Implement difference clip rects with window rectangles

Plumbs the pipeline for window rectangles and uses them for a very
basic implementation of difference clip rects. This puts a common
Blink pattern on fast path, but we will still eventually need to make
more comprehensive use of window rectangles during clipping.

GTX 960 perf result:
                              gpu                     glinst4                 glinst16
desk_jsfiddlebigcar.skp       0.254 -> 0.177 [70%]    0.279 -> 0.197 [71%]    0.577 -> 0.196 [34%]
keymobi_sfgate_com_.skp       0.697 -> 0.513 [74%]    0.766 -> 0.451 [59%]    0.769 -> 0.597 [78%]
keymobi_blogger.skp           0.406 -> 0.314 [77%]    0.436 -> 0.292 [67%]    0.696 -> 0.319 [46%]
desk_pokemonwiki.skp          0.121 -> 0.098 [81%]     0.13 -> 0.105 [81%]    0.216 -> 0.097 [45%]
desk_wikipedia.skp            0.121 -> 0.098 [81%]     0.13 -> 0.104 [80%]    0.199 -> 0.104 [52%]
keymobi_androidpolice_co...   0.443 -> 0.382 [86%]    0.447 -> 0.398 [89%]    0.444 -> 0.396 [89%]
keymobi_booking_com_sear...   1 .15 ->  1.03 [90%]     1.17 ->  1.06 [91%]     1.17 ->  1.05 [90%]
keymobi_theverge_com.skp      0.417 -> 0.396 [95%]    0.426 -> 0.405 [95%]    0.429 ->   0.4 [93%]

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2251573002

Review-Url: https://codereview.chromium.org/2251573002

1 files changed, 92 insertions, 0 deletions

diff --git a/tests/WindowRectanglesTest.cpp b/tests/WindowRectanglesTest.cpp
new file mode 100644
index 0000000000..d569f1d7aa
--- /dev/null
+++ b/tests/WindowRectanglesTest.cpp
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkTypes.h"
+#include "Test.h"
+
+#if SK_SUPPORT_GPU
+
+#include "GrWindowRectangles.h"
+
+static SkIRect next_irect(SkRandom& r) {
+    return {r.nextS(), r.nextS(), r.nextS(), r.nextS()};
+}
+
+DEF_TEST(WindowRectangles, reporter) {
+    SkRandom r;
+
+    SkIRect windowData[GrWindowRectangles::kMaxWindows];
+    for (int i = 0; i < GrWindowRectangles::kMaxWindows; ++i) {
+        windowData[i] = next_irect(r);
+    }
+
+    GrWindowRectangles wr;
+    for (int i = 0; i < GrWindowRectangles::kMaxWindows - 1; ++i) {
+        REPORTER_ASSERT(reporter, wr.count() == i);
+        REPORTER_ASSERT(reporter, !memcmp(wr.data(), windowData, i * sizeof(SkIRect)));
+
+        GrWindowRectangles wr2(wr);
+        REPORTER_ASSERT(reporter, wr2 == wr);
+        REPORTER_ASSERT(reporter, wr2.mode() == wr.mode());
+        REPORTER_ASSERT(reporter, wr2.count() == wr.count());
+        REPORTER_ASSERT(reporter, !memcmp(wr2.data(), wr.data(), i * sizeof(SkIRect)));
+
+        wr.addWindow(windowData[i]);
+    }
+
+    SkASSERT(wr.count() == GrWindowRectangles::kMaxWindows - 1);
+    {
+        GrWindowRectangles A(wr), B(wr);
+        REPORTER_ASSERT(reporter, B == A);
+        REPORTER_ASSERT(reporter, B.data() == A.data()); // Should use copy-on-write.
+
+        A.addWindow(windowData[GrWindowRectangles::kMaxWindows - 1]);
+        REPORTER_ASSERT(reporter, B.data() != A.data());
+        REPORTER_ASSERT(reporter, B != A);
+
+        B.addWindow(SkIRect::MakeLargest());
+        REPORTER_ASSERT(reporter, B != A);
+
+        REPORTER_ASSERT(reporter, !memcmp(A.data(), windowData,
+                                          GrWindowRectangles::kMaxWindows * sizeof(SkIRect)));
+        REPORTER_ASSERT(reporter, !memcmp(B.data(), windowData,
+                                          (GrWindowRectangles::kMaxWindows - 1) * sizeof(SkIRect)));
+        REPORTER_ASSERT(reporter,
+                        B.data()[GrWindowRectangles::kMaxWindows - 1] == SkIRect::MakeLargest());
+    }
+    {
+        GrWindowRectangles A(wr), B(wr);
+        REPORTER_ASSERT(reporter, B == A);
+        REPORTER_ASSERT(reporter, B.data() == A.data()); // Should use copy-on-write.
+
+        A.addWindow(windowData[GrWindowRectangles::kMaxWindows - 1]);
+        B.addWindow(windowData[GrWindowRectangles::kMaxWindows - 1]);
+        REPORTER_ASSERT(reporter, B == A);
+        REPORTER_ASSERT(reporter, B.data() != A.data());
+        REPORTER_ASSERT(reporter, !memcmp(B.data(), A.data(),
+                                          GrWindowRectangles::kMaxWindows * sizeof(SkIRect)));
+        REPORTER_ASSERT(reporter, !memcmp(A.data(), windowData,
+                                          GrWindowRectangles::kMaxWindows * sizeof(SkIRect)));
+    }
+
+    GrWindowRectangles wrI(GrWindowRectangles::Mode::kInclusive);
+    for (int i = 0; i < wr.count(); ++i) {
+        wrI.addWindow(windowData[i]);
+    }
+    REPORTER_ASSERT(reporter, wrI != wr);
+    REPORTER_ASSERT(reporter, wrI.mode() != wr.mode());
+    REPORTER_ASSERT(reporter, wrI.count() == wr.count());
+    REPORTER_ASSERT(reporter, !memcmp(wrI.data(), wr.data(), wr.count() * sizeof(SkIRect)));
+
+    wr.reset(GrWindowRectangles::Mode::kInclusive);
+    for (int i = 0; i < wrI.count(); ++i) {
+        wr.addWindow(windowData[i]);
+    }
+    REPORTER_ASSERT(reporter, wrI == wr);
+}
+
+#endif