There can be only one (SkRandom)!
Remove SkLCGRandom. We already decided the new one was better, which is
why we wrote the new SkRandom.
Convert GMs that were using SkLCGRandom to use the improved SkRandom.
Motivated by the fact that these GMs draw differently on some runs. We
believe this to be a result of using the old SkLCGRandom.
Add each of the tests that were using SkLCGRandom to ignore-tests.txt,
since we expect they'll draw differently using SkRandom.
Move a trimmed down version of SkLCGRandom into SkDiscretePathEffect.
In order to preserve the old behavior, trim down SkLCGRandom to only
the methods used by SkDiscretePathEffect, and hide it in
SkDiscretePathEffect's cpp file.
BUG=skia:3241
Review URL: https://codereview.chromium.org/805963002
diff --git a/expectations/gm/ignored-tests.txt b/expectations/gm/ignored-tests.txt
index 4ba3181..eb7609f 100644
--- a/expectations/gm/ignored-tests.txt
+++ b/expectations/gm/ignored-tests.txt
@@ -60,3 +60,29 @@
#junov skbug.com/3176
pictureimagefilter
+#scroggo skbug.com/3241
+# replacing SkLCGRandom with SkRandom
+beziers
+circles
+complexclip2
+complexclip2_rect_aa
+complexclip2_rect_bw
+complexclip2_path_aa
+complexclip2_path_bw
+complexclip2_rrect_aa
+complexclip2_rrect_bw
+cubicpath
+cubicclosepath
+degeneratesegments
+emptypath
+getpostextpath
+hittestpath
+linepath
+lineclosepath
+points
+polygons
+quadpath
+quadclosepath
+strokerects
+strokes_round
+strokes_poly
diff --git a/gm/beziers.cpp b/gm/beziers.cpp
index 48033bb..2371fdd 100755
--- a/gm/beziers.cpp
+++ b/gm/beziers.cpp
@@ -14,7 +14,7 @@
static const SkScalar SH = SkIntToScalar(H);
-static void rnd_quad(SkPath* p, SkPaint* paint, SkLCGRandom& rand) {
+static void rnd_quad(SkPath* p, SkPaint* paint, SkRandom& rand) {
p->moveTo(rand.nextRangeScalar(0, W), rand.nextRangeScalar(0, H));
for (int x = 0; x < 2; ++x) {
p->quadTo(rand.nextRangeScalar(W / 4, W), rand.nextRangeScalar(0, H),
@@ -27,7 +27,7 @@
paint->setAlpha(0xFF);
}
-static void rnd_cubic(SkPath* p, SkPaint* paint, SkLCGRandom& rand) {
+static void rnd_cubic(SkPath* p, SkPaint* paint, SkRandom& rand) {
p->moveTo(rand.nextRangeScalar(0, W), rand.nextRangeScalar(0, H));
for (int x = 0; x < 2; ++x) {
p->cubicTo(rand.nextRangeScalar(W / 4, W), rand.nextRangeScalar(0, H),
@@ -64,7 +64,7 @@
paint.setStrokeWidth(SkIntToScalar(9)/2);
paint.setAntiAlias(true);
- SkLCGRandom rand;
+ SkRandom rand;
for (int i = 0; i < N; i++) {
SkPath p;
rnd_quad(&p, &paint, rand);
diff --git a/gm/circles.cpp b/gm/circles.cpp
index 2c9368b..6fa682c 100644
--- a/gm/circles.cpp
+++ b/gm/circles.cpp
@@ -156,7 +156,6 @@
}
virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
- SkLCGRandom rand;
// Draw a giant AA circle as the background.
SkISize size = this->getISize();
SkScalar giantRadius = SkTMin(SkIntToScalar(size.fWidth),
@@ -168,6 +167,7 @@
giantPaint.setColor(0x80808080);
canvas->drawCircle(giantCenter.fX, giantCenter.fY, giantRadius, giantPaint);
+ SkRandom rand;
canvas->translate(20 * SK_Scalar1, 20 * SK_Scalar1);
int i;
for (i = 0; i < fPaints.count(); ++i) {
diff --git a/gm/complexclip2.cpp b/gm/complexclip2.cpp
index f99d5b4..8688c86 100644
--- a/gm/complexclip2.cpp
+++ b/gm/complexclip2.cpp
@@ -81,7 +81,7 @@
SkRegion::kReplace_Op,
};
- SkLCGRandom r;
+ SkRandom r;
for (int i = 0; i < kRows; ++i) {
for (int j = 0; j < kCols; ++j) {
for (int k = 0; k < 5; ++k) {
diff --git a/gm/convexpaths.cpp b/gm/convexpaths.cpp
index b869887..4f9633d 100644
--- a/gm/convexpaths.cpp
+++ b/gm/convexpaths.cpp
@@ -265,7 +265,7 @@
SkPaint paint;
paint.setAntiAlias(true);
- SkLCGRandom rand;
+ SkRandom rand;
canvas->translate(20 * SK_Scalar1, 20 * SK_Scalar1);
// As we've added more paths this has gotten pretty big. Scale the whole thing down.
diff --git a/gm/cubicpaths.cpp b/gm/cubicpaths.cpp
index f171522..9c6cffb 100644
--- a/gm/cubicpaths.cpp
+++ b/gm/cubicpaths.cpp
@@ -140,7 +140,7 @@
20 * SK_Scalar1,
titlePaint);
- SkLCGRandom rand;
+ SkRandom rand;
SkRect rect = SkRect::MakeWH(100*SK_Scalar1, 30*SK_Scalar1);
canvas->save();
canvas->translate(10 * SK_Scalar1, 30 * SK_Scalar1);
@@ -290,7 +290,7 @@
20 * SK_Scalar1,
titlePaint);
- SkLCGRandom rand;
+ SkRandom rand;
SkRect rect = SkRect::MakeWH(100*SK_Scalar1, 30*SK_Scalar1);
canvas->save();
canvas->translate(10 * SK_Scalar1, 30 * SK_Scalar1);
diff --git a/gm/degeneratesegments.cpp b/gm/degeneratesegments.cpp
index 17bf83b..5435d53 100644
--- a/gm/degeneratesegments.cpp
+++ b/gm/degeneratesegments.cpp
@@ -302,7 +302,7 @@
20 * SK_Scalar1,
titlePaint);
- SkLCGRandom rand;
+ SkRandom rand;
SkRect rect = SkRect::MakeWH(220*SK_Scalar1, 50*SK_Scalar1);
canvas->save();
canvas->translate(2*SK_Scalar1, 30 * SK_Scalar1); // The title
diff --git a/gm/emptypath.cpp b/gm/emptypath.cpp
index 87e1cc5..3b6fe81 100644
--- a/gm/emptypath.cpp
+++ b/gm/emptypath.cpp
@@ -73,7 +73,7 @@
20 * SK_Scalar1,
titlePaint);
- SkLCGRandom rand;
+ SkRandom rand;
SkRect rect = SkRect::MakeWH(100*SK_Scalar1, 30*SK_Scalar1);
int i = 0;
canvas->save();
diff --git a/gm/getpostextpath.cpp b/gm/getpostextpath.cpp
index a411520..4570107 100644
--- a/gm/getpostextpath.cpp
+++ b/gm/getpostextpath.cpp
@@ -56,7 +56,7 @@
SkAutoTArray<SkScalar> widths(len);
paint.getTextWidths(text, len, &widths[0]);
- SkLCGRandom rand;
+ SkRandom rand;
SkScalar x = SkIntToScalar(20);
SkScalar y = SkIntToScalar(100);
for (int i = 0; i < len; ++i) {
diff --git a/gm/hittestpath.cpp b/gm/hittestpath.cpp
index d971db9..caed98f 100644
--- a/gm/hittestpath.cpp
+++ b/gm/hittestpath.cpp
@@ -46,7 +46,7 @@
virtual void onDraw(SkCanvas* canvas) {
SkPath path;
- SkLCGRandom rand;
+ SkRandom rand;
int scale = 300;
for (int i = 0; i < 4; ++i) {
diff --git a/gm/linepaths.cpp b/gm/linepaths.cpp
index 53a9327..05900c7 100644
--- a/gm/linepaths.cpp
+++ b/gm/linepaths.cpp
@@ -95,7 +95,7 @@
20 * SK_Scalar1,
titlePaint);
- SkLCGRandom rand;
+ SkRandom rand;
SkRect rect = SkRect::MakeWH(100*SK_Scalar1, 30*SK_Scalar1);
canvas->save();
canvas->translate(10 * SK_Scalar1, 30 * SK_Scalar1);
@@ -239,7 +239,7 @@
20 * SK_Scalar1,
titlePaint);
- SkLCGRandom rand;
+ SkRandom rand;
SkRect rect = SkRect::MakeWH(100*SK_Scalar1, 30*SK_Scalar1);
canvas->save();
canvas->translate(10 * SK_Scalar1, 30 * SK_Scalar1);
diff --git a/gm/points.cpp b/gm/points.cpp
index 793e2e8..b241fe0 100644
--- a/gm/points.cpp
+++ b/gm/points.cpp
@@ -27,7 +27,7 @@
return SkISize::Make(640, 490);
}
- static void fill_pts(SkPoint pts[], size_t n, SkLCGRandom* rand) {
+ static void fill_pts(SkPoint pts[], size_t n, SkRandom* rand) {
for (size_t i = 0; i < n; i++) {
// Compute these independently and store in variables, rather
// than in the parameter-passing expression, to get consistent
@@ -41,7 +41,7 @@
virtual void onDraw(SkCanvas* canvas) {
canvas->translate(SK_Scalar1, SK_Scalar1);
- SkLCGRandom rand;
+ SkRandom rand;
SkPaint p0, p1, p2, p3;
const size_t n = 99;
diff --git a/gm/polygons.cpp b/gm/polygons.cpp
index 56b2e97..1d63978 100644
--- a/gm/polygons.cpp
+++ b/gm/polygons.cpp
@@ -88,7 +88,7 @@
canvas->translate(x, y);
}
- static void SetColorAndAlpha(SkPaint* paint, SkLCGRandom* rand) {
+ static void SetColorAndAlpha(SkPaint* paint, SkRandom* rand) {
SkColor color = rand->nextU();
color |= 0xff000000;
paint->setColor(color);
@@ -113,7 +113,7 @@
SkPaint paint;
paint.setAntiAlias(true);
- SkLCGRandom rand;
+ SkRandom rand;
// For stroke style painter
paint.setStyle(SkPaint::kStroke_Style);
for (int join = 0; join < kNumJoins; ++join) {
diff --git a/gm/quadpaths.cpp b/gm/quadpaths.cpp
index f2c4cf1..1dbb3d0 100644
--- a/gm/quadpaths.cpp
+++ b/gm/quadpaths.cpp
@@ -96,7 +96,7 @@
20 * SK_Scalar1,
titlePaint);
- SkLCGRandom rand;
+ SkRandom rand;
SkRect rect = SkRect::MakeWH(100*SK_Scalar1, 30*SK_Scalar1);
canvas->save();
canvas->translate(10 * SK_Scalar1, 30 * SK_Scalar1);
@@ -245,7 +245,7 @@
20 * SK_Scalar1,
titlePaint);
- SkLCGRandom rand;
+ SkRandom rand;
SkRect rect = SkRect::MakeWH(100*SK_Scalar1, 30*SK_Scalar1);
canvas->save();
canvas->translate(10 * SK_Scalar1, 30 * SK_Scalar1);
diff --git a/gm/strokerects.cpp b/gm/strokerects.cpp
index f3445cc..65eadd1 100644
--- a/gm/strokerects.cpp
+++ b/gm/strokerects.cpp
@@ -37,7 +37,7 @@
return SkISize::Make(W*2, H*2);
}
- static void rnd_rect(SkRect* r, SkLCGRandom& rand) {
+ static void rnd_rect(SkRect* r, SkRandom& rand) {
SkScalar x = rand.nextUScalar1() * W;
SkScalar y = rand.nextUScalar1() * H;
SkScalar w = rand.nextUScalar1() * (W >> 2);
@@ -65,7 +65,7 @@
, SW - SkIntToScalar(2), SH - SkIntToScalar(2)
));
- SkLCGRandom rand;
+ SkRandom rand;
for (int i = 0; i < N; i++) {
SkRect r;
rnd_rect(&r, rand);
diff --git a/gm/strokes.cpp b/gm/strokes.cpp
index 8174169..2a92c03 100644
--- a/gm/strokes.cpp
+++ b/gm/strokes.cpp
@@ -18,7 +18,7 @@
static const SkScalar SW = SkIntToScalar(W);
static const SkScalar SH = SkIntToScalar(H);
-static void rnd_rect(SkRect* r, SkPaint* paint, SkLCGRandom& rand) {
+static void rnd_rect(SkRect* r, SkPaint* paint, SkRandom& rand) {
SkScalar x = rand.nextUScalar1() * W;
SkScalar y = rand.nextUScalar1() * H;
SkScalar w = rand.nextUScalar1() * (W >> 2);
@@ -65,7 +65,7 @@
, SW - SkIntToScalar(2), SH - SkIntToScalar(2)
));
- SkLCGRandom rand;
+ SkRandom rand;
for (int i = 0; i < N; i++) {
SkRect r;
rnd_rect(&r, &paint, rand);
@@ -85,7 +85,7 @@
SkPath fPath;
public:
Strokes2GM() {
- SkLCGRandom rand;
+ SkRandom rand;
fPath.moveTo(0, 0);
for (int i = 0; i < 13; i++) {
SkScalar x = rand.nextUScalar1() * (W >> 1);
@@ -129,7 +129,7 @@
SW - SkIntToScalar(2),
SH - SkIntToScalar(2)));
- SkLCGRandom rand;
+ SkRandom rand;
for (int i = 0; i < N/2; i++) {
SkRect r;
rnd_rect(&r, &paint, rand);
diff --git a/include/utils/SkRandom.h b/include/utils/SkRandom.h
index d083fc6..aee2d7a 100644
--- a/include/utils/SkRandom.h
+++ b/include/utils/SkRandom.h
@@ -10,145 +10,6 @@
#include "SkScalar.h"
-/** \class SkLCGRandom
-
- Utility class that implements pseudo random 32bit numbers using a fast
- linear equation. Unlike rand(), this class holds its own seed (initially
- set to 0), so that multiple instances can be used with no side-effects.
-*/
-class SkLCGRandom {
-public:
- SkLCGRandom() : fSeed(0) {}
- SkLCGRandom(uint32_t seed) : fSeed(seed) {}
-
- /** Return the next pseudo random number as an unsigned 32bit value.
- */
- uint32_t nextU() { uint32_t r = fSeed * kMul + kAdd; fSeed = r; return r; }
-
- /** Return the next pseudo random number as a signed 32bit value.
- */
- int32_t nextS() { return (int32_t)this->nextU(); }
-
- /** Return the next pseudo random number as an unsigned 16bit value.
- */
- U16CPU nextU16() { return this->nextU() >> 16; }
-
- /** Return the next pseudo random number as a signed 16bit value.
- */
- S16CPU nextS16() { return this->nextS() >> 16; }
-
- /**
- * Returns value [0...1) as a float
- */
- float nextF() {
- // const is 1 / (2^32 - 1)
- return (float)(this->nextU() * 2.32830644e-10);
- }
-
- /**
- * Returns value [min...max) as a float
- */
- float nextRangeF(float min, float max) {
- return min + this->nextF() * (max - min);
- }
-
- /** Return the next pseudo random number, as an unsigned value of
- at most bitCount bits.
- @param bitCount The maximum number of bits to be returned
- */
- uint32_t nextBits(unsigned bitCount) {
- SkASSERT(bitCount > 0 && bitCount <= 32);
- return this->nextU() >> (32 - bitCount);
- }
-
- /** Return the next pseudo random unsigned number, mapped to lie within
- [min, max] inclusive.
- */
- uint32_t nextRangeU(uint32_t min, uint32_t max) {
- SkASSERT(min <= max);
- uint32_t range = max - min + 1;
- if (0 == range) {
- return this->nextU();
- } else {
- return min + this->nextU() % range;
- }
- }
-
- /** Return the next pseudo random unsigned number, mapped to lie within
- [0, count).
- */
- uint32_t nextULessThan(uint32_t count) {
- SkASSERT(count > 0);
- return this->nextRangeU(0, count - 1);
- }
-
- /** Return the next pseudo random number expressed as an unsigned SkFixed
- in the range [0..SK_Fixed1).
- */
- SkFixed nextUFixed1() { return this->nextU() >> 16; }
-
- /** Return the next pseudo random number expressed as a signed SkFixed
- in the range (-SK_Fixed1..SK_Fixed1).
- */
- SkFixed nextSFixed1() { return this->nextS() >> 15; }
-
- /** Return the next pseudo random number expressed as a SkScalar
- in the range [0..SK_Scalar1).
- */
- SkScalar nextUScalar1() { return SkFixedToScalar(this->nextUFixed1()); }
-
- /** Return the next pseudo random number expressed as a SkScalar
- in the range [min..max).
- */
- SkScalar nextRangeScalar(SkScalar min, SkScalar max) {
- return this->nextUScalar1() * (max - min) + min;
- }
-
- /** Return the next pseudo random number expressed as a SkScalar
- in the range (-SK_Scalar1..SK_Scalar1).
- */
- SkScalar nextSScalar1() { return SkFixedToScalar(this->nextSFixed1()); }
-
- /** Return the next pseudo random number as a bool.
- */
- bool nextBool() { return this->nextU() >= 0x80000000; }
-
- /** A biased version of nextBool().
- */
- bool nextBiasedBool(SkScalar fractionTrue) {
- SkASSERT(fractionTrue >= 0 && fractionTrue <= SK_Scalar1);
- return this->nextUScalar1() <= fractionTrue;
- }
-
- /**
- * Return the next pseudo random number as a signed 64bit value.
- */
- int64_t next64() {
- int64_t hi = this->nextS();
- return (hi << 32) | this->nextU();
- }
-
- /**
- * Return the current seed. This allows the caller to later reset to the
- * same seed (using setSeed) so it can generate the same sequence.
- */
- int32_t getSeed() const { return fSeed; }
-
- /** Set the seed of the random object. The seed is initialized to 0 when the
- object is first created, and is updated each time the next pseudo random
- number is requested.
- */
- void setSeed(int32_t seed) { fSeed = (uint32_t)seed; }
-
-private:
- // See "Numerical Recipes in C", 1992 page 284 for these constants
- enum {
- kMul = 1664525,
- kAdd = 1013904223
- };
- uint32_t fSeed;
-};
-
/** \class SkRandom
Utility class that implements pseudo random 32bit numbers using Marsaglia's
diff --git a/src/effects/SkDiscretePathEffect.cpp b/src/effects/SkDiscretePathEffect.cpp
index 8aa0e22..6765b29 100644
--- a/src/effects/SkDiscretePathEffect.cpp
+++ b/src/effects/SkDiscretePathEffect.cpp
@@ -11,7 +11,6 @@
#include "SkReadBuffer.h"
#include "SkWriteBuffer.h"
#include "SkPathMeasure.h"
-#include "SkRandom.h"
static void Perterb(SkPoint* p, const SkVector& tangent, SkScalar scale) {
SkVector normal = tangent;
@@ -27,6 +26,48 @@
{
}
+/** \class LCGRandom
+
+ Utility class that implements pseudo random 32bit numbers using a fast
+ linear equation. Unlike rand(), this class holds its own seed (initially
+ set to 0), so that multiple instances can be used with no side-effects.
+
+ Copied from the original implementation of SkRandom. Only contains the
+ methods used by SkDiscretePathEffect::filterPath, with methods that were
+ not called directly moved to private.
+*/
+
+class LCGRandom {
+public:
+ LCGRandom(uint32_t seed) : fSeed(seed) {}
+
+ /** Return the next pseudo random number expressed as a SkScalar
+ in the range (-SK_Scalar1..SK_Scalar1).
+ */
+ SkScalar nextSScalar1() { return SkFixedToScalar(this->nextSFixed1()); }
+
+private:
+ /** Return the next pseudo random number as an unsigned 32bit value.
+ */
+ uint32_t nextU() { uint32_t r = fSeed * kMul + kAdd; fSeed = r; return r; }
+
+ /** Return the next pseudo random number as a signed 32bit value.
+ */
+ int32_t nextS() { return (int32_t)this->nextU(); }
+
+ /** Return the next pseudo random number expressed as a signed SkFixed
+ in the range (-SK_Fixed1..SK_Fixed1).
+ */
+ SkFixed nextSFixed1() { return this->nextS() >> 15; }
+
+ // See "Numerical Recipes in C", 1992 page 284 for these constants
+ enum {
+ kMul = 1664525,
+ kAdd = 1013904223
+ };
+ uint32_t fSeed;
+};
+
bool SkDiscretePathEffect::filterPath(SkPath* dst, const SkPath& src,
SkStrokeRec* rec, const SkRect*) const {
bool doFill = rec->isFillStyle();
@@ -36,10 +77,10 @@
/* Caller may supply their own seed assist, which by default is 0 */
uint32_t seed = fSeedAssist ^ SkScalarRoundToInt(meas.getLength());
- SkLCGRandom rand(seed ^ ((seed << 16) | (seed >> 16)));
- SkScalar scale = fPerterb;
- SkPoint p;
- SkVector v;
+ LCGRandom rand(seed ^ ((seed << 16) | (seed >> 16)));
+ SkScalar scale = fPerterb;
+ SkPoint p;
+ SkVector v;
do {
SkScalar length = meas.getLength();
diff --git a/tests/StrokerTest.cpp b/tests/StrokerTest.cpp
index 03e0624..b588cc6 100755
--- a/tests/StrokerTest.cpp
+++ b/tests/StrokerTest.cpp
@@ -116,18 +116,18 @@
cubicPairSetTest(tests, tests_count);
}
-static SkScalar unbounded(SkLCGRandom& r) {
+static SkScalar unbounded(SkRandom& r) {
uint32_t val = r.nextU();
return SkBits2Float(val);
}
-static SkScalar unboundedPos(SkLCGRandom& r) {
+static SkScalar unboundedPos(SkRandom& r) {
uint32_t val = r.nextU() & 0x7fffffff;
return SkBits2Float(val);
}
DEF_TEST(QuadStrokerUnbounded, reporter) {
- SkLCGRandom r;
+ SkRandom r;
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
#if defined(SK_DEBUG) && QUAD_STROKE_APPROXIMATION
@@ -165,7 +165,7 @@
}
DEF_TEST(CubicStrokerUnbounded, reporter) {
- SkLCGRandom r;
+ SkRandom r;
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
#if defined(SK_DEBUG) && QUAD_STROKE_APPROXIMATION
@@ -206,7 +206,7 @@
}
DEF_TEST(QuadStrokerConstrained, reporter) {
- SkLCGRandom r;
+ SkRandom r;
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
#if defined(SK_DEBUG) && QUAD_STROKE_APPROXIMATION
@@ -257,7 +257,7 @@
}
DEF_TEST(CubicStrokerConstrained, reporter) {
- SkLCGRandom r;
+ SkRandom r;
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
#if defined(SK_DEBUG) && QUAD_STROKE_APPROXIMATION
@@ -316,7 +316,7 @@
}
DEF_TEST(QuadStrokerRange, reporter) {
- SkLCGRandom r;
+ SkRandom r;
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
#if defined(SK_DEBUG) && QUAD_STROKE_APPROXIMATION
@@ -361,7 +361,7 @@
}
DEF_TEST(CubicStrokerRange, reporter) {
- SkLCGRandom r;
+ SkRandom r;
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
#if defined(SK_DEBUG) && QUAD_STROKE_APPROXIMATION