C++ SkPath::arcTo方法代码示例

void draw(SkCanvas* canvas) {
    SkPaint paint;
    SkPath path;
    paint.setStyle(SkPaint::kStroke_Style);
    paint.setStrokeWidth(4);
    path.moveTo(0, 0);
    path.arcTo({20, 20, 120, 120}, -90, 90, false);
    canvas->drawPath(path, paint);
    path.rewind();
    path.arcTo({120, 20, 220, 120}, -90, 90, false);
    canvas->drawPath(path, paint);
    path.rewind();
    path.moveTo(0, 0);
    path.arcTo({20, 120, 120, 220}, -90, 90, true);
    canvas->drawPath(path, paint);
}

PathTexture* PathCache::getArc(float width, float height,
        float startAngle, float sweepAngle, bool useCenter, const SkPaint* paint) {
    PathDescription entry(kShapeArc, paint);
    entry.shape.arc.mWidth = width;
    entry.shape.arc.mHeight = height;
    entry.shape.arc.mStartAngle = startAngle;
    entry.shape.arc.mSweepAngle = sweepAngle;
    entry.shape.arc.mUseCenter = useCenter;

    PathTexture* texture = get(entry);

    if (!texture) {
        SkPath path;
        SkRect r;
        r.set(0.0f, 0.0f, width, height);
        if (useCenter) {
            path.moveTo(r.centerX(), r.centerY());
        }
        path.arcTo(r, startAngle, sweepAngle, !useCenter);
        if (useCenter) {
            path.close();
        }

        texture = addTexture(entry, &path, paint);
    }

    return texture;
}

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;
}

static void draw_sweep(SkCanvas* c, int width, int height, SkScalar angle) {
    SkRect  r;
    SkPaint p;
    
    p.setAntiAlias(true);
//    p.setDither(true);
    p.setStrokeWidth(SkIntToScalar(width/10));
    p.setStyle(SkPaint::kStroke_Style);

    r.set(0, 0, SkIntToScalar(width), SkIntToScalar(height));
    
    //    SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN, SK_ColorCYAN };
    SkColor colors[] = { 0x4c737373, 0x4c737373, 0xffffd300 };
    SkShader* s = SkGradientShader::CreateSweep(r.centerX(), r.centerY(),
                                                colors, NULL, SK_ARRAY_COUNT(colors));
    p.setShader(s)->unref();
    
    SkAutoCanvasRestore acr(c, true);

    c->translate(r.centerX(), r.centerY());
    c->rotate(angle);
    c->translate(-r.centerX(), -r.centerY());

    SkRect bounds = r;
    r.inset(p.getStrokeWidth(), p.getStrokeWidth());
    SkRect innerBounds = r;

    if (true) {
        c->drawOval(r, p);
    } else {
        SkScalar x = r.centerX();
        SkScalar y = r.centerY();
        SkScalar radius = r.width() / 2;
        SkScalar thickness = p.getStrokeWidth();
        SkScalar sweep = SkFloatToScalar(360.0f);
        SkPath path;
        
        path.moveTo(x + radius, y);
        // outer top
        path.lineTo(x + radius + thickness, y);
        // outer arc
        path.arcTo(bounds, 0, sweep, false);
        // inner arc
        path.arcTo(innerBounds, sweep, -sweep, false);
        path.close();
    }
}

void mbe_arc(mbe_t *mbe, co_aix x, co_aix y, co_aix radius,
		    co_aix angle_start, co_aix angle_stop) {
    SkPoint point;
    SkPath *subpath = mbe->subpath;
    SkRect rect;
    SkScalar x0, y0;
    SkScalar ang_start, ang_stop;
    SkScalar sweep;
    SkScalar r;			/* radius */

    subpath->getLastPt(&point);
    x0 = point.fX;
    y0 = point.fX;
    r = CO_AIX_2_SKSCALAR(radius);
    ang_start = CO_AIX_2_SKSCALAR(angle_start * 180 / PI);
    ang_stop = CO_AIX_2_SKSCALAR(angle_stop * 180 / PI);

    /* Skia can only draw an arc in clockwise directly.  We negative
     * start and stop point to draw the arc in the mirror along x-axis
     * in a sub-path.  Then, the sub-path are reflected along x-axis,
     * again.  We get a right path, and add it to the path of mbe_t.
     */
    if(ang_start > ang_stop) {
	SkPath tmppath;
	SkMatrix matrix;
	co_aix reflect[6] = { 1, 0, 0,
			      0, -1, 0};

	rect.set(-r, -r, r, r);
	sweep = ang_start - ang_stop;
	tmppath.arcTo(rect, -ang_start, sweep, false);

	reflect[2] = x;
	reflect[5] = y;
	MB_MATRIX_2_SKMATRIX(matrix, reflect);
	subpath->addPath(tmppath, matrix);
    } else {
	rect.set(x0 - r, y0 - r, x0 + r, y0 + r);
	sweep = ang_stop - ang_start;
	subpath->arcTo(rect, ang_start, sweep, false);
    }
}

static void fuzz_drawPath(Fuzz* fuzz) {
    SkPaint p;
    init_paint(fuzz, &p);
    sk_sp<SkSurface> surface;
    init_surface(fuzz, &surface);

    // TODO(kjlubick): put the ability to fuzz a path in shared file, with
    // other common things (e.g. rects, lines)
    uint8_t i, j;
    fuzz->nextRange(&i, 0, 10); // set i to number of operations to perform
    SkPath path;
    SkScalar a, b, c, d, e, f;
    for (int k = 0; k < i; ++k) {
        fuzz->nextRange(&j, 0, 5); // set j to choose operation to perform
        switch (j) {
            case 0:
                fuzz->next(&a, &b);
                path.moveTo(a, b);
                break;
            case 1:
                fuzz->next(&a, &b);
                path.lineTo(a, b);
                break;
            case 2:
                fuzz->next(&a, &b, &c, &d);
                path.quadTo(a, b, c, d);
                break;
            case 3:
                fuzz->next(&a, &b, &c, &d, &e);
                path.conicTo(a, b, c, d, e);
                break;
            case 4:
                fuzz->next(&a, &b, &c, &d, &e, &f);
                path.cubicTo(a, b, c, d, e, f);
                break;
            case 5:
                fuzz->next(&a, &b, &c, &d, &e);
                path.arcTo(a, b, c, d, e);
                break;
        }
    }
    path.close();

    SkCanvas* cnv = surface->getCanvas();
    cnv->drawPath(path, p);

    bool bl;
    fuzz->next(&bl);
    cnv->clipPath(path, kIntersect_SkClipOp, bl);
}

void draw(SkCanvas* canvas) {
    const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
    const int pointCount[]  = {     1 ,     2 ,     3 ,      3 ,      4 ,      1 ,     0  };
    SkPath path;
    path.arcTo(20, 0, 20, 20, 20);
    SkPath::Iter iter(path, false);
    SkPath::Verb verb;
    do {
       SkPoint points[4];
       verb = iter.next(points);
       SkDebugf("%s ", verbNames[(int) verb]);
       for (int i = 0; i < pointCount[(int) verb]; ++i) {
            SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
       }
       if (SkPath::kConic_Verb == verb) {
           SkDebugf("weight = %g", iter.conicWeight());
       }
       SkDebugf("\n");
    } while (SkPath::kDone_Verb != verb);
}

static SkPath make_path() {
    SkPath path;
    uint8_t numOps;
    fuzz->nextRange(&numOps, 0, 30);
    for (uint8_t i = 0; i < numOps; ++i) {
        uint8_t op;
        fuzz->nextRange(&op, 0, 5);
        SkScalar a, b, c, d, e, f;
        switch (op) {
            case 0:
                fuzz->next(&a, &b);
                path.moveTo(a, b);
                break;
            case 1:
                fuzz->next(&a, &b);
                path.lineTo(a, b);
                break;
            case 2:
                fuzz->next(&a, &b, &c, &d);
                path.quadTo(a, b, c, d);
                break;
            case 3:
                fuzz->next(&a, &b, &c, &d, &e);
                path.conicTo(a, b, c, d, e);
                break;
            case 4:
                fuzz->next(&a, &b, &c, &d, &e, &f);
                path.cubicTo(a, b, c, d, e, f);
                break;
            case 5:
            default:
                fuzz->next(&a, &b, &c, &d, &e);
                path.arcTo(a, b, c, d, e);
                break;
        }
    }
    path.close();
    return path;
}

PathTexture* ArcShapeCache::getArc(float width, float height,
        float startAngle, float sweepAngle, bool useCenter, SkPaint* paint) {
    ArcShapeCacheEntry entry(width, height, startAngle, sweepAngle, useCenter, paint);
    PathTexture* texture = get(entry);

    if (!texture) {
        SkPath path;
        SkRect r;
        r.set(0.0f, 0.0f, width, height);
        if (useCenter) {
            path.moveTo(r.centerX(), r.centerY());
        }
        path.arcTo(r, startAngle, sweepAngle, !useCenter);
        if (useCenter) {
            path.close();
        }

        texture = addTexture(entry, &path, paint);
    }

    return texture;
}

//.........这里部分代码省略.........
        radii[1] = SkPoint::Make(7,7);
        radii[2] = SkPoint::Make(7,7);
        radii[3] = SkPoint::Make(7,7);
        rrect.setRectRadii(rect, radii);
        canvas->drawRRect(rrect, paintFill);
#endif
        canvas->restore();

        // Write minutes
        canvas->save();
        canvas->rotate(time.fMinute*(180.f/30.f)
                       + time.fSecond*(180.f/1800.f) );
#ifdef USE_PATH
        paintStroke.setStrokeWidth(10);
        path.reset();
        path.moveTo(-56,0);
        path.lineTo(224,0);
        canvas->drawPath(path, paintStroke);
#else
        rect = SkRect::MakeLTRB(-56-5, -5, 224+5, 5);
        radii[0] = SkPoint::Make(5,5);
        radii[1] = SkPoint::Make(5,5);
        radii[2] = SkPoint::Make(5,5);
        radii[3] = SkPoint::Make(5,5);
        rrect.setRectRadii(rect, radii);
        canvas->drawRRect(rrect, paintFill);
#endif
        canvas->restore();

        // Write seconds
        canvas->save();
        canvas->rotate(time.fSecond*(180.f/30.f));
        paintFill.setColor(0xffd40000);
        paintStroke.setColor(0xffd40000);
        paintStroke.setStrokeWidth(6);
#ifdef USE_PATH
        path.reset();
        path.moveTo(-60,0);
        path.lineTo(166,0);
        canvas->drawPath(path, paintStroke);
#else
        rect = SkRect::MakeLTRB(-60-3, -3, 166+3, 3);
        radii[0] = SkPoint::Make(3,3);
        radii[1] = SkPoint::Make(3,3);
        radii[2] = SkPoint::Make(3,3);
        radii[3] = SkPoint::Make(3,3);
        rrect.setRectRadii(rect, radii);
        canvas->drawRRect(rrect, paintFill);
#endif
        rect = SkRect::MakeLTRB(-20, -20, 20, 20);
#ifdef USE_PATH
        path.reset();
        path.arcTo(rect, 0, 0, false);
        path.addOval(rect, SkPath::kCCW_Direction);
        path.arcTo(rect, 360, 0, true);
        canvas->drawPath(path, paintFill);
#else
        canvas->drawOval(rect, paintFill);
#endif
        rect = SkRect::MakeLTRB(-20+190, -20, 20+190, 20);
#ifdef USE_PATH
        path.reset();
        path.arcTo(rect, 0, 0, false);
        path.addOval(rect, SkPath::kCCW_Direction);
        path.arcTo(rect, 360, 0, true);
        canvas->drawPath(path, paintStroke);
#else
        canvas->drawOval(rect, paintStroke);
#endif
        paintFill.setColor(0xff505050);
#ifdef USE_PATH
        rect = SkRect::MakeLTRB(-6, -6, 6, 6);
        path.arcTo(rect, 0, 0, false);
        path.addOval(rect, SkPath::kCCW_Direction);
        path.arcTo(rect, 360, 0, true);
        canvas->drawPath(path, paintFill);
#else
        canvas->drawOval(rect, paintFill);
        rect = SkRect::MakeLTRB(-6, -6, 6, 6);
        canvas->drawOval(rect, paintFill);
#endif
        canvas->restore();

        paintStroke.setStrokeWidth(18);
        paintStroke.setColor(0xff325FA2);
        rect = SkRect::MakeLTRB(-284, -284, 284, 284);
#ifdef USE_PATH
        path.reset();
        path.arcTo(rect, 0, 0, false);
        path.addOval(rect, SkPath::kCCW_Direction);
        path.arcTo(rect, 360, 0, true);
        canvas->drawPath(path, paintStroke);
#else
        canvas->drawOval(rect, paintStroke);
#endif

        canvas->restore();

        this->inval(nullptr);
    }

    virtual void onDrawContent(SkCanvas* canvas) {
        const char text[] = "Shaded Text";
        const int textLen = SK_ARRAY_COUNT(text) - 1;
        static int pointSize = 36;

        int w = pointSize * textLen;
        int h = pointSize;

        SkPoint pts[2] = {
            { 0, 0 },
            { SkIntToScalar(w), SkIntToScalar(h) }
        };
        SkScalar textBase = SkIntToScalar(h/2);

        SkShader::TileMode tileModes[] = {
            SkShader::kClamp_TileMode,
            SkShader::kRepeat_TileMode,
            SkShader::kMirror_TileMode
        };

        static const int gradCount = SK_ARRAY_COUNT(gGradData) *
                                     SK_ARRAY_COUNT(gGradMakers);
        static const int bmpCount = SK_ARRAY_COUNT(tileModes) *
                                    SK_ARRAY_COUNT(tileModes);
        SkShader* shaders[gradCount + bmpCount];

        int shdIdx = 0;
        for (size_t d = 0; d < SK_ARRAY_COUNT(gGradData); ++d) {
            for (size_t m = 0; m < SK_ARRAY_COUNT(gGradMakers); ++m) {
                shaders[shdIdx++] = gGradMakers[m](pts,
                                                   gGradData[d],
                                                   SkShader::kClamp_TileMode);
            }
        }
        for (size_t tx = 0; tx < SK_ARRAY_COUNT(tileModes); ++tx) {
            for (size_t ty = 0; ty < SK_ARRAY_COUNT(tileModes); ++ty) {
                shaders[shdIdx++] = MakeBitmapShader(tileModes[tx],
                                                     tileModes[ty],
                                                     w/8, h);
            }
        }

        SkPaint paint;
        paint.setDither(true);
        paint.setAntiAlias(true);
        paint.setTextSize(SkIntToScalar(pointSize));

        canvas->save();
        canvas->translate(SkIntToScalar(20), SkIntToScalar(10));

        SkPath path;
        path.arcTo(SkRect::MakeXYWH(SkIntToScalar(-40), SkIntToScalar(15),
                                    SkIntToScalar(300), SkIntToScalar(90)),
                                    SkIntToScalar(225), SkIntToScalar(90),
                                    false);
        path.close();

        static const int testsPerCol = 8;
        static const int rowHeight = 60;
        static const int colWidth = 300;
        canvas->save();
        for (size_t s = 0; s < SK_ARRAY_COUNT(shaders); s++) {
            canvas->save();
            size_t i = 2*s;
            canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
                              SkIntToScalar((i % testsPerCol) * rowHeight));
            paint.setShader(shaders[s])->unref();
            canvas->drawText(text, textLen, 0, textBase, paint);
            canvas->restore();
            canvas->save();
            ++i;
            canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
                              SkIntToScalar((i % testsPerCol) * rowHeight));
            canvas->drawTextOnPath(text, textLen, path, NULL, paint);
            canvas->restore();
        }
        canvas->restore();
    }

//.........这里部分代码省略.........
        outlinePaint.setStyle(SkPaint::kStroke_Style);
        outlinePaint.setStrokeWidth(0.f);

        SkScalar w = fillPaint.measureText(kText, kTextLen);
        static SkScalar kPadY = 0.5f * kPointSize;
        static SkScalar kPadX = 1.5f * kPointSize;

        SkPaint strokePaint(fillPaint);
        strokePaint.setStyle(SkPaint::kStroke_Style);
        strokePaint.setStrokeWidth(kPointSize * 0.1f);

        SkPaint labelPaint;
        labelPaint.setColor(0xff000000);
        labelPaint.setAntiAlias(true);
        sk_tool_utils::set_portable_typeface_always(&labelPaint);
        labelPaint.setTextSize(12.f);

        canvas->translate(15.f, 15.f);
        canvas->drawBitmap(bmp, 0, 0);
        canvas->translate(0, bmp.height() + labelPaint.getTextSize() + 15.f);

        static const char kLabelLabel[] = "localM / canvasM";
        canvas->drawText(kLabelLabel, strlen(kLabelLabel), 0, 0, labelPaint);
        canvas->translate(0, 15.f);

        canvas->save();
        SkScalar maxLabelW = 0;
        canvas->translate(0, kPadY / 2 + kPointSize);
        for (int lm = 0; lm < localMatrices.count(); ++lm) {
            canvas->drawText(matrices[lm].fLabel, strlen(matrices[lm].fLabel),
                             0, labelPaint.getTextSize() - 1, labelPaint);
            SkScalar labelW = labelPaint.measureText(matrices[lm].fLabel,
                              strlen(matrices[lm].fLabel));
            maxLabelW = SkMaxScalar(maxLabelW, labelW);
            canvas->translate(0.f, 2 * kPointSize + 2.5f * kPadY);
        }
        canvas->restore();

        canvas->translate(maxLabelW + kPadX / 2.f, 0.f);

        for (int s = 0; s < 2; ++s) {
            SkPaint& paint = s ? strokePaint : fillPaint;

            SkScalar columnH = 0;
            for (int m = 0; m < matrices.count(); ++m) {
                columnH = 0;
                canvas->save();
                canvas->drawText(matrices[m].fLabel, strlen(matrices[m].fLabel),
                                 0, labelPaint.getTextSize() - 1, labelPaint);
                canvas->translate(0, kPadY / 2 + kPointSize);
                columnH += kPadY / 2 + kPointSize;
                for (int lm = 0; lm < localMatrices.count(); ++lm) {
                    paint.setShader(
                        SkShader::CreateBitmapShader(bmp,
                                                     SkShader::kMirror_TileMode,
                                                     SkShader::kRepeat_TileMode,
                                                     &localMatrices[lm].fMatrix))->unref();

                    canvas->save();
                    canvas->concat(matrices[m].fMatrix);
                    canvas->drawText(kText, kTextLen, 0, 0, paint);
                    canvas->drawText(kText, kTextLen, 0, 0, outlinePaint);
                    canvas->restore();

                    SkPath path;
                    path.arcTo(SkRect::MakeXYWH(-0.1f * w, 0.f,
                                                1.2f * w, 2.f * kPointSize),
                               225.f, 359.f,
                               false);
                    path.close();

                    canvas->translate(0.f, kPointSize + kPadY);
                    columnH += kPointSize + kPadY;

                    canvas->save();
                    canvas->concat(matrices[m].fMatrix);
                    canvas->drawTextOnPath(kText, kTextLen, path, NULL, paint);
                    canvas->drawTextOnPath(kText, kTextLen, path, NULL, outlinePaint);
                    canvas->restore();
                    SkPaint stroke;
                    stroke.setStyle(SkPaint::kStroke_Style);
                    canvas->translate(0.f, kPointSize + kPadY);
                    columnH += kPointSize + kPadY;
                }
                canvas->restore();
                canvas->translate(w + kPadX, 0.f);
            }
            if (0 == s) {
                canvas->drawLine(0.f, -kPadY, 0.f, columnH + kPadY, outlinePaint);
                canvas->translate(kPadX / 2, 0.f);
                static const char kFillLabel[] = "Filled";
                static const char kStrokeLabel[] = "Stroked";
                SkScalar y = columnH + kPadY / 2;
                SkScalar fillX = -outlinePaint.measureText(kFillLabel, strlen(kFillLabel)) - kPadX;
                SkScalar strokeX = kPadX;
                canvas->drawText(kFillLabel, strlen(kFillLabel), fillX, y, labelPaint);
                canvas->drawText(kStrokeLabel, strlen(kStrokeLabel), strokeX, y, labelPaint);
            }
        }
    }

//.........这里部分代码省略.........
                        --fPathDepth;
                        validate(path);
                    }
                    break;
                case kReverseAddPath:
                    if (fPathDepth < fPathDepthLimit) {
                        ++fPathDepth;
                        SkPath src = makePath();
                        validate(src);
                        path.reverseAddPath(src);
                        --fPathDepth;
                        validate(path);
                    }
                    break;
                case kMoveToPath: {
                    SkScalar x = makeScalar();
                    SkScalar y = makeScalar();
                    path.moveTo(x, y);
                    validate(path);
                    } break;
                case kRMoveToPath: {
                    SkScalar x = makeScalar();
                    SkScalar y = makeScalar();
                    path.rMoveTo(x, y);
                    validate(path);
                    } break;
                case kLineToPath: {
                    SkScalar x = makeScalar();
                    SkScalar y = makeScalar();
                    path.lineTo(x, y);
                    validate(path);
                    } break;
                case kRLineToPath: {
                    SkScalar x = makeScalar();
                    SkScalar y = makeScalar();
                    path.rLineTo(x, y);
                    validate(path);
                    } break;
                case kQuadToPath: {
                    SkPoint pt[2];
                    makePointArray(SK_ARRAY_COUNT(pt), pt);
                    path.quadTo(pt[0], pt[1]);
                    validate(path);
                    } break;
                case kRQuadToPath: {
                    SkPoint pt[2];
                    makePointArray(SK_ARRAY_COUNT(pt), pt);
                    path.rQuadTo(pt[0].fX, pt[0].fY, pt[1].fX, pt[1].fY);
                    validate(path);
                    } break;
                case kConicToPath: {
                    SkPoint pt[2];
                    makePointArray(SK_ARRAY_COUNT(pt), pt);
                    SkScalar weight = makeScalar();
                    path.conicTo(pt[0], pt[1], weight);
                    validate(path);
                    } break;
                case kRConicToPath: {
                    SkPoint pt[2];
                    makePointArray(SK_ARRAY_COUNT(pt), pt);
                    SkScalar weight = makeScalar();
                    path.rConicTo(pt[0].fX, pt[0].fY, pt[1].fX, pt[1].fY, weight);
                    validate(path);
                    } break;
                case kCubicToPath: {
                    SkPoint pt[3];
                    makePointArray(SK_ARRAY_COUNT(pt), pt);
                    path.cubicTo(pt[0], pt[1], pt[2]);
                    validate(path);
                    } break;
                case kRCubicToPath: {
                    SkPoint pt[3];
                    makePointArray(SK_ARRAY_COUNT(pt), pt);
                    path.rCubicTo(pt[0].fX, pt[0].fY, pt[1].fX, pt[1].fY, pt[2].fX, pt[2].fY);
                    validate(path);
                    } break;
                case kArcToPath: {
                    SkPoint pt[2];
                    makePointArray(SK_ARRAY_COUNT(pt), pt);
                    SkScalar radius = makeScalar();
                    path.arcTo(pt[0], pt[1], radius);
                    validate(path);
                    } break;
                case kArcTo2Path: {
                    SkRect oval = makeRect();
                    SkScalar startAngle = makeAngle();
                    SkScalar sweepAngle = makeAngle();
                    bool forceMoveTo = makeBool();
                    path.arcTo(oval, startAngle, sweepAngle, forceMoveTo);
                    validate(path);
                    } break;
                case kClosePath:
                    path.close();
                    validate(path);
                    break;
            }
        }
    }
    return path;
}

    void onDraw(SkCanvas* canvas) override {
        const char text[] = "Shaded Text";
        const int textLen = SK_ARRAY_COUNT(text) - 1;
        const int pointSize = 36;

        const int w = pointSize * textLen;
        const int h = pointSize;

        SkPoint pts[2] = {
            { 0, 0 },
            { SkIntToScalar(w), SkIntToScalar(h) }
        };
        SkScalar textBase = SkIntToScalar(h/2);

        SkShader::TileMode tileModes[] = {
            SkShader::kClamp_TileMode,
            SkShader::kRepeat_TileMode,
            SkShader::kMirror_TileMode
        };

        static const int gradCount = SK_ARRAY_COUNT(gGradData) *
                                     SK_ARRAY_COUNT(gGradMakers);
        static const int bmpCount = SK_ARRAY_COUNT(tileModes) *
                                    SK_ARRAY_COUNT(tileModes);
        sk_sp<SkShader> shaders[gradCount + bmpCount];

        int shdIdx = 0;
        for (size_t d = 0; d < SK_ARRAY_COUNT(gGradData); ++d) {
            for (size_t m = 0; m < SK_ARRAY_COUNT(gGradMakers); ++m) {
                shaders[shdIdx++] = gGradMakers[m](pts,
                                                   gGradData[d],
                                                   SkShader::kClamp_TileMode);
            }
        }

        SkBitmap bm;
        makebm(&bm, w/16, h/4);
        for (size_t tx = 0; tx < SK_ARRAY_COUNT(tileModes); ++tx) {
            for (size_t ty = 0; ty < SK_ARRAY_COUNT(tileModes); ++ty) {
                shaders[shdIdx++] = SkShader::MakeBitmapShader(bm, tileModes[tx], tileModes[ty]);
            }
        }

        SkPaint paint;
        paint.setDither(true);
        paint.setAntiAlias(true);
        sk_tool_utils::set_portable_typeface(&paint);
        paint.setTextSize(SkIntToScalar(pointSize));

        canvas->save();
        canvas->translate(SkIntToScalar(20), SkIntToScalar(10));

        SkPath path;
        path.arcTo(SkRect::MakeXYWH(SkIntToScalar(-40), SkIntToScalar(15),
                                    SkIntToScalar(300), SkIntToScalar(90)),
                                    SkIntToScalar(225), SkIntToScalar(90),
                                    false);
        path.close();

        static const int testsPerCol = 8;
        static const int rowHeight = 60;
        static const int colWidth = 300;
        canvas->save();
        for (int s = 0; s < static_cast<int>(SK_ARRAY_COUNT(shaders)); s++) {
            canvas->save();
            int i = 2*s;
            canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
                              SkIntToScalar((i % testsPerCol) * rowHeight));
            paint.setShader(shaders[s]);
            canvas->drawText(text, textLen, 0, textBase, paint);
            canvas->restore();
            canvas->save();
            ++i;
            canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
                              SkIntToScalar((i % testsPerCol) * rowHeight));
            canvas->drawTextOnPath(text, textLen, path, nullptr, paint);
            canvas->restore();
        }
        canvas->restore();

    }

void WRasterImage::Impl::drawPlainPath(SkPath &p, const WPainterPath& path)
{
  const std::vector<WPainterPath::Segment>& segments = path.segments();

  if (segments.size() > 0
      && segments[0].type() != WPainterPath::Segment::MoveTo)
    p.moveTo(SkDoubleToScalar(0), SkDoubleToScalar(0));

  for (unsigned i = 0; i < segments.size(); ++i) {
    const WPainterPath::Segment s = segments[i];

    switch (s.type()) {
    case WPainterPath::Segment::MoveTo:
      p.moveTo(SkDoubleToScalar(s.x()), SkDoubleToScalar(s.y()));
      break;
    case WPainterPath::Segment::LineTo:
      p.lineTo(SkDoubleToScalar(s.x()), SkDoubleToScalar(s.y()));
      break;
    case WPainterPath::Segment::CubicC1: {
      const double x1 = s.x();
      const double y1 = s.y();
      const double x2 = segments[i+1].x();
      const double y2 = segments[i+1].y();
      const double x3 = segments[i+2].x();
      const double y3 = segments[i+2].y();
      p.cubicTo(SkDoubleToScalar(x1), SkDoubleToScalar(y1),
                SkDoubleToScalar(x2), SkDoubleToScalar(y2),
                SkDoubleToScalar(x3), SkDoubleToScalar(y3));
      i += 2;
      break;
    }
    case WPainterPath::Segment::CubicC2:
    case WPainterPath::Segment::CubicEnd:
      assert(false);
    case WPainterPath::Segment::ArcC: {
      const double x = s.x();
      const double y = s.y();
      const double width = segments[i+1].x();
      const double height = segments[i+1].y();
      const double startAngle = segments[i+2].x();
      const double sweepAngle = segments[i+2].y();
      SkRect rect = SkRect::MakeXYWH(SkDoubleToScalar(x - width),
				     SkDoubleToScalar(y - height),
				     SkDoubleToScalar(width * 2.0),
				     SkDoubleToScalar(height * 2.0));
      if (sweepAngle != 360) 
	p.arcTo(rect,
		SkDoubleToScalar(-startAngle), SkDoubleToScalar(-sweepAngle),
		false);
      else
	p.addOval(rect, SkPath::kCCW_Direction);

      i += 2;
      break;
    }
    case WPainterPath::Segment::ArcR:
    case WPainterPath::Segment::ArcAngleSweep:
      assert(false);
    case WPainterPath::Segment::QuadC: {
      const double x1 = s.x();
      const double y1 = s.y();
      const double x2 = segments[i+1].x();
      const double y2 = segments[i+1].y();
      
      p.quadTo(SkDoubleToScalar(x1), SkDoubleToScalar(y1),
              SkDoubleToScalar(x2), SkDoubleToScalar(y2));

      i += 1;

      break;
    }
    case WPainterPath::Segment::QuadEnd:
      assert(false);
    }
  }
}