path ops work in progress

src/pathops/SkLineParameters.h

 /*
  * 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 "SkPathOpsCubic.h"
 #include "SkPathOpsLine.h"
 #include "SkPathOpsQuad.h"
 
@@ skipping 21 matching lines @@
             }
         }
     }
 
     void cubicEndPoints(const SkDCubic& pts, int s, int e) {
         a = pts[s].fY - pts[e].fY;
         b = pts[e].fX - pts[s].fX;
         c = pts[s].fX * pts[e].fY - pts[e].fX * pts[s].fY;
     }
 
+    double cubicPart(const SkDCubic& part) {
+        cubicEndPoints(part);
+        if (part[0] == part[1] || ((const SkDLine& ) part[0]).nearRay(part[2])) {
+            return pointDistance(part[3]);
+        }
+        return pointDistance(part[2]);
+    }
+
     void lineEndPoints(const SkDLine& pts) {
         a = pts[0].fY - pts[1].fY;
         b = pts[1].fX - pts[0].fX;
         c = pts[0].fX * pts[1].fY - pts[1].fX * pts[0].fY;
     }
 
     void quadEndPoints(const SkDQuad& pts) {
         quadEndPoints(pts, 0, 1);
         if (dx() == 0 && dy() == 0) {
             quadEndPoints(pts, 0, 2);
         }
     }
 
     void quadEndPoints(const SkDQuad& pts, int s, int e) {
         a = pts[s].fY - pts[e].fY;
         b = pts[e].fX - pts[s].fX;
         c = pts[s].fX * pts[e].fY - pts[e].fX * pts[s].fY;
     }
 
+    double quadPart(const SkDQuad& part) {
+        quadEndPoints(part);
+        return pointDistance(part[2]);
+    }
+
     double normalSquared() const {
         return a * a + b * b;
     }
 
     bool normalize() {
         double normal = sqrt(normalSquared());
         if (approximately_zero(normal)) {
             a = b = c = 0;
             return false;
         }
@@ skipping 39 matching lines @@
 
     double dy() const {
         return -a;
     }
 
 private:
     double a;
     double b;
     double c;
 };