Mike R: please sanity check SkPostConfig.h

Mike K: please sanity check Test.cpp and skia_test.cpp

Feel free to look at the rest, but I don't expect any in depth review of path ops innards.

Path Ops first iteration used QuickSort to order segments radiating from an intersection to compute the winding rule.

This revision uses a circular sort instead. Breaking out the circular sort into its own long-lived structure (SkOpAngle) allows doing less work and provides a home for caching additional sorting data.

The circle sort is more stable than the former sort, has a robust ordering and fewer exceptions. It finds unsortable ordering less often. It is less reliant on the initial curve  tangent, using convex hulls instead whenever it can.

Additional debug validation makes sure that the computed structures are self-consistent. A new visualization tool helps verify that the angle ordering is correct.

The 70+M tests pass with this change on Windows, Mac, Linux 32 and Linux 64 in debug and release.

R=mtklein@google.com, reed@google.com

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/131103009

git-svn-id: http://skia.googlecode.com/svn/trunk@14183 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 40 insertions, 19 deletions

diff --git a/src/pathops/SkPathOpsPoint.h b/src/pathops/SkPathOpsPoint.h
index c3e0b40ab9..8fd247ee51 100644
--- a/src/pathops/SkPathOpsPoint.h
+++ b/src/pathops/SkPathOpsPoint.h
@@ -15,7 +15,13 @@ inline bool AlmostEqualUlps(const SkPoint& pt1, const SkPoint& pt2) {
 }
 
 struct SkDVector {
-    double fX, fY;
+    double fX;
+    double fY;
+
+    void set(const SkVector& pt) {
+        fX = pt.fX;
+        fY = pt.fY;
+    }
 
     friend SkDPoint operator+(const SkDPoint& a, const SkDVector& b);
 
@@ -48,6 +54,13 @@ struct SkDVector {
         return fX * a.fY - fY * a.fX;
     }
 
+    // similar to cross, this bastardization considers nearly coincident to be zero
+    double crossCheck(const SkDVector& a) const {
+        double xy = fX * a.fY;
+        double yx = fY * a.fX;
+        return AlmostEqualUlps(xy, yx) ? 0 : xy - yx;
+    }
+
     double dot(const SkDVector& a) const {
         return fX * a.fX + fY * a.fY;
     }
@@ -85,7 +98,6 @@ struct SkDPoint {
         fY = pt.fY;
     }
 
-
     void operator+=(const SkDVector& v) {
         fX += v.fX;
         fY += v.fY;
@@ -136,6 +148,15 @@ struct SkDPoint {
         return AlmostBequalUlps((double) largest, largest + dist); // is dist within ULPS tolerance?
     }
 
+#if SK_DEBUG
+    static bool RoughlyEqual(const SkPoint& a, const SkPoint& b) {
+        if (approximately_equal(a.fX, b.fX) && approximately_equal(a.fY, b.fY)) {
+            return true;
+        }
+        return RoughlyEqualUlps(a.fX, b.fX) && RoughlyEqualUlps(a.fY, b.fY);
+    }
+#endif
+
     bool approximatelyPEqual(const SkDPoint& a) const {
         if (approximately_equal(fX, a.fX) && approximately_equal(fY, a.fY)) {
             return true;
@@ -150,6 +171,20 @@ struct SkDPoint {
         return AlmostPequalUlps(largest, largest + dist); // is the dist within ULPS tolerance?
     }
 
+    bool approximatelyDEqual(const SkDPoint& a) const {
+        if (approximately_equal(fX, a.fX) && approximately_equal(fY, a.fY)) {
+            return true;
+        }
+        if (!RoughlyEqualUlps(fX, a.fX) || !RoughlyEqualUlps(fY, a.fY)) {
+            return false;
+        }
+        double dist = distance(a);  // OPTIMIZATION: can we compare against distSq instead ?
+        double tiniest = SkTMin(SkTMin(SkTMin(fX, a.fX), fY), a.fY);
+        double largest = SkTMax(SkTMax(SkTMax(fX, a.fX), fY), a.fY);
+        largest = SkTMax(largest, -tiniest);
+        return AlmostDequalUlps(largest, largest + dist); // is the dist within ULPS tolerance?
+    }
+
     bool approximatelyZero() const {
         return approximately_zero(fX) && approximately_zero(fY);
     }
@@ -191,23 +226,9 @@ struct SkDPoint {
         return roughly_equal(a.fY, fY) && roughly_equal(a.fX, fX);
     }
 
-    #ifdef SK_DEBUG
-    void dump() {
-        SkDebugf("{");
-        DebugDumpDouble(fX);
-        SkDebugf(", ");
-        DebugDumpDouble(fY);
-        SkDebugf("}");
-    }
-
-    static void dump(const SkPoint& pt) {
-        SkDebugf("{");
-        DebugDumpFloat(pt.fX);
-        SkDebugf(", ");
-        DebugDumpFloat(pt.fY);
-        SkDebugf("}");
-    }
-   #endif
+    // utilities callable by the user from the debugger when the implementation code is linked in
+    void dump() const;
+    static void Dump(const SkPoint& pt);
 };
 
 #endif