C++ SkPaint::getDrawCacheProc方法代码示例

void SkPDFDevice::drawPosText(const SkDraw&, const void* text, size_t len,
                              const SkScalar pos[], SkScalar constY,
                              int scalarsPerPos, const SkPaint& paint) {
    SkASSERT(1 == scalarsPerPos || 2 == scalarsPerPos);
    SkPaint textPaint = calculateTextPaint(paint);
    updateGSFromPaint(textPaint, true);

    // Make sure we have a glyph id encoding.
    SkAutoFree glyphStorage;
    uint16_t* glyphIDs;
    size_t numGlyphs;
    if (paint.getTextEncoding() != SkPaint::kGlyphID_TextEncoding) {
        numGlyphs = paint.textToGlyphs(text, len, NULL);
        glyphIDs = (uint16_t*)sk_malloc_flags(numGlyphs * 2,
                                              SK_MALLOC_TEMP | SK_MALLOC_THROW);
        glyphStorage.set(glyphIDs);
        paint.textToGlyphs(text, len, glyphIDs);
        textPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
    } else {
        SkASSERT((len & 1) == 0);
        numGlyphs = len / 2;
        glyphIDs = (uint16_t*)text;
    }

    SkDrawCacheProc glyphCacheProc = textPaint.getDrawCacheProc();
    fContent.writeText("BT\n");
    updateFont(textPaint, glyphIDs[0]);
    for (size_t i = 0; i < numGlyphs; i++) {
        SkPDFFont* font = fGraphicStack[fGraphicStackIndex].fFont;
        uint16_t encodedValue = glyphIDs[i];
        if (font->glyphsToPDFFontEncoding(&encodedValue, 1) != 1) {
            updateFont(textPaint, glyphIDs[i]);
            i--;
            continue;
        }
        SkScalar x = pos[i * scalarsPerPos];
        SkScalar y = scalarsPerPos == 1 ? constY : pos[i * scalarsPerPos + 1];
        alignText(glyphCacheProc, textPaint, glyphIDs + i, 1, &x, &y, NULL);
        setTextTransform(x, y, textPaint.getTextSkewX());
        SkString encodedString =
            SkPDFString::formatString(&encodedValue, 1,
                                      font->multiByteGlyphs());
        fContent.writeText(encodedString.c_str());
        fContent.writeText(" Tj\n");
    }
    fContent.writeText("ET\n");
}

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 SkPDFDevice::drawText(const SkDraw& d, const void* text, size_t len,
                           SkScalar x, SkScalar y, const SkPaint& paint) {
    SkPaint textPaint = calculateTextPaint(paint);
    updateGSFromPaint(textPaint, true);

    // We want the text in glyph id encoding and a writable buffer, so we end
    // up making a copy either way.
    size_t numGlyphs = paint.textToGlyphs(text, len, NULL);
    uint16_t* glyphIDs =
        (uint16_t*)sk_malloc_flags(numGlyphs * 2,
                                   SK_MALLOC_TEMP | SK_MALLOC_THROW);
    SkAutoFree autoFreeGlyphIDs(glyphIDs);
    if (paint.getTextEncoding() != SkPaint::kGlyphID_TextEncoding) {
        paint.textToGlyphs(text, len, glyphIDs);
        textPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
    } else {
        SkASSERT((len & 1) == 0);
        SkASSERT(len / 2 == numGlyphs);
        memcpy(glyphIDs, text, len);
    }

    SkScalar width;
    SkScalar* widthPtr = NULL;
    if (textPaint.isUnderlineText() || textPaint.isStrikeThruText())
        widthPtr = &width;

    SkDrawCacheProc glyphCacheProc = textPaint.getDrawCacheProc();
    alignText(glyphCacheProc, textPaint, glyphIDs, numGlyphs, &x, &y, widthPtr);
    fContent.writeText("BT\n");
    setTextTransform(x, y, textPaint.getTextSkewX());
    size_t consumedGlyphCount = 0;
    while (numGlyphs > consumedGlyphCount) {
        updateFont(textPaint, glyphIDs[consumedGlyphCount]);
        SkPDFFont* font = fGraphicStack[fGraphicStackIndex].fFont;
        size_t availableGlyphs =
            font->glyphsToPDFFontEncoding(glyphIDs + consumedGlyphCount,
                                          numGlyphs - consumedGlyphCount);
        SkString encodedString =
            SkPDFString::formatString(glyphIDs + consumedGlyphCount,
                                      availableGlyphs, font->multiByteGlyphs());
        fContent.writeText(encodedString.c_str());
        consumedGlyphCount += availableGlyphs;
        fContent.writeText(" Tj\n");
    }
    fContent.writeText("ET\n");

    // Draw underline and/or strikethrough if the paint has them.
    // drawPosText() and drawTextOnPath() don't draw underline or strikethrough
    // because the raster versions don't.  Use paint instead of textPaint
    // because we may have changed strokeWidth to do fakeBold text.
    if (paint.isUnderlineText() || paint.isStrikeThruText()) {
        SkScalar textSize = paint.getTextSize();
        SkScalar height = SkScalarMul(textSize, kStdUnderline_Thickness);

        if (paint.isUnderlineText()) {
            SkScalar top = SkScalarMulAdd(textSize, kStdUnderline_Offset, y);
            SkRect r = SkRect::MakeXYWH(x, top - height, width, height);
            drawRect(d, r, paint);
        }
        if (paint.isStrikeThruText()) {
            SkScalar top = SkScalarMulAdd(textSize, kStdStrikeThru_Offset, y);
            SkRect r = SkRect::MakeXYWH(x, top - height, width, height);
            drawRect(d, r, paint);
        }
    }
}