Make fewer copies when using GrDrawTarget::AutoStateRestore
Review URL: http://codereview.appspot.com/5938043/
git-svn-id: http://skia.googlecode.com/svn/trunk@3557 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrDrawTarget.h b/src/gpu/GrDrawTarget.h
index 8f5be3c..ca499db 100644
--- a/src/gpu/GrDrawTarget.h
+++ b/src/gpu/GrDrawTarget.h
@@ -154,43 +154,6 @@
bool willUseHWAALines() const;
/**
- * Used to save and restore the GrGpu's drawing state
- */
- struct SavedDrawState {
- private:
- SkTLazy<GrDrawState> fState;
- friend class GrDrawTarget;
- };
-
- /**
- * Saves the current draw state. The state can be restored at a later time
- * with restoreDrawState.
- *
- * See also AutoStateRestore class.
- *
- * @param state will hold the state after the function returns.
- */
- void saveCurrentDrawState(SavedDrawState* state) const;
-
- /**
- * Restores previously saved draw state. The client guarantees that state
- * was previously passed to saveCurrentDrawState and that the rendertarget
- * and texture set at save are still valid.
- *
- * See also AutoStateRestore class.
- *
- * @param state the previously saved state to restore.
- */
- void restoreDrawState(const SavedDrawState& state);
-
- /**
- * Copies the draw state from another target to this target.
- *
- * @param srcTarget draw target used as src of the draw state.
- */
- void copyDrawState(const GrDrawTarget& srcTarget);
-
- /**
* The format of vertices is represented as a bitfield of flags.
* Flags that indicate the layout of vertex data. Vertices always contain
* positions and may also contain up to GrDrawState::kMaxTexCoords sets
@@ -580,22 +543,62 @@
////////////////////////////////////////////////////////////////////////////
+ /**
+ * See AutoStateRestore below.
+ */
+ enum ASRInit {
+ kPreserve_ASRInit,
+ kReset_ASRInit
+ };
+
+ /**
+ * Saves off the current state and restores it in the destructor. It will
+ * install a new GrDrawState object on the target (setDrawState) and restore
+ * the previous one in the destructor. The caller should call drawState() to
+ * get the new draw state after the ASR is installed.
+ *
+ * GrDrawState* state = target->drawState();
+ * AutoStateRestore asr(target, GrDrawTarget::kReset_ASRInit).
+ * state->setRenderTarget(rt); // state refers to the GrDrawState set on
+ * // target before asr was initialized.
+ * // Therefore, rt is set on the GrDrawState
+ * // that will be restored after asr's
+ * // destructor rather than target's current
+ * // GrDrawState.
+ */
class AutoStateRestore : ::GrNoncopyable {
public:
+ /**
+ * Default ASR will have no effect unless set() is subsequently called.
+ */
AutoStateRestore();
- AutoStateRestore(GrDrawTarget* target);
+
+ /**
+ * Saves the state on target. The state will be restored when the ASR
+ * is destroyed. If this constructor is used do not call set().
+ *
+ * @param init Should the newly installed GrDrawState be a copy of the
+ * previous state or a default-initialized GrDrawState.
+ */
+ AutoStateRestore(GrDrawTarget* target, ASRInit init);
+
~AutoStateRestore();
/**
- * if this object is already saving state for param target then
- * this does nothing. Otherise, it restores previously saved state on
- * previous target (if any) and saves current state on param target.
+ * Saves the state on target. The state will be restored when the ASR
+ * is destroyed. This should only be called once per ASR object and only
+ * when the default constructor was used. For nested saves use multiple
+ * ASR objects.
+ *
+ * @param init Should the newly installed GrDrawState be a copy of the
+ * previous state or a default-initialized GrDrawState.
*/
- void set(GrDrawTarget* target);
+ void set(GrDrawTarget* target, ASRInit init);
private:
- GrDrawTarget* fDrawTarget;
- SavedDrawState fDrawState;
+ GrDrawTarget* fDrawTarget;
+ SkTLazy<GrDrawState> fTempState;
+ GrDrawState* fSavedState;
};
////////////////////////////////////////////////////////////////////////////
@@ -990,15 +993,6 @@
return mask;
}
- // Helpers for GrDrawTarget subclasses that won't have private access to
- // SavedDrawState but need to peek at the state values.
- static GrDrawState& accessSavedDrawState(SavedDrawState& sds) {
- return *sds.fState.get();
- }
- static const GrDrawState& accessSavedDrawState(const SavedDrawState& sds){
- return *sds.fState.get();
- }
-
// A sublcass can optionally overload this function to be notified before
// vertex and index space is reserved.
virtual void willReserveVertexAndIndexSpace(GrVertexLayout vertexLayout,