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-rw-r--r--gfx/skia/skia/src/effects/Sk1DPathEffect.cpp259
1 files changed, 259 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/effects/Sk1DPathEffect.cpp b/gfx/skia/skia/src/effects/Sk1DPathEffect.cpp
new file mode 100644
index 0000000000..98da0d4c8e
--- /dev/null
+++ b/gfx/skia/skia/src/effects/Sk1DPathEffect.cpp
@@ -0,0 +1,259 @@
+/*
+ * 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/Sk1DPathEffect.h"
+
+#include "include/core/SkFlattenable.h"
+#include "include/core/SkMatrix.h"
+#include "include/core/SkPath.h"
+#include "include/core/SkPathEffect.h"
+#include "include/core/SkPathMeasure.h"
+#include "include/core/SkPoint.h"
+#include "include/core/SkRefCnt.h"
+#include "include/core/SkScalar.h"
+#include "include/core/SkStrokeRec.h"
+#include "include/core/SkTypes.h"
+#include "src/core/SkPathEffectBase.h"
+#include "src/core/SkReadBuffer.h"
+#include "src/core/SkWriteBuffer.h"
+
+struct SkRect;
+
+// 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
+
+class Sk1DPathEffect : public SkPathEffectBase {
+public:
+protected:
+ bool onFilterPath(SkPath* dst, const SkPath& src, SkStrokeRec*, const SkRect*,
+ const SkMatrix&) const override {
+ 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;
+ }
+ if (governor < 0) {
+ return false;
+ }
+ } while (meas.nextContour());
+ return true;
+ }
+
+ /** Called at the start of each contour, returns the initial offset
+ into that contour.
+ */
+ virtual SkScalar begin(SkScalar contourLength) const = 0;
+ /** Called with the current distance along the path, with the current matrix
+ for the point/tangent at the specified distance.
+ Return the distance to travel for the next call. If return <= 0, then that
+ contour is done.
+ */
+ virtual SkScalar next(SkPath* dst, SkScalar dist, SkPathMeasure&) const = 0;
+
+private:
+ // For simplicity, assume fast bounds cannot be computed
+ bool computeFastBounds(SkRect*) const override { return false; }
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+class SkPath1DPathEffectImpl : public Sk1DPathEffect {
+public:
+ SkPath1DPathEffectImpl(const SkPath& path, SkScalar advance, SkScalar phase,
+ SkPath1DPathEffect::Style style) : fPath(path) {
+ SkASSERT(advance > 0 && !path.isEmpty());
+
+ // 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;
+ fStyle = style;
+ }
+
+ bool onFilterPath(SkPath* dst, const SkPath& src, SkStrokeRec* rec,
+ const SkRect* cullRect, const SkMatrix& ctm) const override {
+ rec->setFillStyle();
+ return this->INHERITED::onFilterPath(dst, src, rec, cullRect, ctm);
+ }
+
+ SkScalar begin(SkScalar contourLength) const override {
+ return fInitialOffset;
+ }
+
+ SkScalar next(SkPath*, SkScalar, SkPathMeasure&) const override;
+
+ static sk_sp<SkFlattenable> CreateProc(SkReadBuffer& buffer) {
+ SkScalar advance = buffer.readScalar();
+ SkPath path;
+ buffer.readPath(&path);
+ SkScalar phase = buffer.readScalar();
+ SkPath1DPathEffect::Style style = buffer.read32LE(SkPath1DPathEffect::kLastEnum_Style);
+ return buffer.isValid() ? SkPath1DPathEffect::Make(path, advance, phase, style) : nullptr;
+ }
+
+ void flatten(SkWriteBuffer& buffer) const override {
+ buffer.writeScalar(fAdvance);
+ buffer.writePath(fPath);
+ buffer.writeScalar(fInitialOffset);
+ buffer.writeUInt(fStyle);
+ }
+
+ Factory getFactory() const override { return CreateProc; }
+ const char* getTypeName() const override { return "SkPath1DPathEffect"; }
+
+private:
+ SkPath fPath; // copied from constructor
+ SkScalar fAdvance; // copied from constructor
+ SkScalar fInitialOffset; // computed from phase
+ SkPath1DPathEffect::Style fStyle; // copied from constructor
+
+ using INHERITED = Sk1DPathEffect;
+};
+
+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));
+ [[fallthrough]];
+ 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 SkPath1DPathEffectImpl::next(SkPath* dst, SkScalar distance,
+ SkPathMeasure& meas) const {
+#if defined(SK_BUILD_FOR_FUZZER)
+ if (dst->countPoints() > 100000) {
+ return fAdvance;
+ }
+#endif
+ switch (fStyle) {
+ case SkPath1DPathEffect::kTranslate_Style: {
+ SkPoint pos;
+ if (meas.getPosTan(distance, &pos, nullptr)) {
+ dst->addPath(fPath, pos.fX, pos.fY);
+ }
+ } break;
+ case SkPath1DPathEffect::kRotate_Style: {
+ SkMatrix matrix;
+ if (meas.getMatrix(distance, &matrix)) {
+ dst->addPath(fPath, matrix);
+ }
+ } break;
+ case SkPath1DPathEffect::kMorph_Style:
+ morphpath(dst, fPath, meas, distance);
+ 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 SkPath1DPathEffectImpl(path, advance, phase, style));
+}
+
+void SkPath1DPathEffect::RegisterFlattenables() {
+ SK_REGISTER_FLATTENABLE(SkPath1DPathEffectImpl);
+}
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