C++ SkBitmap::config方法代码示例

bool SkBitmapDevice::onReadPixels(const SkBitmap& bitmap,
                                  int x, int y,
                                  SkCanvas::Config8888 config8888) {
    SkASSERT(SkBitmap::kARGB_8888_Config == bitmap.config());
    SkASSERT(!bitmap.isNull());
    SkASSERT(SkIRect::MakeWH(this->width(), this->height()).contains(SkIRect::MakeXYWH(x, y,
                                                                          bitmap.width(),
                                                                          bitmap.height())));

    SkIRect srcRect = SkIRect::MakeXYWH(x, y, bitmap.width(), bitmap.height());
    const SkBitmap& src = this->accessBitmap(false);

    SkBitmap subset;
    if (!src.extractSubset(&subset, srcRect)) {
        return false;
    }
    if (SkBitmap::kARGB_8888_Config != subset.config()) {
        // It'd be preferable to do this directly to bitmap.
        subset.copyTo(&subset, SkBitmap::kARGB_8888_Config);
    }
    SkAutoLockPixels alp(bitmap);
    uint32_t* bmpPixels = reinterpret_cast<uint32_t*>(bitmap.getPixels());
    SkCopyBitmapToConfig8888(bmpPixels, bitmap.rowBytes(), config8888, subset);
    return true;
}

static void report_opaqueness(skiatest::Reporter* reporter, const SkBitmap& src,
                              const SkBitmap& dst) {
    SkString str;
    str.printf("src %s opaque:%d, dst %s opaque:%d",
               gConfigName[src.config()], src.isOpaque(),
               gConfigName[dst.config()], dst.isOpaque());
    reporter->reportFailed(str);
}

static SkBitmap deepSkBitmapCopy(const SkBitmap& bitmap)
{
    SkBitmap tmp;
    if (!bitmap.deepCopyTo(&tmp, bitmap.config()))
        bitmap.copyTo(&tmp, bitmap.config());

    return tmp;
}

PassRefPtr<BitmapImageSingleFrameSkia> BitmapImageSingleFrameSkia::create(const SkBitmap& bitmap, bool copyPixels, float resolutionScale)
{
    if (copyPixels) {
        SkBitmap temp;
        if (!bitmap.deepCopyTo(&temp, bitmap.config()))
            bitmap.copyTo(&temp, bitmap.config());
        return adoptRef(new BitmapImageSingleFrameSkia(temp, resolutionScale));
    }
    return adoptRef(new BitmapImageSingleFrameSkia(bitmap, resolutionScale));
}

/**
 *  Check to ensure that copying a GPU-backed SkBitmap behaved as expected.
 *  @param reporter Used to report failures.
 *  @param desiredConfig Config being copied to. If the copy succeeded, dst must have this Config.
 *  @param success True if the copy succeeded.
 *  @param src A GPU-backed SkBitmap that had copyTo or deepCopyTo called on it.
 *  @param dst SkBitmap that was copied to.
 *  @param deepCopy True if deepCopyTo was used; false if copyTo was used.
 */
static void TestIndividualCopy(skiatest::Reporter* reporter, const SkBitmap::Config desiredConfig,
                               const bool success, const SkBitmap& src, const SkBitmap& dst,
                               const bool deepCopy = true) {
    if (success) {
        REPORTER_ASSERT(reporter, src.width() == dst.width());
        REPORTER_ASSERT(reporter, src.height() == dst.height());
        REPORTER_ASSERT(reporter, dst.config() == desiredConfig);
        if (src.config() == dst.config()) {
            // FIXME: When calling copyTo (so deepCopy is false here), sometimes we copy the pixels
            // exactly, in which case the IDs should be the same, but sometimes we do a bitmap draw,
            // in which case the IDs should not be the same. Is there any way to determine which is
            // the case at this point?
            if (deepCopy) {
                REPORTER_ASSERT(reporter, src.getGenerationID() == dst.getGenerationID());
            }
            REPORTER_ASSERT(reporter, src.pixelRef() != NULL && dst.pixelRef() != NULL);

            // Do read backs and make sure that the two are the same.
            SkBitmap srcReadBack, dstReadBack;
            {
                SkASSERT(src.getTexture() != NULL);
                bool readBack = src.pixelRef()->readPixels(&srcReadBack);
                REPORTER_ASSERT(reporter, readBack);
            }
            if (dst.getTexture() != NULL) {
                bool readBack = dst.pixelRef()->readPixels(&dstReadBack);
                REPORTER_ASSERT(reporter, readBack);
            } else {
                // If dst is not a texture, do a copy instead, to the same config as srcReadBack.
                bool copy = dst.copyTo(&dstReadBack, srcReadBack.config());
                REPORTER_ASSERT(reporter, copy);
            }

            SkAutoLockPixels srcLock(srcReadBack);
            SkAutoLockPixels dstLock(dstReadBack);
            REPORTER_ASSERT(reporter, srcReadBack.readyToDraw() && dstReadBack.readyToDraw());

            const char* srcP = static_cast<const char*>(srcReadBack.getAddr(0, 0));
            const char* dstP = static_cast<const char*>(dstReadBack.getAddr(0, 0));
            REPORTER_ASSERT(reporter, srcP != dstP);

            REPORTER_ASSERT(reporter, !memcmp(srcP, dstP, srcReadBack.getSize()));
        } else {
            REPORTER_ASSERT(reporter, src.getGenerationID() != dst.getGenerationID());
        }
    } else {
        // dst should be unchanged from its initial state
        REPORTER_ASSERT(reporter, dst.config() == SkBitmap::kNo_Config);
        REPORTER_ASSERT(reporter, dst.width() == 0);
        REPORTER_ASSERT(reporter, dst.height() == 0);
    }

}

bool SkBlurImageFilter::onFilterImage(Proxy* proxy,
                                      const SkBitmap& source, const SkMatrix& ctm,
                                      SkBitmap* dst, SkIPoint* offset) {
    SkBitmap src = this->getInputResult(proxy, source, ctm, offset);
    if (src.config() != SkBitmap::kARGB_8888_Config) {
        return false;
    }

    SkAutoLockPixels alp(src);
    if (!src.getPixels()) {
        return false;
    }

    dst->setConfig(src.config(), src.width(), src.height());
    dst->allocPixels();
    int kernelSizeX, kernelSizeX3, lowOffsetX, highOffsetX;
    int kernelSizeY, kernelSizeY3, lowOffsetY, highOffsetY;
    getBox3Params(fSigma.width(), &kernelSizeX, &kernelSizeX3, &lowOffsetX, &highOffsetX);
    getBox3Params(fSigma.height(), &kernelSizeY, &kernelSizeY3, &lowOffsetY, &highOffsetY);

    if (kernelSizeX < 0 || kernelSizeY < 0) {
        return false;
    }

    if (kernelSizeX == 0 && kernelSizeY == 0) {
        src.copyTo(dst, dst->config());
        return true;
    }

    SkBitmap temp;
    temp.setConfig(dst->config(), dst->width(), dst->height());
    if (!temp.allocPixels()) {
        return false;
    }

    if (kernelSizeX > 0 && kernelSizeY > 0) {
        boxBlurX(src,  &temp, kernelSizeX,  lowOffsetX, highOffsetX);
        boxBlurY(temp, dst,   kernelSizeY,  lowOffsetY, highOffsetY);
        boxBlurX(*dst, &temp, kernelSizeX,  highOffsetX,  lowOffsetX);
        boxBlurY(temp, dst,   kernelSizeY,  highOffsetY,  lowOffsetY);
        boxBlurX(*dst, &temp, kernelSizeX3, highOffsetX, highOffsetX);
        boxBlurY(temp, dst,   kernelSizeY3, highOffsetY, highOffsetY);
    } else if (kernelSizeX > 0) {
        boxBlurX(src,  dst,   kernelSizeX,  lowOffsetX, highOffsetX);
        boxBlurX(*dst, &temp, kernelSizeX,  highOffsetX,  lowOffsetX);
        boxBlurX(temp, dst,   kernelSizeX3, highOffsetX, highOffsetX);
    } else if (kernelSizeY > 0) {
        boxBlurY(src,  dst,   kernelSizeY,  lowOffsetY, highOffsetY);
        boxBlurY(*dst, &temp, kernelSizeY,  highOffsetY, lowOffsetY);
        boxBlurY(temp, dst,   kernelSizeY3, highOffsetY, highOffsetY);
    }
    return true;
}

    void force_all_opaque(const SkBitmap& bitmap) {
        SkASSERT(NULL == bitmap.getTexture());
        SkASSERT(SkBitmap::kARGB_8888_Config == bitmap.config());
        if (NULL != bitmap.getTexture() || SkBitmap::kARGB_8888_Config == bitmap.config()) {
            return;
        }

        SkAutoLockPixels lock(bitmap);
        for (int y = 0; y < bitmap.height(); y++) {
            for (int x = 0; x < bitmap.width(); x++) {
                *bitmap.getAddr32(x, y) |= (SK_A32_MASK << SK_A32_SHIFT);
            }
        }
    }

static bool equal(const SkBitmap& bm1, const SkBitmap& bm2) {
    if (bm1.width() != bm2.width() ||
        bm1.height() != bm2.height() ||
        bm1.config() != bm2.config()) {
        return false;
    }

    size_t pixelBytes = bm1.width() * bm1.bytesPerPixel();
    for (int y = 0; y < bm1.height(); y++) {
        if (memcmp(bm1.getAddr(0, y), bm2.getAddr(0, y), pixelBytes)) {
            return false;
        }
    }
    return true;
}

// Utility function to set value of any pixel in bm.
// bm.getConfig() specifies what format 'val' must be
// converted to, but at present uint32_t can handle all formats.
static void setPixel(int x, int y, uint32_t val, SkBitmap& bm) {
    uint16_t val16;
    uint8_t val8;
    SkAutoLockPixels lock(bm);
    void* rawAddr = bm.getAddr(x,y);

    switch (bm.config()) {
        case SkBitmap::kARGB_8888_Config:
            memcpy(rawAddr, &val, sizeof(uint32_t));
            break;
        case SkBitmap::kARGB_4444_Config:
        case SkBitmap::kRGB_565_Config:
            val16 = val & 0xFFFF;
            memcpy(rawAddr, &val16, sizeof(uint16_t));
            break;
        case SkBitmap::kA8_Config:
        case SkBitmap::kIndex8_Config:
            val8 = val & 0xFF;
            memcpy(rawAddr, &val8, sizeof(uint8_t));
            break;
        default:
            // Ignore.
            break;
    }
}

/*  Fill out buffer with the compressed format Ganesh expects from a colortable
 based bitmap. [palette (colortable) + indices].

 At the moment Ganesh only supports 8bit version. If Ganesh allowed we others
 we could detect that the colortable.count is <= 16, and then repack the
 indices as nibbles to save RAM, but it would take more time (i.e. a lot
 slower than memcpy), so skipping that for now.

 Ganesh wants a full 256 palette entry, even though Skia's ctable is only as big
 as the colortable.count says it is.
 */
static void build_compressed_data(void* buffer, const SkBitmap& bitmap) {
    SkASSERT(SkBitmap::kIndex8_Config == bitmap.config());

    SkAutoLockPixels apl(bitmap);
    if (!bitmap.readyToDraw()) {
        SkASSERT(!"bitmap not ready to draw!");
        return;
    }

    SkColorTable* ctable = bitmap.getColorTable();
    char* dst = (char*)buffer;

    memcpy(dst, ctable->lockColors(), ctable->count() * sizeof(SkPMColor));
    ctable->unlockColors(false);

    // always skip a full 256 number of entries, even if we memcpy'd fewer
    dst += kGrColorTableSize;

    if (bitmap.width() == bitmap.rowBytes()) {
        memcpy(dst, bitmap.getPixels(), bitmap.getSize());
    } else {
        // need to trim off the extra bytes per row
        size_t width = bitmap.width();
        size_t rowBytes = bitmap.rowBytes();
        const char* src = (const char*)bitmap.getPixels();
        for (int y = 0; y < bitmap.height(); y++) {
            memcpy(dst, src, width);
            src += rowBytes;
            dst += width;
        }
    }
}

static void erase(SkBitmap& bm) {
    if (bm.config() == SkBitmap::kA8_Config) {
        bm.eraseColor(SK_ColorTRANSPARENT);
    } else {
        bm.eraseColor(SK_ColorWHITE);
    }
}

// Utility function to read the value of a given pixel in bm. All
// values converted to uint32_t for simplification of comparisons.
static uint32_t getPixel(int x, int y, const SkBitmap& bm) {
    uint32_t val = 0;
    uint16_t val16;
    uint8_t val8;
    SkAutoLockPixels lock(bm);
    const void* rawAddr = bm.getAddr(x,y);

    switch (bm.config()) {
        case SkBitmap::kARGB_8888_Config:
            memcpy(&val, rawAddr, sizeof(uint32_t));
            break;
        case SkBitmap::kARGB_4444_Config:
        case SkBitmap::kRGB_565_Config:
            memcpy(&val16, rawAddr, sizeof(uint16_t));
            val = val16;
            break;
        case SkBitmap::kA8_Config:
        case SkBitmap::kIndex8_Config:
            memcpy(&val8, rawAddr, sizeof(uint8_t));
            val = val8;
            break;
        default:
            break;
    }
    return val;
}

static void generate_bitmap_texture_desc(const SkBitmap& bitmap, GrTextureDesc* desc) {
    desc->fFlags = kNone_GrTextureFlags;
    desc->fWidth = bitmap.width();
    desc->fHeight = bitmap.height();
    desc->fConfig = SkBitmapConfig2GrPixelConfig(bitmap.config());
    desc->fSampleCnt = 0;
}

static SkScalar draw_row(SkCanvas* canvas, const SkBitmap& bm) {
    //此为canvas的save操作
	//在超过了作用域之后，会自动调用restore函数
    SkAutoCanvasRestore acr(canvas, true);

    SkPaint paint;
    SkScalar x = 0;
    const int scale = 64;

    //开启抗锯齿　：　见百度百科
    paint.setAntiAlias(true); 
    //绘制行首文字 ： 见结果图每行行头文字
    const char* name = gConfigNames[bm.config()];
    canvas->drawText(name, strlen(name), x, SkIntToScalar(bm.height())*scale*5/8,
                     paint);

    //平移到(48, 0)？？？为何是48--牛群
    canvas->translate(SkIntToScalar(192), 0);
    //缩放 ： x,y轴乘各乘以一个系数, 进行放大或缩小.：　此处因为４个像素很小,所以进行了放大.
    canvas->scale(SkIntToScalar(scale), SkIntToScalar(scale));
    
    /*逐个画每行的6个方块*/
    //画前三个, 正常的, 滤镜的, 滤镜+防抖动的.
    x += draw_set(canvas, bm, 0, &paint);
    //画笔复原
    paint.reset();
    /*开启透明, 画后三个, 正常的, 滤镜的, 滤镜+防抖动的. */
    paint.setAlpha(0x80);
    draw_set(canvas, bm, x, &paint);
    return x * scale / 3;
}

PassRefPtr<BitmapImageSingleFrameSkia> BitmapImageSingleFrameSkia::create(const SkBitmap& bitmap)
{
    RefPtr<BitmapImageSingleFrameSkia> image(adoptRef(new BitmapImageSingleFrameSkia()));
    if (!bitmap.copyTo(&image->m_nativeImage, bitmap.config()))
        return 0;
    return image.release();
}