Index: include/utils/SkCanvasUtils.h |
diff --git a/include/utils/SkCanvasUtils.h b/include/utils/SkCanvasUtils.h |
new file mode 100644 |
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+++ b/include/utils/SkCanvasUtils.h |
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+/* |
+ * Copyright 2013 Google Inc. |
+ * |
+ * Use of this source code is governed by a BSD-style license that can be |
+ * found in the LICENSE file. |
+ */ |
+ |
+#ifndef SkCanvasUtils_DEFINED |
+#define SkCanvasUtils_DEFINED |
+ |
+#include "SkCanvas.h" |
+ |
+struct SkCanvasState; |
+ |
+class SK_API SkCanvasUtils { |
scroggo
2013/08/28 17:22:01
This seems to be a rather generic name, considerin
djsollen
2013/08/29 15:09:19
Done.
|
+public: |
+ /** |
+ * Captures the current state of the canvas into an opaque ptr that is safe |
+ * to pass between different instances of Skia (which may or may not be the |
+ * same version). The function will return NULL in the event that one of the |
+ * following conditions are true. |
+ * 1) the canvas device type is not supported (currently only raster is supported) |
+ * 2) the canvas clip type is not supported (currently only non-AA clips are supported) |
+ * |
+ * It is required that the original SkCanvas remain valid until all canvases |
mtklein
2013/08/28 18:20:46
Can we have the SkCanvasState grab a ref on the Sk
djsollen
2013/08/29 15:09:19
Done.
|
+ * that have been created using its captured state have been dereferenced. It |
+ * is also recommended that the original canvas also to be used during this |
scroggo
2013/08/28 17:22:01
I'm not sure what this sentence means.
joth
2013/08/28 21:04:59
recommended that the original canvas NOT be used..
djsollen
2013/08/29 15:09:19
Done.
|
+ * time. |
+ * |
+ * Finally, it is important to note that any draw filters attached to the |
+ * canvas are NOT currently captured. |
mtklein
2013/08/28 18:20:46
A unit test for this will make sure we don't get t
djsollen
2013/08/29 15:09:19
Done.
|
+ * |
+ * @param canvas The canvas you wish to capture the current state of. |
+ * @return NULL or an opaque ptr that can be passed to CreateFromCanvasState |
+ * to reconstruct the canvas. The caller is responsible for calling |
+ * ReleaseCanvasState to free the memory associated with this state. |
+ */ |
+ static SkCanvasState* CaptureCanvasState(SkCanvas* canvas); |
mtklein
2013/08/28 18:20:46
Given that this is opaque, maybe we can use typede
|
+ |
+ /** |
+ * Create a new SkCanvas from the captured state of another SkCanvas. The |
+ * function will return NULL in the event that one of the |
+ * following conditions are true. |
+ * 1) the captured state is in an unrecognized format |
+ * 2) the captured canvas device type is not supported |
+ * |
+ * @param canvas The canvas you wish to capture the current state of. |
+ * @return NULL or an SkCanvas* whose devices and matrix/clip state are |
+ * identical to the captured canvas. The caller is responsible for |
+ * calling unref on the SkCanvas. |
+ */ |
+ static SkCanvas* CreateFromCanvasState(SkCanvasState* state); |
mtklein
2013/08/28 18:20:46
Can this be a const* or const&? (Or if * is typed
|
+ |
+ /** |
+ * Free the memory associated with the captured canvas state. This function |
+ * can be called as soon as the caller is finished using the state (e.g. calling |
+ * CreateFromCanvasState) and does not need to be retained for the lifecycle |
+ * of any SkCanvas objects that it was used to create. |
mtklein
2013/08/28 18:20:46
This is what needs update after what we all just t
djsollen
2013/08/29 15:09:19
Done.
|
+ * |
+ * @param state The captured state you wish to dispose of. |
+ */ |
+ static void ReleaseCanvasState(SkCanvasState* state); |
scroggo
2013/08/28 17:22:01
I think it would be useful to be explicit in the c
joth
2013/08/28 21:04:59
Yes.
I'd group CaptureCanvasState & ReleaseCanva
djsollen
2013/08/29 15:09:19
Done.
|
+}; |
+ |
+#endif |