C++ SkMatrix::isSimilarity方法代码示例

void draw(SkCanvas* canvas) {
    SkPaint p;
    p.setAntiAlias(true);
    SkMatrix m;
    int pos = 0;
    for (SkScalar sx : { 1, 2 } ) {
        for (SkScalar kx : { 0, 1 } ) {
            m.setAll(sx, kx, 16,    0, 1, 32,   0, 0, 1);
            bool isSimilarity = m.isSimilarity();
            bool preservesRightAngles = m.preservesRightAngles();
            SkString str;
            str.printf("sx: %g kx: %g %s %s", sx, kx, isSimilarity ? "sim" : "",
                        preservesRightAngles ? "right" : "");
            SkAutoCanvasRestore autoRestore(canvas, true);
            canvas->concat(m);
            canvas->drawString(str, 0, pos, p);
            pos += 20;
        }
    }
}

// The general idea here is to, conceptually, start with the original polygon and slide
// the vertices along the bisectors until the first intersection. At that
// point two of the edges collapse and the process repeats on the new polygon.
// The polygon state is captured in the Ring class while the GrAAConvexTessellator
// controls the iteration. The CandidateVerts holds the formative points for the
// next ring.
bool GrAAConvexTessellator::tessellate(const SkMatrix& m, const SkPath& path) {
    if (!this->extractFromPath(m, path)) {
        return false;
    }

    SkScalar coverage = 1.0f;
    SkScalar scaleFactor = 0.0f;
    if (fStrokeWidth >= 0.0f) {
        SkASSERT(m.isSimilarity()); 
        scaleFactor = m.getMaxScale(); // x and y scale are the same
        SkScalar effectiveStrokeWidth = scaleFactor * fStrokeWidth;
        Ring outerStrokeRing;
        this->createOuterRing(fInitialRing, effectiveStrokeWidth / 2 - kAntialiasingRadius, 
                              coverage, &outerStrokeRing);
        outerStrokeRing.init(*this);
        Ring outerAARing;
        this->createOuterRing(outerStrokeRing, kAntialiasingRadius * 2, 0.0f, &outerAARing);
    } else {
        Ring outerAARing;
        this->createOuterRing(fInitialRing, kAntialiasingRadius, 0.0f, &outerAARing);
    }

    // the bisectors are only needed for the computation of the outer ring
    fBisectors.rewind();
    if (fStrokeWidth >= 0.0f && fInitialRing.numPts() > 2) {
        SkScalar effectiveStrokeWidth = scaleFactor * fStrokeWidth;
        Ring* insetStrokeRing;
        SkScalar strokeDepth = effectiveStrokeWidth / 2 - kAntialiasingRadius;
        if (this->createInsetRings(fInitialRing, 0.0f, coverage, strokeDepth, coverage, 
                             &insetStrokeRing)) {
            Ring* insetAARing;
            this->createInsetRings(*insetStrokeRing, strokeDepth, coverage, strokeDepth + 
                             kAntialiasingRadius * 2, 0.0f, &insetAARing);
        }
    } else {
        Ring* insetAARing;
        this->createInsetRings(fInitialRing, 0.0f, 0.5f, kAntialiasingRadius, 1.0f, &insetAARing);
    }

    SkDEBUGCODE(this->validate();)
    return true;

// TODO just use class params
// TODO trying to figure out why lcd is so whack
sk_sp<GrGeometryProcessor> GrAtlasTextBatch::setupDfProcessor(const SkMatrix& viewMatrix,
                                                              SkColor filteredColor,
                                                              GrColor color,
                                                              GrTexture* texture) const {
    GrTextureParams params(SkShader::kClamp_TileMode, GrTextureParams::kBilerp_FilterMode);
    bool isLCD = this->isLCD();
    // set up any flags
    uint32_t flags = viewMatrix.isSimilarity() ? kSimilarity_DistanceFieldEffectFlag : 0;
    flags |= viewMatrix.isScaleTranslate() ? kScaleOnly_DistanceFieldEffectFlag : 0;
    flags |= fUseGammaCorrectDistanceTable ? kGammaCorrect_DistanceFieldEffectFlag : 0;

    // see if we need to create a new effect
    if (isLCD) {
        flags |= kUseLCD_DistanceFieldEffectFlag;
        flags |= fUseBGR ? kBGR_DistanceFieldEffectFlag : 0;

        GrColor colorNoPreMul = skcolor_to_grcolor_nopremultiply(filteredColor);

        float redCorrection = fDistanceAdjustTable->getAdjustment(
            GrColorUnpackR(colorNoPreMul) >> kDistanceAdjustLumShift,
            fUseGammaCorrectDistanceTable);
        float greenCorrection = fDistanceAdjustTable->getAdjustment(
            GrColorUnpackG(colorNoPreMul) >> kDistanceAdjustLumShift,
            fUseGammaCorrectDistanceTable);
        float blueCorrection = fDistanceAdjustTable->getAdjustment(
            GrColorUnpackB(colorNoPreMul) >> kDistanceAdjustLumShift,
            fUseGammaCorrectDistanceTable);
        GrDistanceFieldLCDTextGeoProc::DistanceAdjust widthAdjust =
            GrDistanceFieldLCDTextGeoProc::DistanceAdjust::Make(redCorrection,
                                                                greenCorrection,
                                                                blueCorrection);

        return GrDistanceFieldLCDTextGeoProc::Make(color,
                                                   viewMatrix,
                                                   texture,
                                                   params,
                                                   widthAdjust,
                                                   flags,
                                                   this->usesLocalCoords());
    } else {

bool GrAALinearizingConvexPathRenderer::canDrawPath(const GrDrawTarget* target,
                                                    const GrPipelineBuilder*,
                                                    const SkMatrix& viewMatrix,
                                                    const SkPath& path,
                                                    const GrStrokeInfo& stroke,
                                                    bool antiAlias) const {
    if (!antiAlias) {
        return false;
    }
    if (path.isInverseFillType()) {
        return false;
    }
    if (!path.isConvex()) {
        return false;
    }
    if (stroke.getStyle() == SkStrokeRec::kStroke_Style) {
        return viewMatrix.isSimilarity() && stroke.getWidth() >= 1.0f && 
                stroke.getWidth() <= kMaxStrokeWidth && !stroke.isDashed() && 
                SkPathPriv::LastVerbIsClose(path) && stroke.getJoin() != SkPaint::Join::kRound_Join;
    }
    return stroke.getStyle() == SkStrokeRec::kFill_Style;
}

static void test_matrix_is_similarity(skiatest::Reporter* reporter) {
    SkMatrix mat;

    // identity
    mat.setIdentity();
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // translation only
    mat.reset();
    mat.setTranslate(SkIntToScalar(100), SkIntToScalar(100));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with same size
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with one negative
    mat.reset();
    mat.setScale(SkIntToScalar(-15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with different size
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // scale with same size at a pivot point
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(15),
                 SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with different size at a pivot point
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(20),
                 SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with same size
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with different size
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with same size at a pivot point
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15),
                SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with different size at a pivot point
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20),
                SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // perspective x
    mat.reset();
    mat.setPerspX(SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // perspective y
    mat.reset();
    mat.setPerspY(SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // rotate
    for (int angle = 0; angle < 360; ++angle) {
        mat.reset();
        mat.setRotate(SkIntToScalar(angle));
        REPORTER_ASSERT(reporter, mat.isSimilarity());
    }

    // see if there are any accumulated precision issues
    mat.reset();
    for (int i = 1; i < 360; i++) {
        mat.postRotate(SkIntToScalar(1));
    }
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // rotate + translate
    mat.reset();
    mat.setRotate(SkIntToScalar(30));
    mat.postTranslate(SkIntToScalar(10), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // rotate + uniform scale
    mat.reset();
    mat.setRotate(SkIntToScalar(30));
    mat.postScale(SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // rotate + non-uniform scale
    mat.reset();
    mat.setRotate(SkIntToScalar(30));
//.........这里部分代码省略.........

static void test_matrix_is_similarity(skiatest::Reporter* reporter) {
    SkMatrix mat;

    // identity
    mat.setIdentity();
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // translation only
    mat.reset();
    mat.setTranslate(SkIntToScalar(100), SkIntToScalar(100));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with same size
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with one negative
    mat.reset();
    mat.setScale(SkIntToScalar(-15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with different size
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // scale with same size at a pivot point
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(15),
                 SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with different size at a pivot point
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(20),
                 SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with same size
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with different size
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with same size at a pivot point
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15),
                SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with different size at a pivot point
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20),
                SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // perspective x
    mat.reset();
    mat.setPerspX(SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // perspective y
    mat.reset();
    mat.setPerspY(SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

#ifdef SK_SCALAR_IS_FLOAT
    /* We bypass the following tests for SK_SCALAR_IS_FIXED build.
     * The long discussion can be found in this issue:
     *     http://codereview.appspot.com/5999050/
     * In short, we haven't found a perfect way to fix the precision
     * issue, i.e. the way we use tolerance in isSimilarityTransformation
     * is incorrect. The situation becomes worse in fixed build, so
     * we disabled rotation related tests for fixed build.
     */

    // rotate
    for (int angle = 0; angle < 360; ++angle) {
        mat.reset();
        mat.setRotate(SkIntToScalar(angle));
        REPORTER_ASSERT(reporter, mat.isSimilarity());
    }

    // see if there are any accumulated precision issues
    mat.reset();
    for (int i = 1; i < 360; i++) {
        mat.postRotate(SkIntToScalar(1));
    }
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // rotate + translate
    mat.reset();
    mat.setRotate(SkIntToScalar(30));
    mat.postTranslate(SkIntToScalar(10), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, mat.isSimilarity());
//.........这里部分代码省略.........

static void test_matrix_is_similarity(skiatest::Reporter* reporter) {
    SkMatrix mat;

    // identity
    mat.setIdentity();
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // translation only
    mat.reset();
    mat.setTranslate(SkIntToScalar(100), SkIntToScalar(100));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with same size
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with one negative
    mat.reset();
    mat.setScale(SkIntToScalar(-15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with different size
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // scale with same size at a pivot point
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(15),
                 SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // scale with different size at a pivot point
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(20),
                 SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with same size
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with different size
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with same size at a pivot point
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15),
                SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // skew with different size at a pivot point
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20),
                SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // perspective x
    mat.reset();
    mat.setPerspX(SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // perspective y
    mat.reset();
    mat.setPerspY(SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // rotate
    for (int angle = 0; angle < 360; ++angle) {
        mat.reset();
        mat.setRotate(SkIntToScalar(angle));
#ifndef SK_CPU_ARM64
        REPORTER_ASSERT(reporter, mat.isSimilarity());
#else
        // 64-bit ARM devices built with -O2 and -ffp-contract=fast have a loss
        // of precision and require that we have a higher tolerance
        REPORTER_ASSERT(reporter, mat.isSimilarity(SK_ScalarNearlyZero + 0.00010113f));
#endif
    }

    // see if there are any accumulated precision issues
    mat.reset();
    for (int i = 1; i < 360; i++) {
        mat.postRotate(SkIntToScalar(1));
    }
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // rotate + translate
    mat.reset();
    mat.setRotate(SkIntToScalar(30));
    mat.postTranslate(SkIntToScalar(10), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, mat.isSimilarity());

    // rotate + uniform scale
    mat.reset();
    mat.setRotate(SkIntToScalar(30));
//.........这里部分代码省略.........