virtual void handlePath(SkCanvas* canvas, const SkPath& path,
                            const SkPaint& paint, int N) override {
        SkPoint pts[2];
        if (!path.isLine(pts) || pts[0].fY != pts[1].fY) {
            this->INHERITED::handlePath(canvas, path, paint, N);
        } else {
            SkRect rect;
            rect.fLeft = pts[0].fX;
            rect.fTop = pts[0].fY - paint.getStrokeWidth() / 2;
            rect.fRight = rect.fLeft + SkIntToScalar(fWidth);
            rect.fBottom = rect.fTop + paint.getStrokeWidth();

            SkPaint p(paint);
            p.setStyle(SkPaint::kFill_Style);
            p.setPathEffect(nullptr);

            int count = SkScalarRoundToInt((pts[1].fX - pts[0].fX) / (2*fWidth));
            SkScalar dx = SkIntToScalar(2 * fWidth);

            for (int i = 0; i < N*10; ++i) {
                SkRect r = rect;
                for (int j = 0; j < count; ++j) {
                    canvas->drawRect(r, p);
                    r.offset(dx, 0);
                }
            }
        }
    }
Beispiel #2
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// Only handles lines for now. If returns true, dstPath is the new (smaller)
// path. If returns false, then dstPath parameter is ignored.
static bool cull_path(const SkPath& srcPath, const SkStrokeRec& rec,
                      const SkRect* cullRect, SkScalar intervalLength,
                      SkPath* dstPath) {
    if (nullptr == cullRect) {
        return false;
    }

    SkPoint pts[2];
    if (!srcPath.isLine(pts)) {
        return false;
    }

    SkRect bounds = *cullRect;
    outset_for_stroke(&bounds, rec);

    SkScalar dx = pts[1].x() - pts[0].x();
    SkScalar dy = pts[1].y() - pts[0].y();

    // just do horizontal lines for now (lazy)
    if (dy) {
        return false;
    }

    SkScalar minX = pts[0].fX;
    SkScalar maxX = pts[1].fX;

    if (dx < 0) {
        SkTSwap(minX, maxX);
    }

    SkASSERT(minX <= maxX);
    if (maxX < bounds.fLeft || minX > bounds.fRight) {
        return false;
    }

    // Now we actually perform the chop, removing the excess to the left and
    // right of the bounds (keeping our new line "in phase" with the dash,
    // hence the (mod intervalLength).

    if (minX < bounds.fLeft) {
        minX = bounds.fLeft - SkScalarMod(bounds.fLeft - minX,
                                          intervalLength);
    }
    if (maxX > bounds.fRight) {
        maxX = bounds.fRight + SkScalarMod(maxX - bounds.fRight,
                                           intervalLength);
    }

    SkASSERT(maxX >= minX);
    if (dx < 0) {
        SkTSwap(minX, maxX);
    }
    pts[0].fX = minX;
    pts[1].fX = maxX;

    dstPath->moveTo(pts[0]);
    dstPath->lineTo(pts[1]);
    return true;
}
Beispiel #3
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    bool init(const SkPath& src, SkPath* dst, SkStrokeRec* rec,
              int intervalCount, SkScalar intervalLength) {
        if (rec->isHairlineStyle() || !src.isLine(fPts)) {
            return false;
        }

        // can relax this in the future, if we handle square and round caps
        if (SkPaint::kButt_Cap != rec->getCap()) {
            return false;
        }

        SkScalar pathLength = SkPoint::Distance(fPts[0], fPts[1]);

        fTangent = fPts[1] - fPts[0];
        if (fTangent.isZero()) {
            return false;
        }

        fPathLength = pathLength;
        fTangent.scale(SkScalarInvert(pathLength));
        fTangent.rotateCCW(&fNormal);
        fNormal.scale(SkScalarHalf(rec->getWidth()));

        // now estimate how many quads will be added to the path
        //     resulting segments = pathLen * intervalCount / intervalLen
        //     resulting points = 4 * segments

        SkScalar ptCount = SkScalarMulDiv(pathLength,
                                          SkIntToScalar(intervalCount),
                                          intervalLength);
        ptCount = SkTMin(ptCount, SkDashPath::kMaxDashCount);
        int n = SkScalarCeilToInt(ptCount) << 2;
        dst->incReserve(n);

        // we will take care of the stroking
        rec->setFillStyle();
        return true;
    }
// Currently asPoints is more restrictive then it needs to be. In the future
// we need to:
//      allow kRound_Cap capping (could allow rotations in the matrix with this)
//      allow paths to be returned
bool SkDashPathEffect::asPoints(PointData* results,
                                const SkPath& src,
                                const SkStrokeRec& rec,
                                const SkMatrix& matrix,
                                const SkRect* cullRect) const {
    // width < 0 -> fill && width == 0 -> hairline so requiring width > 0 rules both out
    if (fInitialDashLength < 0 || 0 >= rec.getWidth()) {
        return false;
    }

    // TODO: this next test could be eased up. We could allow any number of
    // intervals as long as all the ons match and all the offs match.
    // Additionally, they do not necessarily need to be integers.
    // We cannot allow arbitrary intervals since we want the returned points
    // to be uniformly sized.
    if (fCount != 2 ||
        !SkScalarNearlyEqual(fIntervals[0], fIntervals[1]) ||
        !SkScalarIsInt(fIntervals[0]) ||
        !SkScalarIsInt(fIntervals[1])) {
        return false;
    }

    SkPoint pts[2];

    if (!src.isLine(pts)) {
        return false;
    }

    // TODO: this test could be eased up to allow circles
    if (SkPaint::kButt_Cap != rec.getCap()) {
        return false;
    }

    // TODO: this test could be eased up for circles. Rotations could be allowed.
    if (!matrix.rectStaysRect()) {
        return false;
    }

    // See if the line can be limited to something plausible.
    if (!cull_line(pts, rec, matrix, cullRect, fIntervalLength)) {
        return false;
    }

    SkScalar length = SkPoint::Distance(pts[1], pts[0]);

    SkVector tangent = pts[1] - pts[0];
    if (tangent.isZero()) {
        return false;
    }

    tangent.scale(SkScalarInvert(length));

    // TODO: make this test for horizontal & vertical lines more robust
    bool isXAxis = true;
    if (SkScalarNearlyEqual(SK_Scalar1, tangent.fX) ||
        SkScalarNearlyEqual(-SK_Scalar1, tangent.fX)) {
        results->fSize.set(SkScalarHalf(fIntervals[0]), SkScalarHalf(rec.getWidth()));
    } else if (SkScalarNearlyEqual(SK_Scalar1, tangent.fY) ||
               SkScalarNearlyEqual(-SK_Scalar1, tangent.fY)) {
        results->fSize.set(SkScalarHalf(rec.getWidth()), SkScalarHalf(fIntervals[0]));
        isXAxis = false;
    } else if (SkPaint::kRound_Cap != rec.getCap()) {
        // Angled lines don't have axis-aligned boxes.
        return false;
    }

    if (results) {
        results->fFlags = 0;
        SkScalar clampedInitialDashLength = SkMinScalar(length, fInitialDashLength);

        if (SkPaint::kRound_Cap == rec.getCap()) {
            results->fFlags |= PointData::kCircles_PointFlag;
        }

        results->fNumPoints = 0;
        SkScalar len2 = length;
        if (clampedInitialDashLength > 0 || 0 == fInitialDashIndex) {
            SkASSERT(len2 >= clampedInitialDashLength);
            if (0 == fInitialDashIndex) {
                if (clampedInitialDashLength > 0) {
                    if (clampedInitialDashLength >= fIntervals[0]) {
                        ++results->fNumPoints;  // partial first dash
                    }
                    len2 -= clampedInitialDashLength;
                }
                len2 -= fIntervals[1];  // also skip first space
                if (len2 < 0) {
                    len2 = 0;
                }
            } else {
                len2 -= clampedInitialDashLength; // skip initial partial empty
            }
        }
        int numMidPoints = SkScalarFloorToInt(len2 / fIntervalLength);
        results->fNumPoints += numMidPoints;
        len2 -= numMidPoints * fIntervalLength;
        bool partialLast = false;
        if (len2 > 0) {
            if (len2 < fIntervals[0]) {
                partialLast = true;
            } else {
                ++numMidPoints;
                ++results->fNumPoints;
            }
        }

        results->fPoints = new SkPoint[results->fNumPoints];

        SkScalar    distance = 0;
        int         curPt = 0;

        if (clampedInitialDashLength > 0 || 0 == fInitialDashIndex) {
            SkASSERT(clampedInitialDashLength <= length);

            if (0 == fInitialDashIndex) {
                if (clampedInitialDashLength > 0) {
                    // partial first block
                    SkASSERT(SkPaint::kRound_Cap != rec.getCap()); // can't handle partial circles
                    SkScalar x = pts[0].fX + SkScalarMul(tangent.fX, SkScalarHalf(clampedInitialDashLength));
                    SkScalar y = pts[0].fY + SkScalarMul(tangent.fY, SkScalarHalf(clampedInitialDashLength));
                    SkScalar halfWidth, halfHeight;
                    if (isXAxis) {
                        halfWidth = SkScalarHalf(clampedInitialDashLength);
                        halfHeight = SkScalarHalf(rec.getWidth());
                    } else {
                        halfWidth = SkScalarHalf(rec.getWidth());
                        halfHeight = SkScalarHalf(clampedInitialDashLength);
                    }
                    if (clampedInitialDashLength < fIntervals[0]) {
                        // This one will not be like the others
                        results->fFirst.addRect(x - halfWidth, y - halfHeight,
                                                x + halfWidth, y + halfHeight);
                    } else {
                        SkASSERT(curPt < results->fNumPoints);
                        results->fPoints[curPt].set(x, y);
                        ++curPt;
                    }

                    distance += clampedInitialDashLength;
                }

                distance += fIntervals[1];  // skip over the next blank block too
            } else {
                distance += clampedInitialDashLength;
            }
        }

        if (0 != numMidPoints) {
            distance += SkScalarHalf(fIntervals[0]);

            for (int i = 0; i < numMidPoints; ++i) {
                SkScalar x = pts[0].fX + SkScalarMul(tangent.fX, distance);
                SkScalar y = pts[0].fY + SkScalarMul(tangent.fY, distance);

                SkASSERT(curPt < results->fNumPoints);
                results->fPoints[curPt].set(x, y);
                ++curPt;

                distance += fIntervalLength;
            }

            distance -= SkScalarHalf(fIntervals[0]);
        }

        if (partialLast) {
            // partial final block
            SkASSERT(SkPaint::kRound_Cap != rec.getCap()); // can't handle partial circles
            SkScalar temp = length - distance;
            SkASSERT(temp < fIntervals[0]);
            SkScalar x = pts[0].fX + SkScalarMul(tangent.fX, distance + SkScalarHalf(temp));
            SkScalar y = pts[0].fY + SkScalarMul(tangent.fY, distance + SkScalarHalf(temp));
            SkScalar halfWidth, halfHeight;
            if (isXAxis) {
                halfWidth = SkScalarHalf(temp);
                halfHeight = SkScalarHalf(rec.getWidth());
            } else {
                halfWidth = SkScalarHalf(rec.getWidth());
                halfHeight = SkScalarHalf(temp);
            }
            results->fLast.addRect(x - halfWidth, y - halfHeight,
                                   x + halfWidth, y + halfHeight);
        }

        SkASSERT(curPt == results->fNumPoints);
    }

    return true;
}