diff options
| -rw-r--r-- | src/gpu/ops/GrAADistanceFieldPathRenderer.cpp | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/src/gpu/ops/GrAADistanceFieldPathRenderer.cpp b/src/gpu/ops/GrAADistanceFieldPathRenderer.cpp index 0bc356db81..c5842c0913 100644 --- a/src/gpu/ops/GrAADistanceFieldPathRenderer.cpp +++ b/src/gpu/ops/GrAADistanceFieldPathRenderer.cpp @@ -39,10 +39,11 @@ static int g_NumFreedShapes = 0; #endif // mip levels +static const SkScalar kIdealMinMIP = 12; static const SkScalar kMaxMIP = 162; static const SkScalar kMaxDim = 73; -static const SkScalar kMinSize = 4; +static const SkScalar kMinSize = SK_ScalarHalf; static const SkScalar kMaxSize = 2*kMaxMIP; // Callback to clear out internal path cache when eviction occurs @@ -252,16 +253,31 @@ private: // In the majority of cases this will yield a crisper rendering. SkScalar mipScale = 1.0f; // Our mipscale is the maxScale clamped to the next highest power of 2 - if (maxScale < SK_ScalarHalf) { + if (maxScale <= SK_ScalarHalf) { SkScalar log = SkScalarFloorToScalar(SkScalarLog2(SkScalarInvert(maxScale))); mipScale = SkScalarPow(2, -log); } else if (maxScale > SK_Scalar1) { SkScalar log = SkScalarCeilToScalar(SkScalarLog2(maxScale)); mipScale = SkScalarPow(2, log); } - - SkScalar mipSize = mipScale*maxDim; - SkASSERT(maxScale * maxDim <= mipSize); + SkASSERT(maxScale <= mipScale); + + SkScalar mipSize = mipScale*SkScalarAbs(maxDim); + // For sizes less than kIdealMinMIP we want to use as large a distance field as we can + // so we can preserve as much detail as possible. However, we can't scale down more + // than a 1/4 of the size without artifacts. So the idea is that we pick the mipsize + // just bigger than the ideal, and then scale down until we are no more than 4x the + // original mipsize. + if (mipSize < kIdealMinMIP) { + SkScalar newMipSize = mipSize; + do { + newMipSize *= 2; + } while (newMipSize < kIdealMinMIP); + while (newMipSize > 4*mipSize) { + newMipSize *= 0.25f; + } + mipSize = newMipSize; + } SkScalar desiredDimension = SkTMin(mipSize, kMaxMIP); // check to see if path is cached @@ -340,6 +356,8 @@ private: SkASSERT(devPathBounds.fLeft == 0); SkASSERT(devPathBounds.fTop == 0); + SkASSERT(devPathBounds.width() > 0); + SkASSERT(devPathBounds.height() > 0); // setup signed distance field storage SkIRect dfBounds = devPathBounds.makeOutset(SK_DistanceFieldPad, SK_DistanceFieldPad); |