diff options
| -rw-r--r-- | gfx/skia/skia/src/core/SkGeometry.cpp | 32 | ||||
| -rw-r--r-- | gfx/skia/skia/src/core/SkRRect.cpp | 18 |
2 files changed, 38 insertions, 12 deletions
diff --git a/gfx/skia/skia/src/core/SkGeometry.cpp b/gfx/skia/skia/src/core/SkGeometry.cpp index 58b45140e..9af6eb774 100644 --- a/gfx/skia/skia/src/core/SkGeometry.cpp +++ b/gfx/skia/skia/src/core/SkGeometry.cpp @@ -62,6 +62,15 @@ static int valid_unit_divide(SkScalar numer, SkScalar denom, SkScalar* ratio) { return 1; } +// Just returns its argument, but makes it easy to set a break-point to know when +// SkFindUnitQuadRoots is going to return 0 (an error). +static int return_check_zero(int value) { + if (value == 0) { + return 0; + } + return value; +} + /** From Numerical Recipes in C. Q = -1/2 (B + sign(B) sqrt[B*B - 4*A*C]) @@ -72,22 +81,21 @@ int SkFindUnitQuadRoots(SkScalar A, SkScalar B, SkScalar C, SkScalar roots[2]) { SkASSERT(roots); if (A == 0) { - return valid_unit_divide(-C, B, roots); + return return_check_zero(valid_unit_divide(-C, B, roots)); } SkScalar* r = roots; - SkScalar R = B*B - 4*A*C; - if (R < 0 || !SkScalarIsFinite(R)) { // complex roots - // if R is infinite, it's possible that it may still produce - // useful results if the operation was repeated in doubles - // the flipside is determining if the more precise answer - // isn't useful because surrounding machinery (e.g., subtracting - // the axis offset from C) already discards the extra precision - // more investigation and unit tests required... - return 0; + // use doubles so we don't overflow temporarily trying to compute R + double dr = (double)B * B - 4 * (double)A * C; + if (dr < 0) { + return return_check_zero(0); + } + dr = sqrt(dr); + SkScalar R = SkDoubleToScalar(dr); + if (!SkScalarIsFinite(R)) { + return return_check_zero(0); } - R = SkScalarSqrt(R); SkScalar Q = (B < 0) ? -(B-R)/2 : -(B+R)/2; r += valid_unit_divide(Q, A, r); @@ -98,7 +106,7 @@ int SkFindUnitQuadRoots(SkScalar A, SkScalar B, SkScalar C, SkScalar roots[2]) { else if (roots[0] == roots[1]) // nearly-equal? r -= 1; // skip the double root } - return (int)(r - roots); + return return_check_zero((int)(r - roots)); } /////////////////////////////////////////////////////////////////////////////// diff --git a/gfx/skia/skia/src/core/SkRRect.cpp b/gfx/skia/skia/src/core/SkRRect.cpp index 1188989cd..f4308debe 100644 --- a/gfx/skia/skia/src/core/SkRRect.cpp +++ b/gfx/skia/skia/src/core/SkRRect.cpp @@ -161,6 +161,19 @@ void SkRRect::setRectRadii(const SkRect& rect, const SkVector radii[4]) { this->scaleRadii(); } +// If we can't distinguish one of the radii relative to the other, force it to zero so it +// doesn't confuse us later. See crbug.com/850350 +// +static void flush_to_zero(SkScalar& a, SkScalar& b) { + SkASSERT(a >= 0); + SkASSERT(b >= 0); + if (a + b == a) { + b = 0; + } else if (a + b == b) { + a = 0; + } +} + void SkRRect::scaleRadii() { // Proportionally scale down all radii to fit. Find the minimum ratio @@ -183,6 +196,11 @@ void SkRRect::scaleRadii() { scale = compute_min_scale(fRadii[2].fX, fRadii[3].fX, width, scale); scale = compute_min_scale(fRadii[3].fY, fRadii[0].fY, height, scale); + flush_to_zero(fRadii[0].fX, fRadii[1].fX); + flush_to_zero(fRadii[1].fY, fRadii[2].fY); + flush_to_zero(fRadii[2].fX, fRadii[3].fX); + flush_to_zero(fRadii[3].fY, fRadii[0].fY); + if (scale < 1.0) { SkScaleToSides::AdjustRadii(width, scale, &fRadii[0].fX, &fRadii[1].fX); SkScaleToSides::AdjustRadii(height, scale, &fRadii[1].fY, &fRadii[2].fY); |