diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/core/SkRRect.cpp | 35 |
1 files changed, 32 insertions, 3 deletions
diff --git a/src/core/SkRRect.cpp b/src/core/SkRRect.cpp index fc1a1cf057..c8d0329fe3 100644 --- a/src/core/SkRRect.cpp +++ b/src/core/SkRRect.cpp @@ -134,6 +134,12 @@ bool SkRRect::contains(SkScalar x, SkScalar y) const { // We know the point is inside the RR's bounds. The only way it can // be out is if it outside one of the corners + return checkCornerContainment(x, y); +} + +// This method determines if a point known to be inside the RRect's bounds is +// inside all the corners. +bool SkRRect::checkCornerContainment(SkScalar x, SkScalar y) const { SkPoint canonicalPt; // (x,y) translated to one of the quadrants int index; @@ -179,9 +185,32 @@ bool SkRRect::contains(SkScalar x, SkScalar y) const { // x^2 y^2 // ----- + ----- <= 1 // a^2 b^2 - SkScalar dist = SkScalarDiv(SkScalarSquare(canonicalPt.fX), SkScalarSquare(fRadii[index].fX)) + - SkScalarDiv(SkScalarSquare(canonicalPt.fY), SkScalarSquare(fRadii[index].fY)); - return dist <= SK_Scalar1; + // or : + // b^2*x^2 + a^2*y^2 <= (ab)^2 + SkScalar dist = SkScalarMul(SkScalarSquare(canonicalPt.fX), SkScalarSquare(fRadii[index].fY)) + + SkScalarMul(SkScalarSquare(canonicalPt.fY), SkScalarSquare(fRadii[index].fX)); + return dist <= SkScalarSquare(SkScalarMul(fRadii[index].fX, fRadii[index].fY)); +} + +bool SkRRect::contains(const SkRect& rect) const { + if (!this->getBounds().contains(rect)) { + // If 'rect' isn't contained by the RR's bounds then the + // RR definitely doesn't contain it + return false; + } + + if (this->isRect()) { + // the prior test was sufficient + return true; + } + + // At this point we know all four corners of 'rect' are inside the + // bounds of of this RR. Check to make sure all the corners are inside + // all the curves + return this->checkCornerContainment(rect.fLeft, rect.fTop) && + this->checkCornerContainment(rect.fRight, rect.fTop) && + this->checkCornerContainment(rect.fRight, rect.fBottom) && + this->checkCornerContainment(rect.fLeft, rect.fBottom); } // There is a simplified version of this method in setRectXY |