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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/core/SkPathMeasure.h"
- #include "include/core/SkStrokeRec.h"
- #include "include/effects/Sk1DPathEffect.h"
- #include "src/core/SkReadBuffer.h"
- #include "src/core/SkWriteBuffer.h"
- // Since we are stepping by a float, the do/while loop might go on forever (or nearly so).
- // Put in a governor to limit crash values from looping too long (and allocating too much ram).
- #define MAX_REASONABLE_ITERATIONS 100000
- bool Sk1DPathEffect::onFilterPath(SkPath* dst, const SkPath& src,
- SkStrokeRec*, const SkRect*) const {
- SkPathMeasure meas(src, false);
- do {
- int governor = MAX_REASONABLE_ITERATIONS;
- SkScalar length = meas.getLength();
- SkScalar distance = this->begin(length);
- while (distance < length && --governor >= 0) {
- SkScalar delta = this->next(dst, distance, meas);
- if (delta <= 0) {
- break;
- }
- distance += delta;
- }
- } while (meas.nextContour());
- return true;
- }
- ///////////////////////////////////////////////////////////////////////////////
- SkPath1DPathEffect::SkPath1DPathEffect(const SkPath& path, SkScalar advance, SkScalar phase,
- Style style) : fPath(path) {
- SkASSERT(advance > 0 && !path.isEmpty());
- SkASSERT((unsigned)style <= kMorph_Style);
- // Make the path thread-safe.
- fPath.updateBoundsCache();
- (void)fPath.getGenerationID();
- // cleanup their phase parameter, inverting it so that it becomes an
- // offset along the path (to match the interpretation in PostScript)
- if (phase < 0) {
- phase = -phase;
- if (phase > advance) {
- phase = SkScalarMod(phase, advance);
- }
- } else {
- if (phase > advance) {
- phase = SkScalarMod(phase, advance);
- }
- phase = advance - phase;
- }
- // now catch the edge case where phase == advance (within epsilon)
- if (phase >= advance) {
- phase = 0;
- }
- SkASSERT(phase >= 0);
- fAdvance = advance;
- fInitialOffset = phase;
- if ((unsigned)style > kMorph_Style) {
- SkDEBUGF("SkPath1DPathEffect style enum out of range %d\n", style);
- }
- fStyle = style;
- }
- bool SkPath1DPathEffect::onFilterPath(SkPath* dst, const SkPath& src,
- SkStrokeRec* rec, const SkRect* cullRect) const {
- rec->setFillStyle();
- return this->INHERITED::onFilterPath(dst, src, rec, cullRect);
- }
- static bool morphpoints(SkPoint dst[], const SkPoint src[], int count,
- SkPathMeasure& meas, SkScalar dist) {
- for (int i = 0; i < count; i++) {
- SkPoint pos;
- SkVector tangent;
- SkScalar sx = src[i].fX;
- SkScalar sy = src[i].fY;
- if (!meas.getPosTan(dist + sx, &pos, &tangent)) {
- return false;
- }
- SkMatrix matrix;
- SkPoint pt;
- pt.set(sx, sy);
- matrix.setSinCos(tangent.fY, tangent.fX, 0, 0);
- matrix.preTranslate(-sx, 0);
- matrix.postTranslate(pos.fX, pos.fY);
- matrix.mapPoints(&dst[i], &pt, 1);
- }
- return true;
- }
- /* TODO
- Need differentially more subdivisions when the follow-path is curvy. Not sure how to
- determine that, but we need it. I guess a cheap answer is let the caller tell us,
- but that seems like a cop-out. Another answer is to get Rob Johnson to figure it out.
- */
- static void morphpath(SkPath* dst, const SkPath& src, SkPathMeasure& meas,
- SkScalar dist) {
- SkPath::Iter iter(src, false);
- SkPoint srcP[4], dstP[3];
- SkPath::Verb verb;
- while ((verb = iter.next(srcP)) != SkPath::kDone_Verb) {
- switch (verb) {
- case SkPath::kMove_Verb:
- if (morphpoints(dstP, srcP, 1, meas, dist)) {
- dst->moveTo(dstP[0]);
- }
- break;
- case SkPath::kLine_Verb:
- srcP[2] = srcP[1];
- srcP[1].set(SkScalarAve(srcP[0].fX, srcP[2].fX),
- SkScalarAve(srcP[0].fY, srcP[2].fY));
- // fall through to quad
- case SkPath::kQuad_Verb:
- if (morphpoints(dstP, &srcP[1], 2, meas, dist)) {
- dst->quadTo(dstP[0], dstP[1]);
- }
- break;
- case SkPath::kConic_Verb:
- if (morphpoints(dstP, &srcP[1], 2, meas, dist)) {
- dst->conicTo(dstP[0], dstP[1], iter.conicWeight());
- }
- break;
- case SkPath::kCubic_Verb:
- if (morphpoints(dstP, &srcP[1], 3, meas, dist)) {
- dst->cubicTo(dstP[0], dstP[1], dstP[2]);
- }
- break;
- case SkPath::kClose_Verb:
- dst->close();
- break;
- default:
- SkDEBUGFAIL("unknown verb");
- break;
- }
- }
- }
- SkScalar SkPath1DPathEffect::begin(SkScalar contourLength) const {
- return fInitialOffset;
- }
- sk_sp<SkFlattenable> SkPath1DPathEffect::CreateProc(SkReadBuffer& buffer) {
- SkScalar advance = buffer.readScalar();
- SkPath path;
- buffer.readPath(&path);
- SkScalar phase = buffer.readScalar();
- Style style = buffer.read32LE(kLastEnum_Style);
- return buffer.isValid() ? SkPath1DPathEffect::Make(path, advance, phase, style) : nullptr;
- }
- void SkPath1DPathEffect::flatten(SkWriteBuffer& buffer) const {
- buffer.writeScalar(fAdvance);
- buffer.writePath(fPath);
- buffer.writeScalar(fInitialOffset);
- buffer.writeUInt(fStyle);
- }
- SkScalar SkPath1DPathEffect::next(SkPath* dst, SkScalar distance,
- SkPathMeasure& meas) const {
- #if defined(IS_FUZZING_WITH_LIBFUZZER)
- if (dst->countPoints() > 100000) {
- return fAdvance;
- }
- #endif
- switch (fStyle) {
- case kTranslate_Style: {
- SkPoint pos;
- if (meas.getPosTan(distance, &pos, nullptr)) {
- dst->addPath(fPath, pos.fX, pos.fY);
- }
- } break;
- case kRotate_Style: {
- SkMatrix matrix;
- if (meas.getMatrix(distance, &matrix)) {
- dst->addPath(fPath, matrix);
- }
- } break;
- case kMorph_Style:
- morphpath(dst, fPath, meas, distance);
- break;
- default:
- SkDEBUGFAIL("unknown Style enum");
- break;
- }
- return fAdvance;
- }
- ///////////////////////////////////////////////////////////////////////////////////////////////////
- sk_sp<SkPathEffect> SkPath1DPathEffect::Make(const SkPath& path, SkScalar advance, SkScalar phase,
- Style style) {
- if (advance <= 0 || !SkScalarIsFinite(advance) || !SkScalarIsFinite(phase) || path.isEmpty()) {
- return nullptr;
- }
- return sk_sp<SkPathEffect>(new SkPath1DPathEffect(path, advance, phase, style));
- }
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