path ops -- fix skp bugs

tests/PathOpsLineIntersectionTest.cpp

Index: tests/PathOpsLineIntersectionTest.cpp
===================================================================
--- tests/PathOpsLineIntersectionTest.cpp	(revision 9040)
+++ tests/PathOpsLineIntersectionTest.cpp	(working copy)
@@ -10,6 +10,8 @@
 
 // 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}}}},
@@ -32,6 +34,20 @@
 
 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) {
@@ -40,22 +56,44 @@
         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"