Add m-esr52 at 52.6.0

1 files changed, 427 insertions, 0 deletions

diff --git a/layout/base/DashedCornerFinder.cpp b/layout/base/DashedCornerFinder.cpp
new file mode 100644
index 000000000..cb58eb51e
--- /dev/null
+++ b/layout/base/DashedCornerFinder.cpp
@@ -0,0 +1,427 @@
+/* -*- Mode: C++; tab-width: 2; 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 "DashedCornerFinder.h"
+
+#include "mozilla/Move.h"
+#include "BorderCache.h"
+#include "BorderConsts.h"
+
+namespace mozilla {
+
+using namespace gfx;
+
+struct BestDashLength
+{
+  typedef mozilla::gfx::Float Float;
+
+  Float dashLength;
+  size_t count;
+
+  BestDashLength()
+   : dashLength(0.0f), count(0)
+  {}
+
+  BestDashLength(Float aDashLength, size_t aCount)
+   : dashLength(aDashLength), count(aCount)
+  {}
+};
+
+static const size_t DashedCornerCacheSize = 256;
+nsDataHashtable<FourFloatsHashKey, BestDashLength> DashedCornerCache;
+
+DashedCornerFinder::DashedCornerFinder(const Bezier& aOuterBezier,
+                                       const Bezier& aInnerBezier,
+                                       Float aBorderWidthH, Float aBorderWidthV,
+                                       const Size& aCornerDim)
+ : mOuterBezier(aOuterBezier),
+   mInnerBezier(aInnerBezier),
+   mLastOuterP(aOuterBezier.mPoints[0]), mLastInnerP(aInnerBezier.mPoints[0]),
+   mLastOuterT(0.0f), mLastInnerT(0.0f),
+   mBestDashLength(DOT_LENGTH * DASH_LENGTH),
+   mHasZeroBorderWidth(false), mHasMore(true),
+   mMaxCount(aCornerDim.width + aCornerDim.height),
+   mType(OTHER),
+   mI(0), mCount(0)
+{
+  NS_ASSERTION(aBorderWidthH > 0.0f || aBorderWidthV > 0.0f,
+               "At least one side should have non-zero width.");
+
+  DetermineType(aBorderWidthH, aBorderWidthV);
+
+  Reset();
+}
+
+void
+DashedCornerFinder::DetermineType(Float aBorderWidthH, Float aBorderWidthV)
+{
+  if (aBorderWidthH < aBorderWidthV) {
+    // Always draw from wider side to thinner side.
+    Swap(mInnerBezier.mPoints[0], mInnerBezier.mPoints[3]);
+    Swap(mInnerBezier.mPoints[1], mInnerBezier.mPoints[2]);
+    Swap(mOuterBezier.mPoints[0], mOuterBezier.mPoints[3]);
+    Swap(mOuterBezier.mPoints[1], mOuterBezier.mPoints[2]);
+    mLastOuterP = mOuterBezier.mPoints[0];
+    mLastInnerP = mInnerBezier.mPoints[0];
+  }
+
+  // See the comment at mType declaration for each condition.
+
+  Float borderRadiusA = fabs(mOuterBezier.mPoints[0].x -
+                             mOuterBezier.mPoints[3].x);
+  Float borderRadiusB = fabs(mOuterBezier.mPoints[0].y -
+                             mOuterBezier.mPoints[3].y);
+  if (aBorderWidthH == aBorderWidthV &&
+      borderRadiusA == borderRadiusB &&
+      borderRadiusA > aBorderWidthH * 2.0f) {
+    Float curveHeight = borderRadiusA - aBorderWidthH / 2.0;
+
+    mType = PERFECT;
+    Float borderLength = M_PI * curveHeight / 2.0f;
+
+    Float dashWidth = aBorderWidthH * DOT_LENGTH * DASH_LENGTH;
+    size_t count = ceil(borderLength / dashWidth);
+    if (count % 2) {
+      count++;
+    }
+    mCount = count / 2 + 1;
+    mBestDashLength = borderLength / (aBorderWidthH * count);
+  }
+
+  Float minBorderWidth = std::min(aBorderWidthH, aBorderWidthV);
+  if (minBorderWidth == 0.0f) {
+    mHasZeroBorderWidth = true;
+  }
+
+  if (mType == OTHER && !mHasZeroBorderWidth) {
+    Float minBorderRadius = std::min(borderRadiusA, borderRadiusB);
+    Float maxBorderRadius = std::max(borderRadiusA, borderRadiusB);
+    Float maxBorderWidth = std::max(aBorderWidthH, aBorderWidthV);
+
+    FindBestDashLength(minBorderWidth, maxBorderWidth,
+                       minBorderRadius, maxBorderRadius);
+  }
+}
+
+bool
+DashedCornerFinder::HasMore(void) const
+{
+  if (mHasZeroBorderWidth) {
+    return mI < mMaxCount && mHasMore;
+  }
+
+  return mI < mCount;
+}
+
+DashedCornerFinder::Result
+DashedCornerFinder::Next(void)
+{
+  Float lastOuterT, lastInnerT, outerT, innerT;
+
+  if (mI == 0) {
+    lastOuterT = 0.0f;
+    lastInnerT = 0.0f;
+  } else {
+    if (mType == PERFECT) {
+      lastOuterT = lastInnerT = (mI * 2.0f - 0.5f) / ((mCount - 1) * 2.0f);
+    } else {
+      Float last2OuterT = mLastOuterT;
+      Float last2InnerT = mLastInnerT;
+
+      (void)FindNext(mBestDashLength);
+
+      //
+      //          mLastOuterT   lastOuterT
+      //                    |   |
+      //                    v   v
+      //            +---+---+---+---+ <- last2OuterT
+      //            |   |###|###|   |
+      //            |   |###|###|   |
+      //            |   |###|###|   |
+      //            +---+---+---+---+ <- last2InnerT
+      //                    ^   ^
+      //                    |   |
+      //          mLastInnerT   lastInnerT
+      lastOuterT = (mLastOuterT + last2OuterT) / 2.0f;
+      lastInnerT = (mLastInnerT + last2InnerT) / 2.0f;
+    }
+  }
+
+  if ((!mHasZeroBorderWidth && mI == mCount - 1) ||
+      (mHasZeroBorderWidth && !mHasMore)) {
+    outerT = 1.0f;
+    innerT = 1.0f;
+  } else {
+    if (mType == PERFECT) {
+      outerT = innerT = (mI * 2.0f + 0.5f) / ((mCount - 1) * 2.0f);
+    } else {
+      Float last2OuterT = mLastOuterT;
+      Float last2InnerT = mLastInnerT;
+
+      (void)FindNext(mBestDashLength);
+
+      //
+      //               outerT   last2OuterT
+      //                    |   |
+      //                    v   v
+      // mLastOuterT -> +---+---+---+---+
+      //                |   |###|###|   |
+      //                |   |###|###|   |
+      //                |   |###|###|   |
+      // mLastInnerT -> +---+---+---+---+
+      //                    ^   ^
+      //                    |   |
+      //               innerT   last2InnerT
+      outerT = (mLastOuterT + last2OuterT) / 2.0f;
+      innerT = (mLastInnerT + last2InnerT) / 2.0f;
+    }
+  }
+
+  mI++;
+
+  Bezier outerSectionBezier;
+  Bezier innerSectionBezier;
+  GetSubBezier(&outerSectionBezier, mOuterBezier, lastOuterT, outerT);
+  GetSubBezier(&innerSectionBezier, mInnerBezier, lastInnerT, innerT);
+  return DashedCornerFinder::Result(outerSectionBezier, innerSectionBezier);
+}
+
+void
+DashedCornerFinder::Reset(void)
+{
+  mLastOuterP = mOuterBezier.mPoints[0];
+  mLastInnerP = mInnerBezier.mPoints[0];
+  mLastOuterT = 0.0f;
+  mLastInnerT = 0.0f;
+  mHasMore = true;
+}
+
+Float
+DashedCornerFinder::FindNext(Float dashLength)
+{
+  Float upper = 1.0f;
+  Float lower = mLastOuterT;
+
+  Point OuterP, InnerP;
+  // Start from upper bound to check if this is the last segment.
+  Float outerT = upper;
+  Float innerT;
+  Float W = 0.0f;
+  Float L = 0.0f;
+
+  const Float LENGTH_MARGIN = 0.1f;
+  for (size_t i = 0; i < MAX_LOOP; i++) {
+    OuterP = GetBezierPoint(mOuterBezier, outerT);
+    InnerP = FindBezierNearestPoint(mInnerBezier, OuterP, outerT, &innerT);
+
+    // Calculate approximate dash length.
+    //
+    //   W = (W1 + W2) / 2
+    //   L = (OuterL + InnerL) / 2
+    //   dashLength = L / W
+    //
+    //              ____----+----____
+    // OuterP ___---        |         ---___    mLastOuterP
+    //    +---              |               ---+
+    //    |                  |                 |
+    //    |                  |                 |
+    //     |               W |              W1 |
+    //     |                  |                |
+    //  W2 |                  |                |
+    //     |                  |    ______------+
+    //     |              ____+----             mLastInnerP
+    //      |       ___---
+    //      |  __---
+    //      +--
+    //    InnerP
+    //                     OuterL
+    //              ____---------____
+    // OuterP ___---                  ---___    mLastOuterP
+    //    +---                              ---+
+    //    |                  L                 |
+    //    |            ___----------______     |
+    //     |      __---                   -----+
+    //     |  __--                             |
+    //     +--                                 |
+    //     |                InnerL ______------+
+    //     |              ____-----             mLastInnerP
+    //      |       ___---
+    //      |  __---
+    //      +--
+    //    InnerP
+    Float W1 = (mLastOuterP - mLastInnerP).Length();
+    Float W2 = (OuterP - InnerP).Length();
+    Float OuterL = GetBezierLength(mOuterBezier, mLastOuterT, outerT);
+    Float InnerL = GetBezierLength(mInnerBezier, mLastInnerT, innerT);
+    W = (W1 + W2) / 2.0f;
+    L = (OuterL + InnerL) / 2.0f;
+    if (L > W * dashLength + LENGTH_MARGIN) {
+      if (i > 0) {
+        upper = outerT;
+      }
+    } else if (L < W * dashLength - LENGTH_MARGIN) {
+      if (i == 0) {
+        // This is the last segment with shorter dashLength.
+        mHasMore = false;
+        break;
+      }
+      lower = outerT;
+    } else {
+      break;
+    }
+
+    outerT = (upper + lower) / 2.0f;
+  }
+
+  mLastOuterP = OuterP;
+  mLastInnerP = InnerP;
+  mLastOuterT = outerT;
+  mLastInnerT = innerT;
+
+  if (W == 0.0f) {
+    return 1.0f;
+  }
+
+  return L / W;
+}
+
+void
+DashedCornerFinder::FindBestDashLength(Float aMinBorderWidth,
+                                       Float aMaxBorderWidth,
+                                       Float aMinBorderRadius,
+                                       Float aMaxBorderRadius)
+{
+  // If dashLength is not calculateable, find it with binary search,
+  // such that there exists i that OuterP_i == OuterP_n and
+  // InnerP_i == InnerP_n with given dashLength.
+
+  FourFloats key(aMinBorderWidth, aMaxBorderWidth,
+                 aMinBorderRadius, aMaxBorderRadius);
+  BestDashLength best;
+  if (DashedCornerCache.Get(key, &best)) {
+    mCount = best.count;
+    mBestDashLength = best.dashLength;
+    return;
+  }
+
+  Float lower = 1.0f;
+  Float upper = DOT_LENGTH * DASH_LENGTH;
+  Float dashLength = upper;
+  size_t targetCount = 0;
+
+  const Float LENGTH_MARGIN = 0.1f;
+  for (size_t j = 0; j < MAX_LOOP; j++) {
+    size_t count;
+    Float actualDashLength;
+    if (!GetCountAndLastDashLength(dashLength, &count, &actualDashLength)) {
+      if (j == 0) {
+        mCount = mMaxCount;
+        break;
+      }
+    }
+
+    if (j == 0) {
+      if (count == 1) {
+        // If only 1 segment fits, fill entire region
+        //
+        //   count = 1
+        //   mCount = 1
+        //   |   1   |
+        //   +---+---+
+        //   |###|###|
+        //   |###|###|
+        //   |###|###|
+        //   +---+---+
+        //       1
+        mCount = 1;
+        break;
+      }
+
+      // targetCount should be 2n.
+      //
+      //   targetCount = 2
+      //   mCount = 2
+      //   |   1   |   2   |
+      //   +---+---+---+---+
+      //   |###|   |   |###|
+      //   |###|   |   |###|
+      //   |###|   |   |###|
+      //   +---+---+---+---+
+      //     1           2
+      //
+      //   targetCount = 6
+      //   mCount = 4
+      //   |   1   |   2   |   3   |   4   |   5   |   6   |
+      //   +---+---+---+---+---+---+---+---+---+---+---+---+
+      //   |###|   |   |###|###|   |   |###|###|   |   |###|
+      //   |###|   |   |###|###|   |   |###|###|   |   |###|
+      //   |###|   |   |###|###|   |   |###|###|   |   |###|
+      //   +---+---+---+---+---+---+---+---+---+---+---+---+
+      //     1             2               3             4
+      if (count % 2) {
+        targetCount = count + 1;
+      } else {
+        targetCount = count;
+      }
+
+      mCount = targetCount / 2 + 1;
+    }
+
+    if (count == targetCount) {
+      mBestDashLength = dashLength;
+
+      // actualDashLength won't be greater than dashLength.
+      if (actualDashLength > dashLength - LENGTH_MARGIN) {
+        break;
+      }
+
+      // We started from upper bound, no need to update range when j == 0.
+      if (j > 0) {
+        upper = dashLength;
+      }
+    } else {
+      // |j == 0 && count != targetCount| means that |targetCount = count + 1|,
+      // and we started from upper bound, no need to update range when j == 0.
+      if (j > 0) {
+        if (count > targetCount) {
+          lower = dashLength;
+        } else {
+          upper = dashLength;
+        }
+      }
+    }
+
+    dashLength = (upper + lower) / 2.0f;
+  }
+
+  if (DashedCornerCache.Count() > DashedCornerCacheSize) {
+    DashedCornerCache.Clear();
+  }
+  DashedCornerCache.Put(key, BestDashLength(mBestDashLength, mCount));
+}
+
+bool
+DashedCornerFinder::GetCountAndLastDashLength(Float aDashLength,
+                                              size_t* aCount,
+                                              Float* aActualDashLength)
+{
+  // Return the number of segments and the last segment's dashLength for
+  // the given dashLength.
+
+  Reset();
+
+  for (size_t i = 0; i < mMaxCount; i++) {
+    Float actualDashLength = FindNext(aDashLength);
+    if (mLastOuterT >= 1.0f) {
+      *aCount = i + 1;
+      *aActualDashLength = actualDashLength;
+      return true;
+    }
+  }
+
+  return false;
+}
+
+} // namespace mozilla