C++ SkMatrix::getMinScale方法代码示例

void SkBaseDevice::LogDrawScaleFactor(const SkMatrix& matrix, SkFilterQuality filterQuality) {
#if SK_HISTOGRAMS_ENABLED
    enum ScaleFactor {
        kUpscale_ScaleFactor,
        kNoScale_ScaleFactor,
        kDownscale_ScaleFactor,
        kLargeDownscale_ScaleFactor,

        kLast_ScaleFactor = kLargeDownscale_ScaleFactor
    };

    float rawScaleFactor = matrix.getMinScale();

    ScaleFactor scaleFactor;
    if (rawScaleFactor < 0.5f) {
        scaleFactor = kLargeDownscale_ScaleFactor;
    } else if (rawScaleFactor < 1.0f) {
        scaleFactor = kDownscale_ScaleFactor;
    } else if (rawScaleFactor > 1.0f) {
        scaleFactor = kUpscale_ScaleFactor;
    } else {
        scaleFactor = kNoScale_ScaleFactor;
    }

    switch (filterQuality) {
        case kNone_SkFilterQuality:
            SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.NoneFilterQuality", scaleFactor,
                                     kLast_ScaleFactor + 1);
            break;
        case kLow_SkFilterQuality:
            SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.LowFilterQuality", scaleFactor,
                                     kLast_ScaleFactor + 1);
            break;
        case kMedium_SkFilterQuality:
            SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.MediumFilterQuality", scaleFactor,
                                     kLast_ScaleFactor + 1);
            break;
        case kHigh_SkFilterQuality:
            SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.HighFilterQuality", scaleFactor,
                                     kLast_ScaleFactor + 1);
            break;
    }

    // Also log filter quality independent scale factor.
    SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.AnyFilterQuality", scaleFactor,
                             kLast_ScaleFactor + 1);

    // Also log an overall histogram of filter quality.
    SK_HISTOGRAM_ENUMERATION("FilterQuality", filterQuality, kLast_SkFilterQuality + 1);
#endif
}

GrSamplerState::Filter GrSkFilterQualityToGrFilterMode(SkFilterQuality paintFilterQuality,
                                                       const SkMatrix& viewM,
                                                       const SkMatrix& localM,
                                                       bool sharpenMipmappedTextures,
                                                       bool* doBicubic) {
    *doBicubic = false;
    GrSamplerState::Filter textureFilterMode;
    switch (paintFilterQuality) {
        case kNone_SkFilterQuality:
            textureFilterMode = GrSamplerState::Filter::kNearest;
            break;
        case kLow_SkFilterQuality:
            textureFilterMode = GrSamplerState::Filter::kBilerp;
            break;
        case kMedium_SkFilterQuality: {
            SkMatrix matrix;
            matrix.setConcat(viewM, localM);
            // With sharp mips, we bias lookups by -0.5. That means our final LOD is >= 0 until the
            // computed LOD is >= 0.5. At what scale factor does a texture get an LOD of 0.5?
            //
            // Want:  0       = log2(1/s) - 0.5
            //        0.5     = log2(1/s)
            //        2^0.5   = 1/s
            //        1/2^0.5 = s
            //        2^0.5/2 = s
            SkScalar mipScale = sharpenMipmappedTextures ? SK_ScalarRoot2Over2 : SK_Scalar1;
            if (matrix.getMinScale() < mipScale) {
                textureFilterMode = GrSamplerState::Filter::kMipMap;
            } else {
                // Don't trigger MIP level generation unnecessarily.
                textureFilterMode = GrSamplerState::Filter::kBilerp;
            }
            break;
        }
        case kHigh_SkFilterQuality: {
            SkMatrix matrix;
            matrix.setConcat(viewM, localM);
            *doBicubic = GrBicubicEffect::ShouldUseBicubic(matrix, &textureFilterMode);
            break;
        }
        default:
            // Should be unreachable.  If not, fall back to mipmaps.
            textureFilterMode = GrSamplerState::Filter::kMipMap;
            break;

    }
    return textureFilterMode;
}

GrTextureParams::FilterMode GrSkFilterQualityToGrFilterMode(SkFilterQuality paintFilterQuality,
                                                            const SkMatrix& viewM,
                                                            const SkMatrix& localM,
                                                            bool* doBicubic) {
    *doBicubic = false;
    GrTextureParams::FilterMode textureFilterMode;
    switch (paintFilterQuality) {
        case kNone_SkFilterQuality:
            textureFilterMode = GrTextureParams::kNone_FilterMode;
            break;
        case kLow_SkFilterQuality:
            textureFilterMode = GrTextureParams::kBilerp_FilterMode;
            break;
        case kMedium_SkFilterQuality: {
            SkMatrix matrix;
            matrix.setConcat(viewM, localM);
            if (matrix.getMinScale() < SK_Scalar1) {
                textureFilterMode = GrTextureParams::kMipMap_FilterMode;
            } else {
                // Don't trigger MIP level generation unnecessarily.
                textureFilterMode = GrTextureParams::kBilerp_FilterMode;
            }
            break;
        }
        case kHigh_SkFilterQuality: {
            SkMatrix matrix;
            matrix.setConcat(viewM, localM);
            *doBicubic = 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;

    }
    return textureFilterMode;
}

static void test_matrix_min_max_scale(skiatest::Reporter* reporter) {
    SkScalar scales[2];
    bool success;

    SkMatrix identity;
    identity.reset();
    REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMinScale());
    REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMaxScale());
    success = identity.getMinMaxScales(scales);
    REPORTER_ASSERT(reporter, success && SK_Scalar1 == scales[0] && SK_Scalar1 == scales[1]);

    SkMatrix scale;
    scale.setScale(SK_Scalar1 * 2, SK_Scalar1 * 4);
    REPORTER_ASSERT(reporter, SK_Scalar1 * 2 == scale.getMinScale());
    REPORTER_ASSERT(reporter, SK_Scalar1 * 4 == scale.getMaxScale());
    success = scale.getMinMaxScales(scales);
    REPORTER_ASSERT(reporter, success && SK_Scalar1 * 2 == scales[0] && SK_Scalar1 * 4 == scales[1]);

    SkMatrix rot90Scale;
    rot90Scale.setRotate(90 * SK_Scalar1);
    rot90Scale.postScale(SK_Scalar1 / 4, SK_Scalar1 / 2);
    REPORTER_ASSERT(reporter, SK_Scalar1 / 4 == rot90Scale.getMinScale());
    REPORTER_ASSERT(reporter, SK_Scalar1 / 2 == rot90Scale.getMaxScale());
    success = rot90Scale.getMinMaxScales(scales);
    REPORTER_ASSERT(reporter, success && SK_Scalar1 / 4  == scales[0] && SK_Scalar1 / 2 == scales[1]);

    SkMatrix rotate;
    rotate.setRotate(128 * SK_Scalar1);
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMinScale(), SK_ScalarNearlyZero));
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMaxScale(), SK_ScalarNearlyZero));
    success = rotate.getMinMaxScales(scales);
    REPORTER_ASSERT(reporter, success);
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, scales[0], SK_ScalarNearlyZero));
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, scales[1], SK_ScalarNearlyZero));

    SkMatrix translate;
    translate.setTranslate(10 * SK_Scalar1, -5 * SK_Scalar1);
    REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMinScale());
    REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMaxScale());
    success = translate.getMinMaxScales(scales);
    REPORTER_ASSERT(reporter, success && SK_Scalar1 == scales[0] && SK_Scalar1 == scales[1]);

    SkMatrix perspX;
    perspX.reset();
    perspX.setPerspX(SkScalarToPersp(SK_Scalar1 / 1000));
    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMinScale());
    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMaxScale());
    // Verify that getMinMaxScales() doesn't update the scales array on failure.
    scales[0] = -5;
    scales[1] = -5;
    success = perspX.getMinMaxScales(scales);
    REPORTER_ASSERT(reporter, !success && -5 * SK_Scalar1 == scales[0] && -5 * SK_Scalar1  == scales[1]);

    SkMatrix perspY;
    perspY.reset();
    perspY.setPerspY(SkScalarToPersp(-SK_Scalar1 / 500));
    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMinScale());
    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMaxScale());
    scales[0] = -5;
    scales[1] = -5;
    success = perspY.getMinMaxScales(scales);
    REPORTER_ASSERT(reporter, !success && -5 * SK_Scalar1 == scales[0] && -5 * SK_Scalar1  == scales[1]);

    SkMatrix baseMats[] = {scale, rot90Scale, rotate,
                           translate, perspX, perspY};
    SkMatrix mats[2*SK_ARRAY_COUNT(baseMats)];
    for (size_t i = 0; i < SK_ARRAY_COUNT(baseMats); ++i) {
        mats[i] = baseMats[i];
        bool invertable = mats[i].invert(&mats[i + SK_ARRAY_COUNT(baseMats)]);
        REPORTER_ASSERT(reporter, invertable);
    }
    SkRandom rand;
    for (int m = 0; m < 1000; ++m) {
        SkMatrix mat;
        mat.reset();
        for (int i = 0; i < 4; ++i) {
            int x = rand.nextU() % SK_ARRAY_COUNT(mats);
            mat.postConcat(mats[x]);
        }

        SkScalar minScale = mat.getMinScale();
        SkScalar maxScale = mat.getMaxScale();
        REPORTER_ASSERT(reporter, (minScale < 0) == (maxScale < 0));
        REPORTER_ASSERT(reporter, (maxScale < 0) == mat.hasPerspective());

        SkScalar scales[2];
        bool success = mat.getMinMaxScales(scales);
        REPORTER_ASSERT(reporter, success == !mat.hasPerspective());
        REPORTER_ASSERT(reporter, !success || (scales[0] == minScale && scales[1] == maxScale));

        if (mat.hasPerspective()) {
            m -= 1; // try another non-persp matrix
            continue;
        }

        // test a bunch of vectors. All should be scaled by between minScale and maxScale
        // (modulo some error) and we should find a vector that is scaled by almost each.
        static const SkScalar gVectorScaleTol = (105 * SK_Scalar1) / 100;
        static const SkScalar gCloseScaleTol = (97 * SK_Scalar1) / 100;
        SkScalar max = 0, min = SK_ScalarMax;
//.........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;
}

void GetLocalBounds(const SkPath& path, const SkDrawShadowRec& rec, const SkMatrix& ctm,
                    SkRect* bounds) {
    SkRect ambientBounds = path.getBounds();
    SkScalar occluderZ;
    if (SkScalarNearlyZero(rec.fZPlaneParams.fX) && SkScalarNearlyZero(rec.fZPlaneParams.fY)) {
        occluderZ = rec.fZPlaneParams.fZ;
    } else {
        occluderZ = compute_z(ambientBounds.fLeft, ambientBounds.fTop, rec.fZPlaneParams);
        occluderZ = SkTMax(occluderZ, compute_z(ambientBounds.fRight, ambientBounds.fTop,
                                                rec.fZPlaneParams));
        occluderZ = SkTMax(occluderZ, compute_z(ambientBounds.fLeft, ambientBounds.fBottom,
                                                rec.fZPlaneParams));
        occluderZ = SkTMax(occluderZ, compute_z(ambientBounds.fRight, ambientBounds.fBottom,
                                                rec.fZPlaneParams));
    }
    SkScalar ambientBlur;
    SkScalar spotBlur;
    SkScalar spotScale;
    SkPoint spotOffset;
    if (ctm.hasPerspective()) {
        // transform ambient and spot bounds into device space
        ctm.mapRect(&ambientBounds);

        // get ambient blur (in device space)
        ambientBlur = SkDrawShadowMetrics::AmbientBlurRadius(occluderZ);

        // get spot params (in device space)
        SkPoint devLightPos = SkPoint::Make(rec.fLightPos.fX, rec.fLightPos.fY);
        ctm.mapPoints(&devLightPos, 1);
        SkDrawShadowMetrics::GetSpotParams(occluderZ, devLightPos.fX, devLightPos.fY,
                                           rec.fLightPos.fZ, rec.fLightRadius,
                                           &spotBlur, &spotScale, &spotOffset);
    } else {
        SkScalar devToSrcScale = SkScalarInvert(ctm.getMinScale());

        // get ambient blur (in local space)
        SkScalar devSpaceAmbientBlur = SkDrawShadowMetrics::AmbientBlurRadius(occluderZ);
        ambientBlur = devSpaceAmbientBlur*devToSrcScale;

        // get spot params (in local space)
        SkDrawShadowMetrics::GetSpotParams(occluderZ, rec.fLightPos.fX, rec.fLightPos.fY,
                                           rec.fLightPos.fZ, rec.fLightRadius,
                                           &spotBlur, &spotScale, &spotOffset);

        // convert spot blur to local space
        spotBlur *= devToSrcScale;
    }

    // in both cases, adjust ambient and spot bounds
    SkRect spotBounds = ambientBounds;
    ambientBounds.outset(ambientBlur, ambientBlur);
    spotBounds.fLeft *= spotScale;
    spotBounds.fTop *= spotScale;
    spotBounds.fRight *= spotScale;
    spotBounds.fBottom *= spotScale;
    spotBounds.offset(spotOffset.fX, spotOffset.fY);
    spotBounds.outset(spotBlur, spotBlur);

    // merge bounds
    *bounds = ambientBounds;
    bounds->join(spotBounds);
    // outset a bit to account for floating point error
    bounds->outset(1, 1);

    // if perspective, transform back to src space
    if (ctm.hasPerspective()) {
        // TODO: create tighter mapping from dev rect back to src rect
        SkMatrix inverse;
        if (ctm.invert(&inverse)) {
            inverse.mapRect(bounds);
        }
    }
}

bool LightingShader::asFragmentProcessor(GrContext* context, const SkPaint& paint, 
                                         const SkMatrix& viewM, const SkMatrix* localMatrix, 
                                         GrColor* color, GrProcessorDataManager*,
                                         GrFragmentProcessor** fp) const {
    // we assume diffuse and normal maps have same width and height
    // TODO: support different sizes
    SkASSERT(fDiffuseMap.width() == fNormalMap.width() &&
             fDiffuseMap.height() == fNormalMap.height());
    SkMatrix matrix;
    matrix.setIDiv(fDiffuseMap.width(), fDiffuseMap.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);

    // 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.
    GrTextureParams::FilterMode textureFilterMode = GrTextureParams::kBilerp_FilterMode;
    switch (paint.getFilterQuality()) {
    case kNone_SkFilterQuality:
        textureFilterMode = GrTextureParams::kNone_FilterMode;
        break;
    case kLow_SkFilterQuality:
        textureFilterMode = GrTextureParams::kBilerp_FilterMode;
        break;
    case kMedium_SkFilterQuality:{                          
        SkMatrix matrix;
        matrix.setConcat(viewM, 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 kHigh_SkFilterQuality:
    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;

    }

    // TODO: support other tile modes
    GrTextureParams params(kClamp_TileMode, textureFilterMode);
    SkAutoTUnref<GrTexture> diffuseTexture(GrRefCachedBitmapTexture(context, fDiffuseMap, &params));
    if (!diffuseTexture) {
        SkErrorInternals::SetError(kInternalError_SkError,
            "Couldn't convert bitmap to texture.");
        return false;
    }

    SkAutoTUnref<GrTexture> normalTexture(GrRefCachedBitmapTexture(context, fNormalMap, &params));
    if (!normalTexture) {
        SkErrorInternals::SetError(kInternalError_SkError,
            "Couldn't convert bitmap to texture.");
        return false;
    }

    GrColor lightColor = GrColorPackRGBA(SkColorGetR(fLight.fColor), SkColorGetG(fLight.fColor),
                                         SkColorGetB(fLight.fColor), SkColorGetA(fLight.fColor));
    GrColor ambientColor = GrColorPackRGBA(SkColorGetR(fAmbientColor), SkColorGetG(fAmbientColor),
                                           SkColorGetB(fAmbientColor), SkColorGetA(fAmbientColor));

    *fp = SkNEW_ARGS(LightingFP, (diffuseTexture, normalTexture, matrix,
                                  fLight.fDirection, lightColor, ambientColor));
    *color = GrColorPackA4(paint.getAlpha());
    return true;
}