C++ SkAutoKern::adjust方法代码示例

void GrStencilAndCoverTextContext::TextRun::setText(const char text[], size_t byteLength,
                                                    SkScalar x, SkScalar y) {
    SkASSERT(byteLength == 0 || text != nullptr);

    SkGlyphCache* glyphCache = this->getGlyphCache();
    SkPaint::GlyphCacheProc glyphCacheProc = SkPaint::GetGlyphCacheProc(fFont.getTextEncoding(),
                                                                        fFont.isDevKernText(),
                                                                        true);

    fTotalGlyphCount = fFont.countText(text, byteLength);
    fInstanceData.reset(InstanceData::Alloc(GrPathRendering::kTranslate_PathTransformType,
                                            fTotalGlyphCount));

    const char* stop = text + byteLength;

    // Measure first if needed.
    if (fFont.getTextAlign() != SkPaint::kLeft_Align) {
        SkScalar   stopX = 0;
        SkScalar   stopY = 0;

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

            stopX += SkFloatToScalar(glyph.fAdvanceX);
            stopY += SkFloatToScalar(glyph.fAdvanceY);
        }
        SkASSERT(textPtr == stop);

        SkScalar alignX = stopX * fTextRatio;
        SkScalar alignY = stopY * fTextRatio;

        if (fFont.getTextAlign() == SkPaint::kCenter_Align) {
            alignX = SkScalarHalf(alignX);
            alignY = SkScalarHalf(alignY);
        }

        x -= alignX;
        y -= alignY;
    }

    SkAutoKern autokern;

    FallbackBlobBuilder fallback;
    while (text < stop) {
        const SkGlyph& glyph = glyphCacheProc(glyphCache, &text);
        x += autokern.adjust(glyph) * fTextRatio;
        if (glyph.fWidth) {
            this->appendGlyph(glyph, SkPoint::Make(x, y), &fallback);
        }

        x += SkFloatToScalar(glyph.fAdvanceX) * fTextRatio;
        y += SkFloatToScalar(glyph.fAdvanceY) * fTextRatio;
    }

    fFallbackTextBlob = fallback.makeIfNeeded(&fFallbackGlyphCount);
}

static size_t linebreak(const char text[], const char stop[], const SkPaint& paint, SkScalar margin)
{
    const char* start = text;

    SkAutoGlyphCache    ac(paint, NULL);
    SkGlyphCache*       cache = ac.getCache();
    SkFixed             w = 0;
    SkFixed             limit = SkScalarToFixed(margin);
    SkAutoKern          autokern;

    const char* word_start = text;
    int         prevWS = true;

    while (text < stop)
    {
        const char* prevText = text;
        SkUnichar   uni = SkUTF8_NextUnichar(&text);
        int         currWS = is_ws(uni);
        const SkGlyph&  glyph = cache->getUnicharMetrics(uni);

        if (!currWS && prevWS)
            word_start = prevText;
        prevWS = currWS;

        w += autokern.adjust(glyph) + glyph.fAdvanceX;
        if (w > limit)
        {
            if (currWS) // eat the rest of the whitespace
            {
                while (text < stop && is_ws(SkUTF8_ToUnichar(text)))
                    text += SkUTF8_CountUTF8Bytes(text);
            }
            else    // backup until a whitespace (or 1 char)
            {
                if (word_start == start)
                {
                    if (prevText > start)
                        text = prevText;
                }
                else
                    text = word_start;
            }
            break;
        }
    }
    return text - start;
}

void GrBitmapTextContext::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) {
    SkASSERT(byteLength == 0 || text != NULL);

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

    this->init(rt, clip, paint, skPaint);

    SkDrawCacheProc glyphCacheProc = fSkPaint.getDrawCacheProc();

    SkAutoGlyphCache    autoCache(fSkPaint, &fDeviceProperties, &viewMatrix);
    SkGlyphCache*       cache = autoCache.getCache();
    GrFontScaler*       fontScaler = GetGrFontScaler(cache);

    // transform our starting point
    {
        SkPoint loc;
        viewMatrix.mapXY(x, y, &loc);
        x = loc.fX;
        y = loc.fY;
    }

    // need to measure first
    int numGlyphs;
    if (fSkPaint.getTextAlign() != SkPaint::kLeft_Align) {
        SkVector    stopVector;
        numGlyphs = MeasureText(cache, glyphCacheProc, text, byteLength, &stopVector);

        SkScalar    stopX = stopVector.fX;
        SkScalar    stopY = stopVector.fY;

        if (fSkPaint.getTextAlign() == SkPaint::kCenter_Align) {
            stopX = SkScalarHalf(stopX);
            stopY = SkScalarHalf(stopY);
        }
        x -= stopX;
        y -= stopY;
    } else {
        numGlyphs = fSkPaint.textToGlyphs(text, byteLength, NULL);
    }
    fTotalVertexCount = kVerticesPerGlyph*numGlyphs;

    const char* stop = text + byteLength;

    SkAutoKern autokern;

    SkFixed fxMask = ~0;
    SkFixed fyMask = ~0;
    SkScalar halfSampleX, halfSampleY;
    if (cache->isSubpixel()) {
        halfSampleX = halfSampleY = SkFixedToScalar(SkGlyph::kSubpixelRound);
        SkAxisAlignment baseline = SkComputeAxisAlignmentForHText(viewMatrix);
        if (kX_SkAxisAlignment == baseline) {
            fyMask = 0;
            halfSampleY = SK_ScalarHalf;
        } else if (kY_SkAxisAlignment == baseline) {
            fxMask = 0;
            halfSampleX = SK_ScalarHalf;
        }
    } else {
        halfSampleX = halfSampleY = SK_ScalarHalf;
    }

    Sk48Dot16 fx = SkScalarTo48Dot16(x + halfSampleX);
    Sk48Dot16 fy = SkScalarTo48Dot16(y + halfSampleY);

    // if we have RGB, then we won't have any SkShaders so no need to use a localmatrix, but for
    // performance reasons we just invert here instead
    if (!viewMatrix.invert(&fLocalMatrix)) {
        SkDebugf("Cannot invert viewmatrix\n");
        return;
    }

    while (text < stop) {
        const SkGlyph& glyph = glyphCacheProc(cache, &text, fx & fxMask, fy & fyMask);

        fx += autokern.adjust(glyph);

        if (glyph.fWidth) {
            this->appendGlyph(GrGlyph::Pack(glyph.getGlyphID(),
                                            glyph.getSubXFixed(),
                                            glyph.getSubYFixed(),
                                            GrGlyph::kCoverage_MaskStyle),
                              Sk48Dot16FloorToInt(fx),
                              Sk48Dot16FloorToInt(fy),
                              fontScaler);
        }

        fx += glyph.fAdvanceX;
        fy += glyph.fAdvanceY;
    }

    this->finish();
}

void GrStencilAndCoverTextContext::onDrawText(GrDrawContext* drawContext, 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);

    if (text == NULL || byteLength == 0 /*|| fRC->isEmpty()*/) {
        return;
    }

    // This is the slow path, mainly used by Skia unit tests.  The other
    // backends (8888, gpu, ...) use device-space dependent glyph caches. In
    // order to match the glyph positions that the other code paths produce, we
    // must also use device-space dependent glyph cache. This has the
    // side-effect that the glyph shape outline will be in device-space,
    // too. This in turn has the side-effect that NVPR can not stroke the paths,
    // as the stroke in NVPR is defined in object-space.
    // NOTE: here we have following coincidence that works at the moment:
    // - When using the device-space glyphs, the transforms we pass to NVPR
    // instanced drawing are the global transforms, and the view transform is
    // identity. NVPR can not use non-affine transforms in the instanced
    // drawing. This is taken care of by SkDraw::ShouldDrawTextAsPaths since it
    // will turn off the use of device-space glyphs when perspective transforms
    // are in use.

    this->init(rt, clip, paint, skPaint, byteLength, kMaxAccuracy_RenderMode, viewMatrix,
               regionClipBounds);

    // Transform our starting point.
    if (fUsingDeviceSpaceGlyphs) {
        SkPoint loc;
        fContextInitialMatrix.mapXY(x, y, &loc);
        x = loc.fX;
        y = loc.fY;
    }

    SkDrawCacheProc glyphCacheProc = fSkPaint.getDrawCacheProc();

    const char* stop = text + byteLength;

    // Measure first if needed.
    if (fSkPaint.getTextAlign() != SkPaint::kLeft_Align) {
        SkFixed    stopX = 0;
        SkFixed    stopY = 0;

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

            stopX += glyph.fAdvanceX;
            stopY += glyph.fAdvanceY;
        }
        SkASSERT(textPtr == stop);

        SkScalar alignX = SkFixedToScalar(stopX) * fTextRatio;
        SkScalar alignY = SkFixedToScalar(stopY) * fTextRatio;

        if (fSkPaint.getTextAlign() == SkPaint::kCenter_Align) {
            alignX = SkScalarHalf(alignX);
            alignY = SkScalarHalf(alignY);
        }

        x -= alignX;
        y -= alignY;
    }

    SkAutoKern autokern;

    SkFixed fixedSizeRatio = SkScalarToFixed(fTextRatio);

    SkFixed fx = SkScalarToFixed(x);
    SkFixed fy = SkScalarToFixed(y);
    while (text < stop) {
        const SkGlyph& glyph = glyphCacheProc(fGlyphCache, &text, 0, 0);
        fx += SkFixedMul(autokern.adjust(glyph), fixedSizeRatio);
        if (glyph.fWidth) {
            this->appendGlyph(drawContext, glyph, 
                              SkPoint::Make(SkFixedToScalar(fx), SkFixedToScalar(fy)));
        }

        fx += SkFixedMul(glyph.fAdvanceX, fixedSizeRatio);
        fy += SkFixedMul(glyph.fAdvanceY, fixedSizeRatio);
    }

    this->finish(drawContext);
}

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 GrStencilAndCoverTextContext::TextRun::setText(const char text[], size_t byteLength,
        SkScalar x, SkScalar y) {
    SkASSERT(byteLength == 0 || text != nullptr);

    SkGlyphCache* glyphCache = this->getGlyphCache();
    SkDrawCacheProc glyphCacheProc = fFont.getDrawCacheProc();

    fTotalGlyphCount = fFont.countText(text, byteLength);
    fInstanceData.reset(InstanceData::Alloc(GrPathRendering::kTranslate_PathTransformType,
                                            fTotalGlyphCount));

    const char* stop = text + byteLength;

    // Measure first if needed.
    if (fFont.getTextAlign() != SkPaint::kLeft_Align) {
        SkFixed    stopX = 0;
        SkFixed    stopY = 0;

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

            stopX += glyph.fAdvanceX;
            stopY += glyph.fAdvanceY;
        }
        SkASSERT(textPtr == stop);

        SkScalar alignX = SkFixedToScalar(stopX) * fTextRatio;
        SkScalar alignY = SkFixedToScalar(stopY) * fTextRatio;

        if (fFont.getTextAlign() == SkPaint::kCenter_Align) {
            alignX = SkScalarHalf(alignX);
            alignY = SkScalarHalf(alignY);
        }

        x -= alignX;
        y -= alignY;
    }

    SkAutoKern autokern;

    SkFixed fixedSizeRatio = SkScalarToFixed(fTextRatio);

    SkFixed fx = SkScalarToFixed(x);
    SkFixed fy = SkScalarToFixed(y);
    FallbackBlobBuilder fallback;
    while (text < stop) {
        const SkGlyph& glyph = glyphCacheProc(glyphCache, &text, 0, 0);
        fx += SkFixedMul(autokern.adjust(glyph), fixedSizeRatio);
        if (glyph.fWidth) {
            this->appendGlyph(glyph, SkPoint::Make(SkFixedToScalar(fx), SkFixedToScalar(fy)),
                              &fallback);
        }

        fx += SkFixedMul(glyph.fAdvanceX, fixedSizeRatio);
        fy += SkFixedMul(glyph.fAdvanceY, fixedSizeRatio);
    }

    fFallbackTextBlob.reset(fallback.buildIfNeeded(&fFallbackGlyphCount));
}

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);
}