diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/effects/Sk1DPathEffect.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gfx/skia/trunk/src/effects/Sk1DPathEffect.cpp Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,201 @@ + +/* + * 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 "Sk1DPathEffect.h" +#include "SkReadBuffer.h" +#include "SkWriteBuffer.h" +#include "SkPathMeasure.h" + +bool Sk1DPathEffect::filterPath(SkPath* dst, const SkPath& src, + SkStrokeRec*, const SkRect*) const { + SkPathMeasure meas(src, false); + do { + SkScalar length = meas.getLength(); + SkScalar distance = this->begin(length); + while (distance < length) { + 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) +{ + if (advance <= 0 || path.isEmpty()) { + SkDEBUGF(("SkPath1DPathEffect can't use advance <= 0\n")); + fAdvance = 0; // signals we can't draw anything + fInitialOffset = 0; + fStyle = kStyleCount; + } else { + // 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 >= kStyleCount) { + SkDEBUGF(("SkPath1DPathEffect style enum out of range %d\n", style)); + } + fStyle = style; + } +} + +bool SkPath1DPathEffect::filterPath(SkPath* dst, const SkPath& src, + SkStrokeRec* rec, const SkRect* cullRect) const { + if (fAdvance > 0) { + rec->setFillStyle(); + return this->INHERITED::filterPath(dst, src, rec, cullRect); + } + return false; +} + +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::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; + } + } +} + +SkPath1DPathEffect::SkPath1DPathEffect(SkReadBuffer& buffer) { + fAdvance = buffer.readScalar(); + if (fAdvance > 0) { + buffer.readPath(&fPath); + fInitialOffset = buffer.readScalar(); + fStyle = (Style) buffer.readUInt(); + } else { + SkDEBUGF(("SkPath1DPathEffect can't use advance <= 0\n")); + // Make Coverity happy. + fInitialOffset = 0; + fStyle = kStyleCount; + } +} + +SkScalar SkPath1DPathEffect::begin(SkScalar contourLength) const { + return fInitialOffset; +} + +void SkPath1DPathEffect::flatten(SkWriteBuffer& buffer) const { + this->INHERITED::flatten(buffer); + buffer.writeScalar(fAdvance); + if (fAdvance > 0) { + buffer.writePath(fPath); + buffer.writeScalar(fInitialOffset); + buffer.writeUInt(fStyle); + } +} + +SkScalar SkPath1DPathEffect::next(SkPath* dst, SkScalar distance, + SkPathMeasure& meas) const { + switch (fStyle) { + case kTranslate_Style: { + SkPoint pos; + if (meas.getPosTan(distance, &pos, NULL)) { + 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; +}