C++ SkAutoTDelete::detach方法代码示例

/**
 * Extract either the color or image data from a SkBitmap into a SkStream.
 * @param bitmap        Bitmap to extract data from.
 * @param srcRect       Region in the bitmap to extract.
 * @param extractAlpha  Set to true to extract the alpha data or false to
 *                      extract the color data.
 * @param isTransparent Pointer to a bool to output whether the alpha is
 *                      completely transparent. May be NULL. Only valid when
 *                      extractAlpha == true.
 * @return              Unencoded image data, or NULL if either data was not
 *                      available or alpha data was requested but the image was
 *                      entirely transparent or opaque.
 */
static SkStream* extract_image_data(const SkBitmap& bitmap,
                                    const SkIRect& srcRect,
                                    bool extractAlpha, bool* isTransparent) {
    SkColorType colorType = bitmap.colorType();
    if (extractAlpha && (kIndex_8_SkColorType == colorType ||
                         kRGB_565_SkColorType == colorType)) {
        if (isTransparent != NULL) {
            *isTransparent = false;
        }
        return NULL;
    }

    SkAutoLockPixels lock(bitmap);
    if (NULL == bitmap.getPixels()) {
        return NULL;
    }

    bool isOpaque = true;
    bool transparent = extractAlpha;
    SkAutoTDelete<SkStream> stream;

    switch (colorType) {
        case kIndex_8_SkColorType:
            if (!extractAlpha) {
                stream.reset(extract_index8_image(bitmap, srcRect));
            }
            break;
        case kARGB_4444_SkColorType:
            stream.reset(extract_argb4444_data(bitmap, srcRect, extractAlpha,
                                               &isOpaque, &transparent));
            break;
        case kRGB_565_SkColorType:
            if (!extractAlpha) {
                stream.reset(extract_rgb565_image(bitmap, srcRect));
            }
            break;
        case kN32_SkColorType:
            stream.reset(extract_argb8888_data(bitmap, srcRect, extractAlpha,
                                               &isOpaque, &transparent));
            break;
        case kAlpha_8_SkColorType:
            if (!extractAlpha) {
                stream.reset(create_black_image());
            } else {
                stream.reset(extract_a8_alpha(bitmap, srcRect,
                                              &isOpaque, &transparent));
            }
            break;
        default:
            SkASSERT(false);
    }

    if (isTransparent != NULL) {
        *isTransparent = transparent;
    }
    if (extractAlpha && (transparent || isOpaque)) {
        return NULL;
    }
    return stream.detach();
}

SkBitmapRegionDecoder* SkBitmapRegionDecoder::Create(
        SkStreamRewindable* stream, Strategy strategy) {
    SkAutoTDelete<SkStreamRewindable> streamDeleter(stream);
    switch (strategy) {
        case kCanvas_Strategy: {
            SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(streamDeleter.detach()));
            if (nullptr == codec) {
                SkCodecPrintf("Error: Failed to create decoder.\n");
                return nullptr;
            }

            SkEncodedFormat format = codec->getEncodedFormat();
            switch (format) {
                case SkEncodedFormat::kJPEG_SkEncodedFormat:
                case SkEncodedFormat::kPNG_SkEncodedFormat:
                    break;
                default:
                    // FIXME: Support webp using a special case.  Webp does not support
                    //        scanline decoding.
                    return nullptr;
            }

            // If the image is a jpeg or a png, the scanline ordering should always be
            // kTopDown or kNone.  It is relevant to check because this implementation
            // only supports these two scanline orderings.
            SkASSERT(SkCodec::kTopDown_SkScanlineOrder == codec->getScanlineOrder() ||
                    SkCodec::kNone_SkScanlineOrder == codec->getScanlineOrder());

            return new SkBitmapRegionCanvas(codec.detach());
        }
        case kAndroidCodec_Strategy: {
            SkAutoTDelete<SkAndroidCodec> codec =
                    SkAndroidCodec::NewFromStream(streamDeleter.detach());
            if (nullptr == codec) {
                SkCodecPrintf("Error: Failed to create codec.\n");
                return NULL;
            }

            SkEncodedFormat format = codec->getEncodedFormat();
            switch (format) {
                case SkEncodedFormat::kJPEG_SkEncodedFormat:
                case SkEncodedFormat::kPNG_SkEncodedFormat:
                case SkEncodedFormat::kWEBP_SkEncodedFormat:
                    break;
                default:
                    return nullptr;
            }

            return new SkBitmapRegionCodec(codec.detach());
        }
        default:
            SkASSERT(false);
            return nullptr;
    }
}

SkBitmapRegionDecoder* SkBitmapRegionDecoder::Create(
        SkStreamRewindable* stream, Strategy strategy) {
    SkAutoTDelete<SkStreamRewindable> streamDeleter(stream);
    switch (strategy) {
        case kCanvas_Strategy: {
            SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(streamDeleter.detach()));
            if (nullptr == codec) {
                SkCodecPrintf("Error: Failed to create decoder.\n");
                return nullptr;
            }

            if (SkEncodedFormat::kWEBP_SkEncodedFormat == codec->getEncodedFormat()) {
                // FIXME: Support webp using a special case.  Webp does not support
                //        scanline decoding.
                return nullptr;
            }

            switch (codec->getScanlineOrder()) {
                case SkCodec::kTopDown_SkScanlineOrder:
                case SkCodec::kNone_SkScanlineOrder:
                    break;
                default:
                    SkCodecPrintf("Error: Scanline ordering not supported.\n");
                    return nullptr;
            }
            return new SkBitmapRegionCanvas(codec.detach());
        }
        case kAndroidCodec_Strategy: {
            SkAutoTDelete<SkAndroidCodec> codec =
                    SkAndroidCodec::NewFromStream(streamDeleter.detach());
            if (NULL == codec) {
                SkCodecPrintf("Error: Failed to create codec.\n");
                return NULL;
            }
            return new SkBitmapRegionCodec(codec.detach());
        }
        default:
            SkASSERT(false);
            return nullptr;
    }
}

/*
 * nine patch not supported
 *
 * purgeable not supported
 * reportSizeToVM not supported
 */
static jobject nativeDecodeRegion(JNIEnv* env, jobject, jlong brdHandle,
                                jint start_x, jint start_y, jint width, jint height, jobject options) {
    SkBitmapRegionDecoder *brd = reinterpret_cast<SkBitmapRegionDecoder*>(brdHandle);
    jobject tileBitmap = NULL;
    SkImageDecoder *decoder = brd->getDecoder();
    int sampleSize = 1;
    SkColorType prefColorType = kUnknown_SkColorType;
    bool doDither = true;
    bool preferQualityOverSpeed = false;
    bool requireUnpremultiplied = false;

    if (NULL != options) {
        sampleSize = env->GetIntField(options, gOptions_sampleSizeFieldID);
        // initialize these, in case we fail later on
        env->SetIntField(options, gOptions_widthFieldID, -1);
        env->SetIntField(options, gOptions_heightFieldID, -1);
        env->SetObjectField(options, gOptions_mimeFieldID, 0);

        jobject jconfig = env->GetObjectField(options, gOptions_configFieldID);
        prefColorType = GraphicsJNI::getNativeBitmapColorType(env, jconfig);
        doDither = env->GetBooleanField(options, gOptions_ditherFieldID);
        preferQualityOverSpeed = env->GetBooleanField(options,
                gOptions_preferQualityOverSpeedFieldID);
        // Get the bitmap for re-use if it exists.
        tileBitmap = env->GetObjectField(options, gOptions_bitmapFieldID);
        requireUnpremultiplied = !env->GetBooleanField(options, gOptions_premultipliedFieldID);
    }

    decoder->setDitherImage(doDither);
    decoder->setPreferQualityOverSpeed(preferQualityOverSpeed);
    decoder->setRequireUnpremultipliedColors(requireUnpremultiplied);
    AutoDecoderCancel adc(options, decoder);

    // To fix the race condition in case "requestCancelDecode"
    // happens earlier than AutoDecoderCancel object is added
    // to the gAutoDecoderCancelMutex linked list.
    if (NULL != options && env->GetBooleanField(options, gOptions_mCancelID)) {
        return nullObjectReturn("gOptions_mCancelID");;
    }

    SkIRect region;
    region.fLeft = start_x;
    region.fTop = start_y;
    region.fRight = start_x + width;
    region.fBottom = start_y + height;
    SkBitmap* bitmap = NULL;
    SkAutoTDelete<SkBitmap> adb;

    if (tileBitmap != NULL) {
        // Re-use bitmap.
        bitmap = GraphicsJNI::getNativeBitmap(env, tileBitmap);
    }
    if (bitmap == NULL) {
        bitmap = new SkBitmap;
        adb.reset(bitmap);
    }

    if (!brd->decodeRegion(bitmap, region, prefColorType, sampleSize)) {
        return nullObjectReturn("decoder->decodeRegion returned false");
    }

    // update options (if any)
    if (NULL != options) {
        env->SetIntField(options, gOptions_widthFieldID, bitmap->width());
        env->SetIntField(options, gOptions_heightFieldID, bitmap->height());
        // TODO: set the mimeType field with the data from the codec.
        // but how to reuse a set of strings, rather than allocating new one
        // each time?
        env->SetObjectField(options, gOptions_mimeFieldID,
                            getMimeTypeString(env, decoder->getFormat()));
    }

    if (tileBitmap != NULL) {
        return tileBitmap;
    }

    // detach bitmap from its autodeleter, since we want to own it now
    adb.detach();

    JavaPixelAllocator* allocator = (JavaPixelAllocator*) decoder->getAllocator();
    jbyteArray buff = allocator->getStorageObjAndReset();

    int bitmapCreateFlags = 0;
    if (!requireUnpremultiplied) bitmapCreateFlags |= GraphicsJNI::kBitmapCreateFlag_Premultiplied;
    return GraphicsJNI::createBitmap(env, bitmap, buff, bitmapCreateFlags, NULL, NULL, -1);
}

//.........这里部分代码省略.........
    int repeatedAdvances = 0;
    int wildCardsInRun = 0;
    int trailingWildCards = 0;
    uint32_t subsetIndex = 0;

    // Limit the loop count to glyph id ranges provided.
    int firstIndex = 0;
    int lastIndex = num_glyphs;
    if (subsetGlyphIDs) {
        firstIndex = static_cast<int>(subsetGlyphIDs[0]);
        lastIndex =
                static_cast<int>(subsetGlyphIDs[subsetGlyphIDsLength - 1]) + 1;
    }
    curRange = appendRange(&result, firstIndex);

    for (int gId = firstIndex; gId <= lastIndex; gId++) {
        Data advance = kInvalidAdvance;
        if (gId < lastIndex) {
            // Get glyph id only when subset is NULL, or the id is in subset.
            if (!subsetGlyphIDs ||
                (subsetIndex < subsetGlyphIDsLength &&
                 static_cast<uint32_t>(gId) == subsetGlyphIDs[subsetIndex])) {
                SkAssertResult(getAdvance(fontHandle, gId, &advance));
                ++subsetIndex;
            } else {
                advance = kDontCareAdvance;
            }
        }
        if (advance == lastAdvance) {
            repeatedAdvances++;
            trailingWildCards = 0;
        } else if (advance == kDontCareAdvance) {
            wildCardsInRun++;
            trailingWildCards++;
        } else if (curRange->fAdvance.count() ==
                   repeatedAdvances + 1 + wildCardsInRun) {  // All in run.
            if (lastAdvance == 0) {
                resetRange(curRange, gId);
                trailingWildCards = 0;
            } else if (repeatedAdvances + 1 >= 2 || trailingWildCards >= 4) {
                finishRange(curRange, gId - 1,
                            SkAdvancedTypefaceMetrics::WidthRange::kRun);
                prevRange = curRange;
                curRange = appendRange(&curRange->fNext, gId);
                trailingWildCards = 0;
            }
            repeatedAdvances = 0;
            wildCardsInRun = trailingWildCards;
            trailingWildCards = 0;
        } else {
            if (lastAdvance == 0 &&
                    repeatedAdvances + 1 + wildCardsInRun >= 4) {
                finishRange(curRange,
                            gId - repeatedAdvances - wildCardsInRun - 2,
                            SkAdvancedTypefaceMetrics::WidthRange::kRange);
                prevRange = curRange;
                curRange = appendRange(&curRange->fNext, gId);
                trailingWildCards = 0;
            } else if (trailingWildCards >= 4 && repeatedAdvances + 1 < 2) {
                finishRange(curRange,
                            gId - trailingWildCards - 1,
                            SkAdvancedTypefaceMetrics::WidthRange::kRange);
                prevRange = curRange;
                curRange = appendRange(&curRange->fNext, gId);
                trailingWildCards = 0;
            } else if (lastAdvance != 0 &&
                       (repeatedAdvances + 1 >= 3 ||
                        (repeatedAdvances + 1 >= 2 && wildCardsInRun >= 3))) {
                finishRange(curRange,
                            gId - repeatedAdvances - wildCardsInRun - 2,
                            SkAdvancedTypefaceMetrics::WidthRange::kRange);
                curRange =
                    appendRange(&curRange->fNext,
                                gId - repeatedAdvances - wildCardsInRun - 1);
                curRange->fAdvance.append(1, &lastAdvance);
                finishRange(curRange, gId - 1,
                            SkAdvancedTypefaceMetrics::WidthRange::kRun);
                prevRange = curRange;
                curRange = appendRange(&curRange->fNext, gId);
                trailingWildCards = 0;
            }
            repeatedAdvances = 0;
            wildCardsInRun = trailingWildCards;
            trailingWildCards = 0;
        }
        curRange->fAdvance.append(1, &advance);
        if (advance != kDontCareAdvance) {
            lastAdvance = advance;
        }
    }
    if (curRange->fStartId == lastIndex) {
        SkASSERT(prevRange);
        SkASSERT(prevRange->fNext->fStartId == lastIndex);
        prevRange->fNext.free();
    } else {
        finishRange(curRange, lastIndex - 1,
                    SkAdvancedTypefaceMetrics::WidthRange::kRange);
    }
    return result.detach();
}