The Tor Browser: gfx/2d/SVGTurbulenceRenderer-inl.h@97036ab72558 (annotated)

gfx/2d/SVGTurbulenceRenderer-inl.h@97036ab72558 (annotated)

gfx/2d/SVGTurbulenceRenderer-inl.h

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "2D.h"
 #include "Filters.h"
 #include "SIMD.h"
 namespace mozilla {
 namespace gfx {
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 class SVGTurbulenceRenderer
 {
 public:
   SVGTurbulenceRenderer(const Size &aBaseFrequency, int32_t aSeed,
                         int aNumOctaves, const Rect &aTileRect);
   TemporaryRef<DataSourceSurface> Render(const IntSize &aSize, const Point &aOffset) const;
 private:
   /* The turbulence calculation code is an adapted version of what
      appears in the SVG 1.1 specification:
          http://www.w3.org/TR/SVG11/filters.html#feTurbulence
   */
   struct StitchInfo {
     int32_t width;     // How much to subtract to wrap for stitching.
     int32_t height;
     int32_t wrapX;     // Minimum value to wrap.
     int32_t wrapY;
   };
   const static int sBSize = 0x100;
   const static int sBM = 0xff;
   void InitFromSeed(int32_t aSeed);
   void AdjustBaseFrequencyForStitch(const Rect &aTileRect);
   IntPoint AdjustForStitch(IntPoint aLatticePoint, const StitchInfo& aStitchInfo) const;
   StitchInfo CreateStitchInfo(const Rect &aTileRect) const;
   f32x4_t Noise2(Point aVec, const StitchInfo& aStitchInfo) const;
   i32x4_t Turbulence(const Point &aPoint) const;
   Point EquivalentNonNegativeOffset(const Point &aOffset) const;
   Size mBaseFrequency;
   int32_t mNumOctaves;
   StitchInfo mStitchInfo;
   bool mStitchable;
   TurbulenceType mType;
   uint8_t mLatticeSelector[sBSize];
   f32x4_t mGradient[sBSize][2];
 };
 namespace {
 struct RandomNumberSource
 {
   RandomNumberSource(int32_t aSeed) : mLast(SetupSeed(aSeed)) {}
   int32_t Next() { mLast = Random(mLast); return mLast; }
 private:
   static const int32_t RAND_M = 2147483647; /* 2**31 - 1 */
   static const int32_t RAND_A = 16807;      /* 7**5; primitive root of m */
   static const int32_t RAND_Q = 127773;     /* m / a */
   static const int32_t RAND_R = 2836;       /* m % a */
   /* Produces results in the range [1, 2**31 - 2].
      Algorithm is: r = (a * r) mod m
      where a = 16807 and m = 2**31 - 1 = 2147483647
      See [Park & Miller], CACM vol. 31 no. 10 p. 1195, Oct. 1988
      To test: the algorithm should produce the result 1043618065
      as the 10,000th generated number if the original seed is 1.
   */
   static int32_t
   SetupSeed(int32_t aSeed) {
     if (aSeed <= 0)
       aSeed = -(aSeed % (RAND_M - 1)) + 1;
     if (aSeed > RAND_M - 1)
       aSeed = RAND_M - 1;
     return aSeed;
   }
   static int32_t
   Random(int32_t aSeed)
   {
     int32_t result = RAND_A * (aSeed % RAND_Q) - RAND_R * (aSeed / RAND_Q);
     if (result <= 0)
       result += RAND_M;
     return result;
   }
   int32_t mLast;
 };
 } // unnamed namespace
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::SVGTurbulenceRenderer(const Size &aBaseFrequency, int32_t aSeed,
                                                             int aNumOctaves, const Rect &aTileRect)
  : mBaseFrequency(aBaseFrequency)
  , mNumOctaves(aNumOctaves)
 {
   InitFromSeed(aSeed);
   if (Stitch) {
     AdjustBaseFrequencyForStitch(aTileRect);
     mStitchInfo = CreateStitchInfo(aTileRect);
   }
 }
 template<typename T>
 static void
 Swap(T& a, T& b) {
   T c = a;
   a = b;
   b = c;
 }
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 void
 SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::InitFromSeed(int32_t aSeed)
 {
   RandomNumberSource rand(aSeed);
   float gradient[4][sBSize][2];
   for (int32_t k = 0; k < 4; k++) {
     for (int32_t i = 0; i < sBSize; i++) {
       float a = float((rand.Next() % (sBSize + sBSize)) - sBSize) / sBSize;
       float b = float((rand.Next() % (sBSize + sBSize)) - sBSize) / sBSize;
       float s = sqrt(a * a + b * b);
       gradient[k][i][0] = a / s;
       gradient[k][i][1] = b / s;
     }
   }
   for (int32_t i = 0; i < sBSize; i++) {
     mLatticeSelector[i] = i;
   }
   for (int32_t i1 = sBSize - 1; i1 > 0; i1--) {
     int32_t i2 = rand.Next() % sBSize;
     Swap(mLatticeSelector[i1], mLatticeSelector[i2]);
   }
   for (int32_t i = 0; i < sBSize; i++) {
     // Contrary to the code in the spec, we build the first lattice selector
     // lookup into mGradient so that we don't need to do it again for every
     // pixel.
     // We also change the order of the gradient indexing so that we can process
     // all four color channels at the same time.
     uint8_t j = mLatticeSelector[i];
     mGradient[i][0] = simd::FromF32<f32x4_t>(gradient[2][j][0], gradient[1][j][0],
                                              gradient[0][j][0], gradient[3][j][0]);
     mGradient[i][1] = simd::FromF32<f32x4_t>(gradient[2][j][1], gradient[1][j][1],
                                              gradient[0][j][1], gradient[3][j][1]);
   }
 }
 // Adjust aFreq such that aLength * AdjustForLength(aFreq, aLength) is integer
 // and as close to aLength * aFreq as possible.
 static inline float
 AdjustForLength(float aFreq, float aLength)
 {
   float lowFreq = floor(aLength * aFreq) / aLength;
   float hiFreq = ceil(aLength * aFreq) / aLength;
   if (aFreq / lowFreq < hiFreq / aFreq) {
     return lowFreq;
   }
   return hiFreq;
 }
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 void
 SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::AdjustBaseFrequencyForStitch(const Rect &aTileRect)
 {
   mBaseFrequency = Size(AdjustForLength(mBaseFrequency.width, aTileRect.width),
                         AdjustForLength(mBaseFrequency.height, aTileRect.height));
 }
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 typename SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::StitchInfo
 SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::CreateStitchInfo(const Rect &aTileRect) const
 {
   StitchInfo stitch;
   stitch.width = int32_t(floorf(aTileRect.width * mBaseFrequency.width + 0.5f));
   stitch.height = int32_t(floorf(aTileRect.height * mBaseFrequency.height + 0.5f));
   stitch.wrapX = int32_t(aTileRect.x * mBaseFrequency.width) + stitch.width;
   stitch.wrapY = int32_t(aTileRect.y * mBaseFrequency.height) + stitch.height;
   return stitch;
 }
 static MOZ_ALWAYS_INLINE Float
 SCurve(Float t)
 {
   return t * t * (3 - 2 * t);
 }
 static MOZ_ALWAYS_INLINE Point
 SCurve(Point t)
 {
   return Point(SCurve(t.x), SCurve(t.y));
 }
 template<typename f32x4_t>
 static MOZ_ALWAYS_INLINE f32x4_t
 BiMix(const f32x4_t& aa, const f32x4_t& ab,
       const f32x4_t& ba, const f32x4_t& bb, Point s)
 {
   return simd::MixF32(simd::MixF32(aa, ab, s.x),
                       simd::MixF32(ba, bb, s.x), s.y);
 }
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 IntPoint
 SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::AdjustForStitch(IntPoint aLatticePoint,
                                                       const StitchInfo& aStitchInfo) const
 {
   if (Stitch) {
     if (aLatticePoint.x >= aStitchInfo.wrapX) {
       aLatticePoint.x -= aStitchInfo.width;
     }
     if (aLatticePoint.y >= aStitchInfo.wrapY) {
       aLatticePoint.y -= aStitchInfo.height;
     }
   }
   return aLatticePoint;
 }
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 f32x4_t
 SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::Noise2(Point aVec, const StitchInfo& aStitchInfo) const
 {
   // aVec is guaranteed to be non-negative, so casting to int32_t always
   // rounds towards negative infinity.
   IntPoint topLeftLatticePoint(int32_t(aVec.x), int32_t(aVec.y));
   Point r = aVec - topLeftLatticePoint; // fractional offset
   IntPoint b0 = AdjustForStitch(topLeftLatticePoint, aStitchInfo);
   IntPoint b1 = AdjustForStitch(b0 + IntPoint(1, 1), aStitchInfo);
   uint8_t i = mLatticeSelector[b0.x & sBM];
   uint8_t j = mLatticeSelector[b1.x & sBM];
   const f32x4_t* qua = mGradient[(i + b0.y) & sBM];
   const f32x4_t* qub = mGradient[(i + b1.y) & sBM];
   const f32x4_t* qva = mGradient[(j + b0.y) & sBM];
   const f32x4_t* qvb = mGradient[(j + b1.y) & sBM];
   return BiMix(simd::WSumF32(qua[0], qua[1], r.x, r.y),
                simd::WSumF32(qva[0], qva[1], r.x - 1, r.y),
                simd::WSumF32(qub[0], qub[1], r.x, r.y - 1),
                simd::WSumF32(qvb[0], qvb[1], r.x - 1, r.y - 1),
                SCurve(r));
 }
 template<typename f32x4_t, typename i32x4_t, typename u8x16_t>
 static inline i32x4_t
 ColorToBGRA(f32x4_t aUnscaledUnpreFloat)
 {
   // Color is an unpremultiplied float vector where 1.0f means white. We will
   // convert it into an integer vector where 255 means white.
   f32x4_t alpha = simd::SplatF32<3>(aUnscaledUnpreFloat);
   f32x4_t scaledUnpreFloat = simd::MulF32(aUnscaledUnpreFloat, simd::FromF32<f32x4_t>(255));
   i32x4_t scaledUnpreInt = simd::F32ToI32(scaledUnpreFloat);
   // Multiply all channels with alpha.
   i32x4_t scaledPreInt = simd::F32ToI32(simd::MulF32(scaledUnpreFloat, alpha));
   // Use the premultiplied color channels and the unpremultiplied alpha channel.
   i32x4_t alphaMask = simd::From32<i32x4_t>(0, 0, 0, -1);
   return simd::Pick(alphaMask, scaledPreInt, scaledUnpreInt);
 }
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 i32x4_t
 SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::Turbulence(const Point &aPoint) const
 {
   StitchInfo stitchInfo = mStitchInfo;
   f32x4_t sum = simd::FromF32<f32x4_t>(0);
   Point vec(aPoint.x * mBaseFrequency.width, aPoint.y * mBaseFrequency.height);
   f32x4_t ratio = simd::FromF32<f32x4_t>(1);
   for (int octave = 0; octave < mNumOctaves; octave++) {
     f32x4_t thisOctave = Noise2(vec, stitchInfo);
     if (Type == TURBULENCE_TYPE_TURBULENCE) {
       thisOctave = simd::AbsF32(thisOctave);
     }
     sum = simd::AddF32(sum, simd::DivF32(thisOctave, ratio));
     vec = vec * 2;
     ratio = simd::MulF32(ratio, simd::FromF32<f32x4_t>(2));
     if (Stitch) {
       stitchInfo.width *= 2;
       stitchInfo.wrapX *= 2;
       stitchInfo.height *= 2;
       stitchInfo.wrapY *= 2;
     }
   }
   if (Type == TURBULENCE_TYPE_FRACTAL_NOISE) {
     sum = simd::DivF32(simd::AddF32(sum, simd::FromF32<f32x4_t>(1)), simd::FromF32<f32x4_t>(2));
   }
   return ColorToBGRA<f32x4_t,i32x4_t,u8x16_t>(sum);
 }
 static inline Float
 MakeNonNegative(Float aValue, Float aIncrementSize)
 {
   if (aValue >= 0) {
     return aValue;
   }
   return aValue + ceilf(-aValue / aIncrementSize) * aIncrementSize;
 }
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 Point
 SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::EquivalentNonNegativeOffset(const Point &aOffset) const
 {
   Size basePeriod = Stitch ? Size(mStitchInfo.width, mStitchInfo.height) :
                              Size(sBSize, sBSize);
   Size repeatingSize(basePeriod.width / mBaseFrequency.width,
                      basePeriod.height / mBaseFrequency.height);
   return Point(MakeNonNegative(aOffset.x, repeatingSize.width),
                MakeNonNegative(aOffset.y, repeatingSize.height));
 }
 template<TurbulenceType Type, bool Stitch, typename f32x4_t, typename i32x4_t, typename u8x16_t>
 TemporaryRef<DataSourceSurface>
 SVGTurbulenceRenderer<Type,Stitch,f32x4_t,i32x4_t,u8x16_t>::Render(const IntSize &aSize, const Point &aOffset) const
 {
   RefPtr<DataSourceSurface> target =
     Factory::CreateDataSourceSurface(aSize, SurfaceFormat::B8G8R8A8);
   if (!target) {
     return nullptr;
   }
   uint8_t* targetData = target->GetData();
   uint32_t stride = target->Stride();
   Point startOffset = EquivalentNonNegativeOffset(aOffset);
   for (int32_t y = 0; y < aSize.height; y++) {
     for (int32_t x = 0; x < aSize.width; x += 4) {
       int32_t targIndex = y * stride + x * 4;
       i32x4_t a = Turbulence(startOffset + Point(x, y));
       i32x4_t b = Turbulence(startOffset + Point(x + 1, y));
       i32x4_t c = Turbulence(startOffset + Point(x + 2, y));
       i32x4_t d = Turbulence(startOffset + Point(x + 3, y));
       u8x16_t result1234 = simd::PackAndSaturate32To8(a, b, c, d);
       simd::Store8(&targetData[targIndex], result1234);
     }
   }
   return target;
 }
 } // namespace gfx
 } // namespace mozilla

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gfx/2d/SVGTurbulenceRenderer-inl.h@97036ab72558 (annotated)

gfx/2d/SVGTurbulenceRenderer-inl.h