When a bitmap is texture-backed, change SkBitmap::copyTo() to do a deep

copy of the texels in VRAM rather than a readback and re-upload.  This
gives a 3-10X speedup on recursive canvas-to-canvas draws.

N.B.:  This introduces a new GM test, which will need new baselines.



git-svn-id: http://skia.googlecode.com/svn/trunk@2790 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 23 insertions, 0 deletions

diff --git a/src/core/SkBitmap.cpp b/src/core/SkBitmap.cpp
index 760bab7d8a..24a1839ff2 100644
--- a/src/core/SkBitmap.cpp
+++ b/src/core/SkBitmap.cpp
@@ -938,6 +938,29 @@ bool SkBitmap::copyTo(SkBitmap* dst, Config dstConfig, Allocator* alloc) const {
     return true;
 }
 
+bool SkBitmap::deepCopyTo(SkBitmap* dst, Config dstConfig) const {
+    if (!this->canCopyTo(dstConfig)) {
+        return false;
+    }
+
+    // If we have a PixelRef, and it supports deep copy, use it.
+    // Currently supported only by texture-backed bitmaps.
+    if (fPixelRef) {
+        SkPixelRef* pixelRef = fPixelRef->deepCopy(dstConfig);
+        if (pixelRef) {
+            dst->setConfig(dstConfig, fWidth, fHeight);
+            dst->setPixelRef(pixelRef)->unref();
+            return true;
+        }
+    }
+
+    if (this->getTexture()) {
+        return false;
+    } else {
+        return this->copyTo(dst, dstConfig, NULL);
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////