C++ SkPath::quadTo方法代码示例

void SkPathStroker::quad_to(const SkPoint pts[3],
                      const SkVector& normalAB, const SkVector& unitNormalAB,
                      SkVector* normalBC, SkVector* unitNormalBC,
                      int subDivide) {
    if (!set_normal_unitnormal(pts[1], pts[2], fRadius,
                               normalBC, unitNormalBC)) {
        // pts[1] nearly equals pts[2], so just draw a line to pts[2]
        this->line_to(pts[2], normalAB);
        *normalBC = normalAB;
        *unitNormalBC = unitNormalAB;
        return;
    }

    if (--subDivide >= 0 && normals_too_curvy(unitNormalAB, *unitNormalBC)) {
        SkPoint     tmp[5];
        SkVector    norm, unit;

        SkChopQuadAtHalf(pts, tmp);
        this->quad_to(&tmp[0], normalAB, unitNormalAB, &norm, &unit, subDivide);
        this->quad_to(&tmp[2], norm, unit, normalBC, unitNormalBC, subDivide);
    } else {
        SkVector    normalB, unitB;
        SkAssertResult(set_normal_unitnormal(pts[0], pts[2], fRadius,
                                             &normalB, &unitB));

        fOuter.quadTo(  pts[1].fX + normalB.fX, pts[1].fY + normalB.fY,
                        pts[2].fX + normalBC->fX, pts[2].fY + normalBC->fY);
        fInner.quadTo(  pts[1].fX - normalB.fX, pts[1].fY - normalB.fY,
                        pts[2].fX - normalBC->fX, pts[2].fY - normalBC->fY);
    }
}

// Need to exercise drawing an inverse-path whose bounds intersect the clip,
// but whose edges do not (since its a quad which draws only in the bottom half
// of its bounds).
// In the debug build, we used to assert in this case, until it was fixed.
//
static void test_inversepathwithclip() {
    SkPath path;

    path.moveTo(0, 20);
    path.quadTo(10, 10, 20, 20);
    path.toggleInverseFillType();

    SkPaint paint;

    auto surface(SkSurface::MakeRasterN32Premul(640, 480));
    SkCanvas* canvas = surface->getCanvas();
    canvas->save();
    canvas->clipRect(SkRect::MakeWH(19, 11));

    paint.setAntiAlias(false);
    canvas->drawPath(path, paint);
    paint.setAntiAlias(true);
    canvas->drawPath(path, paint);

    canvas->restore();

    // Now do the test again, with the path flipped, so we only draw in the
    // top half of our bounds, and have the clip intersect our bounds at the
    // bottom.
    path.reset();   // preserves our filltype
    path.moveTo(0, 10);
    path.quadTo(10, 20, 20, 10);
    canvas->clipRect(SkRect::MakeXYWH(0, 19, 19, 11));

    paint.setAntiAlias(false);
    canvas->drawPath(path, paint);
    paint.setAntiAlias(true);
    canvas->drawPath(path, paint);
}

void SkPathStroker::quad_to(const SkPoint pts[3],
                      const SkVector& normalAB, const SkVector& unitNormalAB,
                      SkVector* normalBC, SkVector* unitNormalBC,
                      int subDivide) {
    if (!set_normal_unitnormal(pts[1], pts[2], fRadius,
                               normalBC, unitNormalBC)) {
        // pts[1] nearly equals pts[2], so just draw a line to pts[2]
        this->line_to(pts[2], normalAB);
        *normalBC = normalAB;
        *unitNormalBC = unitNormalAB;
        return;
    }

    if (--subDivide >= 0 && normals_too_curvy(unitNormalAB, *unitNormalBC)) {
        SkPoint     tmp[5];
        SkVector    norm, unit;

        SkChopQuadAtHalf(pts, tmp);
        this->quad_to(&tmp[0], normalAB, unitNormalAB, &norm, &unit, subDivide);
        this->quad_to(&tmp[2], norm, unit, normalBC, unitNormalBC, subDivide);
    } else {
        SkVector    normalB;

        normalB = pts[2] - pts[0];
        normalB.rotateCCW();
        SkScalar dot = SkPoint::DotProduct(unitNormalAB, *unitNormalBC);
        SkAssertResult(normalB.setLength(SkScalarDiv(fRadius,
                                     SkScalarSqrt((SK_Scalar1 + dot)/2))));

        fOuter.quadTo(  pts[1].fX + normalB.fX, pts[1].fY + normalB.fY,
                        pts[2].fX + normalBC->fX, pts[2].fY + normalBC->fY);
        fInner.quadTo(  pts[1].fX - normalB.fX, pts[1].fY - normalB.fY,
                        pts[2].fX - normalBC->fX, pts[2].fY - normalBC->fY);
    }
}

static void PathOpsSimplifyFailTest(skiatest::Reporter* reporter) {
    for (int index = 0; index < (int) (13 * nonFinitePtsCount * finitePtsCount); ++index) {
        SkPath path;
        int i = (int) (index % nonFinitePtsCount);
        int f = (int) (index % finitePtsCount);
        int g = (int) ((f + 1) % finitePtsCount);
        switch (index % 13) {
            case 0: path.lineTo(nonFinitePts[i]); break;
            case 1: path.quadTo(nonFinitePts[i], nonFinitePts[i]); break;
            case 2: path.quadTo(nonFinitePts[i], finitePts[f]); break;
            case 3: path.quadTo(finitePts[f], nonFinitePts[i]); break;
            case 4: path.cubicTo(nonFinitePts[i], finitePts[f], finitePts[f]); break;
            case 5: path.cubicTo(finitePts[f], nonFinitePts[i], finitePts[f]); break;
            case 6: path.cubicTo(finitePts[f], finitePts[f], nonFinitePts[i]); break;
            case 7: path.cubicTo(nonFinitePts[i], nonFinitePts[i], finitePts[f]); break;
            case 8: path.cubicTo(nonFinitePts[i], finitePts[f], nonFinitePts[i]); break;
            case 9: path.cubicTo(finitePts[f], nonFinitePts[i], nonFinitePts[i]); break;
            case 10: path.cubicTo(nonFinitePts[i], nonFinitePts[i], nonFinitePts[i]); break;
            case 11: path.cubicTo(nonFinitePts[i], finitePts[f], finitePts[g]); break;
            case 12: path.moveTo(nonFinitePts[i]); break;
        }
        SkPath result;
        result.setFillType(SkPath::kWinding_FillType);
        bool success = Simplify(path, &result);
        REPORTER_ASSERT(reporter, !success);
        REPORTER_ASSERT(reporter, result.isEmpty());
        REPORTER_ASSERT(reporter, result.getFillType() == SkPath::kWinding_FillType);
        reporter->bumpTestCount();
    }
    if (sizeof(reporter) == 4) {
        return;
    }
    for (int index = 0; index < (int) (11 * finitePtsCount); ++index) {
        SkPath path;
        int f = (int) (index % finitePtsCount);
        int g = (int) ((f + 1) % finitePtsCount);
        switch (index % 11) {
            case 0: path.lineTo(finitePts[f]); break;
            case 1: path.quadTo(finitePts[f], finitePts[f]); break;
            case 2: path.quadTo(finitePts[f], finitePts[g]); break;
            case 3: path.quadTo(finitePts[g], finitePts[f]); break;
            case 4: path.cubicTo(finitePts[f], finitePts[f], finitePts[f]); break;
            case 5: path.cubicTo(finitePts[f], finitePts[f], finitePts[g]); break;
            case 6: path.cubicTo(finitePts[f], finitePts[g], finitePts[f]); break;
            case 7: path.cubicTo(finitePts[f], finitePts[g], finitePts[g]); break;
            case 8: path.cubicTo(finitePts[g], finitePts[f], finitePts[f]); break;
            case 9: path.cubicTo(finitePts[g], finitePts[f], finitePts[g]); break;
            case 10: path.moveTo(finitePts[f]); break;
        }
        SkPath result;
        result.setFillType(SkPath::kWinding_FillType);
        bool success = Simplify(path, &result);
        REPORTER_ASSERT(reporter, success);
        REPORTER_ASSERT(reporter, result.getFillType() != SkPath::kWinding_FillType);
        reporter->bumpTestCount();
    }
}

static SkPath make_path() {
    SkPath path;
    int numOps = R(30);
    for (int i = 0; i < numOps; ++i) {
        switch (R(6)) {
            case 0:
                path.moveTo(make_scalar(), make_scalar());
                break;
            case 1:
                path.lineTo(make_scalar(), make_scalar());
                break;
            case 2:
                path.quadTo(make_scalar(), make_scalar(), make_scalar(), make_scalar());
                break;
            case 3:
                path.conicTo(make_scalar(), make_scalar(), make_scalar(), make_scalar(), make_scalar());
                break;
            case 4:
                path.cubicTo(make_scalar(), make_scalar(), make_scalar(),
                             make_scalar(), make_scalar(), make_scalar());
                break;
            case 5:
            default:
                path.arcTo(make_scalar(), make_scalar(), make_scalar(), make_scalar(), make_scalar());
                break;

        }
    }
    path.close();
    return path;
}

    void onDraw(SkCanvas* canvas) override {
        SkPath path;
        SkRandom rand;

        int scale = 300;
        for (int i = 0; i < 4; ++i) {
            // get the random values deterministically
            SkScalar randoms[12];
            for (int index = 0; index < (int) SK_ARRAY_COUNT(randoms); ++index) {
                randoms[index] = rand.nextUScalar1();
            }
            path.lineTo(randoms[0] * scale, randoms[1] * scale);
            path.quadTo(randoms[2] * scale, randoms[3] * scale,
                        randoms[4] * scale, randoms[5] * scale);
            path.cubicTo(randoms[6] * scale, randoms[7] * scale,
                         randoms[8] * scale, randoms[9] * scale,
                         randoms[10] * scale, randoms[11] * scale);
        }

        path.setFillType(SkPath::kEvenOdd_FillType);
        path.offset(SkIntToScalar(20), SkIntToScalar(20));

        test_hittest(canvas, path);

        canvas->translate(SkIntToScalar(scale), 0);
        path.setFillType(SkPath::kWinding_FillType);

        test_hittest(canvas, path);
    }

// A quad which generates a huge number of points (>2B) when uniformly
// linearized. This should not hang or OOM.
static SkPath create_path_29() {
    SkPath path;
    path.moveTo(10, 0);
    path.lineTo(0, 0);
    path.quadTo(10, 0, 0, 8315084722602508288);
    return path;
}

static int quad_proc(const FT_Vector* pt0, const FT_Vector* pt1,
                     void* ctx) {
    SkPath* path = (SkPath*)ctx;
    path->quadTo(SkFDot6ToScalar(pt0->x), -SkFDot6ToScalar(pt0->y),
                 SkFDot6ToScalar(pt1->x), -SkFDot6ToScalar(pt1->y));
    return 0;
}

SkPath SubsetVerbs::getSubsetPath() const {
    SkPath result;
    result.setFillType(fPath.getFillType());
    if (!fSelected.count()) {
        return result;
    }
    SkPath::RawIter iter(fPath);
    uint8_t verb;
    SkPoint pts[4];
    int verbIndex = 0;
    bool addMoveTo = true;
    bool addLineTo = false;
    while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
        bool enabled = SkPath::kLine_Verb <= verb && verb <= SkPath::kCubic_Verb
            ? fSelected[verbIndex++] : false;
        if (enabled) {
            if (addMoveTo) {
                result.moveTo(pts[0]);
                addMoveTo = false;
            } else if (addLineTo) {
                result.lineTo(pts[0]);
                addLineTo = false;
            }
        }
        switch (verb) {
            case SkPath::kMove_Verb:
                break;
            case SkPath::kLine_Verb:
                if (enabled) {
                    result.lineTo(pts[1]);
                }
                break;
            case SkPath::kQuad_Verb:
                if (enabled) {
                    result.quadTo(pts[1], pts[2]);
                }
                break;
            case SkPath::kConic_Verb:
                if (enabled) {
                    result.conicTo(pts[1], pts[2], iter.conicWeight());
                }
                break;
            case SkPath::kCubic_Verb:
                 if (enabled) {
                    result.cubicTo(pts[1], pts[2], pts[3]);
                }
                break;
            case SkPath::kClose_Verb:
                result.close();
                addMoveTo = true;
                addLineTo = false;
                continue;
            default:
                SkDEBUGFAIL("bad verb");
                return result;
        }
        addLineTo = !enabled;
    }
    return result;
}

static void test_flattening(skiatest::Reporter* reporter) {
    SkPath p;

    static const SkPoint pts[] = {
        { 0, 0 },
        { SkIntToScalar(10), SkIntToScalar(10) },
        { SkIntToScalar(20), SkIntToScalar(10) }, { SkIntToScalar(20), 0 },
        { 0, 0 }, { 0, SkIntToScalar(10) }, { SkIntToScalar(1), SkIntToScalar(10) }
    };
    p.moveTo(pts[0]);
    p.lineTo(pts[1]);
    p.quadTo(pts[2], pts[3]);
    p.cubicTo(pts[4], pts[5], pts[6]);

    SkWriter32 writer(100);
    p.flatten(writer);
    size_t size = writer.size();
    SkAutoMalloc storage(size);
    writer.flatten(storage.get());
    SkReader32 reader(storage.get(), size);

    SkPath p1;
    REPORTER_ASSERT(reporter, p1 != p);
    p1.unflatten(reader);
    REPORTER_ASSERT(reporter, p1 == p);
}

 static SkPoint AddMoveDegenQuadClose(SkPath& path, SkPoint& startPt) {
     SkPoint moveToPt = startPt + SkPoint::Make(0, 10*SK_Scalar1);
     path.moveTo(moveToPt);
     path.quadTo(moveToPt, moveToPt);
     path.close();
     return moveToPt;
 }

static void testQuads() {
    SkPath path;
    path.moveTo(2,0);
    path.quadTo(1,1, 0,0);
    path.close();
    test(path);
}

 static SkPoint AddMoveQuad(SkPath& path, SkPoint& startPt) {
     SkPoint moveToPt = startPt + SkPoint::Make(0, 10*SK_Scalar1);
     SkPoint midPt = moveToPt + SkPoint::Make(20*SK_Scalar1, 5*SK_Scalar1);
     SkPoint endPt = moveToPt + SkPoint::Make(40*SK_Scalar1, 0);
     path.moveTo(moveToPt);
     path.quadTo(midPt, endPt);
     return endPt;
 }

    void onOnceBeforeDraw() override {
        {
            SkPath* bigQuad = &fPaths.push_back();
            bigQuad->moveTo(0, 0);
            bigQuad->quadTo(kWidth/2, kHeight, kWidth, 0);
        }

        {
            SkPath* degenBigQuad = &fPaths.push_back();
            SkScalar yPos = kHeight / 2 + 10;
            degenBigQuad->moveTo(0, yPos);
            degenBigQuad->quadTo(0, yPos, kWidth, yPos);
        }


        {
            SkPath* bigCubic = &fPaths.push_back();
            bigCubic->moveTo(0, 0);
            bigCubic->cubicTo(0, kHeight,
                              kWidth, kHeight,
                              kWidth, 0);
        }

        {
            SkPath* degenBigCubic = &fPaths.push_back();
            SkScalar yPos = kHeight / 2;
            degenBigCubic->moveTo(0, yPos);
            degenBigCubic->cubicTo(0, yPos,
                                   0, yPos,
                                   kWidth, yPos);
        }

        {
            SkPath* bigConic = &fPaths.push_back();
            bigConic->moveTo(0, 0);
            bigConic->conicTo(kWidth/2, kHeight, kWidth, 0, .5);
        }

        {
            SkPath* degenBigConic = &fPaths.push_back();
            SkScalar yPos = kHeight / 2 - 10;
            degenBigConic->moveTo(0, yPos);
            degenBigConic->conicTo(0, yPos, kWidth, yPos, .5);
        }
    }

static void textonpath_slide(SkCanvas* canvas) {
    const char* text = "Displacement";
    size_t len =strlen(text);
    SkPath path;
    path.moveTo(100, 300);
    path.quadTo(300, 100, 500, 300);
    path.offset(0, -100);

    SkPaint paint;
    paint.setAntiAlias(true);
    paint.setTextSize(40);

    paint.setStyle(SkPaint::kStroke_Style);
    canvas->drawPath(path, paint);
    paint.setStyle(SkPaint::kFill_Style);

    SkScalar x = 50;
    paint.setColor(0xFF008800);
    canvas->drawTextOnPathHV(text, len, path,
                             x, paint.getTextSize()*2/3, paint);
    paint.setColor(SK_ColorRED);
    canvas->drawTextOnPathHV(text, len, path,
                             x + 60, 0, paint);
    paint.setColor(SK_ColorBLUE);
    canvas->drawTextOnPathHV(text, len, path,
                             x + 120, -paint.getTextSize()*2/3, paint);

    path.offset(0, 200);
    paint.setTextAlign(SkPaint::kRight_Align);

    text = "Matrices";
    len = strlen(text);
    SkScalar pathLen = getpathlen(path);
    SkMatrix matrix;

    paint.setColor(SK_ColorBLACK);
    paint.setStyle(SkPaint::kStroke_Style);
    canvas->drawPath(path, paint);
    paint.setStyle(SkPaint::kFill_Style);

    paint.setTextSize(50);
    canvas->drawTextOnPath(text, len, path, NULL, paint);

    paint.setColor(SK_ColorRED);
    matrix.setScale(-SK_Scalar1, SK_Scalar1);
    matrix.postTranslate(pathLen, 0);
    canvas->drawTextOnPath(text, len, path, &matrix, paint);

    paint.setColor(SK_ColorBLUE);
    matrix.setScale(SK_Scalar1, -SK_Scalar1);
    canvas->drawTextOnPath(text, len, path, &matrix, paint);

    paint.setColor(0xFF008800);
    matrix.setScale(-SK_Scalar1, -SK_Scalar1);
    matrix.postTranslate(pathLen, 0);
    canvas->drawTextOnPath(text, len, path, &matrix, paint);
}