epoger@google.com | ec3ed6a | 2011-07-28 14:26:00 +0000 | [diff] [blame] | 1 | |
| 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 | */ |
| 8 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 9 | |
| 10 | #include "SkDiscretePathEffect.h" |
commit-bot@chromium.org | 8b0e8ac | 2014-01-30 18:58:24 +0000 | [diff] [blame] | 11 | #include "SkReadBuffer.h" |
| 12 | #include "SkWriteBuffer.h" |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 13 | #include "SkPathMeasure.h" |
| 14 | #include "SkRandom.h" |
| 15 | |
mike@reedtribe.org | 3334c3a | 2011-04-20 11:39:28 +0000 | [diff] [blame] | 16 | static void Perterb(SkPoint* p, const SkVector& tangent, SkScalar scale) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 17 | SkVector normal = tangent; |
| 18 | normal.rotateCCW(); |
| 19 | normal.setLength(scale); |
| 20 | *p += normal; |
| 21 | } |
| 22 | |
rs.prinja | 39e58ad | 2014-06-12 22:55:08 -0700 | [diff] [blame] | 23 | SkDiscretePathEffect::SkDiscretePathEffect(SkScalar segLength, |
| 24 | SkScalar deviation, |
| 25 | uint32_t seedAssist) |
| 26 | : fSegLength(segLength), fPerterb(deviation), fSeedAssist(seedAssist) |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 27 | { |
| 28 | } |
| 29 | |
mike@reedtribe.org | 3334c3a | 2011-04-20 11:39:28 +0000 | [diff] [blame] | 30 | bool SkDiscretePathEffect::filterPath(SkPath* dst, const SkPath& src, |
reed@google.com | 4bbdeac | 2013-01-24 21:03:11 +0000 | [diff] [blame] | 31 | SkStrokeRec* rec, const SkRect*) const { |
reed@google.com | fd4be26 | 2012-05-25 01:04:12 +0000 | [diff] [blame] | 32 | bool doFill = rec->isFillStyle(); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 33 | |
| 34 | SkPathMeasure meas(src, doFill); |
rs.prinja | 39e58ad | 2014-06-12 22:55:08 -0700 | [diff] [blame] | 35 | |
| 36 | /* Caller may supply their own seed assist, which by default is 0 */ |
| 37 | uint32_t seed = fSeedAssist ^ SkScalarRoundToInt(meas.getLength()); |
| 38 | |
commit-bot@chromium.org | e0e7cfe | 2013-09-09 20:09:12 +0000 | [diff] [blame] | 39 | SkLCGRandom rand(seed ^ ((seed << 16) | (seed >> 16))); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 40 | SkScalar scale = fPerterb; |
| 41 | SkPoint p; |
| 42 | SkVector v; |
| 43 | |
| 44 | do { |
| 45 | SkScalar length = meas.getLength(); |
| 46 | |
mike@reedtribe.org | 3334c3a | 2011-04-20 11:39:28 +0000 | [diff] [blame] | 47 | if (fSegLength * (2 + doFill) > length) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 48 | meas.getSegment(0, length, dst, true); // to short for us to mangle |
mike@reedtribe.org | 3334c3a | 2011-04-20 11:39:28 +0000 | [diff] [blame] | 49 | } else { |
reed@google.com | e1ca705 | 2013-12-17 19:22:07 +0000 | [diff] [blame] | 50 | int n = SkScalarRoundToInt(length / fSegLength); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 51 | SkScalar delta = length / n; |
| 52 | SkScalar distance = 0; |
| 53 | |
mike@reedtribe.org | 3334c3a | 2011-04-20 11:39:28 +0000 | [diff] [blame] | 54 | if (meas.isClosed()) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 55 | n -= 1; |
| 56 | distance += delta/2; |
| 57 | } |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 58 | |
reed@google.com | f3edf9f | 2012-04-12 19:44:38 +0000 | [diff] [blame] | 59 | if (meas.getPosTan(distance, &p, &v)) { |
| 60 | Perterb(&p, v, SkScalarMul(rand.nextSScalar1(), scale)); |
| 61 | dst->moveTo(p); |
| 62 | } |
mike@reedtribe.org | 3334c3a | 2011-04-20 11:39:28 +0000 | [diff] [blame] | 63 | while (--n >= 0) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 64 | distance += delta; |
reed@google.com | f3edf9f | 2012-04-12 19:44:38 +0000 | [diff] [blame] | 65 | if (meas.getPosTan(distance, &p, &v)) { |
| 66 | Perterb(&p, v, SkScalarMul(rand.nextSScalar1(), scale)); |
| 67 | dst->lineTo(p); |
| 68 | } |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 69 | } |
mike@reedtribe.org | 3334c3a | 2011-04-20 11:39:28 +0000 | [diff] [blame] | 70 | if (meas.isClosed()) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 71 | dst->close(); |
mike@reedtribe.org | 3334c3a | 2011-04-20 11:39:28 +0000 | [diff] [blame] | 72 | } |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 73 | } |
| 74 | } while (meas.nextContour()); |
| 75 | return true; |
| 76 | } |
| 77 | |
reed | 9fa60da | 2014-08-21 07:59:51 -0700 | [diff] [blame] | 78 | SkFlattenable* SkDiscretePathEffect::CreateProc(SkReadBuffer& buffer) { |
| 79 | SkScalar segLength = buffer.readScalar(); |
| 80 | SkScalar perterb = buffer.readScalar(); |
| 81 | uint32_t seed = buffer.readUInt(); |
| 82 | return Create(segLength, perterb, seed); |
| 83 | } |
| 84 | |
commit-bot@chromium.org | 8b0e8ac | 2014-01-30 18:58:24 +0000 | [diff] [blame] | 85 | void SkDiscretePathEffect::flatten(SkWriteBuffer& buffer) const { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 86 | buffer.writeScalar(fSegLength); |
| 87 | buffer.writeScalar(fPerterb); |
rs.prinja | 39e58ad | 2014-06-12 22:55:08 -0700 | [diff] [blame] | 88 | buffer.writeUInt(fSeedAssist); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 89 | } |