C++ SkMatrix::preRotate方法代码示例

    /**
     * Called on a background thread. Here we can only modify fBackMatrices.
     */
    virtual void runAnimationTask(double t, double dt, int w, int h) {
        for (int idx = 0; idx < kNumPaths; ++idx) {
            Velocity* v = &fVelocities[idx];
            Glyph* glyph = &fGlyphs[idx];
            SkMatrix* backMatrix = &fBackMatrices[idx];

            glyph->fPosition.fX += v->fDx * dt;
            if (glyph->fPosition.x() < 0) {
                glyph->fPosition.fX -= 2 * glyph->fPosition.x();
                v->fDx = -v->fDx;
            } else if (glyph->fPosition.x() > w) {
                glyph->fPosition.fX -= 2 * (glyph->fPosition.x() - w);
                v->fDx = -v->fDx;
            }

            glyph->fPosition.fY += v->fDy * dt;
            if (glyph->fPosition.y() < 0) {
                glyph->fPosition.fY -= 2 * glyph->fPosition.y();
                v->fDy = -v->fDy;
            } else if (glyph->fPosition.y() > h) {
                glyph->fPosition.fY -= 2 * (glyph->fPosition.y() - h);
                v->fDy = -v->fDy;
            }

            glyph->fSpin += v->fDSpin * dt;

            backMatrix->setTranslate(glyph->fPosition.x(), glyph->fPosition.y());
            backMatrix->preScale(glyph->fZoom, glyph->fZoom);
            backMatrix->preRotate(glyph->fSpin);
            backMatrix->preTranslate(-glyph->fMidpt.x(), -glyph->fMidpt.y());
        }
    }

void Matrix::NativePreRotate(
    /* [in] */ Int64 nObj,
    /* [in] */ Float degrees)
{
    SkMatrix* obj = reinterpret_cast<SkMatrix*>(nObj);
    obj->preRotate(degrees);
}

void draw(SkCanvas* canvas) {
    SkMatrix matrix;
    SkPoint bitmapBounds[4], perspect[4] = {{50, 10}, {180, 40}, {236, 176}, {10, 206}};
    SkRect::Make(source.bounds()).toQuad(bitmapBounds);
    matrix.setPolyToPoly(bitmapBounds, perspect, 4);
    matrix.preRotate(45, source.width() / 2, source.height() / 2);
    canvas->concat(matrix);
    canvas->drawBitmap(source, 0, 0);
}

void draw(SkCanvas* canvas) {
    canvas->clear(SK_ColorWHITE);
    SkMatrix matrix;
    matrix.setScale(0.75f, 0.75f);
    matrix.preRotate(30.0f);
    SkPaint paint;
    paint.setShader(image->makeShader(SkShader::kRepeat_TileMode,
                                      SkShader::kRepeat_TileMode,
                                      &matrix));
    canvas->drawPaint(paint);
}

void draw(SkCanvas* canvas) {
    canvas->clear(SK_ColorWHITE);
    SkMatrix matrix;
    matrix.setScale(0.75f, 0.75f);
    matrix.preRotate(frame * 30.0f * duration); // If an animation, rotate at 30 deg/s.
    SkPaint paint;
    paint.setShader(image->makeShader(SkShader::kRepeat_TileMode,
                                      SkShader::kRepeat_TileMode,
                                      &matrix));
    canvas->drawPaint(paint);
    SkDebugf("This is text output: %d", 2);
}

static void rotated_checkerboard_shader(SkPaint* paint,
                                        SkColor c1,
                                        SkColor c2,
                                        int size) {
    SkBitmap bm;
    bm.allocN32Pixels(2 * size, 2 * size);
    bm.eraseColor(c1);
    bm.eraseArea(SkIRect::MakeLTRB(0, 0, size, size), c2);
    bm.eraseArea(SkIRect::MakeLTRB(size, size, 2 * size, 2 * size), c2);
    SkMatrix matrix;
    matrix.setScale(0.75f, 0.75f);
    matrix.preRotate(30.0f);
    SkAutoTUnref<SkShader> shader(
            SkShader::CreateBitmapShader(bm, SkShader::kRepeat_TileMode,
                                         SkShader::kRepeat_TileMode, &matrix));
    paint->setShader(shader);
}

void LayerAndroid::updatePositions() {
    // apply the viewport to us
    SkMatrix matrix;
    if (!m_isFixed) {
        // turn our fields into a matrix.
        //
        // TODO: this should happen in the caller, and we should remove these
        // fields from our subclass
        matrix.setTranslate(m_translation.fX, m_translation.fY);
        if (m_doRotation) {
            matrix.preRotate(m_angleTransform);
        }
        matrix.preScale(m_scale.fX, m_scale.fY);
        this->setMatrix(matrix);
    }

    // now apply it to our children
    int count = this->countChildren();
    for (int i = 0; i < count; i++) {
        this->getChild(i)->updatePositions();
    }
}

    void onDraw(int loops, SkCanvas* canvas) override {
        SkRandom scaleRand;
        SkRandom transRand;
        SkRandom rotRand;

        int width, height;
        if (fUseAtlas) {
            width = kAtlasCellWidth;
            height = kAtlasCellHeight;
        } else {
            width = kCheckerboardWidth;
            height = kCheckerboardHeight;
        }

        SkPaint clearPaint;
        clearPaint.setColor(0xFF000000);
        clearPaint.setAntiAlias(true);

        SkISize size = canvas->getDeviceSize();

        SkScalar maxTransX, maxTransY;

        if (kScale_Type == fType) {
            maxTransX = size.fWidth  - (1.5f * width);
            maxTransY = size.fHeight - (1.5f * height);
        } else if (kTranslate_Type == fType) {
            maxTransX = SkIntToScalar(size.fWidth  - width);
            maxTransY = SkIntToScalar(size.fHeight - height);
        } else {
            SkASSERT(kRotate_Type == fType);
            // Yes, some rotations will be off the top and left sides
            maxTransX = size.fWidth  - SK_ScalarSqrt2 * height;
            maxTransY = size.fHeight - SK_ScalarSqrt2 * height;
        }

        SkMatrix mat;
        SkRect dst = { 0, 0, SkIntToScalar(width), SkIntToScalar(height) };
        SkRect clearRect = { -1.0f, -1.0f, width+1.0f, height+1.0f };
        SkPoint verts[4] = { // for drawVertices path
            { 0, 0 },
            { 0, SkIntToScalar(height) },
            { SkIntToScalar(width), SkIntToScalar(height) },
            { SkIntToScalar(width), 0 }
        };
        uint16_t indices[6] = { 0, 1, 2, 0, 2, 3 };

        SkPaint p;
        p.setColor(0xFF000000);
        p.setFilterQuality(kLow_SkFilterQuality);

        SkPaint p2;         // for drawVertices path
        p2.setColor(0xFF000000);
        p2.setFilterQuality(kLow_SkFilterQuality);
        p2.setShader(SkShader::MakeBitmapShader(fAtlas,
                                                SkShader::kClamp_TileMode,
                                                SkShader::kClamp_TileMode));

        for (int i = 0; i < loops; ++i, ++fNumSaved) {
            if (0 == i % kNumBeforeClear) {
                if (kPartial_Clear == fClear) {
                    for (int j = 0; j < fNumSaved; ++j) {
                        canvas->setMatrix(SkMatrix::I());
                        mat.setTranslate(fSaved[j][0], fSaved[j][1]);

                        if (kScale_Type == fType) {
                            mat.preScale(fSaved[j][2], fSaved[j][2]);
                        } else if (kRotate_Type == fType) {
                            mat.preRotate(fSaved[j][2]);
                        }

                        canvas->concat(mat);
                        canvas->drawRect(clearRect, clearPaint);
                    }
                } else {
                    canvas->clear(0xFF000000);
                }

                fNumSaved = 0;
            }

            SkASSERT(fNumSaved < kNumBeforeClear);

            canvas->setMatrix(SkMatrix::I());

            fSaved[fNumSaved][0] = transRand.nextRangeScalar(0.0f, maxTransX);
            fSaved[fNumSaved][1] = transRand.nextRangeScalar(0.0f, maxTransY);
            if (fAligned) {
                // make the translations integer aligned
                fSaved[fNumSaved][0] = SkScalarFloorToScalar(fSaved[fNumSaved][0]);
                fSaved[fNumSaved][1] = SkScalarFloorToScalar(fSaved[fNumSaved][1]);
            }

            mat.setTranslate(fSaved[fNumSaved][0], fSaved[fNumSaved][1]);

            if (kScale_Type == fType) {
                fSaved[fNumSaved][2] = scaleRand.nextRangeScalar(0.5f, 1.5f);
                mat.preScale(fSaved[fNumSaved][2], fSaved[fNumSaved][2]);
            } else if (kRotate_Type == fType) {
                fSaved[fNumSaved][2] = rotRand.nextRangeScalar(0.0f, 360.0f);
                mat.preRotate(fSaved[fNumSaved][2]);
//.........这里部分代码省略.........

    void onDraw(SkCanvas* canvas) override {
        fShader = gBleedRec[fBT].fShaderMaker();

        canvas->clear(SK_ColorGRAY);
        SkTDArray<SkMatrix> matrices;
        // Draw with identity
        *matrices.append() = SkMatrix::I();

        // Draw with rotation and scale down in x, up in y.
        SkMatrix m;
        constexpr SkScalar kBottom = SkIntToScalar(kRow4Y + kBlockSize + kBlockSpacing);
        m.setTranslate(0, kBottom);
        m.preRotate(15.f, 0, kBottom + kBlockSpacing);
        m.preScale(0.71f, 1.22f);
        *matrices.append() = m;

        // Align the next set with the middle of the previous in y, translated to the right in x.
        SkPoint corners[] = {{0, 0}, { 0, kBottom }, { kWidth, kBottom }, {kWidth, 0} };
        matrices[matrices.count()-1].mapPoints(corners, 4);
        SkScalar y = (corners[0].fY + corners[1].fY + corners[2].fY + corners[3].fY) / 4;
        SkScalar x = SkTMax(SkTMax(corners[0].fX, corners[1].fX),
                            SkTMax(corners[2].fX, corners[3].fX));
        m.setTranslate(x, y);
        m.preScale(0.2f, 0.2f);
        *matrices.append() = m;

        SkScalar maxX = 0;
        for (int antiAlias = 0; antiAlias < 2; ++antiAlias) {
            canvas->save();
            canvas->translate(maxX, 0);
            for (int m = 0; m < matrices.count(); ++m) {
                canvas->save();
                canvas->concat(matrices[m]);
                bool aa = SkToBool(antiAlias);

                // First draw a column with no bleeding and no filtering
                this->drawCase1(canvas, kCol0X, kRow0Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase2(canvas, kCol0X, kRow1Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase3(canvas, kCol0X, kRow2Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase4(canvas, kCol0X, kRow3Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase5(canvas, kCol0X, kRow4Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);

                // Then draw a column with no bleeding and low filtering
                this->drawCase1(canvas, kCol1X, kRow0Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase2(canvas, kCol1X, kRow1Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase3(canvas, kCol1X, kRow2Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase4(canvas, kCol1X, kRow3Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase5(canvas, kCol1X, kRow4Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);

                // Then draw a column with no bleeding and high filtering
                this->drawCase1(canvas, kCol2X, kRow0Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase2(canvas, kCol2X, kRow1Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase3(canvas, kCol2X, kRow2Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase4(canvas, kCol2X, kRow3Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase5(canvas, kCol2X, kRow4Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);

                // Then draw a column with bleeding and no filtering (bleed should have no effect w/out blur)
                this->drawCase1(canvas, kCol3X, kRow0Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase2(canvas, kCol3X, kRow1Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase3(canvas, kCol3X, kRow2Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase4(canvas, kCol3X, kRow3Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase5(canvas, kCol3X, kRow4Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);

                // Then draw a column with bleeding and low filtering
                this->drawCase1(canvas, kCol4X, kRow0Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase2(canvas, kCol4X, kRow1Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase3(canvas, kCol4X, kRow2Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase4(canvas, kCol4X, kRow3Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase5(canvas, kCol4X, kRow4Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);

                // Finally draw a column with bleeding and high filtering
                this->drawCase1(canvas, kCol5X, kRow0Y, aa, SkCanvas::kFast_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase2(canvas, kCol5X, kRow1Y, aa, SkCanvas::kFast_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase3(canvas, kCol5X, kRow2Y, aa, SkCanvas::kFast_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase4(canvas, kCol5X, kRow3Y, aa, SkCanvas::kFast_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase5(canvas, kCol5X, kRow4Y, aa, SkCanvas::kFast_SrcRectConstraint, kHigh_SkFilterQuality);

                SkPoint corners[] = { { 0, 0 },{ 0, kBottom },{ kWidth, kBottom },{ kWidth, 0 } };
                matrices[m].mapPoints(corners, 4);
                SkScalar x = kBlockSize + SkTMax(SkTMax(corners[0].fX, corners[1].fX),
                                                 SkTMax(corners[2].fX, corners[3].fX));
                maxX = SkTMax(maxX, x);
                canvas->restore();
            }
            canvas->restore();
        }
    }

 static void preRotate__F(JNIEnv* env, jobject clazz, jlong objHandle, jfloat degrees) {
     SkMatrix* obj = reinterpret_cast<SkMatrix*>(objHandle);
     obj->preRotate(degrees);
 }

    void onDraw(SkCanvas* canvas) override {
        // We don't create pixels in an onOnceBeforeDraw() override because we want access to
        // GrContext.
        GrContext* context = canvas->getGrContext();
#if SK_SUPPORT_GPU
        // Workaround for SampleApp.
        if (GrTexture* tex = fBigTestPixels.fBitmap.getTexture()) {
            if (tex->wasDestroyed()) {
                fCreatedPixels = false;
            }
        }
#endif
        bool madePixels = fCreatedPixels;

        if (!madePixels) {
            madePixels =  gBleedRec[fBT].fPixelMaker(context, &fSmallTestPixels, kSmallTextureSize,
                                                     kSmallTextureSize);
            madePixels &= gBleedRec[fBT].fPixelMaker(context, &fBigTestPixels, 2 * kMaxTileSize,
                                                     2 * kMaxTileSize);
            fCreatedPixels = madePixels;
        }

        // Assume that if we coulnd't make the bitmap/image it's because it's a GPU test on a
        // non-GPU backend.
        if (!madePixels) {
            skiagm::GM::DrawGpuOnlyMessage(canvas);
            return;
        }

        fShader = gBleedRec[fBT].fShaderMaker();

        canvas->clear(SK_ColorGRAY);
        SkTDArray<SkMatrix> matrices;
        // Draw with identity
        *matrices.append() = SkMatrix::I();

        // Draw with rotation and scale down in x, up in y.
        SkMatrix m;
        static const SkScalar kBottom = SkIntToScalar(kRow4Y + kBlockSize + kBlockSpacing);
        m.setTranslate(0, kBottom);
        m.preRotate(15.f, 0, kBottom + kBlockSpacing);
        m.preScale(0.71f, 1.22f);
        *matrices.append() = m;

        // Align the next set with the middle of the previous in y, translated to the right in x.
        SkPoint corners[] = {{0, 0}, { 0, kBottom }, { kWidth, kBottom }, {kWidth, 0} };
        matrices[matrices.count()-1].mapPoints(corners, 4);
        SkScalar y = (corners[0].fY + corners[1].fY + corners[2].fY + corners[3].fY) / 4;
        SkScalar x = SkTMax(SkTMax(corners[0].fX, corners[1].fX),
                            SkTMax(corners[2].fX, corners[3].fX));
        m.setTranslate(x, y);
        m.preScale(0.2f, 0.2f);
        *matrices.append() = m;

        SkScalar maxX = 0;
        for (int antiAlias = 0; antiAlias < 2; ++antiAlias) {
            canvas->save();
            canvas->translate(maxX, 0);
            for (int m = 0; m < matrices.count(); ++m) {
                canvas->save();
                canvas->concat(matrices[m]);
                bool aa = SkToBool(antiAlias);

                // First draw a column with no bleeding and no filtering
                this->drawCase1(canvas, kCol0X, kRow0Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase2(canvas, kCol0X, kRow1Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase3(canvas, kCol0X, kRow2Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase4(canvas, kCol0X, kRow3Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase5(canvas, kCol0X, kRow4Y, aa, SkCanvas::kStrict_SrcRectConstraint, kNone_SkFilterQuality);

                // Then draw a column with no bleeding and low filtering
                this->drawCase1(canvas, kCol1X, kRow0Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase2(canvas, kCol1X, kRow1Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase3(canvas, kCol1X, kRow2Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase4(canvas, kCol1X, kRow3Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase5(canvas, kCol1X, kRow4Y, aa, SkCanvas::kStrict_SrcRectConstraint, kLow_SkFilterQuality);

                // Then draw a column with no bleeding and high filtering
                this->drawCase1(canvas, kCol2X, kRow0Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase2(canvas, kCol2X, kRow1Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase3(canvas, kCol2X, kRow2Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase4(canvas, kCol2X, kRow3Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);
                this->drawCase5(canvas, kCol2X, kRow4Y, aa, SkCanvas::kStrict_SrcRectConstraint, kHigh_SkFilterQuality);

                // Then draw a column with bleeding and no filtering (bleed should have no effect w/out blur)
                this->drawCase1(canvas, kCol3X, kRow0Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase2(canvas, kCol3X, kRow1Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase3(canvas, kCol3X, kRow2Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase4(canvas, kCol3X, kRow3Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);
                this->drawCase5(canvas, kCol3X, kRow4Y, aa, SkCanvas::kFast_SrcRectConstraint, kNone_SkFilterQuality);

                // Then draw a column with bleeding and low filtering
                this->drawCase1(canvas, kCol4X, kRow0Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase2(canvas, kCol4X, kRow1Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase3(canvas, kCol4X, kRow2Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase4(canvas, kCol4X, kRow3Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);
                this->drawCase5(canvas, kCol4X, kRow4Y, aa, SkCanvas::kFast_SrcRectConstraint, kLow_SkFilterQuality);

                // Finally draw a column with bleeding and high filtering
                this->drawCase1(canvas, kCol5X, kRow0Y, aa, SkCanvas::kFast_SrcRectConstraint, kHigh_SkFilterQuality);
//.........这里部分代码省略.........