Backfill unit tests for SkRecord

tests/RecordOptsTest.cpp

Index: tests/RecordOptsTest.cpp
diff --git a/tests/RecordOptsTest.cpp b/tests/RecordOptsTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..140ad7e583d6018ed2223b47fdaad1f73c7f0822
--- /dev/null
+++ b/tests/RecordOptsTest.cpp
@@ -0,0 +1,136 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Test.h"
+
+#include "SkRecord.h"
+#include "SkRecordOpts.h"
+#include "SkRecorder.h"
+#include "SkRecords.h"
+
+static const int W = 1920, H = 1080;
+
+// If the command we're reading is a U, set ptr to it, otherwise set it to NULL.
+template <typename U>
+struct ReadAs {
+    explicit ReadAs(const U** ptr) : ptr(ptr) {}
+    const U** ptr;
+
+    void operator()(const U& r) { *ptr = &r; }
+
+    template <typename T>
+    void operator()(const T&) { *ptr = NULL; }
+};
+
+// Assert that the ith command in record is of type T, and return it.
+template <typename T>
+static const T* assert_type(const SkRecord& record, unsigned index) {
+    const T* ptr = NULL;
+    ReadAs<T> reader(&ptr);
+    record.visit(index, reader);
+    SkASSERT(ptr != NULL);

[f(malita), 2014/04/30 12:58:18]

Should we use REPORTER_ASSERT instead?

[mtklein, 2014/04/30 13:03:16]

Ah, yeah, good question.  I started with that, but it was hard to debug. 
REPORTER_ASSERT just gives you "Failed: ptr != NULL", without any sort of
provenance.  You end up putting in an SkASSERT(ptr != NULL) anyway so that you
can break gdb and see who called assert_type.

We could add REPORTER_ASSERT in addition, but since it doesn't bail out early,
if the assert fails we'll still just crash (here in Debug, dereferencing NULL
later in Release).

+    return ptr;
+}
+
+DEF_TEST(RecordOpts_Culling, r) {
+    SkRecord record;
+    SkRecorder recorder(SkRecorder::kWriteOnly_Mode, &record, W, H);
+
+    recorder.drawRect(SkRect::MakeWH(1000, 10000), SkPaint());
+
+    recorder.pushCull(SkRect::MakeWH(100, 100));
+        recorder.drawRect(SkRect::MakeWH(10, 10), SkPaint());
+        recorder.drawRect(SkRect::MakeWH(30, 30), SkPaint());
+        recorder.pushCull(SkRect::MakeWH(5, 5));
+            recorder.drawRect(SkRect::MakeWH(1, 1), SkPaint());
+        recorder.popCull();
+    recorder.popCull();
+
+    SkRecordAnnotateCullingPairs(&record);
+
+    REPORTER_ASSERT(r, 6 == assert_type<SkRecords::PairedPushCull>(record, 1)->skip);
+    REPORTER_ASSERT(r, 2 == assert_type<SkRecords::PairedPushCull>(record, 4)->skip);
+}
+
+static void draw_pos_text(SkCanvas* canvas, const char* text, bool constantY) {
+    const size_t len = strlen(text);
+    SkAutoTMalloc<SkPoint> pos(len);
+    for (size_t i = 0; i < len; i++) {
+        pos[i].fX = (SkScalar)i;
+        pos[i].fY = constantY ? SK_Scalar1 : (SkScalar)i;
+    }
+    canvas->drawPosText(text, len, pos, SkPaint());
+}
+
+DEF_TEST(RecordOpts_StrengthReduction, r) {
+    SkRecord record;
+    SkRecorder recorder(SkRecorder::kWriteOnly_Mode, &record, W, H);
+
+    // We can convert a drawPosText into a drawPosTextH when all the Ys are the same.
+    draw_pos_text(&recorder, "This will be reduced to drawPosTextH.", true);
+    draw_pos_text(&recorder, "This cannot be reduced to drawPosTextH.", false);
+
+    SkRecordReduceDrawPosTextStrength(&record);
+
+    assert_type<SkRecords::DrawPosTextH>(record, 0);
+    assert_type<SkRecords::DrawPosText>(record, 1);
+}
+
+DEF_TEST(RecordOpts_TextBounding, r) {
+    SkRecord record;
+    SkRecorder recorder(SkRecorder::kWriteOnly_Mode, &record, W, H);
+
+    // First, get a drawPosTextH.  Here's a handy way.  Its text size will be the default (12).
+    draw_pos_text(&recorder, "This will be reduced to drawPosTextH.", true);
+    SkRecordReduceDrawPosTextStrength(&record);
+
+    const SkRecords::DrawPosTextH* original =
+        assert_type<SkRecords::DrawPosTextH>(record, 0);
+
+    // This should wrap the original DrawPosTextH with minY and maxY.
+    SkRecordBoundDrawPosTextH(&record);
+
+    const SkRecords::BoundedDrawPosTextH* bounded =
+        assert_type<SkRecords::BoundedDrawPosTextH>(record, 0);
+
+    const SkPaint defaults;
+    REPORTER_ASSERT(r, bounded->base == original);
+    REPORTER_ASSERT(r, bounded->minY <= SK_Scalar1 - defaults.getTextSize());
+    REPORTER_ASSERT(r, bounded->maxY >= SK_Scalar1 + defaults.getTextSize());
+}
+
+DEF_TEST(RecordOpts_NoopSaveRestores, r) {
+    SkRecord record;
+    SkRecorder recorder(SkRecorder::kWriteOnly_Mode, &record, W, H);
+
+    // The second pass will clean up this pair after the first pass noops all the innards.
+    recorder.save();
+        // A simple pointless pair of save/restore.
+        recorder.save();
+        recorder.restore();
+
+        // As long as we don't draw in there, everything is a noop.
+        recorder.save();
+            recorder.clipRect(SkRect::MakeWH(200, 200));
+            recorder.clipRect(SkRect::MakeWH(100, 100));
+        recorder.restore();
+    recorder.restore();
+
+    // These will be kept (though some future optimization might noop the save and restore).
+    recorder.save();
+        recorder.drawRect(SkRect::MakeWH(200, 200), SkPaint());
+    recorder.restore();
+
+    SkRecordNoopSaveRestores(&record);
+
+    for (unsigned index = 0; index < 8; index++) {
+        assert_type<SkRecords::NoOp>(record, index);
+    }
+    assert_type<SkRecords::Save>(record, 8);
+    assert_type<SkRecords::DrawRect>(record, 9);
+    assert_type<SkRecords::Restore>(record, 10);
+}