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- /*
- * 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 "include/effects/SkDashPathEffect.h"
- #include "include/core/SkStrokeRec.h"
- #include "include/private/SkTo.h"
- #include "src/core/SkReadBuffer.h"
- #include "src/core/SkWriteBuffer.h"
- #include "src/effects/SkDashImpl.h"
- #include "src/utils/SkDashPathPriv.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::onFilterPath(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::onAsPoints(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::onAsADash(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));
- }
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