Revert[6] "Remove SkDraw from device-draw methods, and enable device-centric clipping.""""""

Previous failure was failure to detect that the clip wasn't wide-open when
optimizing for retain-vs-discard in copy-on-write. gm:copy_on_write_retain
detected this. Now fixed by adding new method to SkBaseDevice.h

This reverts commit 27d07f0acb85eea4062075dfbe9148ce12d92c66.

BUG=skia:6214

Change-Id: I532d16ec075a4525c2a550b1157bcec695dd8efd
Reviewed-on: https://skia-review.googlesource.com/9341
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/gm/surface.cpp b/gm/surface.cpp
index 9c47b4badc..baa84ebdc0 100644
--- a/gm/surface.cpp
+++ b/gm/surface.cpp
@@ -169,3 +169,28 @@ DEF_SIMPLE_GM(copy_on_write_retain, canvas, 256, 256) {
     // expect to see two rects: blue | red
     canvas->drawImage(surf->makeImageSnapshot(), 0, 0, nullptr);
 }
+
+DEF_SIMPLE_GM(copy_on_write_savelayer, canvas, 256, 256) {
+    const SkImageInfo info = SkImageInfo::MakeN32Premul(256, 256);
+    sk_sp<SkSurface> surf = canvas->makeSurface(info, nullptr);
+    if (!surf) {
+        surf = SkSurface::MakeRaster(info, nullptr);
+    }
+
+    surf->getCanvas()->clear(SK_ColorRED);
+    // its important that image survives longer than the next draw, so the surface will see
+    // an outstanding image, and have to decide if it should retain or discard those pixels
+    sk_sp<SkImage> image = surf->makeImageSnapshot();
+
+    // now draw into a full-screen layer. This should (a) trigger a copy-on-write, but it should
+    // not trigger discard, even tho its alpha (SK_ColorBLUE) is opaque, since it is in a layer
+    // with a non-opaque paint.
+    SkPaint paint;
+    paint.setAlpha(0x40);
+    surf->getCanvas()->saveLayer({0, 0, 256, 256}, &paint);
+    surf->getCanvas()->clear(SK_ColorBLUE);
+    surf->getCanvas()->restore();
+
+    // expect to see two rects: blue blended on red
+    canvas->drawImage(surf->makeImageSnapshot(), 0, 0, nullptr);
+}