path ops work in progress

src/pathops/SkOpAngle.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkIntersections.h"
 #include "SkOpAngle.h"
 #include "SkOpSegment.h"
 #include "SkPathOpsCurve.h"
 #include "SkTSort.h"
 
 #if DEBUG_ANGLE
 #include "SkString.h"
 
 static const char funcName[] = "SkOpSegment::operator<";
 static const int bugChar = strlen(funcName) + 1;
 #endif
 
 /* Angles are sorted counterclockwise. The smallest angle has a positive x and the smallest
    positive y. The largest angle has a positive x and a zero y. */
 
 #if DEBUG_ANGLE
     static bool CompareResult(SkString* bugOut, const char* append, bool compare) {
-        bugOut->appendf(append);
+        bugOut->appendf("%s", append);
         bugOut->writable_str()[bugChar] = "><"[compare];
         SkDebugf("%s\n", bugOut->c_str());
         return compare;
     }
 
     #define COMPARE_RESULT(append, compare) CompareResult(&bugOut, append, compare)
 #else
     #define COMPARE_RESULT(append, compare) compare
 #endif
 
@@ skipping 98 matching lines @@
             bool sloppy1 = x_ry < rx_y;
             bool sloppy2 = !sloppy1;
             if ((!fComputed || calcSlop(x, y, rx, ry, &sloppy1))
                     && (!rh.fComputed || rh.calcSlop(rx, ry, x, y, &sloppy2))
                     && sloppy1 != sloppy2) {
                 return COMPARE_RESULT("8 CalcSlop(x, y ...", sloppy1);
             }
         }
     }
     if (fSide * rh.fSide == 0) {
-        SkASSERT(fSide + rh.fSide != 0);
+        SkASSERT(fSide + rh.fSide != 0); // hitting this assert means coincidence was undetected
         return COMPARE_RESULT("9 fSide * rh.fSide == 0 ...", fSide < rh.fSide);
     }
     // at this point, the initial tangent line is nearly coincident
     // see if edges curl away from each other
     if (fSide * rh.fSide < 0 && (!approximately_zero(fSide) || !approximately_zero(rh.fSide))) {
         return COMPARE_RESULT("9b fSide * rh.fSide < 0 ...", fSide < rh.fSide);
     }
     if (fUnsortable || rh.fUnsortable) {
         // even with no solution, return a stable sort
         return COMPARE_RESULT("11 fUnsortable || rh.fUnsortable", this < &rh);
@@ skipping 266 matching lines @@
 #if 1
 #if DEBUG_UNSORTABLE
     SkPoint iPt = fSegment->xyAtT(fStart);
     SkPoint ePt = fSegment->xyAtT(fEnd);
     SkDebugf("%s all tiny unsortable [%d] (%1.9g,%1.9g) [%d] (%1.9g,%1.9g)\n", __FUNCTION__,
         fStart, iPt.fX, iPt.fY, fEnd, ePt.fX, ePt.fY);
 #endif
     fUnsortable = true;
 #endif
 }