test picture-ops for savelayer

tests/RecordOptsTest.cpp

Index: tests/RecordOptsTest.cpp
diff --git a/tests/RecordOptsTest.cpp b/tests/RecordOptsTest.cpp
index 4341b870bf4d46a6433461023bba92cabcdda579..4567a01409b7d5bdbfc6c8a6c778496428db3c27 100644
--- a/tests/RecordOptsTest.cpp
+++ b/tests/RecordOptsTest.cpp
@@ -16,6 +16,7 @@
 #include "SkXfermode.h"
 #include "SkPictureRecorder.h"
 #include "SkPictureImageFilter.h"
+#include "SkSurface.h"
 
 static const int W = 1920, H = 1080;
 
@@ -343,3 +344,71 @@ DEF_TEST(RecordOpts_MergeSvgOpacityAndFilterLayers, r) {
     assert_type<SkRecords::Restore>(r, record, index + 3);
     index += 4;
 }
+
+static void do_draw(SkCanvas* canvas, SkColor color, bool doLayer) {
+    canvas->drawColor(SK_ColorWHITE);
+
+    SkPaint p;
+    p.setColor(color);
+
+    if (doLayer) {
+        canvas->saveLayer(nullptr, nullptr);
+        p.setXfermodeMode(SkXfermode::kSrc_Mode);
+        canvas->drawPaint(p);
+        canvas->restore();
+    } else {
+        canvas->drawPaint(p);
+    }
+}
+
+static bool is_equal(SkSurface* a, SkSurface* b) {
+    const SkImageInfo info = SkImageInfo::MakeN32Premul(1, 1);
+    SkPMColor ca, cb;
+    a->readPixels(info, &ca, sizeof(SkPMColor), 0, 0);
+    b->readPixels(info, &cb, sizeof(SkPMColor), 0, 0);
+    return ca == cb;
+}
+
+// Test drawing w/ and w/o a simple layer (no bounds or paint), so see that drawing ops
+// that *should* draw the same in fact do.
+//
+// Perform this test twice : once directly, and once via a picture
+//
+static void do_savelayer_srcmode(skiatest::Reporter* r, SkColor color) {
+    for (int doPicture = 0; doPicture <= 1; ++doPicture) {
+        sk_sp<SkSurface> surf0 = SkSurface::MakeRasterN32Premul(10, 10);
+        sk_sp<SkSurface> surf1 = SkSurface::MakeRasterN32Premul(10, 10);
+        SkCanvas* c0 = surf0->getCanvas();
+        SkCanvas* c1 = surf1->getCanvas();
+
+        SkPictureRecorder rec0, rec1;
+        if (doPicture) {
+            c0 = rec0.beginRecording(10, 10);
+            c1 = rec1.beginRecording(10, 10);
+        }
+
+        do_draw(c0, color, false);
+        do_draw(c1, color, true);
+
+        if (doPicture) {
+            surf0->getCanvas()->drawPicture(rec0.finishRecordingAsPicture());
+            surf1->getCanvas()->drawPicture(rec1.finishRecordingAsPicture());
+        }
+
+        // we replicate the assert so we can see which line is reported if there is a failure
+        if (doPicture) {
+            REPORTER_ASSERT(r, is_equal(surf0.get(), surf1.get()));
+        } else {
+            REPORTER_ASSERT(r, is_equal(surf0.get(), surf1.get()));
+        }
+    }
+}
+
+DEF_TEST(savelayer_srcmode_opaque, r) {
+    do_savelayer_srcmode(r, SK_ColorRED);
+}
+
+DEF_TEST(savelayer_srcmode_alpha, r) {
+    do_savelayer_srcmode(r, 0x80FF0000);
+}
+