Add implementation of path ops

src/pathops/TSearch.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.
+ */
+#ifndef TSearch_DEFINED
+#define TSearch_DEFINED
+
+// FIXME: Move this templated version into SKTSearch.h
+
+template <typename T>
+static T* QSort_Partition(T* left, T* right, T* pivot)
+{
+    T pivotValue = *pivot;
+    SkTSwap(*pivot, *right);
+    T* newPivot = left;
+    while (left < right) {
+        if (*left < pivotValue) {
+            SkTSwap(*left, *newPivot);
+            newPivot += 1;
+        }
+        left += 1;
+    }
+    SkTSwap(*newPivot, *right);
+    return newPivot;
+}
+
+template <typename T>
+void QSort(T* left, T* right)
+{
+    if (left >= right) {
+        return;
+    }
+    T* pivot = left + (right - left >> 1);
+    pivot = QSort_Partition(left, right, pivot);
+    QSort(left, pivot - 1);
+    QSort(pivot + 1, right);
+}
+
+template <typename T>
+static T** QSort_Partition(T** left, T** right, T** pivot)
+{
+    T* pivotValue = *pivot;
+    SkTSwap(*pivot, *right);
+    T** newPivot = left;
+    while (left < right) {
+        if (**left < *pivotValue) {
+            SkTSwap(*left, *newPivot);
+            newPivot += 1;
+        }
+        left += 1;
+    }
+    SkTSwap(*newPivot, *right);
+    return newPivot;
+}
+
+template <typename T>
+void QSort(T** left, T** right)
+{
+    if (left >= right) {
+        return;
+    }
+    T** pivot = left + (right - left >> 1);
+    pivot = QSort_Partition(left, right, pivot);
+    QSort(left, pivot - 1);
+    QSort(pivot + 1, right);
+}
+
+template <typename S, typename T>
+static T* QSort_Partition(S& context, T* left, T* right, T* pivot,
+        bool (*lessThan)(S&, const T, const T))
+{
+    T pivotValue = *pivot;
+    SkTSwap(*pivot, *right);
+    T* newPivot = left;
+    while (left < right) {
+        if (lessThan(context, *left, pivotValue)) {
+            SkTSwap(*left, *newPivot);
+            newPivot += 1;
+        }
+        left += 1;
+    }
+    SkTSwap(*newPivot, *right);
+    return newPivot;
+}
+
+template <typename S, typename T>
+void QSort(S& context, T* left, T* right,
+        bool (*lessThan)(S& , const T, const T))
+{
+    if (left >= right) {
+        return;
+    }
+    T* pivot = left + (right - left >> 1);
+    pivot = QSort_Partition(context, left, right, pivot, lessThan);
+    QSort(context, left, pivot - 1, lessThan);
+    QSort(context, pivot + 1, right, lessThan);
+}
+
+#endif