C++ SkPaint::getFilterLevel方法代码示例

    virtual void onDrawContent(SkCanvas* canvas) {
        canvas->translate(SkIntToScalar(10), SkIntToScalar(50));

        const SkScalar W = SkIntToScalar(fBitmaps[0].width() + 1);
        const SkScalar H = SkIntToScalar(fBitmaps[0].height() + 1);
        SkPaint paint;

        const SkScalar scale = 0.897917f;
        canvas->scale(SK_Scalar1, scale);

        for (int k = 0; k < 2; k++) {
            paint.setFilterLevel(k == 1 ? SkPaint::kLow_FilterLevel : SkPaint::kNone_FilterLevel);
            for (int j = 0; j < 2; j++) {
                paint.setDither(j == 1);
                for (int i = 0; i < fBitmapCount; i++) {
                    SkScalar x = (k * fBitmapCount + j) * W;
                    SkScalar y = i * H;
                    x = SkScalarRoundToScalar(x);
                    y = SkScalarRoundToScalar(y);
                    canvas->drawBitmap(fBitmaps[i], x, y, &paint);
                    if (i == 0) {
                        SkPaint p;
                        p.setAntiAlias(true);
                        p.setTextAlign(SkPaint::kCenter_Align);
                        p.setTextSize(SkIntToScalar(18));
                        SkString s("dither=");
                        s.appendS32(paint.isDither());
                        s.append(" filter=");
                        s.appendS32(paint.getFilterLevel() != SkPaint::kNone_FilterLevel);
                        canvas->drawText(s.c_str(), s.size(), x + W/2,
                                         y - p.getTextSize(), p);
                    }
                    if (k+j == 2) {
                        SkPaint p;
                        p.setAntiAlias(true);
                        p.setTextSize(SkIntToScalar(18));
                        SkString s;
                        s.append(" depth=");
                        s.appendS32(fBitmaps[i].colorType() == kRGB_565_SkColorType ? 16 : 32);
                        canvas->drawText(s.c_str(), s.size(), x + W + SkIntToScalar(4),
                                         y + H/2, p);
                    }
                }
            }
        }
    }

bool SkBitmapProcState::chooseProcs(const SkMatrix& inv, const SkPaint& paint) {
    SkASSERT(fOrigBitmap.width() && fOrigBitmap.height());

    fBitmap = NULL;
    fInvMatrix = inv;
    fFilterLevel = paint.getFilterLevel();

    // possiblyScaleImage will look to see if it can rescale the image as a
    // preprocess; either by scaling up to the target size, or by selecting
    // a nearby mipmap level.  If it does, it will adjust the working
    // matrix as well as the working bitmap.  It may also adjust the filter
    // quality to avoid re-filtering an already perfectly scaled image.
    if (!this->possiblyScaleImage()) {
        if (!this->lockBaseBitmap()) {
            return false;
        }
    }
    // The above logic should have always assigned fBitmap, but in case it
    // didn't, we check for that now...
    // TODO(dominikg): Ask [email protected] if we can just use an SkASSERT(fBitmap)?
    if (NULL == fBitmap) {
        return false;
    }

    // If we are "still" kMedium_FilterLevel, then the request was not fulfilled by possiblyScale,
    // so we downgrade to kLow (so the rest of the sniffing code can assume that)
    if (SkPaint::kMedium_FilterLevel == fFilterLevel) {
        fFilterLevel = SkPaint::kLow_FilterLevel;
    }

    bool trivialMatrix = (fInvMatrix.getType() & ~SkMatrix::kTranslate_Mask) == 0;
    bool clampClamp = SkShader::kClamp_TileMode == fTileModeX &&
                      SkShader::kClamp_TileMode == fTileModeY;

    if (!(fAdjustedMatrix || clampClamp || trivialMatrix)) {
        fInvMatrix.postIDiv(fOrigBitmap.width(), fOrigBitmap.height());
    }

    // Now that all possible changes to the matrix have taken place, check
    // to see if we're really close to a no-scale matrix.  If so, explicitly
    // set it to be so.  Subsequent code may inspect this matrix to choose
    // a faster path in this case.

    // This code will only execute if the matrix has some scale component;
    // if it's already pure translate then we won't do this inversion.

    if (matrix_only_scale_translate(fInvMatrix)) {
        SkMatrix forward;
        if (fInvMatrix.invert(&forward)) {
            if (clampClamp ? just_trans_clamp(forward, *fBitmap)
                            : just_trans_general(forward)) {
                SkScalar tx = -SkScalarRoundToScalar(forward.getTranslateX());
                SkScalar ty = -SkScalarRoundToScalar(forward.getTranslateY());
                fInvMatrix.setTranslate(tx, ty);
            }
        }
    }

    fInvProc        = fInvMatrix.getMapXYProc();
    fInvType        = fInvMatrix.getType();
    fInvSx          = SkScalarToFixed(fInvMatrix.getScaleX());
    fInvSxFractionalInt = SkScalarToFractionalInt(fInvMatrix.getScaleX());
    fInvKy          = SkScalarToFixed(fInvMatrix.getSkewY());
    fInvKyFractionalInt = SkScalarToFractionalInt(fInvMatrix.getSkewY());

    fAlphaScale = SkAlpha255To256(paint.getAlpha());

    fShaderProc32 = NULL;
    fShaderProc16 = NULL;
    fSampleProc32 = NULL;
    fSampleProc16 = NULL;

    // recompute the triviality of the matrix here because we may have
    // changed it!

    trivialMatrix = (fInvMatrix.getType() & ~SkMatrix::kTranslate_Mask) == 0;

    if (SkPaint::kHigh_FilterLevel == fFilterLevel) {
        // If this is still set, that means we wanted HQ sampling
        // but couldn't do it as a preprocess.  Let's try to install
        // the scanline version of the HQ sampler.  If that process fails,
        // downgrade to bilerp.

        // NOTE: Might need to be careful here in the future when we want
        // to have the platform proc have a shot at this; it's possible that
        // the chooseBitmapFilterProc will fail to install a shader but a
        // platform-specific one might succeed, so it might be premature here
        // to fall back to bilerp.  This needs thought.

        if (!this->setBitmapFilterProcs()) {
            fFilterLevel = SkPaint::kLow_FilterLevel;
        }
    }

    if (SkPaint::kLow_FilterLevel == fFilterLevel) {
        // Only try bilerp if the matrix is "interesting" and
        // the image has a suitable size.

        if (fInvType <= SkMatrix::kTranslate_Mask ||
                !valid_for_filtering(fBitmap->width() | fBitmap->height())) {
//.........这里部分代码省略.........

bool SkBitmapProcShader::asNewEffect(GrContext* context, const SkPaint& paint,
                                     const SkMatrix* localMatrix, GrColor* grColor,
                                     GrEffectRef** grEffect) const {
    SkMatrix matrix;
    matrix.setIDiv(fRawBitmap.width(), fRawBitmap.height());

    SkMatrix lmInverse;
    if (!this->getLocalMatrix().invert(&lmInverse)) {
        return false;
    }
    if (localMatrix) {
        SkMatrix inv;
        if (!localMatrix->invert(&inv)) {
            return false;
        }
        lmInverse.postConcat(inv);
    }
    matrix.preConcat(lmInverse);

    SkShader::TileMode tm[] = {
        (TileMode)fTileModeX,
        (TileMode)fTileModeY,
    };

    // Must set wrap and filter on the sampler before requesting a texture. In two places below
    // we check the matrix scale factors to determine how to interpret the filter quality setting.
    // This completely ignores the complexity of the drawVertices case where explicit local coords
    // are provided by the caller.
    bool useBicubic = false;
    GrTextureParams::FilterMode textureFilterMode;
    switch(paint.getFilterLevel()) {
        case SkPaint::kNone_FilterLevel:
            textureFilterMode = GrTextureParams::kNone_FilterMode;
            break;
        case SkPaint::kLow_FilterLevel:
            textureFilterMode = GrTextureParams::kBilerp_FilterMode;
            break;
        case SkPaint::kMedium_FilterLevel: {
            SkMatrix matrix;
            matrix.setConcat(context->getMatrix(), this->getLocalMatrix());
            if (matrix.getMinScale() < SK_Scalar1) {
                textureFilterMode = GrTextureParams::kMipMap_FilterMode;
            } else {
                // Don't trigger MIP level generation unnecessarily.
                textureFilterMode = GrTextureParams::kBilerp_FilterMode;
            }
            break;
        }
        case SkPaint::kHigh_FilterLevel: {
            SkMatrix matrix;
            matrix.setConcat(context->getMatrix(), this->getLocalMatrix());
            useBicubic = GrBicubicEffect::ShouldUseBicubic(matrix, &textureFilterMode);
            break;
        }
        default:
            SkErrorInternals::SetError( kInvalidPaint_SkError,
                                        "Sorry, I don't understand the filtering "
                                        "mode you asked for.  Falling back to "
                                        "MIPMaps.");
            textureFilterMode = GrTextureParams::kMipMap_FilterMode;
            break;

    }
    GrTextureParams params(tm, textureFilterMode);
    GrTexture* texture = GrLockAndRefCachedBitmapTexture(context, fRawBitmap, &params);

    if (NULL == texture) {
        SkErrorInternals::SetError( kInternalError_SkError,
                                    "Couldn't convert bitmap to texture.");
        return false;
    }
    
    *grColor = (kAlpha_8_SkColorType == fRawBitmap.colorType()) ? SkColor2GrColor(paint.getColor())
                                        : SkColor2GrColorJustAlpha(paint.getColor());

    if (useBicubic) {
        *grEffect = GrBicubicEffect::Create(texture, matrix, tm);
    } else {
        *grEffect = GrSimpleTextureEffect::Create(texture, matrix, params);
    }
    GrUnlockAndUnrefCachedBitmapTexture(texture);

    return true;
}