C++ SkMatrix::setAll方法代码示例

	extern void SetTransform(RenderingContext*ctx, float*m)
	{
		SkMatrix matrix;
		matrix.setAll(m[0], m[1], m[2], m[3], m[4], m[5], 0, 0, 1);

		ctx->Canvas->setMatrix(ConvertPerspexMatrix(m));
	}

// Test drawing text with some unusual matricies.
// We measure success by not crashing or asserting.
DEF_TEST(DrawText_weirdMatricies, r) {
    auto surface = SkSurface::MakeRasterN32Premul(100,100);
    auto canvas = surface->getCanvas();

    SkPaint paint;
    paint.setAntiAlias(true);
    paint.setLCDRenderText(true);

    struct {
        SkScalar textSize;
        SkScalar matrix[9];
    } testCases[] = {
        // 2x2 singular
        {10, { 0,  0,  0,  0,  0,  0,  0,  0,  1}},
        {10, { 0,  0,  0,  0,  1,  0,  0,  0,  1}},
        {10, { 0,  0,  0,  1,  0,  0,  0,  0,  1}},
        {10, { 0,  0,  0,  1,  1,  0,  0,  0,  1}},
        {10, { 0,  1,  0,  0,  1,  0,  0,  0,  1}},
        {10, { 1,  0,  0,  0,  0,  0,  0,  0,  1}},
        {10, { 1,  0,  0,  1,  0,  0,  0,  0,  1}},
        {10, { 1,  1,  0,  0,  0,  0,  0,  0,  1}},
        {10, { 1,  1,  0,  1,  1,  0,  0,  0,  1}},
        // See https://bugzilla.mozilla.org/show_bug.cgi?id=1305085 .
        { 1, {10, 20,  0, 20, 40,  0,  0,  0,  1}},
    };

    for (const auto& testCase : testCases) {
        paint.setTextSize(testCase.textSize);
        const SkScalar(&m)[9] = testCase.matrix;
        SkMatrix mat;
        mat.setAll(m[0], m[1], m[2], m[3], m[4], m[5], m[6], m[7], m[8]);
        canvas->setMatrix(mat);
        canvas->drawString("Hamburgefons", 10, 10, paint);
    }
}

void draw(SkCanvas* canvas) {
    SkMatrix matrix;
    matrix.setAll(1, 0, 0,  0, 1, 0,   0, 0, 0);
    if (matrix.invert(&matrix)) {
        SkScalar factor[2] = {2, 2};
        bool result = matrix.getMinMaxScales(factor);
        SkDebugf("matrix.getMinMaxScales() %s %g %g\n",
                result ? "true" : "false", factor[0], factor[1]);
    }
}

static void test_wacky_bitmapshader(skiatest::Reporter* reporter,
                                    int width, int height, bool shouldBeDrawn) {
    SkBitmap dev;
    dev.allocN32Pixels(0x56F, 0x4f6);
    dev.eraseColor(SK_ColorTRANSPARENT);  // necessary, so we know if we draw to it

    SkMatrix matrix;

    SkCanvas c(dev);
    matrix.setAll(-119.34097f,
                  -43.436558f,
                  93489.945f,
                  43.436558f,
                  -119.34097f,
                  123.98426f,
                  0, 0, SK_Scalar1);
    c.concat(matrix);

    SkBitmap bm;
    if (bm.tryAllocN32Pixels(width, height)) {
        // allow this to fail silently, to test the code downstream
    }
    bm.eraseColor(SK_ColorRED);

    matrix.setAll(0.0078740157f,
                  0,
                  SkIntToScalar(249),
                  0,
                  0.0078740157f,
                  SkIntToScalar(239),
                  0, 0, SK_Scalar1);
    SkShader* s = SkShader::CreateBitmapShader(bm, SkShader::kRepeat_TileMode,
                                               SkShader::kRepeat_TileMode, &matrix);

    SkPaint paint;
    paint.setShader(s)->unref();

    SkRect r = SkRect::MakeXYWH(681, 239, 695, 253);
    c.drawRect(r, paint);

    assert_ifDrawnTo(reporter, dev, shouldBeDrawn);
}

void WRasterImage::Impl::applyTransform(const WTransform& t)
{
  SkMatrix sm;
  sm.setAll(SkDoubleToScalar(t.m11()),
	    SkDoubleToScalar(t.m12()),
	    SkDoubleToScalar(t.dx()),
	    SkDoubleToScalar(t.m21()),
	    SkDoubleToScalar(t.m22()),
	    SkDoubleToScalar(t.dy()),
	    0,
	    0,
	    SkDoubleToScalar(1.0));
  canvas_->concat(sm);
}

// Solves linear system to extract klm
// P.K = k (similarly for l, m)
// Where P is matrix of control points
// K is coefficients for the line K
// k is vector of values of K evaluated at the control points
// Solving for K, thus K = P^(-1) . k
static void calc_cubic_klm(const SkPoint p[4], const SkScalar controlK[4],
                           const SkScalar controlL[4], const SkScalar controlM[4],
                           SkScalar k[3], SkScalar l[3], SkScalar m[3]) {
    SkMatrix matrix;
    matrix.setAll(p[0].fX, p[0].fY, 1.f,
                  p[1].fX, p[1].fY, 1.f,
                  p[2].fX, p[2].fY, 1.f);
    SkMatrix inverse;
    if (matrix.invert(&inverse)) {
       inverse.mapHomogeneousPoints(k, controlK, 1);
       inverse.mapHomogeneousPoints(l, controlL, 1);
       inverse.mapHomogeneousPoints(m, controlM, 1);
    }

}

static SkMatrix
Matrix3DToSkia(const gfx3DMatrix& aMatrix)
{
  SkMatrix transform;
  transform.setAll(aMatrix._11,
                   aMatrix._21,
                   aMatrix._41,
                   aMatrix._12,
                   aMatrix._22,
                   aMatrix._42,
                   aMatrix._14,
                   aMatrix._24,
                   aMatrix._44);

  return transform;
}

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;
        }
    }
}

    void onOnceBeforeDraw() override {
        SkBitmap emptyBmp;

        SkBitmap blueBmp;
        blueBmp.allocN32Pixels(10, 10);
        blueBmp.eraseColor(SK_ColorBLUE);

        SkMatrix badMatrix;
        badMatrix.setAll(0, 0, 0, 0, 0, 0, 0, 0, 0);

#if 0 // This crashes pipe!
        // Empty bitmap.
        fPaints.push_back().setColor(SK_ColorGREEN);
        fPaints.back().setShader(SkShader::CreateBitmapShader(emptyBmp, SkShader::kClamp_TileMode,
                                                              SkShader::kClamp_TileMode))->unref();
#endif

        // Non-invertible local matrix.
        fPaints.push_back().setColor(SK_ColorGREEN);
        fPaints.back().setShader(SkShader::CreateBitmapShader(blueBmp, SkShader::kClamp_TileMode,
                                                              SkShader::kClamp_TileMode,
                                                              &badMatrix))->unref();
    }

// Test out the case where an oval already off in space is translated/scaled 
// further off into space - yielding numerical issues when the rect & radii
// are transformed separatly
// BUG=skia:2696
static void test_issue_2696(skiatest::Reporter* reporter) {
    SkRRect rrect;
    SkRect r = { 28443.8594f, 53.1428604f, 28446.7148f, 56.0000038f };
    rrect.setOval(r);

    SkMatrix xform;
    xform.setAll(2.44f,  0.0f, 485411.7f,
                 0.0f,  2.44f,   -438.7f,
                 0.0f,   0.0f,      1.0f);
    SkRRect dst;

    bool success = rrect.transform(xform, &dst);
    REPORTER_ASSERT(reporter, success);

    SkScalar halfWidth = SkScalarHalf(dst.width());
    SkScalar halfHeight = SkScalarHalf(dst.height());

    for (int i = 0; i < 4; ++i) {
        REPORTER_ASSERT(reporter, 
                        SkScalarNearlyEqual(dst.radii((SkRRect::Corner)i).fX, halfWidth));
        REPORTER_ASSERT(reporter, 
                        SkScalarNearlyEqual(dst.radii((SkRRect::Corner)i).fY, halfHeight));
    }
}

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

    const float kRotation0 = 15.5f;
    const float kRotation1 = -50.f;
    const float kScale0 = 5000.f;

    const int kTripleCount = 1000;
    const int kMatrixCount = 1000;
    SkRandom rand;

    SkScalar randTriples[3*kTripleCount];
    for (int i = 0; i < 3*kTripleCount; ++i) {
        randTriples[i] = rand.nextRangeF(-3000.f, 3000.f);
    }

    SkMatrix mats[kMatrixCount];
    for (int i = 0; i < kMatrixCount; ++i) {
        for (int j = 0; j < 9; ++j) {
            mats[i].set(j, rand.nextRangeF(-3000.f, 3000.f));
        }
    }

    // identity
    {
    mat.reset();
    SkScalar dst[3*kTripleCount];
    mat.mapHomogeneousPoints(dst, randTriples, kTripleCount);
    REPORTER_ASSERT(reporter, scalar_array_nearly_equal_relative(randTriples, dst, kTripleCount*3));
    }

    // zero matrix
    {
    mat.setAll(0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f);
    SkScalar dst[3*kTripleCount];
    mat.mapHomogeneousPoints(dst, randTriples, kTripleCount);
    SkScalar zeros[3] = {0.f, 0.f, 0.f};
    for (int i = 0; i < kTripleCount; ++i) {
        REPORTER_ASSERT(reporter, scalar_array_nearly_equal_relative(&dst[i*3], zeros, 3));
    }
    }

    // zero point
    {
    SkScalar zeros[3] = {0.f, 0.f, 0.f};
    for (int i = 0; i < kMatrixCount; ++i) {
        SkScalar dst[3];
        mats[i].mapHomogeneousPoints(dst, zeros, 1);
        REPORTER_ASSERT(reporter, scalar_array_nearly_equal_relative(dst, zeros, 3));
    }
    }

    // doesn't crash with null dst, src, count == 0
    {
    mats[0].mapHomogeneousPoints(NULL, NULL, 0);
    }

    // uniform scale of point
    {
    mat.setScale(kScale0, kScale0);
    SkScalar dst[3];
    SkScalar src[3] = {randTriples[0], randTriples[1], 1.f};
    SkPoint pnt;
    pnt.set(src[0], src[1]);
    mat.mapHomogeneousPoints(dst, src, 1);
    mat.mapPoints(&pnt, &pnt, 1);
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[0], pnt.fX));
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[1], pnt.fY));
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[2], SK_Scalar1));
    }

    // rotation of point
    {
    mat.setRotate(kRotation0);
    SkScalar dst[3];
    SkScalar src[3] = {randTriples[0], randTriples[1], 1.f};
    SkPoint pnt;
    pnt.set(src[0], src[1]);
    mat.mapHomogeneousPoints(dst, src, 1);
    mat.mapPoints(&pnt, &pnt, 1);
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[0], pnt.fX));
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[1], pnt.fY));
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[2], SK_Scalar1));
    }

    // rotation, scale, rotation of point
    {
    mat.setRotate(kRotation1);
    mat.postScale(kScale0, kScale0);
    mat.postRotate(kRotation0);
    SkScalar dst[3];
    SkScalar src[3] = {randTriples[0], randTriples[1], 1.f};
    SkPoint pnt;
    pnt.set(src[0], src[1]);
    mat.mapHomogeneousPoints(dst, src, 1);
    mat.mapPoints(&pnt, &pnt, 1);
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[0], pnt.fX));
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[1], pnt.fY));
    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[2], SK_Scalar1));
    }
//.........这里部分代码省略.........

//.........这里部分代码省略.........
    // 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));
    mat.postScale(SkIntToScalar(3), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // all zero
    mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, 0);
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // all zero except perspective
    mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, SK_Scalar1);
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // scales zero, only skews
    mat.setAll(0, SK_Scalar1, 0,
               SK_Scalar1, 0, 0,
               0, 0, SkMatrix::I()[8]);
    REPORTER_ASSERT(reporter, mat.isSimilarity());
}

//.........这里部分代码省略.........
        }


        // check gamma-corrected blending
        const SkColor fg[] = {
            0xFFFFFFFF,
            0xFFFFFF00, 0xFFFF00FF, 0xFF00FFFF,
            0xFFFF0000, 0xFF00FF00, 0xFF0000FF,
            0xFF000000,
        };

        paint.setColor(0xFFF7F3F7);
        SkRect r = SkRect::MakeLTRB(670, 215, 820, 397);
        canvas->drawRect(r, paint);

        x = SkIntToScalar(680);
        y = SkIntToScalar(235);
        font.setSize(SkIntToScalar(19));
        for (size_t i = 0; i < SK_ARRAY_COUNT(fg); ++i) {
            paint.setColor(fg[i]);

            canvas->drawSimpleText(text, textLen, SkTextEncoding::kUTF8, x, y, font, paint);
            y += font.getMetrics(nullptr);
        }

        paint.setColor(0xFF181C18);
        r = SkRect::MakeLTRB(820, 215, 970, 397);
        canvas->drawRect(r, paint);

        x = SkIntToScalar(830);
        y = SkIntToScalar(235);
        font.setSize(SkIntToScalar(19));
        for (size_t i = 0; i < SK_ARRAY_COUNT(fg); ++i) {
            paint.setColor(fg[i]);

            canvas->drawSimpleText(text, textLen, SkTextEncoding::kUTF8, x, y, font, paint);
            y += font.getMetrics(nullptr);
        }

        // check skew
        {
            font.setEdging(SkFont::Edging::kAntiAlias);
            SkAutoCanvasRestore acr(canvas, true);
            canvas->skew(0.0f, 0.151515f);
            font.setSize(SkIntToScalar(32));
            canvas->drawSimpleText(text, textLen, SkTextEncoding::kUTF8, 745, 70, font, paint);
        }
        {
            font.setEdging(SkFont::Edging::kSubpixelAntiAlias);
            SkAutoCanvasRestore acr(canvas, true);
            canvas->skew(0.5f, 0.0f);
            font.setSize(SkIntToScalar(32));
            canvas->drawSimpleText(text, textLen, SkTextEncoding::kUTF8, 580, 125, font, paint);
        }

        // check perspective
        {
            font.setEdging(SkFont::Edging::kAntiAlias);
            SkAutoCanvasRestore acr(canvas, true);
            SkMatrix persp;
            persp.setAll(0.9839f, 0, 0,
                         0.2246f, 0.6829f, 0,
                         0.0002352f, -0.0003844f, 1);
            canvas->concat(persp);
            canvas->translate(1100, -295);
            font.setSize(37.5f);
            canvas->drawSimpleText(text, textLen, SkTextEncoding::kUTF8, 0, 0, font, paint);
        }
        {
            font.setSubpixel(false);
            font.setEdging(SkFont::Edging::kAlias);
            SkAutoCanvasRestore acr(canvas, true);
            SkMatrix persp;
            persp.setAll(0.9839f, 0, 0,
                         0.2246f, 0.6829f, 0,
                         0.0002352f, -0.0003844f, 1);
            canvas->concat(persp);
            canvas->translate(1075, -245);
            canvas->scale(375, 375);
            font.setSize(0.1f);
            canvas->drawSimpleText(text, textLen, SkTextEncoding::kUTF8, 0, 0, font, paint);
        }

        // check color emoji
        if (fEmojiTypeface) {
            SkFont emoiFont;
            emoiFont.setSubpixel(true);
            emoiFont.setTypeface(fEmojiTypeface);
            emoiFont.setSize(SkIntToScalar(19));
            canvas->drawSimpleText(fEmojiText, strlen(fEmojiText), SkTextEncoding::kUTF8, 670, 90, emoiFont, paint);
        }

        // render offscreen buffer
        if (surface) {
            SkAutoCanvasRestore acr(inputCanvas, true);
            // since we prepended this matrix already, we blit using identity
            inputCanvas->resetMatrix();
            inputCanvas->drawImage(surface->makeImageSnapshot().get(), 0, 0, nullptr);
        }
    }

//.........这里部分代码省略.........
    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());

    // 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));
    mat.postScale(SkIntToScalar(3), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !mat.isSimilarity());
#endif

    // all zero
    mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, 0);
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // all zero except perspective
    mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, SK_Scalar1);
    REPORTER_ASSERT(reporter, !mat.isSimilarity());

    // scales zero, only skews
    mat.setAll(0, SK_Scalar1, 0,
               SK_Scalar1, 0, 0,
               0, 0, SkMatrix::I()[8]);
    REPORTER_ASSERT(reporter, mat.isSimilarity());
}

void GrGpuGL::flushViewMatrix(DrawType type) {
    const GrGLRenderTarget* rt = static_cast<const GrGLRenderTarget*>(this->getDrawState().getRenderTarget());
    SkISize viewportSize;
    const GrGLIRect& viewport = rt->getViewport();
    viewportSize.set(viewport.fWidth, viewport.fHeight);

    const SkMatrix& vm = this->getDrawState().getViewMatrix();

    if (kStencilPath_DrawType == type) {
        if (fHWPathMatrixState.fViewMatrix != vm ||
            fHWPathMatrixState.fRTSize != viewportSize) {
            // rescale the coords from skia's "device" coords to GL's normalized coords,
            // and perform a y-flip.
            SkMatrix m;
            m.setScale(SkIntToScalar(2) / rt->width(), SkIntToScalar(-2) / rt->height());
            m.postTranslate(-SK_Scalar1, SK_Scalar1);
            m.preConcat(vm);

            // GL wants a column-major 4x4.
            GrGLfloat mv[]  = {
                // col 0
                SkScalarToFloat(m[SkMatrix::kMScaleX]),
                SkScalarToFloat(m[SkMatrix::kMSkewY]),
                0,
                SkScalarToFloat(m[SkMatrix::kMPersp0]),

                // col 1
                SkScalarToFloat(m[SkMatrix::kMSkewX]),
                SkScalarToFloat(m[SkMatrix::kMScaleY]),
                0,
                SkScalarToFloat(m[SkMatrix::kMPersp1]),

                // col 2
                0, 0, 0, 0,

                // col3
                SkScalarToFloat(m[SkMatrix::kMTransX]),
                SkScalarToFloat(m[SkMatrix::kMTransY]),
                0.0f,
                SkScalarToFloat(m[SkMatrix::kMPersp2])
            };
            GL_CALL(MatrixMode(GR_GL_PROJECTION));
            GL_CALL(LoadMatrixf(mv));
            fHWPathMatrixState.fViewMatrix = vm;
            fHWPathMatrixState.fRTSize = viewportSize;
        }
    } else if (!fCurrentProgram->fViewMatrix.cheapEqualTo(vm) ||
               fCurrentProgram->fViewportSize != viewportSize) {
        SkMatrix m;
        m.setAll(
            SkIntToScalar(2) / viewportSize.fWidth, 0, -SK_Scalar1,
            0,-SkIntToScalar(2) / viewportSize.fHeight, SK_Scalar1,
            0, 0, SkMatrix::I()[8]);
        m.setConcat(m, vm);

        // ES doesn't allow you to pass true to the transpose param,
        // so do our own transpose
        GrGLfloat mt[]  = {
            SkScalarToFloat(m[SkMatrix::kMScaleX]),
            SkScalarToFloat(m[SkMatrix::kMSkewY]),
            SkScalarToFloat(m[SkMatrix::kMPersp0]),
            SkScalarToFloat(m[SkMatrix::kMSkewX]),
            SkScalarToFloat(m[SkMatrix::kMScaleY]),
            SkScalarToFloat(m[SkMatrix::kMPersp1]),
            SkScalarToFloat(m[SkMatrix::kMTransX]),
            SkScalarToFloat(m[SkMatrix::kMTransY]),
            SkScalarToFloat(m[SkMatrix::kMPersp2])
        };
        fCurrentProgram->fUniformManager.setMatrix3f(
                                            fCurrentProgram->fUniformHandles.fViewMatrixUni,
                                            mt);
        fCurrentProgram->fViewMatrix = vm;
        fCurrentProgram->fViewportSize = viewportSize;
    }
}