// Use the intersection of the corners' diagonals with their ellipses to shrink
// the bounding rect
SkRect compute_central_occluder(const SkRRect& rr) {
const SkRect r = rr.getBounds();
SkScalar newL = r.fLeft, newT = r.fTop, newR = r.fRight, newB = r.fBottom;
SkVector radii = rr.radii(SkRRect::kUpperLeft_Corner);
if (!radii.isZero()) {
SkPoint p = intersection(radii.fX, radii.fY);
newL = SkTMax(newL, r.fLeft + radii.fX - p.fX);
newT = SkTMax(newT, r.fTop + radii.fY - p.fY);
}
radii = rr.radii(SkRRect::kUpperRight_Corner);
if (!radii.isZero()) {
SkPoint p = intersection(radii.fX, radii.fY);
newR = SkTMin(newR, r.fRight + p.fX - radii.fX);
newT = SkTMax(newT, r.fTop + radii.fY - p.fY);
}
radii = rr.radii(SkRRect::kLowerRight_Corner);
if (!radii.isZero()) {
SkPoint p = intersection(radii.fX, radii.fY);
newR = SkTMin(newR, r.fRight + p.fX - radii.fX);
newB = SkTMin(newB, r.fBottom - radii.fY + p.fY);
}
radii = rr.radii(SkRRect::kLowerLeft_Corner);
if (!radii.isZero()) {
SkPoint p = intersection(radii.fX, radii.fY);
newL = SkTMax(newL, r.fLeft + radii.fX - p.fX);
newB = SkTMin(newB, r.fBottom - radii.fY + p.fY);
}
return SkRect::MakeLTRB(newL, newT, newR, newB);
}
// 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;
}
