Harden degenerate gradient context handling

include/core/SkMatrix.h

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkMatrix_DEFINED
@@ skipping 718 matching lines @@
         unsigned mask = 0;
         if (sx != 1 || sy != 1) {
             mask |= kScale_Mask;
         }
         if (tx || ty) {
             mask |= kTranslate_Mask;
         }
         this->setTypeMask(mask | kRectStaysRect_Mask);
     }
     
+    /**
+     *  Are all elements of the matrix finite?
+     */
+    bool isFinite() const { return SkScalarsAreFinite(fMat, 9); }
+
 private:
     enum {
         /** Set if the matrix will map a rectangle to another rectangle. This
             can be true if the matrix is scale-only, or rotates a multiple of
             90 degrees.
 
             This bit will be set on identity matrices
         */
         kRectStaysRect_Mask = 0x10,
 
@@ skipping 12 matching lines @@
         kAllMasks = kTranslate_Mask |
                     kScale_Mask |
                     kAffine_Mask |
                     kPerspective_Mask |
                     kRectStaysRect_Mask
     };
 
     SkScalar         fMat[9];
     mutable uint32_t fTypeMask;
 
-    /** Are all elements of the matrix finite?
-     */
-    bool isFinite() const { return SkScalarsAreFinite(fMat, 9); }
-
     static void ComputeInv(SkScalar dst[9], const SkScalar src[9], double invDet, bool isPersp);
 
     uint8_t computeTypeMask() const;
     uint8_t computePerspectiveTypeMask() const;
 
     void setTypeMask(int mask) {
         // allow kUnknown or a valid mask
         SkASSERT(kUnknown_Mask == mask || (mask & kAllMasks) == mask ||
                  ((kUnknown_Mask | kOnlyPerspectiveValid_Mask) & mask)
                  == (kUnknown_Mask | kOnlyPerspectiveValid_Mask));
@@ skipping 55 matching lines @@
     static void Affine_vpts(const SkMatrix&, SkPoint dst[], const SkPoint[], int);
 
     static const MapPtsProc gMapPtsProcs[];
 
     friend class SkPerspIter;
     friend class SkMatrixPriv;
 };
 SK_END_REQUIRE_DENSE
 
 #endif