Exemple #1
0
static void convertToIndex666(const SkBitmap& src, SkBitmap* dst) {
    SkColorTable* ctable = new SkColorTable(216);
    SkPMColor* colors = ctable->lockColors();
    // rrr ggg bbb
    for (int r = 0; r < 6; r++) {
        int rr = conv6ToByte(r);
        for (int g = 0; g < 6; g++) {
            int gg = conv6ToByte(g);
            for (int b = 0; b < 6; b++) {
                int bb = conv6ToByte(b);
                *colors++ = SkPreMultiplyARGB(0xFF, rr, gg, bb);
            }
        }
    }
    ctable->unlockColors(true);
    dst->setConfig(SkBitmap::kIndex8_Config, src.width(), src.height());
    dst->allocPixels(ctable);
    ctable->unref();

    SkAutoLockPixels alps(src);
    SkAutoLockPixels alpd(*dst);

    for (int y = 0; y < src.height(); y++) {
        const SkPMColor* srcP = src.getAddr32(0, y);
        uint8_t* dstP = dst->getAddr8(0, y);
        for (int x = src.width() - 1; x >= 0; --x) {
            *dstP++ = compute666Index(*srcP++);
        }
    }
}
static SkBitmap make_bitmap()
    {
    SkBitmap bm;
    SkColorTable* ctable = new SkColorTable(256);

    SkPMColor* c = ctable->lockColors();
    for (int i = 0; i < 256; i++)
        {
        c[i] = SkPackARGB32(0xFF, i, 0, 0);
        }
    ctable->unlockColors(true);
    bm.setConfig(SkBitmap::kIndex8_Config, 256, 32);
    bm.allocPixels(ctable);
    ctable->unref();

    bm.lockPixels();
    for (int y = 0; y < bm.height(); y++)
        {
        uint8_t* p = bm.getAddr8(0, y);
        for (int x = 0; x < 256; x++)
            {
            p[x] = x;
            }
        }
    bm.unlockPixels();
    return bm;
    }
static SkBitmap make_bitmap() {
    SkBitmap bm;
    SkColorTable* ctable = new SkColorTable(256);

    SkPMColor* c = ctable->lockColors();
    for (int i = 0; i < 256; i++) {
        c[i] = SkPackARGB32(255 - i, 0, 0, 0);
    }
    ctable->unlockColors(true);
    bm.setConfig(SkBitmap::kIndex8_Config, 256, 256);
    bm.allocPixels(ctable);
    ctable->unref();

    bm.lockPixels();
    const float cx = bm.width() * 0.5f;
    const float cy = bm.height() * 0.5f;
    for (int y = 0; y < bm.height(); y++) {
        float dy = y - cy;
        dy *= dy;
        uint8_t* p = bm.getAddr8(0, y);
        for (int x = 0; x < 256; x++) {
            float dx = x - cx;
            dx *= dx;
            float d = (dx + dy) / (cx/2);
            int id = (int)d;
            if (id > 255) {
                id = 255;
            }
            p[x] = id;
        }
    }
    bm.unlockPixels();
    return bm;
}
static SkBitmap make_bitmap() {
    SkPMColor c[256];
    for (int i = 0; i < 256; i++) {
        c[i] = SkPackARGB32(255 - i, 0, 0, 0);
    }

    SkBitmap bm;
    SkColorTable* ctable = new SkColorTable(c, 256);

    bm.allocPixels(SkImageInfo::Make(256, 256, kIndex_8_SkColorType,
                                     kPremul_SkAlphaType),
                   nullptr, ctable);
    ctable->unref();

    bm.lockPixels();
    const float cx = bm.width() * 0.5f;
    const float cy = bm.height() * 0.5f;
    for (int y = 0; y < bm.height(); y++) {
        float dy = y - cy;
        dy *= dy;
        uint8_t* p = bm.getAddr8(0, y);
        for (int x = 0; x < 256; x++) {
            float dx = x - cx;
            dx *= dx;
            float d = (dx + dy) / (cx/2);
            int id = (int)d;
            if (id > 255) {
                id = 255;
            }
            p[x] = id;
        }
    }
    bm.unlockPixels();
    return bm;
}
static void convert_to_index666(const SkBitmap& src, SkBitmap* dst) {
    SkPMColor storage[216];
    SkPMColor* colors = storage;
    // rrr ggg bbb
    for (int r = 0; r < 6; r++) {
        int rr = conv_6_to_byte(r);
        for (int g = 0; g < 6; g++) {
            int gg = conv_6_to_byte(g);
            for (int b = 0; b < 6; b++) {
                int bb = conv_6_to_byte(b);
                *colors++ = SkPreMultiplyARGB(0xFF, rr, gg, bb);
            }
        }
    }
    SkColorTable* ctable = new SkColorTable(storage, 216);
    dst->allocPixels(SkImageInfo::Make(src.width(), src.height(),
                                       kIndex_8_SkColorType, kOpaque_SkAlphaType),
                     NULL, ctable);
    ctable->unref();

    SkAutoLockPixels alps(src);
    SkAutoLockPixels alpd(*dst);

    for (int y = 0; y < src.height(); y++) {
        const SkPMColor* srcP = src.getAddr32(0, y);
        uint8_t* dstP = dst->getAddr8(0, y);
        for (int x = src.width() - 1; x >= 0; --x) {
            *dstP++ = compute_666_index(*srcP++);
        }
    }
}
Exemple #6
0
/*  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;
        }
    }
}
    virtual Result onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
                               const Options&,
                               SkPMColor ctableEntries[], int* ctableCount) override {
        SkMemoryStream stream(fData->data(), fData->size(), false);
        SkAutoTUnref<BareMemoryAllocator> allocator(SkNEW_ARGS(BareMemoryAllocator,
                                                               (info, pixels, rowBytes)));
        fDecoder->setAllocator(allocator);
        fDecoder->setRequireUnpremultipliedColors(kUnpremul_SkAlphaType == info.alphaType());

        SkBitmap bm;
        const SkImageDecoder::Result result = fDecoder->decode(&stream, &bm, info.colorType(),
                                                               SkImageDecoder::kDecodePixels_Mode);
        if (SkImageDecoder::kFailure == result) {
            return kInvalidInput;
        }

        SkASSERT(info.colorType() == bm.info().colorType());

        if (kIndex_8_SkColorType == info.colorType()) {
            SkASSERT(ctableEntries);

            SkColorTable* ctable = bm.getColorTable();
            if (NULL == ctable) {
                return kInvalidConversion;
            }
            const int count = ctable->count();
            memcpy(ctableEntries, ctable->readColors(), count * sizeof(SkPMColor));
            *ctableCount = count;
        }
        if (SkImageDecoder::kPartialSuccess == result) {
            return kIncompleteInput;
        }
        return kSuccess;
    }
Exemple #8
0
 static void setBitmapOpaque(SkBitmap* bm, bool isOpaque) {
     SkAutoLockPixels alp(*bm);  // needed for ctable
     bm->setIsOpaque(isOpaque);
     SkColorTable* ctable = bm->getColorTable();
     if (ctable) {
         ctable->setIsOpaque(isOpaque);
     }
 }
Exemple #9
0
static jboolean Bitmap_writeToParcel(JNIEnv* env, jobject,
                                     jlong bitmapHandle,
                                     jboolean isMutable, jint density,
                                     jobject parcel) {
    const SkBitmap* bitmap = reinterpret_cast<SkBitmap*>(bitmapHandle);
    if (parcel == NULL) {
        SkDebugf("------- writeToParcel null parcel\n");
        return JNI_FALSE;
    }

    android::Parcel* p = android::parcelForJavaObject(env, parcel);

    p->writeInt32(isMutable);
    p->writeInt32(bitmap->colorType());
    p->writeInt32(bitmap->alphaType());
    p->writeInt32(bitmap->width());
    p->writeInt32(bitmap->height());
    p->writeInt32(bitmap->rowBytes());
    p->writeInt32(density);

    if (bitmap->colorType() == kIndex_8_SkColorType) {
        SkColorTable* ctable = bitmap->getColorTable();
        if (ctable != NULL) {
            int count = ctable->count();
            p->writeInt32(count);
            memcpy(p->writeInplace(count * sizeof(SkPMColor)),
                   ctable->lockColors(), count * sizeof(SkPMColor));
            ctable->unlockColors();
        } else {
            p->writeInt32(0);   // indicate no ctable
        }
    }

    size_t size = bitmap->getSize();

    android::Parcel::WritableBlob blob;
    android::status_t status = p->writeBlob(size, &blob);
    if (status) {
        doThrowRE(env, "Could not write bitmap to parcel blob.");
        return JNI_FALSE;
    }

    bitmap->lockPixels();
    const void* pSrc =  bitmap->getPixels();
    if (pSrc == NULL) {
        memset(blob.data(), 0, size);
    } else {
        memcpy(blob.data(), pSrc, size);
    }
    bitmap->unlockPixels();

    blob.release();
    return JNI_TRUE;
}
Exemple #10
0
static void make_image(SkBitmap* bm, SkColorType ct, int configIndex) {
    const int   width = 98;
    const int   height = 100;
    const SkImageInfo info = SkImageInfo::Make(width, height, ct, kPremul_SkAlphaType);

    SkBitmap    device;
    device.allocN32Pixels(width, height);
    SkCanvas    canvas(device);
    SkPaint     paint;

    paint.setAntiAlias(true);
    canvas.drawColor(SK_ColorRED);
    paint.setColor(SK_ColorBLUE);
    canvas.drawCircle(SkIntToScalar(width)/2, SkIntToScalar(height)/2,
                      SkIntToScalar(width)/2, paint);

    switch (ct) {
        case kPMColor_SkColorType:
            bm->swap(device);
            break;
        case kRGB_565_SkColorType: {
            bm->allocPixels(info);
            for (int y = 0; y < height; y++) {
                for (int x = 0; x < width; x++) {
                    *bm->getAddr16(x, y) = SkPixel32ToPixel16(*device.getAddr32(x, y));
                }
            }
            break;
        }
        case kIndex_8_SkColorType: {
            SkPMColor colors[256];
            for (int i = 0; i < 256; i++) {
                if (configIndex & 1) {
                    colors[i] = SkPackARGB32(255-i, 0, 0, 255-i);
                } else {
                    colors[i] = SkPackARGB32(0xFF, i, 0, 255-i);
                }
            }
            SkColorTable* ctable = new SkColorTable(colors, 256);
            bm->allocPixels(info, NULL, ctable);
            ctable->unref();
            for (int y = 0; y < height; y++) {
                for (int x = 0; x < width; x++) {
                    *bm->getAddr8(x, y) = SkGetPackedR32(*device.getAddr32(x, y));
                }
            }
            break;
        }
        default:
            SkASSERT(0);
    }
}
Exemple #11
0
/*  Fill out buffer with the compressed format GL expects from a colortable
    based bitmap. [palette (colortable) + indices].

    At the moment I always take the 8bit version, since that's what my data
    is. I 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 I'm skipping that for now.

    GL wants a full 256 palette entry, even though my ctable is only as big
    as the colortable.count says it is. I presume it is OK to leave any
    trailing entries uninitialized, since none of my indices should exceed
    ctable->count().
*/
static void build_compressed_data(void* buffer, const SkBitmap& bitmap) {
    SkASSERT(SkBitmap::kIndex8_Config == bitmap.config());

    SkColorTable* ctable = bitmap.getColorTable();
    uint8_t* dst = (uint8_t*)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 += SK_GL_SIZE_OF_PALETTE;
    memcpy(dst, bitmap.getPixels(), bitmap.getSize());
}
static void make_bm(SkBitmap* bm) {
    const SkColor colors[] = {
        SK_ColorRED, SK_ColorGREEN,
        SK_ColorBLUE, SK_ColorWHITE
    };
    SkColorTable* ctable = new SkColorTable(colors, 4);
    bm->setConfig(SkBitmap::kIndex8_Config, 2, 2);
    bm->allocPixels(ctable);
    ctable->unref();
    
    *bm->getAddr8(0, 0) = 0;
    *bm->getAddr8(1, 0) = 1;
    *bm->getAddr8(0, 1) = 2;
    *bm->getAddr8(1, 1) = 3;
}
Exemple #13
0
static SkBitmap make_bitmap() {
    const SkPMColor c[] = { SkPackARGB32(0x80, 0x80, 0, 0) };
    SkColorTable* ctable = new SkColorTable(c, SK_ARRAY_COUNT(c));

    SkBitmap bm;
    bm.allocPixels(SkImageInfo::Make(1, 1, kIndex_8_SkColorType,
                                     kPremul_SkAlphaType),
                   NULL, ctable);
    ctable->unref();

    bm.lockPixels();
    *bm.getAddr8(0, 0) = 0;
    bm.unlockPixels();
    return bm;
}
Exemple #14
0
static void make_bm(SkBitmap* bm) {
    const SkPMColor colors[] = {
        SkPreMultiplyColor(SK_ColorRED), SkPreMultiplyColor(SK_ColorGREEN),
        SkPreMultiplyColor(SK_ColorBLUE), SkPreMultiplyColor(SK_ColorWHITE)
    };
    SkColorTable* ctable = new SkColorTable(colors, 4);
    bm->allocPixels(SkImageInfo::Make(2, 2, kIndex_8_SkColorType,
                                      kOpaque_SkAlphaType),
                    nullptr, ctable);
    ctable->unref();

    *bm->getAddr8(0, 0) = 0;
    *bm->getAddr8(1, 0) = 1;
    *bm->getAddr8(0, 1) = 2;
    *bm->getAddr8(1, 1) = 3;
}
Exemple #15
0
/*  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 alp(bitmap);
    if (!bitmap.readyToDraw()) {
        SkDEBUGFAIL("bitmap not ready to draw!");
        return;
    }

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

    const int count = ctable->count();

    SkDstPixelInfo dstPI;
    dstPI.fColorType = kRGBA_8888_SkColorType;
    dstPI.fAlphaType = kPremul_SkAlphaType;
    dstPI.fPixels = buffer;
    dstPI.fRowBytes = count * sizeof(SkPMColor);

    SkSrcPixelInfo srcPI;
    srcPI.fColorType = kPMColor_SkColorType;
    srcPI.fAlphaType = kPremul_SkAlphaType;
    srcPI.fPixels = ctable->lockColors();
    srcPI.fRowBytes = count * sizeof(SkPMColor);

    srcPI.convertPixelsTo(&dstPI, count, 1);

    ctable->unlockColors();

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

    if ((unsigned)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;
        }
    }
}
Exemple #16
0
static SkBitmap make_bitmap() {
    SkBitmap bm;

    SkColorTable* ctable = new SkColorTable(1);
    SkPMColor* c = ctable->lockColors();
    c[0] = SkPackARGB32(0x80, 0x80, 0, 0);
    ctable->unlockColors(true);

    bm.setConfig(SkBitmap::kIndex8_Config, 1, 1);
    bm.allocPixels(ctable);
    ctable->unref();

    bm.lockPixels();
    *bm.getAddr8(0, 0) = 0;
    bm.unlockPixels();
    return bm;
}
// As copy constructor is hidden in the class hierarchy, we need to call
// default constructor explicitly to suppress a compiler warning.
SkColorTable::SkColorTable(const SkColorTable& src) : INHERITED() {
    f16BitCache = NULL;
    fAlphaType = src.fAlphaType;
    int count = src.count();
    fCount = SkToU16(count);
    fColors = reinterpret_cast<SkPMColor*>(
                                    sk_malloc_throw(count * sizeof(SkPMColor)));
    memcpy(fColors, src.fColors, count * sizeof(SkPMColor));

    SkDEBUGCODE(fColorLockCount = 0;)
Exemple #18
0
static void make_bm(SkBitmap* bm) {
    const SkColor colors[4] = {
        SK_ColorRED, SK_ColorGREEN,
        SK_ColorBLUE, SK_ColorWHITE
    };
    SkPMColor colorsPM[4];
    for (size_t i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
        colorsPM[i] = SkPreMultiplyColor(colors[i]);
    }
    SkColorTable* ctable = new SkColorTable(colorsPM, 4);

    bm->setConfig(SkBitmap::kIndex8_Config, 2, 2);
    bm->allocPixels(ctable);
    ctable->unref();

    *bm->getAddr8(0, 0) = 0;
    *bm->getAddr8(1, 0) = 1;
    *bm->getAddr8(0, 1) = 2;
    *bm->getAddr8(1, 1) = 3;
}
Exemple #19
0
static void make_bm(SkBitmap* bm) {
    const SkColor colors[4] = {
        SK_ColorRED, SK_ColorGREEN,
        SK_ColorBLUE, SK_ColorWHITE
    };
    SkPMColor colorsPM[4];
    for (size_t i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
        colorsPM[i] = SkPreMultiplyColor(colors[i]);
    }
    SkColorTable* ctable = new SkColorTable(colorsPM, 4);

    bm->allocPixels(SkImageInfo::Make(2, 2, kIndex_8_SkColorType,
                                      kPremul_SkAlphaType),
                    NULL, ctable);
    ctable->unref();

    *bm->getAddr8(0, 0) = 0;
    *bm->getAddr8(1, 0) = 1;
    *bm->getAddr8(0, 1) = 2;
    *bm->getAddr8(1, 1) = 3;
}
    void drawBG(SkCanvas* canvas)
    {
        canvas->drawColor(0xFFDDDDDD);
        return;

#if 0
        SkColorTable    ct;
        SkPMColor       colors[] = { SK_ColorRED, SK_ColorBLUE };
        ct.setColors(colors, 2);
        ct.setFlags(ct.getFlags() | SkColorTable::kColorsAreOpaque_Flag);

        SkBitmap        bm;
        bm.setConfig(SkBitmap::kIndex8_Config, 20, 20, 21);
        bm.setColorTable(&ct);
        bm.allocPixels();
        sk_memset16((uint16_t*)bm.getAddr8(0, 0), 0x0001, bm.rowBytes() * bm.height() / 2);
#endif
#if 0
        SkBitmap        bm;
        bm.setConfig(SkBitmap::kRGB_565_Config, 20, 20, 42);
        bm.allocPixels();
        sk_memset32((uint32_t*)bm.getAddr16(0, 0), 0x0000FFFF, bm.rowBytes() * bm.height() / 4);
#endif
#if 1
        SkBitmap        bm;
        bm.setConfig(SkBitmap::kARGB_8888_Config, 20, 20);
        bm.allocPixels();
        sk_memset32((uint32_t*)bm.getAddr32(0, 0), 0xFFDDDDDD, bm.rowBytes() * bm.height() / 4);
#endif

        SkPaint paint;

//        SkShader* shader = SkShader::CreateBitmapShader(bm, false, SkPaint::kBilinear_FilterType, SkShader::kRepeat_TileMode);
        SkPoint pts[] = { 0, 0, SkIntToScalar(100), SkIntToScalar(0) };
        SkColor colors[] = { SK_ColorBLACK, SK_ColorWHITE };
        SkShader* shader = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kMirror_TileMode);
        paint.setShader(shader)->unref();

        canvas->drawPaint(paint);
    }
static SkBitmap make_bitmap() {
    SkPMColor c[256];
    for (int i = 0; i < 256; i++) {
        c[i] = SkPackARGB32(0xFF, i, 0, 0);
    }
    SkColorTable* ctable = new SkColorTable(c, 256);

    SkBitmap bm;
    bm.allocPixels(SkImageInfo::Make(256, 32, kIndex_8_SkColorType, kPremul_SkAlphaType),
                   nullptr, ctable);
    ctable->unref();

    bm.lockPixels();
    for (int y = 0; y < bm.height(); y++) {
        uint8_t* p = bm.getAddr8(0, y);
        for (int x = 0; x < 256; x++) {
            p[x] = x;
        }
    }
    bm.unlockPixels();
    return bm;
}
/*
  SampleFilter = 滤镜样子 : 滤镜的作用与效果 见 百度百科
  流程 : FilterView() -> make_bm() ->
         onDrawContent() ->  draw_row() -> draw_set() -> draw_bm()
*/
static void make_bm(SkBitmap* bm) {
    const SkColor colors[] = {
        SK_ColorRED, SK_ColorGREEN,
        SK_ColorBLUE, SK_ColorWHITE
    };
    //颜色表 存储4个颜色
    SkColorTable* ctable = new SkColorTable(colors, 4);
    //bitmap设置格式 为一个像素8位, 共2*2个像素
    bm->setConfig(SkBitmap::kIndex8_Config, 2, 2);
    //bitmap分配实际内存, 按照以上格式
    bm->allocPixels(ctable);

    //颜色表的引用值-1 :见到0时释放, 
    ctable->unref();
    
    /*获取kIndex8_Config的bitmap的 (0,0)像素内存位置, 赋值0, 为索引0的颜色..
      依次将红, 绿, 蓝, 白赋值给4个像素 : 见结果图样式. */
    *bm->getAddr8(0, 0) = 0;
    *bm->getAddr8(1, 0) = 1;
    *bm->getAddr8(0, 1) = 2;
    *bm->getAddr8(1, 1) = 3;
}
Exemple #23
0
/*  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 alp(bitmap);
    if (!bitmap.readyToDraw()) {
        SkDEBUGFAIL("bitmap not ready to draw!");
        return;
    }

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

    uint32_t* colorTableDst = reinterpret_cast<uint32_t*>(dst);
    const uint32_t* colorTableSrc = reinterpret_cast<const uint32_t*>(ctable->lockColors());
    SkConvertConfig8888Pixels(colorTableDst, 0, SkCanvas::kRGBA_Premul_Config8888,
                              colorTableSrc, 0, SkCanvas::kNative_Premul_Config8888,
                              ctable->count(), 1);
    ctable->unlockColors();

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

    if ((unsigned)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 SkBitmap make_bitmap() {
    const int N = 1;

    SkPMColor c[N];
    for (int i = 0; i < N; i++) {
        c[i] = SkPackARGB32(0x80, 0x80, 0, 0);
    }
    SkColorTable* ctable = new SkColorTable(c, N);

    SkBitmap bm;
    bm.setConfig(SkBitmap::kIndex8_Config, 1, 1);
    bm.allocPixels(ctable);
    ctable->unref();

    bm.lockPixels();
    for (int y = 0; y < bm.height(); y++) {
        uint8_t* p = bm.getAddr8(0, y);
        for (int x = 0; x < bm.width(); x++) {
            p[x] = 0;
        }
    }
    bm.unlockPixels();
    return bm;
}
// copyTo() should preserve isOpaque when it makes sense
static void test_isOpaque(skiatest::Reporter* reporter, const SkBitmap& src,
                          SkBitmap::Config dstConfig) {
    SkBitmap bitmap(src);
    SkBitmap dst;

    // we need the lock so that we get a valid colorTable (when available)
    SkAutoLockPixels alp(bitmap);
    SkColorTable* ctable = bitmap.getColorTable();
    unsigned ctableFlags = ctable ? ctable->getFlags() : 0;

    if (canHaveAlpha(bitmap.config()) && canHaveAlpha(dstConfig)) {
        bitmap.setIsOpaque(false);
        if (ctable) {
            ctable->setFlags(ctableFlags & ~SkColorTable::kColorsAreOpaque_Flag);
        }
        REPORTER_ASSERT(reporter, bitmap.copyTo(&dst, dstConfig));
        REPORTER_ASSERT(reporter, dst.config() == dstConfig);
        if (bitmap.isOpaque() != dst.isOpaque()) {
            report_opaqueness(reporter, bitmap, dst);
        }
    }

    bitmap.setIsOpaque(true);
    if (ctable) {
        ctable->setFlags(ctableFlags | SkColorTable::kColorsAreOpaque_Flag);
    }
    REPORTER_ASSERT(reporter, bitmap.copyTo(&dst, dstConfig));
    REPORTER_ASSERT(reporter, dst.config() == dstConfig);
    if (bitmap.isOpaque() != dst.isOpaque()) {
        report_opaqueness(reporter, bitmap, dst);
    }

    if (ctable) {
        ctable->setFlags(ctableFlags);
    }
}
QImage toQImage(const SkBitmap &bitmap)
{
    QImage image;
    switch (bitmap.colorType()) {
    case kUnknown_SkColorType:
        break;
    case kAlpha_8_SkColorType:
        image = toQImage(bitmap, QImage::Format_Alpha8);
        break;
    case kRGB_565_SkColorType:
        image = toQImage(bitmap, QImage::Format_RGB16);
        break;
    case kARGB_4444_SkColorType:
        switch (bitmap.alphaType()) {
        case kUnknown_SkAlphaType:
            break;
        case kUnpremul_SkAlphaType:
        // not supported - treat as opaque
        case kOpaque_SkAlphaType:
            image = toQImage(bitmap, QImage::Format_RGB444);
            break;
        case kPremul_SkAlphaType:
            image = toQImage(bitmap, QImage::Format_ARGB4444_Premultiplied);
            break;
        }
        break;
    case kRGBA_8888_SkColorType:
        switch (bitmap.alphaType()) {
        case kUnknown_SkAlphaType:
            break;
        case kOpaque_SkAlphaType:
            image = toQImage(bitmap, QImage::Format_RGBX8888);
            break;
        case kPremul_SkAlphaType:
            image = toQImage(bitmap, QImage::Format_RGBA8888_Premultiplied);
            break;
        case kUnpremul_SkAlphaType:
            image = toQImage(bitmap, QImage::Format_RGBA8888);
            break;
        }
        break;
    case kBGRA_8888_SkColorType:
        // we are assuming little-endian arch here.
        switch (bitmap.alphaType()) {
        case kUnknown_SkAlphaType:
            break;
        case kOpaque_SkAlphaType:
            image = toQImage(bitmap, QImage::Format_RGB32);
            break;
        case kPremul_SkAlphaType:
            image = toQImage(bitmap, QImage::Format_ARGB32_Premultiplied);
            break;
        case kUnpremul_SkAlphaType:
            image = toQImage(bitmap, QImage::Format_ARGB32);
            break;
        }
        break;
    case kIndex_8_SkColorType: {
        image = toQImage(bitmap, QImage::Format_Indexed8);
        SkColorTable *skTable = bitmap.getColorTable();
        if (skTable) {
            QVector<QRgb> qTable(skTable->count());
            for (int i = 0; i < skTable->count(); ++i)
                qTable[i] = (*skTable)[i];
            image.setColorTable(qTable);
        }
        break;
    }
    case kGray_8_SkColorType:
        image = toQImage(bitmap, QImage::Format_Grayscale8);
        break;
    }
    return image;
}
static void TestBitmapCopy(skiatest::Reporter* reporter) {
    static const Pair gPairs[] = {
        { SkBitmap::kNo_Config,         "00000000"  },
        { SkBitmap::kA1_Config,         "01000000"  },
        { SkBitmap::kA8_Config,         "00101110"  },
        { SkBitmap::kIndex8_Config,     "00111110"  },
        { SkBitmap::kRGB_565_Config,    "00101110"  },
        { SkBitmap::kARGB_4444_Config,  "00101110"  },
        { SkBitmap::kARGB_8888_Config,  "00101110"  },
// TODO: create valid RLE bitmap to test with
 //       { SkBitmap::kRLE_Index8_Config, "00101111"  }
    };

    const int W = 20;
    const int H = 33;

    for (size_t i = 0; i < SK_ARRAY_COUNT(gPairs); i++) {
        for (size_t j = 0; j < SK_ARRAY_COUNT(gPairs); j++) {
            SkBitmap src, dst;
            SkColorTable* ct = NULL;

            src.setConfig(gPairs[i].fConfig, W, H);
            if (SkBitmap::kIndex8_Config == src.config() ||
                    SkBitmap::kRLE_Index8_Config == src.config()) {
                ct = init_ctable();
            }
            src.allocPixels(ct);
            ct->safeRef();

            init_src(src);
            bool success = src.copyTo(&dst, gPairs[j].fConfig);
            bool expected = gPairs[i].fValid[j] != '0';
            if (success != expected) {
                SkString str;
                str.printf("SkBitmap::copyTo from %s to %s. expected %s returned %s",
                           gConfigName[i], gConfigName[j], boolStr(expected),
                           boolStr(success));
                reporter->reportFailed(str);
            }
            
            bool canSucceed = src.canCopyTo(gPairs[j].fConfig);
            if (success != canSucceed) {
                SkString str;
                str.printf("SkBitmap::copyTo from %s to %s. returned %s canCopyTo %s",
                           gConfigName[i], gConfigName[j], boolStr(success),
                           boolStr(canSucceed));
                reporter->reportFailed(str);
            }

            if (success) {
                REPORTER_ASSERT(reporter, src.width() == dst.width());
                REPORTER_ASSERT(reporter, src.height() == dst.height());
                REPORTER_ASSERT(reporter, dst.config() == gPairs[j].fConfig);
                test_isOpaque(reporter, src, dst.config());
                if (src.config() == dst.config()) {
                    SkAutoLockPixels srcLock(src);
                    SkAutoLockPixels dstLock(dst);
                    REPORTER_ASSERT(reporter, src.readyToDraw());
                    REPORTER_ASSERT(reporter, dst.readyToDraw());
                    const char* srcP = (const char*)src.getAddr(0, 0);
                    const char* dstP = (const char*)dst.getAddr(0, 0);
                    REPORTER_ASSERT(reporter, srcP != dstP);
                    REPORTER_ASSERT(reporter, !memcmp(srcP, dstP,
                                                      src.getSize()));
                }
                // test extractSubset
                {
                    SkBitmap subset;
                    SkIRect r;
                    r.set(1, 1, 2, 2);
                    if (src.extractSubset(&subset, r)) {
                        REPORTER_ASSERT(reporter, subset.width() == 1);
                        REPORTER_ASSERT(reporter, subset.height() == 1);

                        SkBitmap copy;
                        REPORTER_ASSERT(reporter,
                                        subset.copyTo(&copy, subset.config()));
                        REPORTER_ASSERT(reporter, copy.width() == 1);
                        REPORTER_ASSERT(reporter, copy.height() == 1);
                        REPORTER_ASSERT(reporter, copy.rowBytes() <= 4);
                        
                        SkAutoLockPixels alp0(subset);
                        SkAutoLockPixels alp1(copy);
                        // they should both have, or both not-have, a colortable
                        bool hasCT = subset.getColorTable() != NULL;
                        REPORTER_ASSERT(reporter,
                                    (copy.getColorTable() != NULL) == hasCT);
                    }
                }
            } 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 SkPNGImageDecoder::onDecode(SkStream* sk_stream, SkBitmap* decodedBitmap,
                                 SkBitmap::Config prefConfig, Mode mode) {
//    SkAutoTrace    apr("SkPNGImageDecoder::onDecode");

    /* Create and initialize the png_struct with the desired error handler
    * functions.  If you want to use the default stderr and longjump method,
    * you can supply NULL for the last three parameters.  We also supply the
    * the compiler header file version, so that we know if the application
    * was compiled with a compatible version of the library.  */
    png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
        NULL, sk_error_fn, NULL);
    //   png_voidp user_error_ptr, user_error_fn, user_warning_fn);
    if (png_ptr == NULL) {
        return false;
    }

    /* Allocate/initialize the memory for image information. */
    png_infop info_ptr = png_create_info_struct(png_ptr);
    if (info_ptr == NULL) {
        png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
        return false;
    }

    PNGAutoClean autoClean(png_ptr, info_ptr);

    /* Set error handling if you are using the setjmp/longjmp method (this is
    * the normal method of doing things with libpng).  REQUIRED unless you
    * set up your own error handlers in the png_create_read_struct() earlier.
    */
    if (setjmp(png_jmpbuf(png_ptr))) {
        return false;
    }

    /* If you are using replacement read functions, instead of calling
    * png_init_io() here you would call:
    */
    png_set_read_fn(png_ptr, (void *)sk_stream, sk_read_fn);
    /* where user_io_ptr is a structure you want available to the callbacks */
    /* If we have already read some of the signature */
//  png_set_sig_bytes(png_ptr, 0 /* sig_read */ );

    // hookup our peeker so we can see any user-chunks the caller may be interested in
    png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS, (png_byte*)"", 0);
    if (this->getPeeker()) {
        png_set_read_user_chunk_fn(png_ptr, (png_voidp)this->getPeeker(), sk_read_user_chunk);
    }

    /* The call to png_read_info() gives us all of the information from the
    * PNG file before the first IDAT (image data chunk). */
    png_read_info(png_ptr, info_ptr);
    png_uint_32 origWidth, origHeight;
    int bit_depth, color_type, interlace_type;
    png_get_IHDR(png_ptr, info_ptr, &origWidth, &origHeight, &bit_depth, &color_type,
        &interlace_type, int_p_NULL, int_p_NULL);

    SkBitmap::Config    config;
    bool                hasAlpha = false;
    bool                doDither = this->getDitherImage();
    
    // check for sBIT chunk data, in case we should disable dithering because
    // our data is not truely 8bits per component
    if (doDither) {
#if 0
        SkDebugf("----- sBIT %d %d %d %d\n", info_ptr->sig_bit.red,
                 info_ptr->sig_bit.green, info_ptr->sig_bit.blue,
                 info_ptr->sig_bit.alpha);
#endif
        // 0 seems to indicate no information available
        if (pos_le(info_ptr->sig_bit.red, SK_R16_BITS) &&
                pos_le(info_ptr->sig_bit.green, SK_G16_BITS) &&
                pos_le(info_ptr->sig_bit.blue, SK_B16_BITS)) {
            doDither = false;
        }
    }
    
    if (color_type == PNG_COLOR_TYPE_PALETTE) {
        config = SkBitmap::kIndex8_Config;  // defer sniffing for hasAlpha
    } else {
        png_color_16p   transColor;
        
        png_get_tRNS(png_ptr, info_ptr, NULL, NULL, &transColor);
        
        if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) ||
                PNG_COLOR_TYPE_RGB_ALPHA == color_type ||
                PNG_COLOR_TYPE_GRAY_ALPHA == color_type) {
            hasAlpha = true;
            config = SkBitmap::kARGB_8888_Config;
        } else {    // we get to choose the config
            config = prefConfig;
            if (config == SkBitmap::kNo_Config) {
                config = SkImageDecoder::GetDeviceConfig();
            }
            if (config != SkBitmap::kRGB_565_Config &&
                    config != SkBitmap::kARGB_4444_Config) {
                config = SkBitmap::kARGB_8888_Config;
            }
        }
    }
    
    if (!this->chooseFromOneChoice(config, origWidth, origHeight)) {
        return false;
    }
    
    const int sampleSize = this->getSampleSize();
    SkScaledBitmapSampler sampler(origWidth, origHeight, sampleSize);

    decodedBitmap->setConfig(config, sampler.scaledWidth(),
                             sampler.scaledHeight(), 0);
    if (SkImageDecoder::kDecodeBounds_Mode == mode) {
        return true;
    }
    
    // from here down we are concerned with colortables and pixels

    /* tell libpng to strip 16 bit/color files down to 8 bits/color */
    if (bit_depth == 16) {
        png_set_strip_16(png_ptr);
    }
    /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
    * byte into separate bytes (useful for paletted and grayscale images). */
    if (bit_depth < 8) {
        png_set_packing(png_ptr);
    }
    /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */
    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
        png_set_gray_1_2_4_to_8(png_ptr);
    }

    /* Make a grayscale image into RGB. */
    if (color_type == PNG_COLOR_TYPE_GRAY ||
            color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
        png_set_gray_to_rgb(png_ptr);
    }

    // we track if we actually see a non-opaque pixels, since sometimes a PNG sets its colortype
    // to |= PNG_COLOR_MASK_ALPHA, but all of its pixels are in fact opaque. We care, since we
    // draw lots faster if we can flag the bitmap has being opaque
    bool reallyHasAlpha = false;

    SkColorTable* colorTable = NULL;

    if (color_type == PNG_COLOR_TYPE_PALETTE) {
        int num_palette;
        png_colorp palette;
        png_bytep trans;
        int num_trans;

        png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette);
        
        /*  BUGGY IMAGE WORKAROUND
            
            We hit some images (e.g. fruit_.png) who contain bytes that are == colortable_count
            which is a problem since we use the byte as an index. To work around this we grow
            the colortable by 1 (if its < 256) and duplicate the last color into that slot.
        */
        int colorCount = num_palette + (num_palette < 256);

        colorTable = SkNEW_ARGS(SkColorTable, (colorCount));

        SkPMColor* colorPtr = colorTable->lockColors();
        if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
            png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, NULL);
            hasAlpha = (num_trans > 0);
        } else {
            num_trans = 0;
            colorTable->setFlags(colorTable->getFlags() | SkColorTable::kColorsAreOpaque_Flag);
        }        
        // check for bad images that might make us crash
        if (num_trans > num_palette) {
            num_trans = num_palette;
        }

        int index = 0;
        int transLessThanFF = 0;

        for (; index < num_trans; index++) {
            transLessThanFF |= (int)*trans - 0xFF;
            *colorPtr++ = SkPreMultiplyARGB(*trans++, palette->red, palette->green, palette->blue);
            palette++;
        }
        reallyHasAlpha |= (transLessThanFF < 0);

        for (; index < num_palette; index++) {
            *colorPtr++ = SkPackARGB32(0xFF, palette->red, palette->green, palette->blue);
            palette++;
        }

        // see BUGGY IMAGE WORKAROUND comment above
        if (num_palette < 256) {
            *colorPtr = colorPtr[-1];
        }
        colorTable->unlockColors(true);
    }
    
    SkAutoUnref aur(colorTable);

    if (!this->allocPixelRef(decodedBitmap, colorTable)) {
        delete colorTable;
        return false;
    }
    
    SkAutoLockPixels alp(*decodedBitmap);

    /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
//  if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
//      ; // png_set_swap_alpha(png_ptr);

    /* swap bytes of 16 bit files to least significant byte first */
    //   png_set_swap(png_ptr);

    /* Add filler (or alpha) byte (before/after each RGB triplet) */
    if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_GRAY) {
        png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
    }

    /* Turn on interlace handling.  REQUIRED if you are not using
    * png_read_image().  To see how to handle interlacing passes,
    * see the png_read_row() method below:
    */
    const int number_passes = interlace_type != PNG_INTERLACE_NONE ? 
                        png_set_interlace_handling(png_ptr) : 1;

    /* Optional call to gamma correct and add the background to the palette
    * and update info structure.  REQUIRED if you are expecting libpng to
    * update the palette for you (ie you selected such a transform above).
    */
    png_read_update_info(png_ptr, info_ptr);

    if (SkBitmap::kIndex8_Config == config && 1 == sampleSize) {
        for (int i = 0; i < number_passes; i++) {
            for (png_uint_32 y = 0; y < origHeight; y++) {
                uint8_t* bmRow = decodedBitmap->getAddr8(0, y);
                png_read_rows(png_ptr, &bmRow, png_bytepp_NULL, 1);
            }
        }
    } else {
        SkScaledBitmapSampler::SrcConfig sc;
        int srcBytesPerPixel = 4;
        
        if (SkBitmap::kIndex8_Config == config) {
            sc = SkScaledBitmapSampler::kIndex;
            srcBytesPerPixel = 1;
        } else if (hasAlpha) {
            sc = SkScaledBitmapSampler::kRGBA;
        } else {
            sc = SkScaledBitmapSampler::kRGBX;
        }

        SkAutoMalloc storage(origWidth * srcBytesPerPixel);
        const int height = decodedBitmap->height();

        for (int i = 0; i < number_passes; i++) {
            if (!sampler.begin(decodedBitmap, sc, doDither)) {
                return false;
            }

            uint8_t* srcRow = (uint8_t*)storage.get();
            skip_src_rows(png_ptr, srcRow, sampler.srcY0());

            for (int y = 0; y < height; y++) {
                uint8_t* tmp = srcRow;
                png_read_rows(png_ptr, &tmp, png_bytepp_NULL, 1);
                reallyHasAlpha |= sampler.next(srcRow);
                if (y < height - 1) {
                    skip_src_rows(png_ptr, srcRow, sampler.srcDY() - 1);
                }
            }
            
            // skip the rest of the rows (if any)
            png_uint_32 read = (height - 1) * sampler.srcDY() +
                               sampler.srcY0() + 1;
            SkASSERT(read <= origHeight);
            skip_src_rows(png_ptr, srcRow, origHeight - read);
        }

        if (hasAlpha && !reallyHasAlpha) {
            SkDEBUGF(("Image doesn't really have alpha [%d %d]\n",
                      origWidth, origHeight));
        }
    }

    /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
    png_read_end(png_ptr, info_ptr);

    decodedBitmap->setIsOpaque(!reallyHasAlpha);
    return true;
}