C++ SkMatrix::rectStaysRect方法代码示例

static void test_matrix_recttorect(skiatest::Reporter* reporter) {
    SkRect src, dst;
    SkMatrix matrix;

    src.set(0, 0, SK_Scalar1*10, SK_Scalar1*10);
    dst = src;
    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
    REPORTER_ASSERT(reporter, SkMatrix::kIdentity_Mask == matrix.getType());
    REPORTER_ASSERT(reporter, matrix.rectStaysRect());

    dst.offset(SK_Scalar1, SK_Scalar1);
    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
    REPORTER_ASSERT(reporter, SkMatrix::kTranslate_Mask == matrix.getType());
    REPORTER_ASSERT(reporter, matrix.rectStaysRect());

    dst.fRight += SK_Scalar1;
    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
    REPORTER_ASSERT(reporter,
                    (SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask) == matrix.getType());
    REPORTER_ASSERT(reporter, matrix.rectStaysRect());

    dst = src;
    dst.fRight = src.fRight * 2;
    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
    REPORTER_ASSERT(reporter, SkMatrix::kScale_Mask == matrix.getType());
    REPORTER_ASSERT(reporter, matrix.rectStaysRect());
}

bool shouldDrawAntiAliased(const GraphicsContext* context, const SkRect& destRect)
{
    if (!context->shouldAntialias())
        return false;
    const SkMatrix totalMatrix = context->getTotalMatrix();
    // Don't disable anti-aliasing if we're rotated or skewed.
    if (!totalMatrix.rectStaysRect())
        return true;
    // Disable anti-aliasing for scales or n*90 degree rotations.
    // Allow to opt out of the optimization though for "hairline" geometry
    // images - using the shouldAntialiasHairlineImages() GraphicsContext flag.
    if (!context->shouldAntialiasHairlineImages())
        return false;
    // Check if the dimensions of the destination are "small" (less than one
    // device pixel). To prevent sudden drop-outs. Since we know that
    // kRectStaysRect_Mask is set, the matrix either has scale and no skew or
    // vice versa. We can query the kAffine_Mask flag to determine which case
    // it is.
    // FIXME: This queries the CTM while drawing, which is generally
    // discouraged. Always drawing with AA can negatively impact performance
    // though - that's why it's not always on.
    SkScalar widthExpansion, heightExpansion;
    if (totalMatrix.getType() & SkMatrix::kAffine_Mask)
        widthExpansion = totalMatrix[SkMatrix::kMSkewY], heightExpansion = totalMatrix[SkMatrix::kMSkewX];
    else
        widthExpansion = totalMatrix[SkMatrix::kMScaleX], heightExpansion = totalMatrix[SkMatrix::kMScaleY];
    return destRect.width() * fabs(widthExpansion) < 1 || destRect.height() * fabs(heightExpansion) < 1;
}

void Matrix4::load(const SkMatrix& v) {
    memset(data, 0, sizeof(data));

    data[kScaleX]     = v[SkMatrix::kMScaleX];
    data[kSkewX]      = v[SkMatrix::kMSkewX];
    data[kTranslateX] = v[SkMatrix::kMTransX];

    data[kSkewY]      = v[SkMatrix::kMSkewY];
    data[kScaleY]     = v[SkMatrix::kMScaleY];
    data[kTranslateY] = v[SkMatrix::kMTransY];

    data[kPerspective0]  = v[SkMatrix::kMPersp0];
    data[kPerspective1]  = v[SkMatrix::kMPersp1];
    data[kPerspective2]  = v[SkMatrix::kMPersp2];

    data[kScaleZ] = 1.0f;

    // NOTE: The flags are compatible between SkMatrix and this class.
    //       However, SkMatrix::getType() does not return the flag
    //       kRectStaysRect. The return value is masked with 0xF
    //       so we need the extra rectStaysRect() check
    mType = v.getType();
    if (v.rectStaysRect()) {
        mType |= kTypeRectToRect;
    }
}

bool GrBicubicEffect::ShouldUseBicubic(const SkMatrix& matrix,
                                       GrTextureParams::FilterMode* filterMode) {
    if (matrix.isIdentity()) {
        *filterMode = GrTextureParams::kNone_FilterMode;
        return false;
    }

    SkScalar scales[2];
    if (!matrix.getMinMaxScales(scales) || scales[0] < SK_Scalar1) {
        // Bicubic doesn't handle arbitrary minimization well, as src texels can be skipped
        // entirely,
        *filterMode = GrTextureParams::kMipMap_FilterMode;
        return false;
    }
    // At this point if scales[1] == SK_Scalar1 then the matrix doesn't do any scaling.
    if (scales[1] == SK_Scalar1) {
        if (matrix.rectStaysRect() && SkScalarIsInt(matrix.getTranslateX()) &&
                SkScalarIsInt(matrix.getTranslateY())) {
            *filterMode = GrTextureParams::kNone_FilterMode;
        } else {
            // Use bilerp to handle rotation or fractional translation.
            *filterMode = GrTextureParams::kBilerp_FilterMode;
        }
        return false;
    }
    // When we use the bicubic filtering effect each sample is read from the texture using
    // nearest neighbor sampling.
    *filterMode = GrTextureParams::kNone_FilterMode;
    return true;
}

    void onDraw(SkCanvas* canvas) override {
        static const int kOn = 4;
        static const int kOff = 4;
        static const int kIntervalLength = kOn + kOff;

        static const SkColor gColors[kIntervalLength] = {
            SK_ColorRED,
            SK_ColorGREEN,
            SK_ColorBLUE,
            SK_ColorCYAN,
            SK_ColorMAGENTA,
            SK_ColorYELLOW,
            SK_ColorGRAY,
            SK_ColorDKGRAY
        };

        SkPaint paint;
        paint.setStyle(SkPaint::kStroke_Style);

        paint.setAntiAlias(fDoAA);

        SkMatrix rot;
        rot.setRotate(90);
        SkASSERT(rot.rectStaysRect());

        canvas->concat(rot);

        int sign;       // used to toggle the direction of the lines
        int phase = 0;

        for (int x = 0; x < 200; x += 10) {
            paint.setStrokeWidth(SkIntToScalar(phase+1));
            paint.setColor(gColors[phase]);
            sign = (x % 20) ? 1 : -1;
            drawline(canvas, kOn, kOff, paint, 
                     SkIntToScalar(x), -sign * SkIntToScalar(10003), 
                     SkIntToScalar(phase),
                     SkIntToScalar(x),  sign * SkIntToScalar(10003));
            phase = (phase + 1) % kIntervalLength;
        }

        for (int y = -400; y < 0; y += 10) {
            paint.setStrokeWidth(SkIntToScalar(phase+1));
            paint.setColor(gColors[phase]);
            sign = (y % 20) ? 1 : -1;
            drawline(canvas, kOn, kOff, paint, 
                     -sign * SkIntToScalar(10003), SkIntToScalar(y), 
                     SkIntToScalar(phase),
                      sign * SkIntToScalar(10003), SkIntToScalar(y));
            phase = (phase + 1) % kIntervalLength;
        }
    }

static bool can_ignore_bilerp_constraint(const GrTextureProducer& producer,
                                         const SkRect& srcRect,
                                         const SkMatrix& srcRectToDeviceSpace,
                                         bool isMSAA) {
    if (srcRectToDeviceSpace.rectStaysRect()) {
        // sampling is axis-aligned
        SkRect transformedRect;
        srcRectToDeviceSpace.mapRect(&transformedRect, srcRect);

        if (has_aligned_samples(srcRect, transformedRect) ||
            !may_color_bleed(srcRect, transformedRect, srcRectToDeviceSpace, isMSAA)) {
            return true;
        }
    }
    return false;
}

void GrAARectRenderer::FillAANestedRects(GrDrawTarget* target,
                                         const GrPipelineBuilder& pipelineBuilder,
                                         GrColor color,
                                         const SkMatrix& viewMatrix,
                                         const SkRect rects[2]) {
    SkASSERT(viewMatrix.rectStaysRect());
    SkASSERT(!rects[0].isEmpty() && !rects[1].isEmpty());

    SkRect devOutside, devInside;
    viewMatrix.mapRect(&devOutside, rects[0]);
    viewMatrix.mapRect(&devInside, rects[1]);

    if (devInside.isEmpty()) {
        FillAARect(target, pipelineBuilder, color, viewMatrix, devOutside, devOutside);
        return;
    }

    GeometryStrokeAARect(target, pipelineBuilder, color, viewMatrix, devOutside,
                         devOutside, devInside, true);
}

void GrAARectRenderer::fillAANestedRects(GrDrawTarget* target,
                                         GrDrawState* drawState,
                                         GrColor color,
                                         const SkRect rects[2],
                                         const SkMatrix& combinedMatrix) {
    SkASSERT(combinedMatrix.rectStaysRect());
    SkASSERT(!rects[1].isEmpty());

    SkRect devOutside, devOutsideAssist, devInside;
    combinedMatrix.mapRect(&devOutside, rects[0]);
    // can't call mapRect for devInside since it calls sort
    combinedMatrix.mapPoints((SkPoint*)&devInside, (const SkPoint*)&rects[1], 2);

    if (devInside.isEmpty()) {
        this->fillAARect(target, drawState, color, devOutside, SkMatrix::I(), devOutside);
        return;
    }

    this->geometryStrokeAARect(target, drawState, color, devOutside, devOutsideAssist, devInside,
                               true);
}

static bool apply_aa_to_rect(GrDrawTarget* target,
                             GrPipelineBuilder* pipelineBuilder,
                             SkRect* devBoundRect,
                             const SkRect& rect,
                             SkScalar strokeWidth,
                             const SkMatrix& combinedMatrix,
                             GrColor color) {
    if (pipelineBuilder->getRenderTarget()->isUnifiedMultisampled() ||
        !combinedMatrix.preservesAxisAlignment()) {
        return false;
    }

    combinedMatrix.mapRect(devBoundRect, rect);
    if (!combinedMatrix.rectStaysRect()) {
        return true;
    }

    if (strokeWidth < 0) {
        return !is_irect(*devBoundRect);
    }

    return true;
}

static bool apply_aa_to_rect(GrDrawTarget* target,
                             GrPipelineBuilder* pipelineBuilder,
                             SkRect* devBoundRect,
                             const SkRect& rect,
                             SkScalar strokeWidth,
                             const SkMatrix& combinedMatrix,
                             GrColor color) {
    if (pipelineBuilder->getRenderTarget()->isUnifiedMultisampled()) {
        return false;
    }

#if defined(SHADER_AA_FILL_RECT) || !defined(IGNORE_ROT_AA_RECT_OPT)
    if (strokeWidth >= 0) {
#endif
        if (!combinedMatrix.preservesAxisAlignment()) {
            return false;
        }

#if defined(SHADER_AA_FILL_RECT) || !defined(IGNORE_ROT_AA_RECT_OPT)
    } else {
        if (!combinedMatrix.preservesRightAngles()) {
            return false;
        }
    }
#endif

    combinedMatrix.mapRect(devBoundRect, rect);
    if (!combinedMatrix.rectStaysRect()) {
        return true;
    }

    if (strokeWidth < 0) {
        return !is_irect(*devBoundRect);
    }

    return true;
}

// Attempt to trim the line to minimally cover the cull rect (currently
// only works for horizontal and vertical lines).
// Return true if processing should continue; false otherwise.
static bool cull_line(SkPoint* pts, const SkStrokeRec& rec,
                      const SkMatrix& ctm, const SkRect* cullRect,
                      const SkScalar intervalLength) {
    if (nullptr == cullRect) {
        SkASSERT(false); // Shouldn't ever occur in practice
        return false;
    }

    SkScalar dx = pts[1].x() - pts[0].x();
    SkScalar dy = pts[1].y() - pts[0].y();

    if ((dx && dy) || (!dx && !dy)) {
        return false;
    }

    SkRect bounds = *cullRect;
    outset_for_stroke(&bounds, rec);

    // cullRect is in device space while pts are in the local coordinate system
    // defined by the ctm. We want our answer in the local coordinate system.

    SkASSERT(ctm.rectStaysRect());
    SkMatrix inv;
    if (!ctm.invert(&inv)) {
        return false;
    }

    inv.mapRect(&bounds);

    if (dx) {
        SkASSERT(dx && !dy);
        SkScalar minX = pts[0].fX;
        SkScalar maxX = pts[1].fX;

        if (dx < 0) {
            SkTSwap(minX, maxX);
        }

        SkASSERT(minX < maxX);
        if (maxX <= bounds.fLeft || minX >= bounds.fRight) {
            return false;
        }

        // Now we actually perform the chop, removing the excess to the left and
        // right of the bounds (keeping our new line "in phase" with the dash,
        // hence the (mod intervalLength).

        if (minX < bounds.fLeft) {
            minX = bounds.fLeft - SkScalarMod(bounds.fLeft - minX, intervalLength);
        }
        if (maxX > bounds.fRight) {
            maxX = bounds.fRight + SkScalarMod(maxX - bounds.fRight, intervalLength);
        }

        SkASSERT(maxX > minX);
        if (dx < 0) {
            SkTSwap(minX, maxX);
        }
        pts[0].fX = minX;
        pts[1].fX = maxX;
    } else {
        SkASSERT(dy && !dx);
        SkScalar minY = pts[0].fY;
        SkScalar maxY = pts[1].fY;

        if (dy < 0) {
            SkTSwap(minY, maxY);
        }

        SkASSERT(minY < maxY);
        if (maxY <= bounds.fTop || minY >= bounds.fBottom) {
            return false;
        }

        // Now we actually perform the chop, removing the excess to the top and
        // bottom of the bounds (keeping our new line "in phase" with the dash,
        // hence the (mod intervalLength).

        if (minY < bounds.fTop) {
            minY = bounds.fTop - SkScalarMod(bounds.fTop - minY, intervalLength);
        }
        if (maxY > bounds.fBottom) {
            maxY = bounds.fBottom + SkScalarMod(maxY - bounds.fBottom, intervalLength);
        }

        SkASSERT(maxY > minY);
        if (dy < 0) {
            SkTSwap(minY, maxY);
        }
        pts[0].fY = minY;
        pts[1].fY = maxY;
    }

    return true;
}

// Currently asPoints is more restrictive then it needs to be. In the future
// we need to:
//      allow kRound_Cap capping (could allow rotations in the matrix with this)
//      allow paths to be returned
bool SkDashPathEffect::asPoints(PointData* results,
                                const SkPath& src,
                                const SkStrokeRec& rec,
                                const SkMatrix& matrix,
                                const SkRect* cullRect) const {
    // width < 0 -> fill && width == 0 -> hairline so requiring width > 0 rules both out
    if (fInitialDashLength < 0 || 0 >= rec.getWidth()) {
        return false;
    }

    // TODO: this next test could be eased up. We could allow any number of
    // intervals as long as all the ons match and all the offs match.
    // Additionally, they do not necessarily need to be integers.
    // We cannot allow arbitrary intervals since we want the returned points
    // to be uniformly sized.
    if (fCount != 2 ||
        !SkScalarNearlyEqual(fIntervals[0], fIntervals[1]) ||
        !SkScalarIsInt(fIntervals[0]) ||
        !SkScalarIsInt(fIntervals[1])) {
        return false;
    }

    SkPoint pts[2];

    if (!src.isLine(pts)) {
        return false;
    }

    // TODO: this test could be eased up to allow circles
    if (SkPaint::kButt_Cap != rec.getCap()) {
        return false;
    }

    // TODO: this test could be eased up for circles. Rotations could be allowed.
    if (!matrix.rectStaysRect()) {
        return false;
    }

    // See if the line can be limited to something plausible.
    if (!cull_line(pts, rec, matrix, cullRect, fIntervalLength)) {
        return false;
    }

    SkScalar length = SkPoint::Distance(pts[1], pts[0]);

    SkVector tangent = pts[1] - pts[0];
    if (tangent.isZero()) {
        return false;
    }

    tangent.scale(SkScalarInvert(length));

    // TODO: make this test for horizontal & vertical lines more robust
    bool isXAxis = true;
    if (SkScalarNearlyEqual(SK_Scalar1, tangent.fX) ||
        SkScalarNearlyEqual(-SK_Scalar1, tangent.fX)) {
        results->fSize.set(SkScalarHalf(fIntervals[0]), SkScalarHalf(rec.getWidth()));
    } else if (SkScalarNearlyEqual(SK_Scalar1, tangent.fY) ||
               SkScalarNearlyEqual(-SK_Scalar1, tangent.fY)) {
        results->fSize.set(SkScalarHalf(rec.getWidth()), SkScalarHalf(fIntervals[0]));
        isXAxis = false;
    } else if (SkPaint::kRound_Cap != rec.getCap()) {
        // Angled lines don't have axis-aligned boxes.
        return false;
    }

    if (results) {
        results->fFlags = 0;
        SkScalar clampedInitialDashLength = SkMinScalar(length, fInitialDashLength);

        if (SkPaint::kRound_Cap == rec.getCap()) {
            results->fFlags |= PointData::kCircles_PointFlag;
        }

        results->fNumPoints = 0;
        SkScalar len2 = length;
        if (clampedInitialDashLength > 0 || 0 == fInitialDashIndex) {
            SkASSERT(len2 >= clampedInitialDashLength);
            if (0 == fInitialDashIndex) {
                if (clampedInitialDashLength > 0) {
                    if (clampedInitialDashLength >= fIntervals[0]) {
                        ++results->fNumPoints;  // partial first dash
                    }
                    len2 -= clampedInitialDashLength;
                }
                len2 -= fIntervals[1];  // also skip first space
                if (len2 < 0) {
                    len2 = 0;
                }
            } else {
                len2 -= clampedInitialDashLength; // skip initial partial empty
            }
        }
        int numMidPoints = SkScalarFloorToInt(len2 / fIntervalLength);
        results->fNumPoints += numMidPoints;
        len2 -= numMidPoints * fIntervalLength;
//.........这里部分代码省略.........

 static jboolean rectStaysRect(JNIEnv* env, jobject clazz, jlong objHandle) {
     SkMatrix* obj = reinterpret_cast<SkMatrix*>(objHandle);
     return obj->rectStaysRect() ? JNI_TRUE : JNI_FALSE;
 }

void TestMatrix(skiatest::Reporter* reporter) {
    SkMatrix    mat, inverse, iden1, iden2;

    mat.reset();
    mat.setTranslate(SK_Scalar1, SK_Scalar1);
    mat.invert(&inverse);
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));

    mat.setScale(SkIntToScalar(2), SkIntToScalar(2));
    mat.invert(&inverse);
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));
    test_flatten(reporter, mat);

    mat.setScale(SK_Scalar1/2, SK_Scalar1/2);
    mat.invert(&inverse);
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));
    test_flatten(reporter, mat);

    mat.setScale(SkIntToScalar(3), SkIntToScalar(5), SkIntToScalar(20), 0);
    mat.postRotate(SkIntToScalar(25));
    REPORTER_ASSERT(reporter, mat.invert(NULL));
    mat.invert(&inverse);
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));
    iden2.setConcat(inverse, mat);
    REPORTER_ASSERT(reporter, is_identity(iden2));
    test_flatten(reporter, mat);
    test_flatten(reporter, iden2);

    // rectStaysRect test
    {
        static const struct {
            SkScalar    m00, m01, m10, m11;
            bool        mStaysRect;
        }
        gRectStaysRectSamples[] = {
            {          0,          0,          0,           0, false },
            {          0,          0,          0,  SK_Scalar1, false },
            {          0,          0, SK_Scalar1,           0, false },
            {          0,          0, SK_Scalar1,  SK_Scalar1, false },
            {          0, SK_Scalar1,          0,           0, false },
            {          0, SK_Scalar1,          0,  SK_Scalar1, false },
            {          0, SK_Scalar1, SK_Scalar1,           0, true },
            {          0, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false },
            { SK_Scalar1,          0,          0,           0, false },
            { SK_Scalar1,          0,          0,  SK_Scalar1, true },
            { SK_Scalar1,          0, SK_Scalar1,           0, false },
            { SK_Scalar1,          0, SK_Scalar1,  SK_Scalar1, false },
            { SK_Scalar1, SK_Scalar1,          0,           0, false },
            { SK_Scalar1, SK_Scalar1,          0,  SK_Scalar1, false },
            { SK_Scalar1, SK_Scalar1, SK_Scalar1,           0, false },
            { SK_Scalar1, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false }
        };

        for (size_t i = 0; i < SK_ARRAY_COUNT(gRectStaysRectSamples); i++) {
            SkMatrix    m;

            m.reset();
            m.set(SkMatrix::kMScaleX, gRectStaysRectSamples[i].m00);
            m.set(SkMatrix::kMSkewX,  gRectStaysRectSamples[i].m01);
            m.set(SkMatrix::kMSkewY,  gRectStaysRectSamples[i].m10);
            m.set(SkMatrix::kMScaleY, gRectStaysRectSamples[i].m11);
            REPORTER_ASSERT(reporter,
                    m.rectStaysRect() == gRectStaysRectSamples[i].mStaysRect);
        }
    }
}

DEF_TEST(Matrix, reporter) {
    SkMatrix    mat, inverse, iden1, iden2;

    mat.reset();
    mat.setTranslate(SK_Scalar1, SK_Scalar1);
    REPORTER_ASSERT(reporter, mat.invert(&inverse));
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));

    mat.setScale(SkIntToScalar(2), SkIntToScalar(4));
    REPORTER_ASSERT(reporter, mat.invert(&inverse));
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));
    test_flatten(reporter, mat);

    mat.setScale(SK_Scalar1/2, SkIntToScalar(2));
    REPORTER_ASSERT(reporter, mat.invert(&inverse));
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));
    test_flatten(reporter, mat);

    mat.setScale(SkIntToScalar(3), SkIntToScalar(5), SkIntToScalar(20), 0);
    mat.postRotate(SkIntToScalar(25));
    REPORTER_ASSERT(reporter, mat.invert(NULL));
    REPORTER_ASSERT(reporter, mat.invert(&inverse));
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));
    iden2.setConcat(inverse, mat);
    REPORTER_ASSERT(reporter, is_identity(iden2));
    test_flatten(reporter, mat);
    test_flatten(reporter, iden2);

    mat.setScale(0, SK_Scalar1);
    REPORTER_ASSERT(reporter, !mat.invert(NULL));
    REPORTER_ASSERT(reporter, !mat.invert(&inverse));
    mat.setScale(SK_Scalar1, 0);
    REPORTER_ASSERT(reporter, !mat.invert(NULL));
    REPORTER_ASSERT(reporter, !mat.invert(&inverse));

    // rectStaysRect test
    {
        static const struct {
            SkScalar    m00, m01, m10, m11;
            bool        mStaysRect;
        }
        gRectStaysRectSamples[] = {
            {          0,          0,          0,           0, false },
            {          0,          0,          0,  SK_Scalar1, false },
            {          0,          0, SK_Scalar1,           0, false },
            {          0,          0, SK_Scalar1,  SK_Scalar1, false },
            {          0, SK_Scalar1,          0,           0, false },
            {          0, SK_Scalar1,          0,  SK_Scalar1, false },
            {          0, SK_Scalar1, SK_Scalar1,           0, true },
            {          0, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false },
            { SK_Scalar1,          0,          0,           0, false },
            { SK_Scalar1,          0,          0,  SK_Scalar1, true },
            { SK_Scalar1,          0, SK_Scalar1,           0, false },
            { SK_Scalar1,          0, SK_Scalar1,  SK_Scalar1, false },
            { SK_Scalar1, SK_Scalar1,          0,           0, false },
            { SK_Scalar1, SK_Scalar1,          0,  SK_Scalar1, false },
            { SK_Scalar1, SK_Scalar1, SK_Scalar1,           0, false },
            { SK_Scalar1, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false }
        };

        for (size_t i = 0; i < SK_ARRAY_COUNT(gRectStaysRectSamples); i++) {
            SkMatrix    m;

            m.reset();
            m.set(SkMatrix::kMScaleX, gRectStaysRectSamples[i].m00);
            m.set(SkMatrix::kMSkewX,  gRectStaysRectSamples[i].m01);
            m.set(SkMatrix::kMSkewY,  gRectStaysRectSamples[i].m10);
            m.set(SkMatrix::kMScaleY, gRectStaysRectSamples[i].m11);
            REPORTER_ASSERT(reporter,
                    m.rectStaysRect() == gRectStaysRectSamples[i].mStaysRect);
        }
    }

    mat.reset();
    mat.set(SkMatrix::kMScaleX, SkIntToScalar(1));
    mat.set(SkMatrix::kMSkewX,  SkIntToScalar(2));
    mat.set(SkMatrix::kMTransX, SkIntToScalar(3));
    mat.set(SkMatrix::kMSkewY,  SkIntToScalar(4));
    mat.set(SkMatrix::kMScaleY, SkIntToScalar(5));
    mat.set(SkMatrix::kMTransY, SkIntToScalar(6));
    SkScalar affine[6];
    REPORTER_ASSERT(reporter, mat.asAffine(affine));

    #define affineEqual(e) affine[SkMatrix::kA##e] == mat.get(SkMatrix::kM##e)
    REPORTER_ASSERT(reporter, affineEqual(ScaleX));
    REPORTER_ASSERT(reporter, affineEqual(SkewY));
    REPORTER_ASSERT(reporter, affineEqual(SkewX));
    REPORTER_ASSERT(reporter, affineEqual(ScaleY));
    REPORTER_ASSERT(reporter, affineEqual(TransX));
    REPORTER_ASSERT(reporter, affineEqual(TransY));
    #undef affineEqual

    mat.set(SkMatrix::kMPersp1, SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !mat.asAffine(affine));

    SkMatrix mat2;
//.........这里部分代码省略.........