C++ SkPixmap::height方法代码示例

bool SkPixmap::scalePixels(const SkPixmap& dst, SkFilterQuality quality) const {
    // Can't do anthing with empty src or dst
    if (this->width() <= 0 || this->height() <= 0 || dst.width() <= 0 || dst.height() <= 0) {
        return false;
    }

    // no scaling involved?
    if (dst.width() == this->width() && dst.height() == this->height()) {
        return this->readPixels(dst);
    }

    SkBitmap bitmap;
    if (!bitmap.installPixels(*this)) {
        return false;
    }
    bitmap.setIsVolatile(true); // so we don't try to cache it

    SkAutoTUnref<SkSurface> surface(SkSurface::NewRasterDirect(dst.info(), dst.writable_addr(),
                                                               dst.rowBytes()));
    if (!surface) {
        return false;
    }

    SkPaint paint;
    paint.setFilterQuality(quality);
    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
    surface->getCanvas()->drawBitmapRect(bitmap, SkRect::MakeIWH(dst.width(), dst.height()),
                                         &paint);
    return true;
}

bool SkBitmapScaler::Resize(const SkPixmap& result, const SkPixmap& source, ResizeMethod method) {
    if (!valid_for_resize(source, result.width(), result.height())) {
        return false;
    }
    if (!result.addr() || result.colorType() != source.colorType()) {
        return false;
    }

    SkConvolutionProcs convolveProcs= { 0, nullptr, nullptr, nullptr, nullptr };
    PlatformConvolutionProcs(&convolveProcs);

    SkRect destSubset = SkRect::MakeIWH(result.width(), result.height());

    SkResizeFilter filter(method, source.width(), source.height(),
                          result.width(), result.height(), destSubset, convolveProcs);

    // Get a subset encompassing this touched area. We construct the
    // offsets and row strides such that it looks like a new bitmap, while
    // referring to the old data.
    const uint8_t* sourceSubset = reinterpret_cast<const uint8_t*>(source.addr());

    return BGRAConvolve2D(sourceSubset, static_cast<int>(source.rowBytes()),
                          !source.isOpaque(), filter.xFilter(), filter.yFilter(),
                          static_cast<int>(result.rowBytes()),
                          static_cast<unsigned char*>(result.writable_addr()),
                          convolveProcs, true);
}

void SkDrawCommandGeometryWidget::paintEvent(QPaintEvent* event) {
    this->QFrame::paintEvent(event);

    if (!fSurface) {
        return;
    }

    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);

    SkPixmap pixmap;

    if (fSurface->peekPixels(&pixmap)) {
        SkASSERT(pixmap.width() > 0);
        SkASSERT(pixmap.height() > 0);

        QRectF resultRect;
        if (this->width() < this->height()) {
            float ratio = this->width() / pixmap.width();
            resultRect = QRectF(0, 0, this->width(), ratio * pixmap.height());
        } else {
            float ratio = this->height() / pixmap.height();
            resultRect = QRectF(0, 0, ratio * pixmap.width(), this->height());
        }

        resultRect.moveCenter(this->contentsRect().center());

        QImage image(reinterpret_cast<const uchar*>(pixmap.addr()),
                     pixmap.width(),
                     pixmap.height(),
                     pixmap.rowBytes(),
                     QImage::Format_ARGB32_Premultiplied);
        painter.drawImage(resultRect, image);
    }
}

bool SkBitmapScaler::Resize(SkBitmap* resultPtr, const SkPixmap& source, ResizeMethod method,
                            int destWidth, int destHeight, SkBitmap::Allocator* allocator) {
    if (nullptr == source.addr() || source.colorType() != kN32_SkColorType ||
        source.width() < 1 || source.height() < 1)
    {
        return false;
    }

    if (destWidth < 1 || destHeight < 1) {
        return false;
    }

    SkConvolutionProcs convolveProcs= { 0, nullptr, nullptr, nullptr, nullptr };
    PlatformConvolutionProcs(&convolveProcs);

    SkRect destSubset = SkRect::MakeIWH(destWidth, destHeight);

    SkResizeFilter filter(method, source.width(), source.height(),
                        destWidth, destHeight, destSubset, convolveProcs);

    // Get a subset encompassing this touched area. We construct the
    // offsets and row strides such that it looks like a new bitmap, while
    // referring to the old data.
    const uint8_t* sourceSubset = reinterpret_cast<const uint8_t*>(source.addr());

    // Convolve into the result.
    SkBitmap result;
    result.setInfo(SkImageInfo::MakeN32(SkScalarCeilToInt(destSubset.width()),
                                      SkScalarCeilToInt(destSubset.height()),
                                      source.alphaType()));
    result.allocPixels(allocator, nullptr);
    if (!result.readyToDraw()) {
      return false;
    }

    if (!BGRAConvolve2D(sourceSubset, static_cast<int>(source.rowBytes()),
                        !source.isOpaque(), filter.xFilter(), filter.yFilter(),
                        static_cast<int>(result.rowBytes()),
                        static_cast<unsigned char*>(result.getPixels()),
                        convolveProcs, true)) {
        return false;
    }

    *resultPtr = result;
    resultPtr->lockPixels();
    SkASSERT(resultPtr->getPixels());
    return true;
}

bool SkPixmap::erase(const SkColor4f& origColor, const SkIRect* subset) const {
    SkPixmap pm;
    if (subset) {
        if (!this->extractSubset(&pm, *subset)) {
            return false;
        }
    } else {
        pm = *this;
    }

    const SkColor4f color = origColor.pin();

    if (kRGBA_F16_SkColorType != pm.colorType()) {
        Sk4f c4 = Sk4f::Load(color.vec());
        SkColor c;
        (c4 * Sk4f(255) + Sk4f(0.5f)).store(&c);
        return pm.erase(c);
    }

    const uint64_t half4 = color.premul().toF16();
    for (int y = 0; y < pm.height(); ++y) {
        sk_memset64(pm.writable_addr64(0, y), half4, pm.width());
    }
    return true;
}

/**
 *  For the purposes of drawing bitmaps, if a matrix is "almost" translate
 *  go ahead and treat it as if it were, so that subsequent code can go fast.
 */
static bool just_trans_clamp(const SkMatrix& matrix, const SkPixmap& pixmap) {
    SkASSERT(matrix_only_scale_translate(matrix));

    if (matrix.getType() & SkMatrix::kScale_Mask) {
        SkRect dst;
        SkRect src = SkRect::Make(pixmap.bounds());

        // Can't call mapRect(), since that will fix up inverted rectangles,
        // e.g. when scale is negative, and we don't want to return true for
        // those.
        matrix.mapPoints(SkTCast<SkPoint*>(&dst),
                         SkTCast<const SkPoint*>(&src),
                         2);

        // Now round all 4 edges to device space, and then compare the device
        // width/height to the original. Note: we must map all 4 and subtract
        // rather than map the "width" and compare, since we care about the
        // phase (in pixel space) that any translate in the matrix might impart.
        SkIRect idst;
        dst.round(&idst);
        return idst.width() == pixmap.width() && idst.height() == pixmap.height();
    }
    // if we got here, we're either kTranslate_Mask or identity
    return true;
}

    size_t getSize() const override {
#if SK_SUPPORT_GPU
        if (GrTexture* texture = as_IB(fImage.get())->peekTexture()) {
            return texture->gpuMemorySize();
        } else
#endif
        {
            SkPixmap pm;
            if (fImage->peekPixels(&pm)) {
                return pm.height() * pm.rowBytes();
            }
        }
        return 0;
    }

SkLinearBitmapPipeline::SkLinearBitmapPipeline(
    const SkMatrix& inverse,
    SkFilterQuality filterQuality,
    SkShader::TileMode xTile, SkShader::TileMode yTile,
    const SkPixmap& srcPixmap) {
    SkSize size = SkSize::Make(srcPixmap.width(), srcPixmap.height());
    const SkImageInfo& srcImageInfo = srcPixmap.info();

    // As the stages are built, the chooser function may skip a stage. For example, with the
    // identity matrix, the matrix stage is skipped, and the tilerStage is the first stage.
    auto placementStage = choose_pixel_placer(srcImageInfo.alphaType(), &fPixelStage);
    auto samplerStage   = choose_pixel_sampler(placementStage, srcPixmap, &fSampleStage);
    auto tilerStage     = choose_tiler(samplerStage, size, xTile, yTile, &fTileXOrBothStage,
                                       &fTileYStage);
    auto filterStage    = choose_filter(tilerStage, filterQuality, &fFilterStage);
    fFirstStage         = choose_matrix(filterStage, inverse, &fMatrixStage);
}

bool SkImage::scalePixels(const SkPixmap& dst, SkFilterQuality quality, CachingHint chint) const {
    if (this->width() == dst.width() && this->height() == dst.height()) {
        return this->readPixels(dst, 0, 0, chint);
    }

    // Idea: If/when SkImageGenerator supports a native-scaling API (where the generator itself
    //       can scale more efficiently) we should take advantage of it here.
    //
    SkBitmap bm;
    if (as_IB(this)->getROPixels(&bm, dst.info().colorSpace(), chint)) {
        SkPixmap pmap;
        // Note: By calling the pixmap scaler, we never cache the final result, so the chint
        //       is (currently) only being applied to the getROPixels. If we get a request to
        //       also attempt to cache the final (scaled) result, we would add that logic here.
        //
        return bm.peekPixels(&pmap) && pmap.scalePixels(dst, quality);
    }
    return false;
}

static void test_blender(std::string resourceName, skiatest::Reporter* reporter) {
    std::string fileName = resourceName + ".png";
    sk_sp<SkImage> image = GetResourceAsImage(fileName.c_str());
    if (image == nullptr) {
        ERRORF(reporter, "image is NULL");
        return;
    }
    SkBitmap bm;
    if (!as_IB(image)->getROPixels(&bm)) {
        ERRORF(reporter, "Could not read resource");
        return;
    }

    SkPixmap pixmap;
    bm.peekPixels(&pixmap);
    SkASSERTF(pixmap.colorType() == kN32_SkColorType, "colorType: %d", pixmap.colorType());
    SkASSERT(pixmap.alphaType() != kUnpremul_SkAlphaType);
    const uint32_t* src = pixmap.addr32();
    const int width = pixmap.rowBytesAsPixels();
    SkASSERT(width > 0);
    SkASSERT(width < 4000);
    SkAutoTArray<uint32_t> correctDst(width);
    SkAutoTArray<uint32_t> testDst(width);

    for (int y = 0; y < pixmap.height(); y++) {
        // TODO: zero is not the most interesting dst to test srcover...
        sk_bzero(correctDst.get(), width * sizeof(uint32_t));
        sk_bzero(testDst.get(), width * sizeof(uint32_t));
        brute_force_srcover_srgb_srgb(correctDst.get(), src, width, width);
        SkOpts::    srcover_srgb_srgb(   testDst.get(), src, width, width);
        for (int x = 0; x < width; x++) {
            REPORTER_ASSERT_MESSAGE(
                reporter, correctDst[x] == testDst[x],
                mismatch_message(resourceName, x, y, src[x], correctDst[x], testDst[x]));
            if (correctDst[x] != testDst[x]) break;
        }
        src += width;
    }
}

static bool generate_pixels(SkImageGenerator* gen, const SkPixmap& pmap, int originX, int originY,
                            SkTransferFunctionBehavior behavior) {
    const int genW = gen->getInfo().width();
    const int genH = gen->getInfo().height();
    const SkIRect srcR = SkIRect::MakeWH(genW, genH);
    const SkIRect dstR = SkIRect::MakeXYWH(originX, originY, pmap.width(), pmap.height());
    if (!srcR.contains(dstR)) {
        return false;
    }

    // If they are requesting a subset, we have to have a temp allocation for full image, and
    // then copy the subset into their allocation
    SkBitmap full;
    SkPixmap fullPM;
    const SkPixmap* dstPM = &pmap;
    if (srcR != dstR) {
        if (!full.tryAllocPixels(pmap.info().makeWH(genW, genH))) {
            return false;
        }
        if (!full.peekPixels(&fullPM)) {
            return false;
        }
        dstPM = &fullPM;
    }

    SkImageGenerator::Options opts;
    opts.fBehavior = behavior;
    if (!gen->getPixels(dstPM->info(), dstPM->writable_addr(), dstPM->rowBytes(), &opts)) {
        return false;
    }

    if (srcR != dstR) {
        if (!full.readPixels(pmap, originX, originY)) {
            return false;
        }
    }
    return true;
}

SkCanvasState* SkCanvasStateUtils::CaptureCanvasState(SkCanvas* canvas) {
    SkASSERT(canvas);

    // Check the clip can be decomposed into rectangles (i.e. no soft clips).
    ClipValidator validator;
    canvas->replayClips(&validator);
    if (validator.failed()) {
        SkErrorInternals::SetError(kInvalidOperation_SkError,
                "CaptureCanvasState does not support canvases with antialiased clips.\n");
        return nullptr;
    }

    SkAutoTDelete<SkCanvasState_v1> canvasState(new SkCanvasState_v1(canvas));

    // decompose the total matrix and clip
    setup_MC_state(&canvasState->mcState, canvas->getTotalMatrix(),
                   canvas->internal_private_getTotalClip());

    /*
     * decompose the layers
     *
     * storage is allocated on the stack for the first 3 layers. It is common in
     * some view systems (e.g. Android) that a few non-clipped layers are present
     * and we will not need to malloc any additional memory in those cases.
     */
    SkSWriter32<3*sizeof(SkCanvasLayerState)> layerWriter;
    int layerCount = 0;
    for (SkCanvas::LayerIter layer(canvas); !layer.done(); layer.next()) {

        // we currently only work for bitmap backed devices
        SkPixmap pmap;
        if (!layer.device()->accessPixels(&pmap) || 0 == pmap.width() || 0 == pmap.height()) {
            return nullptr;
        }

        SkCanvasLayerState* layerState =
                (SkCanvasLayerState*) layerWriter.reserve(sizeof(SkCanvasLayerState));
        layerState->type = kRaster_CanvasBackend;
        layerState->x = layer.x();
        layerState->y = layer.y();
        layerState->width = pmap.width();
        layerState->height = pmap.height();

        switch (pmap.colorType()) {
            case kN32_SkColorType:
                layerState->raster.config = kARGB_8888_RasterConfig;
                break;
            case kRGB_565_SkColorType:
                layerState->raster.config = kRGB_565_RasterConfig;
                break;
            default:
                return nullptr;
        }
        layerState->raster.rowBytes = pmap.rowBytes();
        layerState->raster.pixels = pmap.writable_addr();

        setup_MC_state(&layerState->mcState, layer.matrix(), layer.clip().bwRgn());
        layerCount++;
    }

    // allocate memory for the layers and then and copy them to the struct
    SkASSERT(layerWriter.bytesWritten() == layerCount * sizeof(SkCanvasLayerState));
    canvasState->layerCount = layerCount;
    canvasState->layers = (SkCanvasLayerState*) sk_malloc_throw(layerWriter.bytesWritten());
    layerWriter.flatten(canvasState->layers);

    return canvasState.release();
}

static void pack4xHToLCD16(const SkPixmap& src, const SkMask& dst,
                           const SkMaskGamma::PreBlend& maskPreBlend) {
#define SAMPLES_PER_PIXEL 4
#define LCD_PER_PIXEL 3
    SkASSERT(kAlpha_8_SkColorType == src.colorType());
    SkASSERT(SkMask::kLCD16_Format == dst.fFormat);

    const int sample_width = src.width();
    const int height = src.height();

    uint16_t* dstP = (uint16_t*)dst.fImage;
    size_t dstRB = dst.fRowBytes;
    // An N tap FIR is defined by
    // out[n] = coeff[0]*x[n] + coeff[1]*x[n-1] + ... + coeff[N]*x[n-N]
    // or
    // out[n] = sum(i, 0, N, coeff[i]*x[n-i])

    // The strategy is to use one FIR (different coefficients) for each of r, g, and b.
    // This means using every 4th FIR output value of each FIR and discarding the rest.
    // The FIRs are aligned, and the coefficients reach 5 samples to each side of their 'center'.
    // (For r and b this is technically incorrect, but the coeffs outside round to zero anyway.)

    // These are in some fixed point repesentation.
    // Adding up to more than one simulates ink spread.
    // For implementation reasons, these should never add up to more than two.

    // Coefficients determined by a gausian where 5 samples = 3 std deviations (0x110 'contrast').
    // Calculated using tools/generate_fir_coeff.py
    // With this one almost no fringing is ever seen, but it is imperceptibly blurry.
    // The lcd smoothed text is almost imperceptibly different from gray,
    // but is still sharper on small stems and small rounded corners than gray.
    // This also seems to be about as wide as one can get and only have a three pixel kernel.
    // TODO: caculate these at runtime so parameters can be adjusted (esp contrast).
    static const unsigned int coefficients[LCD_PER_PIXEL][SAMPLES_PER_PIXEL*3] = {
        //The red subpixel is centered inside the first sample (at 1/6 pixel), and is shifted.
        { 0x03, 0x0b, 0x1c, 0x33,  0x40, 0x39, 0x24, 0x10,  0x05, 0x01, 0x00, 0x00, },
        //The green subpixel is centered between two samples (at 1/2 pixel), so is symetric
        { 0x00, 0x02, 0x08, 0x16,  0x2b, 0x3d, 0x3d, 0x2b,  0x16, 0x08, 0x02, 0x00, },
        //The blue subpixel is centered inside the last sample (at 5/6 pixel), and is shifted.
        { 0x00, 0x00, 0x01, 0x05,  0x10, 0x24, 0x39, 0x40,  0x33, 0x1c, 0x0b, 0x03, },
    };

    for (int y = 0; y < height; ++y) {
        const uint8_t* srcP = src.addr8(0, y);

        // TODO: this fir filter implementation is straight forward, but slow.
        // It should be possible to make it much faster.
        for (int sample_x = -4, pixel_x = 0; sample_x < sample_width + 4; sample_x += 4, ++pixel_x) {
            int fir[LCD_PER_PIXEL] = { 0 };
            for (int sample_index = SkMax32(0, sample_x - 4), coeff_index = sample_index - (sample_x - 4)
                ; sample_index < SkMin32(sample_x + 8, sample_width)
                ; ++sample_index, ++coeff_index)
            {
                int sample_value = srcP[sample_index];
                for (int subpxl_index = 0; subpxl_index < LCD_PER_PIXEL; ++subpxl_index) {
                    fir[subpxl_index] += coefficients[subpxl_index][coeff_index] * sample_value;
                }
            }
            for (int subpxl_index = 0; subpxl_index < LCD_PER_PIXEL; ++subpxl_index) {
                fir[subpxl_index] /= 0x100;
                fir[subpxl_index] = SkMin32(fir[subpxl_index], 255);
            }

            U8CPU r = sk_apply_lut_if<APPLY_PREBLEND>(fir[0], maskPreBlend.fR);
            U8CPU g = sk_apply_lut_if<APPLY_PREBLEND>(fir[1], maskPreBlend.fG);
            U8CPU b = sk_apply_lut_if<APPLY_PREBLEND>(fir[2], maskPreBlend.fB);
#if SK_SHOW_TEXT_BLIT_COVERAGE
            r = SkMax32(r, 10); g = SkMax32(g, 10); b = SkMax32(b, 10);
#endif
            dstP[pixel_x] = SkPack888ToRGB16(r, g, b);
        }
        dstP = (uint16_t*)((char*)dstP + dstRB);
    }
}

static bool valid_for_resize(const SkPixmap& source, int dstW, int dstH) {
    // TODO: Seems like we shouldn't care about the swizzle of source, just that it's 8888
    return source.addr() && source.colorType() == kN32_SkColorType &&
           source.width() >= 1 && source.height() >= 1 && dstW >= 1 && dstH >= 1;
}

bool SkJpegEncoder::Encode(SkWStream* dst, const SkPixmap& src, const Options& options) {
    auto encoder = SkJpegEncoder::Make(dst, src, options);
    return encoder.get() && encoder->encodeRows(src.height());
}