ATTRIBUTE_TEXTALIGN] = SKJSONCANVAS_ALIGN_RIGHT;
                break;
            }
            default: SkASSERT(false);
        }
    }
}

void GrTextUtils::DrawBmpPosText(GrAtlasTextBlob* blob, int runIndex,
                                 GrBatchFontCache* fontCache,
                                 const SkSurfaceProps& props, const SkPaint& skPaint,
                                 GrColor color,
                                 const SkMatrix& viewMatrix,
                                 const char text[], size_t byteLength,
                                 const SkScalar pos[], int scalarsPerPosition,
                                 const SkPoint& offset) {
    SkASSERT(byteLength == 0 || text != nullptr);
    SkASSERT(1 == scalarsPerPosition || 2 == scalarsPerPosition);

    // nothing to draw
    if (text == nullptr || byteLength == 0) {
        return;
    }

    // Ensure the blob is set for bitmaptext
    blob->setHasBitmap();

    GrBatchTextStrike* currStrike = nullptr;

    // Get GrFontScaler from cache
    SkGlyphCache* cache = blob->setupCache(runIndex, props, SkPaint::FakeGamma::On,
                                           skPaint, &viewMatrix);
    GrFontScaler* fontScaler = GrTextUtils::GetGrFontScaler(cache);

    SkFindAndPlaceGlyph::ProcessPosText(
        skPaint.getTextEncoding(), text, byteLength,
        offset, viewMatrix, pos, scalarsPerPosition,
        skPaint.getTextAlign(), cache,
        [&](const SkGlyph& glyph, SkPoint position, SkPoint rounding) {
            position += rounding;
            BmpAppendGlyph(
                blob, runIndex, fontCache, &currStrike, glyph,
                SkScalarFloorToInt(position.fX), SkScalarFloorToInt(position.fY),
                color, fontScaler);
        }
    );

    SkGlyphCache::AttachCache(cache);
}

PassRefPtr<JSONObject> LoggingCanvas::objectForSkPaint(const SkPaint& paint)
{
    RefPtr<JSONObject> paintItem = JSONObject::create();
    paintItem->setNumber("textSize", paint.getTextSize());
    paintItem->setNumber("textScaleX", paint.getTextScaleX());
    paintItem->setNumber("textSkewX", paint.getTextSkewX());
    if (SkShader* shader = paint.getShader())
        paintItem->setObject("shader", objectForSkShader(*shader));
    paintItem->setString("color", stringForSkColor(paint.getColor()));
    paintItem->setNumber("strokeWidth", paint.getStrokeWidth());
    paintItem->setNumber("strokeMiter", paint.getStrokeMiter());
    paintItem->setString("flags", stringForSkPaintFlags(paint));
    paintItem->setString("filterLevel", filterQualityName(paint.getFilterQuality()));
    paintItem->setString("textAlign", textAlignName(paint.getTextAlign()));
    paintItem->setString("strokeCap", strokeCapName(paint.getStrokeCap()));
    paintItem->setString("strokeJoin", strokeJoinName(paint.getStrokeJoin()));
    paintItem->setString("styleName", styleName(paint.getStyle()));
    paintItem->setString("textEncoding", textEncodingName(paint.getTextEncoding()));
    paintItem->setString("hinting", hintingName(paint.getHinting()));
    return paintItem.release();
}

/*
 *  Header:
 *      paint flags     : 32
 *      non_def bits    : 16
 *      xfermode enum   : 8
 *      pad zeros       : 8
 */
static void write_paint(SkWriteBuffer& writer, const SkPaint& paint, unsigned usage) {
    uint32_t packedFlags = pack_paint_flags(paint.getFlags(), paint.getHinting(),
                                            paint.getTextAlign(), paint.getFilterQuality(),
                                            paint.getStyle(), paint.getStrokeCap(),
                                            paint.getStrokeJoin(), paint.getTextEncoding());
    writer.write32(packedFlags);

    unsigned nondef = compute_nondef(paint, (PaintUsage)usage);
    const uint8_t pad = 0;
    writer.write32((nondef << 16) | ((unsigned)paint.getBlendMode() << 8) | pad);

    CHECK_WRITE_SCALAR(writer, nondef, paint, TextSize);
    CHECK_WRITE_SCALAR(writer, nondef, paint, TextScaleX);
    CHECK_WRITE_SCALAR(writer, nondef, paint, TextSkewX);
    CHECK_WRITE_SCALAR(writer, nondef, paint, StrokeWidth);
    CHECK_WRITE_SCALAR(writer, nondef, paint, StrokeMiter);

    if (nondef & kColor_NonDef) {
        writer.write32(paint.getColor());
    }
    if (nondef & kTypeface_NonDef) {
        // TODO: explore idea of writing bits indicating "use the prev (or prev N) face"
        // e.g. 1-N bits is an index into a ring buffer of typefaces
        SkTypeface* tf = paint.getTypeface();
        SkASSERT(tf);
        writer.writeTypeface(tf);
    }

    CHECK_WRITE_FLATTENABLE(writer, nondef, paint, PathEffect);
    CHECK_WRITE_FLATTENABLE(writer, nondef, paint, Shader);
    CHECK_WRITE_FLATTENABLE(writer, nondef, paint, MaskFilter);
    CHECK_WRITE_FLATTENABLE(writer, nondef, paint, ColorFilter);
    CHECK_WRITE_FLATTENABLE(writer, nondef, paint, Rasterizer);
    CHECK_WRITE_FLATTENABLE(writer, nondef, paint, ImageFilter);
    CHECK_WRITE_FLATTENABLE(writer, nondef, paint, DrawLooper);
}

SkPath TextArt::EnvelopeWarp::warp(const std::string& text, SkTypeface* typeface)
{
	SkPath				warpedPath;

	if (text.empty())
		return warpedPath;

	//prepare paint
	SkPaint paint;
	paint.setTextSize(SkIntToScalar(64));
	paint.setTypeface(typeface);
	paint.setTextAlign(SkPaint::kCenter_Align);

	//measure Bottom path to center text on it
	SkPathMeasure   bMeasure(bSkeleton_, false);
	SkScalar        hBOffset = 0;

    if (paint.getTextAlign() != SkPaint::kLeft_Align)
	{
        SkScalar pathLen = bMeasure.getLength();
        if (paint.getTextAlign() == SkPaint::kCenter_Align)
		{
            pathLen = SkScalarHalf(pathLen);
        }
        hBOffset += pathLen;
    }

	//get text boundaries on normal(non-warped) state
	{
		SkMatrix scaleMartix;
		scaleMartix.setIdentity();

		SkTextToPathIter	iter(text.c_str(), text.size(), paint, true);
		const SkPath*   glypthPath;
		SkScalar        xpos;

		SkScalar        scale = iter.getPathScale();
		scaleMartix.setScale(scale, scale);

		while (iter.next(&glypthPath, &xpos))
		{
			if (glypthPath)
			{
				//prepare resulting transformatiom Matrix
				SkMatrix	compositeMatrix(scaleMartix);
				compositeMatrix.postTranslate(xpos + hBOffset, 0);
				
				SkPath p;
				(*glypthPath).transform(compositeMatrix, &p);
				//get normal(without any warps) text boundaries
				boundsRect_.join( p.getBounds() );
			}
		}
	}

	//center text on Top skeleton
	SkPathMeasure   tMeasure(tSkeleton_, false);
	SkScalar        hTOffset = 0;	
	{
		if (paint.getTextAlign() != SkPaint::kLeft_Align)
		{
			SkScalar pathLen = tMeasure.getLength();
			if (paint.getTextAlign() == SkPaint::kCenter_Align)
			{
				pathLen = SkScalarHalf(pathLen);
			}
			hTOffset += pathLen;
		}
	}		
	
	//warp text on Bottom and Top skeletons
	{
		SkTextToPathIter	iter(text.c_str(), text.size(), paint, true);
		SkScalar        xpos;

		SkMatrix        scaleMartix;
		SkScalar        scale = iter.getPathScale();
		scaleMartix.setScale(scale, scale);

		SkPath line;
		line.lineTo(SkIntToScalar(100), SkIntToScalar(0));
		SkPathMeasure   lineMeasure(line, false);

		SkPathCrossing bCrossing(bSkeleton_);
		SkPathCrossing tCrossing(tSkeleton_);

		const SkPath*   glypthPathOrig;
		while (iter.next(&glypthPathOrig, &xpos))
		{
			if (glypthPathOrig)
			{
				SkPath glypthPath;
				SkRect glypthBound;
				glypthBound = (*glypthPathOrig).getBounds();
				glypthPathOrig->offset(-glypthBound.fLeft, 0, &glypthPath);

				morph(bSkeleton_, bMeasure, bCrossing,
						tSkeleton_, tMeasure, tCrossing,
						glypthPath, lineMeasure, scaleMartix,
						xpos, hBOffset, hTOffset, warpedPath);
//.........这里部分代码省略.........

SkScalar SkTextBox::visit(Visitor& visitor, const char text[], size_t len,
                          const SkPaint& paint) const {
    SkScalar marginWidth = fBox.width();

    if (marginWidth <= 0 || len == 0) {
        return fBox.top();
    }

    const char* textStop = text + len;

    SkScalar                x, y, scaledSpacing, height, fontHeight;
    SkPaint::FontMetrics    metrics;

    switch (paint.getTextAlign()) {
    case SkPaint::kLeft_Align:
        x = 0;
        break;
    case SkPaint::kCenter_Align:
        x = SkScalarHalf(marginWidth);
        break;
    default:
        x = marginWidth;
        break;
    }
    x += fBox.fLeft;

    fontHeight = paint.getFontMetrics(&metrics);
    scaledSpacing = SkScalarMul(fontHeight, fSpacingMul) + fSpacingAdd;
    height = fBox.height();

    //  compute Y position for first line
    {
        SkScalar textHeight = fontHeight;

        if (fMode == kLineBreak_Mode && fSpacingAlign != kStart_SpacingAlign) {
            int count = SkTextLineBreaker::CountLines(text, textStop - text, paint, marginWidth);
            SkASSERT(count > 0);
            textHeight += scaledSpacing * (count - 1);
        }

        switch (fSpacingAlign) {
        case kStart_SpacingAlign:
            y = 0;
            break;
        case kCenter_SpacingAlign:
            y = SkScalarHalf(height - textHeight);
            break;
        default:
            SkASSERT(fSpacingAlign == kEnd_SpacingAlign);
            y = height - textHeight;
            break;
        }
        y += fBox.fTop - metrics.fAscent;
    }

    for (;;) {
        size_t trailing;
        len = linebreak(text, textStop, paint, marginWidth, &trailing);
        if (y + metrics.fDescent + metrics.fLeading > 0) {
            visitor(text, len - trailing, x, y, paint);
        }
        text += len;
        if (text >= textStop) {
            break;
        }
        y += scaledSpacing;
        if (y + metrics.fAscent >= fBox.fBottom) {
            break;
        }
    }
    return y + metrics.fDescent + metrics.fLeading;
}

void GrDistanceFieldTextContext::onDrawText(GrRenderTarget* rt, const GrClip& clip,
                                            const GrPaint& paint,
                                            const SkPaint& skPaint, const SkMatrix& viewMatrix,
                                            const char text[], size_t byteLength,
                                            SkScalar x, SkScalar y,
                                            const SkIRect& regionClipBounds) {
    SkASSERT(byteLength == 0 || text != NULL);

    // nothing to draw
    if (text == NULL || byteLength == 0) {
        return;
    }

    fViewMatrix = viewMatrix;
    SkDrawCacheProc          glyphCacheProc = skPaint.getDrawCacheProc();
    SkAutoGlyphCache         autoCache(skPaint, &fDeviceProperties, NULL);
    SkGlyphCache*            cache = autoCache.getCache();

    SkTArray<SkScalar> positions;

    const char* textPtr = text;
    SkFixed stopX = 0;
    SkFixed stopY = 0;
    SkFixed origin;
    switch (skPaint.getTextAlign()) {
        case SkPaint::kRight_Align: origin = SK_Fixed1; break;
        case SkPaint::kCenter_Align: origin = SK_FixedHalf; break;
        case SkPaint::kLeft_Align: origin = 0; break;
        default: SkFAIL("Invalid paint origin"); return;
    }

    SkAutoKern autokern;
    const char* stop = text + byteLength;
    while (textPtr < stop) {
        // don't need x, y here, since all subpixel variants will have the
        // same advance
        const SkGlyph& glyph = glyphCacheProc(cache, &textPtr, 0, 0);

        SkFixed width = glyph.fAdvanceX + autokern.adjust(glyph);
        positions.push_back(SkFixedToScalar(stopX + SkFixedMul(origin, width)));

        SkFixed height = glyph.fAdvanceY;
        positions.push_back(SkFixedToScalar(stopY + SkFixedMul(origin, height)));

        stopX += width;
        stopY += height;
    }
    SkASSERT(textPtr == stop);

    // now adjust starting point depending on alignment
    SkScalar alignX = SkFixedToScalar(stopX);
    SkScalar alignY = SkFixedToScalar(stopY);
    if (skPaint.getTextAlign() == SkPaint::kCenter_Align) {
        alignX = SkScalarHalf(alignX);
        alignY = SkScalarHalf(alignY);
    } else if (skPaint.getTextAlign() == SkPaint::kLeft_Align) {
        alignX = 0;
        alignY = 0;
    }
    x -= alignX;
    y -= alignY;
    SkPoint offset = SkPoint::Make(x, y);

    this->onDrawPosText(rt, clip, paint, skPaint, viewMatrix, text, byteLength, positions.begin(),
                        2, offset, regionClipBounds);
}

void GrTextUtils::DrawDFText(GrAtlasTextBlob* blob, int runIndex,
                             GrBatchFontCache* fontCache, const SkSurfaceProps& props,
                             const SkPaint& skPaint, GrColor color,
                             const SkMatrix& viewMatrix,
                             const char text[], size_t byteLength,
                             SkScalar x, SkScalar y) {
    SkASSERT(byteLength == 0 || text != nullptr);

    // nothing to draw
    if (text == nullptr || byteLength == 0) {
        return;
    }

    SkPaint::GlyphCacheProc glyphCacheProc = skPaint.getGlyphCacheProc(true);
    SkAutoDescriptor desc;
    skPaint.getScalerContextDescriptor(&desc, props, SkPaint::FakeGamma::Off, nullptr);
    SkGlyphCache* origPaintCache = SkGlyphCache::DetachCache(skPaint.getTypeface(),
                                                             desc.getDesc());

    SkTArray<SkScalar> positions;

    const char* textPtr = text;
    SkFixed stopX = 0;
    SkFixed stopY = 0;
    SkFixed origin = 0;
    switch (skPaint.getTextAlign()) {
        case SkPaint::kRight_Align: origin = SK_Fixed1; break;
        case SkPaint::kCenter_Align: origin = SK_FixedHalf; break;
        case SkPaint::kLeft_Align: origin = 0; break;
    }

    SkAutoKern autokern;
    const char* stop = text + byteLength;
    while (textPtr < stop) {
        // don't need x, y here, since all subpixel variants will have the
        // same advance
        const SkGlyph& glyph = glyphCacheProc(origPaintCache, &textPtr);

        SkFixed width = glyph.fAdvanceX + autokern.adjust(glyph);
        positions.push_back(SkFixedToScalar(stopX + SkFixedMul(origin, width)));

        SkFixed height = glyph.fAdvanceY;
        positions.push_back(SkFixedToScalar(stopY + SkFixedMul(origin, height)));

        stopX += width;
        stopY += height;
    }
    SkASSERT(textPtr == stop);

    SkGlyphCache::AttachCache(origPaintCache);

    // now adjust starting point depending on alignment
    SkScalar alignX = SkFixedToScalar(stopX);
    SkScalar alignY = SkFixedToScalar(stopY);
    if (skPaint.getTextAlign() == SkPaint::kCenter_Align) {
        alignX = SkScalarHalf(alignX);
        alignY = SkScalarHalf(alignY);
    } else if (skPaint.getTextAlign() == SkPaint::kLeft_Align) {
        alignX = 0;
        alignY = 0;
    }
    x -= alignX;
    y -= alignY;
    SkPoint offset = SkPoint::Make(x, y);

    DrawDFPosText(blob, runIndex, fontCache, props, skPaint, color, viewMatrix, text, byteLength,
                  positions.begin(), 2, offset);
}

void SkTextBox::draw(SkCanvas* canvas, const char text[], size_t len, const SkPaint& paint)
{
    SkASSERT(canvas && &paint && (text || len == 0));

    SkScalar marginWidth = fBox.width();

    if (marginWidth <= 0 || len == 0)
        return;

    const char* textStop = text + len;

    SkScalar                x, y, scaledSpacing, height, fontHeight;
    SkPaint::FontMetrics    metrics;

    switch (paint.getTextAlign()) {
    case SkPaint::kLeft_Align:
        x = 0;
        break;
    case SkPaint::kCenter_Align:
        x = SkScalarHalf(marginWidth);
        break;
    default:
        x = marginWidth;
        break;
    }
    x += fBox.fLeft;

    fontHeight = paint.getFontMetrics(&metrics);
    scaledSpacing = SkScalarMul(fontHeight, fSpacingMul) + fSpacingAdd;
    height = fBox.height();

    //  compute Y position for first line
    {
        SkScalar textHeight = fontHeight;

        if (fMode == kLineBreak_Mode && fSpacingAlign != kStart_SpacingAlign)
        {
            int count = SkTextLineBreaker::CountLines(text, textStop - text, paint, marginWidth);
            SkASSERT(count > 0);
            textHeight += scaledSpacing * (count - 1);
        }

        switch (fSpacingAlign) {
        case kStart_SpacingAlign:
            y = 0;
            break;
        case kCenter_SpacingAlign:
            y = SkScalarHalf(height - textHeight);
            break;
        default:
            SkASSERT(fSpacingAlign == kEnd_SpacingAlign);
            y = height - textHeight;
            break;
        }
        y += fBox.fTop - metrics.fAscent;
    }

    for (;;)
    {
        len = linebreak(text, textStop, paint, marginWidth);
        if (y + metrics.fDescent + metrics.fLeading > 0)
            canvas->drawText(text, len, x, y, paint);
        text += len;
        if (text >= textStop)
            break;
        y += scaledSpacing;
        if (y + metrics.fAscent >= height)
            break;
    } 
}