C++ SkColorTable类代码示例

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++);
        }
    }
}

/*  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;
    }

 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);
     }
 }

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;
}

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);
    }
}

/*  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;
}

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;
}

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;
}

/*  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;
        }
    }
}