| /* |
| * Copyright 2006 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkDashPathEffect.h" |
| |
| #include "SkDashImpl.h" |
| #include "SkDashPathPriv.h" |
| #include "SkFlattenablePriv.h" |
| #include "SkReadBuffer.h" |
| #include "SkStrokeRec.h" |
| #include "SkTo.h" |
| #include "SkWriteBuffer.h" |
| |
| #include <utility> |
| |
| SkDashImpl::SkDashImpl(const SkScalar intervals[], int count, SkScalar phase) |
| : fPhase(0) |
| , fInitialDashLength(-1) |
| , fInitialDashIndex(0) |
| , fIntervalLength(0) { |
| SkASSERT(intervals); |
| SkASSERT(count > 1 && SkIsAlign2(count)); |
| |
| fIntervals = (SkScalar*)sk_malloc_throw(sizeof(SkScalar) * count); |
| fCount = count; |
| for (int i = 0; i < count; i++) { |
| fIntervals[i] = intervals[i]; |
| } |
| |
| // set the internal data members |
| SkDashPath::CalcDashParameters(phase, fIntervals, fCount, |
| &fInitialDashLength, &fInitialDashIndex, &fIntervalLength, &fPhase); |
| } |
| |
| SkDashImpl::~SkDashImpl() { |
| sk_free(fIntervals); |
| } |
| |
| bool SkDashImpl::filterPath(SkPath* dst, const SkPath& src, SkStrokeRec* rec, |
| const SkRect* cullRect) const { |
| return SkDashPath::InternalFilter(dst, src, rec, cullRect, fIntervals, fCount, |
| fInitialDashLength, fInitialDashIndex, fIntervalLength); |
| } |
| |
| static void outset_for_stroke(SkRect* rect, const SkStrokeRec& rec) { |
| SkScalar radius = SkScalarHalf(rec.getWidth()); |
| if (0 == radius) { |
| radius = SK_Scalar1; // hairlines |
| } |
| if (SkPaint::kMiter_Join == rec.getJoin()) { |
| radius *= rec.getMiter(); |
| } |
| rect->outset(radius, radius); |
| } |
| |
| // Attempt to trim the line to minimally cover the cull rect (currently |
| // only works for horizontal and vertical lines). |
| // Return true if processing should continue; false otherwise. |
| static bool cull_line(SkPoint* pts, const SkStrokeRec& rec, |
| const SkMatrix& ctm, const SkRect* cullRect, |
| const SkScalar intervalLength) { |
| if (nullptr == cullRect) { |
| SkASSERT(false); // Shouldn't ever occur in practice |
| return false; |
| } |
| |
| SkScalar dx = pts[1].x() - pts[0].x(); |
| SkScalar dy = pts[1].y() - pts[0].y(); |
| |
| if ((dx && dy) || (!dx && !dy)) { |
| return false; |
| } |
| |
| SkRect bounds = *cullRect; |
| outset_for_stroke(&bounds, rec); |
| |
| // cullRect is in device space while pts are in the local coordinate system |
| // defined by the ctm. We want our answer in the local coordinate system. |
| |
| SkASSERT(ctm.rectStaysRect()); |
| SkMatrix inv; |
| if (!ctm.invert(&inv)) { |
| return false; |
| } |
| |
| inv.mapRect(&bounds); |
| |
| if (dx) { |
| SkASSERT(dx && !dy); |
| SkScalar minX = pts[0].fX; |
| SkScalar maxX = pts[1].fX; |
| |
| if (dx < 0) { |
| using std::swap; |
| swap(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) { |
| using std::swap; |
| swap(minX, maxX); |
| } |
| pts[0].fX = minX; |
| pts[1].fX = maxX; |
| } else { |
| SkASSERT(dy && !dx); |
| SkScalar minY = pts[0].fY; |
| SkScalar maxY = pts[1].fY; |
| |
| if (dy < 0) { |
| using std::swap; |
| swap(minY, maxY); |
| } |
| |
| SkASSERT(minY < maxY); |
| if (maxY <= bounds.fTop || minY >= bounds.fBottom) { |
| return false; |
| } |
| |
| // Now we actually perform the chop, removing the excess to the top and |
| // bottom of the bounds (keeping our new line "in phase" with the dash, |
| // hence the (mod intervalLength). |
| |
| if (minY < bounds.fTop) { |
| minY = bounds.fTop - SkScalarMod(bounds.fTop - minY, intervalLength); |
| } |
| if (maxY > bounds.fBottom) { |
| maxY = bounds.fBottom + SkScalarMod(maxY - bounds.fBottom, intervalLength); |
| } |
| |
| SkASSERT(maxY > minY); |
| if (dy < 0) { |
| using std::swap; |
| swap(minY, maxY); |
| } |
| pts[0].fY = minY; |
| pts[1].fY = maxY; |
| } |
| |
| 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 SkDashImpl::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 (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 |
| } |
| } |
| // Too many midpoints can cause results->fNumPoints to overflow or |
| // otherwise cause the results->fPoints allocation below to OOM. |
| // Cap it to a sane value. |
| SkScalar numIntervals = len2 / fIntervalLength; |
| if (!SkScalarIsFinite(numIntervals) || numIntervals > SkDashPath::kMaxDashCount) { |
| return false; |
| } |
| int numMidPoints = SkScalarFloorToInt(numIntervals); |
| 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 + tangent.fX * SkScalarHalf(clampedInitialDashLength); |
| SkScalar y = pts[0].fY + 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 + tangent.fX * distance; |
| SkScalar y = pts[0].fY + 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 + tangent.fX * (distance + SkScalarHalf(temp)); |
| SkScalar y = pts[0].fY + 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; |
| } |
| |
| SkPathEffect::DashType SkDashImpl::asADash(DashInfo* info) const { |
| if (info) { |
| if (info->fCount >= fCount && info->fIntervals) { |
| memcpy(info->fIntervals, fIntervals, fCount * sizeof(SkScalar)); |
| } |
| info->fCount = fCount; |
| info->fPhase = fPhase; |
| } |
| return kDash_DashType; |
| } |
| |
| void SkDashImpl::flatten(SkWriteBuffer& buffer) const { |
| buffer.writeScalar(fPhase); |
| buffer.writeScalarArray(fIntervals, fCount); |
| } |
| |
| sk_sp<SkFlattenable> SkDashImpl::CreateProc(SkReadBuffer& buffer) { |
| const SkScalar phase = buffer.readScalar(); |
| uint32_t count = buffer.getArrayCount(); |
| |
| // Don't allocate gigantic buffers if there's not data for them. |
| if (!buffer.validateCanReadN<SkScalar>(count)) { |
| return nullptr; |
| } |
| |
| SkAutoSTArray<32, SkScalar> intervals(count); |
| if (buffer.readScalarArray(intervals.get(), count)) { |
| return SkDashPathEffect::Make(intervals.get(), SkToInt(count), phase); |
| } |
| return nullptr; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////////////////////////// |
| |
| sk_sp<SkPathEffect> SkDashPathEffect::Make(const SkScalar intervals[], int count, SkScalar phase) { |
| if (!SkDashPath::ValidDashPath(phase, intervals, count)) { |
| return nullptr; |
| } |
| return sk_sp<SkPathEffect>(new SkDashImpl(intervals, count, phase)); |
| } |