commit 49f8da020999e82f1d38beb080fc1a5ce0ef7f8b
author Mike Reed <reed@google.com> Mon Aug 27 10:48:52 2018 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Mon Aug 27 15:31:24 2018 +0000
tree 69c1ee29762f7eb5543441f24d6a69f614c70014
parent 3fee9235a465fbb7f6c0af6b0d7370fb795ce3aa

use nothingToDraw more often

Bug: skia:
Change-Id: Ifafd8d90649f5aeb020335f46496a828dffac98e
Reviewed-on: https://skia-review.googlesource.com/149481
Auto-Submit: Mike Reed <reed@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>

src/core/SkCanvas.cpp

diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index fb9e499..ff8afaa 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -920,9 +920,15 @@
 }
 
 int SkCanvas::saveLayer(const SaveLayerRec& rec) {
-    SaveLayerStrategy strategy = this->getSaveLayerStrategy(rec);
-    fSaveCount += 1;
-    this->internalSaveLayer(rec, strategy);
+    if (rec.fPaint && rec.fPaint->nothingToDraw()) {
+        // no need for the layer (or any of the draws until the matching restore()
+        this->save();
+        this->clipRect({0,0,0,0});
+    } else {
+        SaveLayerStrategy strategy = this->getSaveLayerStrategy(rec);
+        fSaveCount += 1;
+        this->internalSaveLayer(rec, strategy);
+    }
     return this->getSaveCount() - 1;
 }
 
@@ -2001,7 +2007,7 @@
         }
 
         LOOPER_END
-    } else {
+    } else if (!paint.nothingToDraw()) {
         this->predrawNotify(&r, &paint, false);
         SkDrawIter iter(this);
         while (iter.next()) {