Add implementation of path ops

tests/PathOpsQuadLineIntersectionThreadedTest.cpp

Index: tests/PathOpsQuadLineIntersectionThreadedTest.cpp
===================================================================
--- tests/PathOpsQuadLineIntersectionThreadedTest.cpp	(revision 0)
+++ tests/PathOpsQuadLineIntersectionThreadedTest.cpp	(revision 0)
@@ -0,0 +1,135 @@
+/*
+ * 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 "PathOpsExtendedTest.h"
+#include "SkIntersections.h"
+#include "SkPathOpsLine.h"
+#include "SkPathOpsQuad.h"
+#include "SkReduceOrder.h"
+
+static int doIntersect(SkIntersections& intersections, const SkDQuad& quad, const SkDLine& line,
+                       bool& flipped) {
+    int result;
+    flipped = false;
+    if (line[0].fX == line[1].fX) {
+        double top = line[0].fY;
+        double bottom = line[1].fY;
+        flipped = top > bottom;
+        if (flipped) {
+            SkTSwap<double>(top, bottom);
+        }
+        result = intersections.vertical(quad, top, bottom, line[0].fX, flipped);
+    } else if (line[0].fY == line[1].fY) {
+        double left = line[0].fX;
+        double right = line[1].fX;
+        flipped = left > right;
+        if (flipped) {
+            SkTSwap<double>(left, right);
+        }
+        result = intersections.horizontal(quad, left, right, line[0].fY, flipped);
+    } else {
+        intersections.intersect(quad, line);
+        result = intersections.used();
+    }
+    return result;
+}
+
+static void testLineIntersect(skiatest::Reporter* reporter, const SkDQuad& quad,
+                              const SkDLine& line, const double x, const double y) {
+    char pathStr[1024];
+    bzero(pathStr, sizeof(pathStr));
+    char* str = pathStr;
+    str += sprintf(str, "    path.moveTo(%1.9g, %1.9g);\n", quad[0].fX, quad[0].fY);
+    str += sprintf(str, "    path.quadTo(%1.9g, %1.9g, %1.9g, %1.9g);\n", quad[1].fX, quad[1].fY, quad[2].fX, quad[2].fY);
+    str += sprintf(str, "    path.moveTo(%1.9g, %1.9g);\n", line[0].fX, line[0].fY);
+    str += sprintf(str, "    path.lineTo(%1.9g, %1.9g);\n", line[1].fX, line[1].fY);
+
+    SkIntersections intersections;
+    bool flipped = false;
+    int result = doIntersect(intersections, quad, line, flipped);
+    bool found = false;
+    for (int index = 0; index < result; ++index) {
+        double quadT = intersections[0][index];
+        SkDPoint quadXY = quad.xyAtT(quadT);
+        double lineT = intersections[1][index];
+        SkDPoint lineXY = line.xyAtT(lineT);
+        if (quadXY.approximatelyEqual(lineXY)) {
+            found = true;
+        }
+    }
+    REPORTER_ASSERT(reporter, found);
+}
+
+
+// find a point on a quad by choosing a t from 0 to 1
+// create a vertical span above and below the point
+// verify that intersecting the vertical span and the quad returns t
+// verify that a vertical span starting at quad[0] intersects at t=0
+// verify that a vertical span starting at quad[2] intersects at t=1
+static void* testQuadLineIntersectMain(void* data)
+{
+    State4& state = *(State4*) data;
+    REPORTER_ASSERT(state.reporter, data);
+    do {
+        int ax = state.a & 0x03;
+        int ay = state.a >> 2;
+        int bx = state.b & 0x03;
+        int by = state.b >> 2;
+        int cx = state.c & 0x03;
+        int cy = state.c >> 2;
+        SkDQuad quad = {{{ax, ay}, {bx, by}, {cx, cy}}};
+        SkReduceOrder reducer;
+        int order = reducer.reduce(quad, SkReduceOrder::kFill_Style);
+        if (order < 3) {
+            continue; // skip degenerates
+        }
+        for (int tIndex = 0; tIndex <= 4; ++tIndex) {
+            SkDPoint xy = quad.xyAtT(tIndex / 4.0);
+            for (int h = -2; h <= 2; ++h) {
+                for (int v = -2; v <= 2; ++v) {
+                    if (h == v && abs(h) != 1) {
+                        continue;
+                    }
+                    double x = xy.fX;
+                    double y = xy.fY;
+                    SkDLine line = {{{x - h, y - v}, {x, y}}};
+                    testLineIntersect(state.reporter, quad, line, x, y);
+                    SkDLine line2 = {{{x, y}, {x + h, y + v}}};
+                    testLineIntersect(state.reporter, quad, line2, x, y);
+                    SkDLine line3 = {{{x - h, y - v}, {x + h, y + v}}};
+                    testLineIntersect(state.reporter, quad, line3, x, y);
+                    state.testsRun += 3;
+                }
+            }
+        }
+    } while (runNextTestSet(state));
+    return NULL;
+}
+
+static void TestQuadLineIntersectionThreaded(skiatest::Reporter* reporter)
+{
+    int testsRun = 0;
+    if (gShowTestProgress) SkDebugf("%s\n", __FUNCTION__);
+    const char testStr[] = "testQuadLineIntersect";
+    initializeTests(reporter, testStr, sizeof(testStr));
+    for (int a = 0; a < 16; ++a) {
+        for (int b = 0 ; b < 16; ++b) {
+            for (int c = 0 ; c < 16; ++c) {
+                testsRun += dispatchTest4(testQuadLineIntersectMain, a, b, c, 0);
+            }
+            if (!gAllowExtendedTest) goto finish;
+            if (gShowTestProgress) SkDebugf(".");
+        }
+        if (gShowTestProgress) SkDebugf("%d", a);
+    }
+finish:
+    testsRun += waitForCompletion();
+    if (gShowTestProgress) SkDebugf("\n%s tests=%d\n", __FUNCTION__, testsRun);
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("PathOpsQuadLineIntersectionThreaded", QuadLineIntersectionThreadedTestClass, \
+        TestQuadLineIntersectionThreaded)