Add SkPathPriv::IsSimpleClosedRect

tests/PathTest.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <cmath>
 #include "SkCanvas.h"
 #include "SkGeometry.h"
@@ skipping 1957 matching lines @@
     for (index = 1; index < SkToInt(SK_ARRAY_COUNT(r1)); ++index) {
         if (index == 2) {
             path1.cubicTo(1, .5f, 1, .5f, 1, .5f);
         }
         path1.lineTo(r1[index].fX, r1[index].fY);
     }
     path1.close();
     REPORTER_ASSERT(reporter, !path1.isRect(nullptr));
 }
 
+static void check_simple_closed_rect(skiatest::Reporter* reporter, const SkPath& path,
+                                     const SkRect& rect, SkPath::Direction dir, unsigned start) {
+    SkRect r = SkRect::MakeEmpty();
+    SkPath::Direction d = SkPath::kCCW_Direction;
+    unsigned s = ~0U;
+
+    REPORTER_ASSERT(reporter, SkPathPriv::IsSimpleClosedRect(path, &r, &d, &s));
+    REPORTER_ASSERT(reporter, r == rect);
+    REPORTER_ASSERT(reporter, d == dir);
+    REPORTER_ASSERT(reporter, s == start);
+}
+
+static void test_is_simple_closed_rect(skiatest::Reporter* reporter) {
+    SkRect r = SkRect::MakeEmpty();
+    SkPath::Direction d = SkPath::kCCW_Direction;
+    unsigned s = ~0U;
+
+    const SkRect testRect = SkRect::MakeXYWH(10, 10, 50, 70);
+    const SkRect emptyRect = SkRect::MakeEmpty();
+    SkPath path;
+    for (int start = 0; start < 4; ++start) {
+        for (auto dir : {SkPath::kCCW_Direction, SkPath::kCW_Direction}) {
+            SkPath path;
+            path.addRect(testRect, dir, start);
+            check_simple_closed_rect(reporter, path, testRect, dir, start);
+            path.close();
+            check_simple_closed_rect(reporter, path, testRect, dir, start);
+            SkPath path2 = path;
+            path2.lineTo(10, 10);
+            REPORTER_ASSERT(reporter, !SkPathPriv::IsSimpleClosedRect(path2, &r, &d, &s));
+            path2 = path;
+            path2.moveTo(10, 10);
+            REPORTER_ASSERT(reporter, !SkPathPriv::IsSimpleClosedRect(path2, &r, &d, &s));
+            path2 = path;
+            path2.addRect(testRect, dir, start);
+            REPORTER_ASSERT(reporter, !SkPathPriv::IsSimpleClosedRect(path2, &r, &d, &s));
+            // Make the path by hand, manually closing it.
+            path2.reset();
+            SkPath::RawIter iter(path);
+            SkPath::Verb v;
+            SkPoint verbPts[4];
+            SkPoint firstPt = {0.f, 0.f};
+            while ((v = iter.next(verbPts)) != SkPath::kDone_Verb) {
+                switch(v) {
+                    case SkPath::kMove_Verb:
+                        firstPt = verbPts[0];
+                        path2.moveTo(verbPts[0]);
+                        break;
+                    case SkPath::kLine_Verb:
+                        path2.lineTo(verbPts[1]);
+                        break;
+                    default:
+                        break;
+                }
+            }
+            // We haven't closed it yet...
+            REPORTER_ASSERT(reporter, !SkPathPriv::IsSimpleClosedRect(path2, &r, &d, &s));
+            // ... now we do and test again.
+            path2.lineTo(firstPt);
+            check_simple_closed_rect(reporter, path2, testRect, dir, start);
+            // A redundant close shouldn't cause a failure.
+            path2.close();
+            check_simple_closed_rect(reporter, path2, testRect, dir, start);
+            // Degenerate point and line rects are not allowed
+            path2.reset();
+            path2.addRect(emptyRect, dir, start);
+            REPORTER_ASSERT(reporter, !SkPathPriv::IsSimpleClosedRect(path2, &r, &d, &s));
+            SkRect degenRect = testRect;
+            degenRect.fLeft = degenRect.fRight;
+            path2.reset();
+            path2.addRect(degenRect, dir, start);
+            REPORTER_ASSERT(reporter, !SkPathPriv::IsSimpleClosedRect(path2, &r, &d, &s));
+            degenRect = testRect;
+            degenRect.fTop = degenRect.fBottom;
+            path2.reset();
+            path2.addRect(degenRect, dir, start);
+            REPORTER_ASSERT(reporter, !SkPathPriv::IsSimpleClosedRect(path2, &r, &d, &s));
+            // An inverted rect makes a rect path, but changes the winding dir and start point.
+            SkPath::Direction swapDir = (dir == SkPath::kCW_Direction)
+                                            ? SkPath::kCCW_Direction
+                                            : SkPath::kCW_Direction;
+            static constexpr unsigned kXSwapStarts[] = { 1, 0, 3, 2 };
+            static constexpr unsigned kYSwapStarts[] = { 3, 2, 1, 0 };
+            SkRect swapRect = testRect;
+            SkTSwap(swapRect.fLeft, swapRect.fRight);
+            path2.reset();
+            path2.addRect(swapRect, dir, start);
+            check_simple_closed_rect(reporter, path2, testRect, swapDir, kXSwapStarts[start]);
+            swapRect = testRect;
+            SkTSwap(swapRect.fTop, swapRect.fBottom);
+            path2.reset();
+            path2.addRect(swapRect, dir, start);
+            check_simple_closed_rect(reporter, path2, testRect, swapDir, kYSwapStarts[start]);
+        }
+    }
+}
+
 static void test_isNestedFillRects(skiatest::Reporter* reporter) {
     // passing tests (all moveTo / lineTo...
     SkPoint r1[] = {{0, 0}, {1, 0}, {1, 1}, {0, 1}}; // CW
     SkPoint r2[] = {{1, 0}, {1, 1}, {0, 1}, {0, 0}};
     SkPoint r3[] = {{1, 1}, {0, 1}, {0, 0}, {1, 0}};
     SkPoint r4[] = {{0, 1}, {0, 0}, {1, 0}, {1, 1}};
     SkPoint r5[] = {{0, 0}, {0, 1}, {1, 1}, {1, 0}}; // CCW
     SkPoint r6[] = {{0, 1}, {1, 1}, {1, 0}, {0, 0}};
     SkPoint r7[] = {{1, 1}, {1, 0}, {0, 0}, {0, 1}};
     SkPoint r8[] = {{1, 0}, {0, 0}, {0, 1}, {1, 1}};
@@ skipping 2155 matching lines @@
         REPORTER_ASSERT(reporter, r == bounds);
         // add a moveTo outside of our bounds
         p.moveTo(bounds.fLeft + 10, bounds.fBottom + 10);
         REPORTER_ASSERT(reporter, p.isRect(&r));
         REPORTER_ASSERT(reporter, r == bounds);
     }
 
     test_operatorEqual(reporter);
     test_isLine(reporter);
     test_isRect(reporter);
+    test_is_simple_closed_rect(reporter);
     test_isNestedFillRects(reporter);
     test_zero_length_paths(reporter);
     test_direction(reporter);
     test_convexity(reporter);
     test_convexity2(reporter);
     test_conservativelyContains(reporter);
     test_close(reporter);
     test_segment_masks(reporter);
     test_flattening(reporter);
     test_transform(reporter);
@@ skipping 39 matching lines @@
     PathTest_Private::TestPathTo(reporter);
     PathRefTest_Private::TestPathRef(reporter);
     PathTest_Private::TestPathrefListeners(reporter);
     test_dump(reporter);
     test_path_crbug389050(reporter);
     test_path_crbugskia2820(reporter);
     test_skbug_3469(reporter);
     test_skbug_3239(reporter);
     test_bounds_crbug_513799(reporter);
 }