path ops -- fix skp bugs

tests/PathOpsLineIntersectionTest.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 "SkPathOpsLine.h"
 #include "Test.h"
 
 // FIXME: add tests for intersecting, non-intersecting, degenerate, coincident
 static const SkDLine tests[][2] = {
+    {{{{192, 4}, {243, 4}}}, {{{246, 4}, {189, 4}}}},
+    {{{{246, 4}, {189, 4}}}, {{{192, 4}, {243, 4}}}},
     {{{{5, 0}, {0, 5}}}, {{{5, 4}, {1, 4}}}},
     {{{{0, 0}, {1, 0}}}, {{{1, 0}, {0, 0}}}},
     {{{{0, 0}, {0, 0}}}, {{{0, 0}, {1, 0}}}},
     {{{{0, 1}, {0, 1}}}, {{{0, 0}, {0, 2}}}},
     {{{{0, 0}, {1, 0}}}, {{{0, 0}, {2, 0}}}},
     {{{{1, 1}, {2, 2}}}, {{{0, 0}, {3, 3}}}},
     {{{{166.86950047022856, 112.69654129527828}, {166.86948801592692, 112.69655741235339}}},
      {{{166.86960700313026, 112.6965477747386}, {166.86925794355412, 112.69656471103423}}}}
 };
 
 static const size_t tests_count = SK_ARRAY_COUNT(tests);
 
 static const SkDLine noIntersect[][2] = {
     {{{{0, 0}, {1, 0}}}, {{{3, 0}, {2, 0}}}},
     {{{{0, 0}, {0, 0}}}, {{{1, 0}, {2, 0}}}},
     {{{{0, 1}, {0, 1}}}, {{{0, 3}, {0, 2}}}},
     {{{{0, 0}, {1, 0}}}, {{{2, 0}, {3, 0}}}},
     {{{{1, 1}, {2, 2}}}, {{{4, 4}, {3, 3}}}},
 };
 
 static const size_t noIntersect_count = SK_ARRAY_COUNT(noIntersect);
 
+static void check_results(skiatest::Reporter* reporter, const SkDLine& line1, const SkDLine& line2,
+                          const SkIntersections& ts) {
+    for (int i = 0; i < ts.used(); ++i) {
+        SkDPoint result1 = line1.xyAtT(ts[0][i]);
+        SkDPoint result2 = line2.xyAtT(ts[1][i]);
+        if (!result1.approximatelyEqual(result2)) {
+            REPORTER_ASSERT(reporter, ts.used() != 1);
+            result2 = line2.xyAtT(ts[1][i ^ 1]);
+            REPORTER_ASSERT(reporter, result1.approximatelyEqual(result2));
+            REPORTER_ASSERT(reporter, result1.approximatelyEqual(ts.pt(i).asSkPoint()));
+        }
+    }
+}
+
 static void PathOpsLineIntersectionTest(skiatest::Reporter* reporter) {
     size_t index;
     for (index = 0; index < tests_count; ++index) {
         const SkDLine& line1 = tests[index][0];
         const SkDLine& line2 = tests[index][1];
         SkIntersections ts;
         int pts = ts.intersect(line1, line2);
         REPORTER_ASSERT(reporter, pts);
-        for (int i = 0; i < pts; ++i) {
-            SkDPoint result1 = line1.xyAtT(ts[0][i]);
-            SkDPoint result2 = line2.xyAtT(ts[1][i]);
-            if (!result1.approximatelyEqual(result2)) {
-                REPORTER_ASSERT(reporter, pts != 1);
-                result2 = line2.xyAtT(ts[1][i ^ 1]);
-                REPORTER_ASSERT(reporter, result1.approximatelyEqual(result2));
-            }
+        REPORTER_ASSERT(reporter, pts == ts.used());
+        check_results(reporter, line1, line2, ts);
+        if (line1[0] == line1[1] || line2[0] == line2[1]) {
+            continue;
+        }
+        if (line1[0].fY == line1[1].fY) {
+            double left = SkTMin(line1[0].fX, line1[1].fX);
+            double right = SkTMax(line1[0].fX, line1[1].fX);
+            ts.horizontal(line2, left, right, line1[0].fY, line1[0].fX != left);
+            check_results(reporter, line2, line1, ts);
+        }
+        if (line2[0].fY == line2[1].fY) {
+            double left = SkTMin(line2[0].fX, line2[1].fX);
+            double right = SkTMax(line2[0].fX, line2[1].fX);
+            ts.horizontal(line1, left, right, line2[0].fY, line2[0].fX != left);
+            check_results(reporter, line1, line2, ts);
+        }
+        if (line1[0].fX == line1[1].fX) {
+            double top = SkTMin(line1[0].fY, line1[1].fY);
+            double bottom = SkTMax(line1[0].fY, line1[1].fY);
+            ts.vertical(line2, top, bottom, line1[0].fX, line1[0].fY != top);
+            check_results(reporter, line2, line1, ts);
+        }
+        if (line2[0].fX == line2[1].fX) {
+            double top = SkTMin(line2[0].fY, line2[1].fY);
+            double bottom = SkTMax(line2[0].fY, line2[1].fY);
+            ts.vertical(line1, top, bottom, line2[0].fX, line2[0].fY != top);
+            check_results(reporter, line1, line2, ts);
         }
     }
     for (index = 0; index < noIntersect_count; ++index) {
         const SkDLine& line1 = noIntersect[index][0];
         const SkDLine& line2 = noIntersect[index][1];
         SkIntersections ts;
         int pts = ts.intersect(line1, line2);
-        REPORTER_ASSERT(reporter, !pts);    }
+        REPORTER_ASSERT(reporter, !pts);    
+        REPORTER_ASSERT(reporter, pts == ts.used());
+    }
 }
 
 #include "TestClassDef.h"
 DEFINE_TESTCLASS_SHORT(PathOpsLineIntersectionTest)