The Tor Browser: gfx/skia/trunk/src/effects/SkDiscretePathEffect.cpp@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     2 /*

     3  * Copyright 2006 The Android Open Source Project

     4  *

     5  * Use of this source code is governed by a BSD-style license that can be

     6  * found in the LICENSE file.

     7  */

    10 #include "SkDiscretePathEffect.h"

    11 #include "SkReadBuffer.h"

    12 #include "SkWriteBuffer.h"

    13 #include "SkPathMeasure.h"

    14 #include "SkRandom.h"

    16 static void Perterb(SkPoint* p, const SkVector& tangent, SkScalar scale) {

    17     SkVector normal = tangent;

    18     normal.rotateCCW();

    19     normal.setLength(scale);

    20     *p += normal;

    21 }

    24 SkDiscretePathEffect::SkDiscretePathEffect(SkScalar segLength, SkScalar deviation)

    25     : fSegLength(segLength), fPerterb(deviation)

    26 {

    27 }

    29 bool SkDiscretePathEffect::filterPath(SkPath* dst, const SkPath& src,

    30                                       SkStrokeRec* rec, const SkRect*) const {

    31     bool doFill = rec->isFillStyle();

    33     SkPathMeasure   meas(src, doFill);

    34     uint32_t        seed = SkScalarRoundToInt(meas.getLength());

    35     SkLCGRandom     rand(seed ^ ((seed << 16) | (seed >> 16)));

    36     SkScalar        scale = fPerterb;

    37     SkPoint         p;

    38     SkVector        v;

    40     do {

    41         SkScalar    length = meas.getLength();

    43         if (fSegLength * (2 + doFill) > length) {

    44             meas.getSegment(0, length, dst, true);  // to short for us to mangle

    45         } else {

    46             int         n = SkScalarRoundToInt(length / fSegLength);

    47             SkScalar    delta = length / n;

    48             SkScalar    distance = 0;

    50             if (meas.isClosed()) {

    51                 n -= 1;

    52                 distance += delta/2;

    53             }

    55             if (meas.getPosTan(distance, &p, &v)) {

    56                 Perterb(&p, v, SkScalarMul(rand.nextSScalar1(), scale));

    57                 dst->moveTo(p);

    58             }

    59             while (--n >= 0) {

    60                 distance += delta;

    61                 if (meas.getPosTan(distance, &p, &v)) {

    62                     Perterb(&p, v, SkScalarMul(rand.nextSScalar1(), scale));

    63                     dst->lineTo(p);

    64                 }

    65             }

    66             if (meas.isClosed()) {

    67                 dst->close();

    68             }

    69         }

    70     } while (meas.nextContour());

    71     return true;

    72 }

    74 void SkDiscretePathEffect::flatten(SkWriteBuffer& buffer) const {

    75     this->INHERITED::flatten(buffer);

    76     buffer.writeScalar(fSegLength);

    77     buffer.writeScalar(fPerterb);

    78 }

    80 SkDiscretePathEffect::SkDiscretePathEffect(SkReadBuffer& buffer) {

    81     fSegLength = buffer.readScalar();

    82     fPerterb = buffer.readScalar();

    83 }

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