Move clip off of draw target

BUG=skia:

Review URL: https://codereview.chromium.org/947443003

3 files changed, 183 insertions, 69 deletions

diff --git a/include/gpu/GrClip.h b/include/gpu/GrClip.h
new file mode 100644
index 0000000000..f07a9749ca
--- /dev/null
+++ b/include/gpu/GrClip.h
@@ -0,0 +1,175 @@
+/*
+ * Copyright 2010 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrClip_DEFINED
+#define GrClip_DEFINED
+
+#include "SkClipStack.h"
+#include "GrSurface.h"
+
+struct SkIRect;
+
+/**
+ * GrClip encapsulates the information required to construct the clip
+ * masks. 'A GrClip is either wide open, just an IRect, just a Rect(TODO), or a full clipstack.
+ * If the clip is a clipstack than the origin is used to translate the stack with
+ * respect to device coordinates. This allows us to use a clip stack that is
+ * specified for a root device with a layer device that is restricted to a subset
+ * of the original canvas. For other clip types the origin will always be (0,0).
+ *
+ * NOTE: GrClip *must* point to a const clipstack
+ */
+class GrClip : SkNoncopyable {
+public:
+    GrClip() : fClipType(kWideOpen_ClipType) {}
+    GrClip(const SkIRect& rect) : fClipType(kIRect_ClipType) {
+        fClip.fIRect = rect;
+    }
+    ~GrClip() { this->reset(); }
+
+    const GrClip& operator=(const GrClip& other) {
+        this->reset();
+        fClipType = other.fClipType;
+        switch (other.fClipType) {
+            default:
+                SkFAIL("Incomplete Switch\n");
+            case kWideOpen_ClipType:
+                break;
+            case kClipStack_ClipType:
+                fClip.fClipStack.fStack = SkRef(other.clipStack());
+                fClip.fClipStack.fOrigin = other.origin();
+                break;
+            case kIRect_ClipType:
+                fClip.fIRect = other.irect();
+                break;
+        }
+        return *this;
+    }
+
+    bool operator==(const GrClip& other) const {
+        if (this->clipType() != other.clipType()) {
+            return false;
+        }
+
+        switch (fClipType) {
+            default:
+                SkFAIL("Incomplete Switch\n");
+                return false;
+            case kWideOpen_ClipType:
+                return true;
+            case kClipStack_ClipType:
+                if (this->origin() != other.origin()) {
+                    return false;
+                }
+
+                if (this->clipStack() && other.clipStack()) {
+                    return *this->clipStack() == *other.clipStack();
+                } else {
+                    return this->clipStack() == other.clipStack();
+                }
+                break;
+            case kIRect_ClipType:
+                return this->irect() == other.irect();
+                break;
+        }
+    }
+
+    bool operator!=(const GrClip& other) const {
+        return !(*this == other);
+    }
+
+    const SkClipStack* clipStack() const {
+        SkASSERT(kClipStack_ClipType == fClipType);
+        return fClip.fClipStack.fStack;
+    }
+
+    void setClipStack(const SkClipStack* clipStack, const SkIPoint* origin = NULL) {
+        if (clipStack->isWideOpen()) {
+            fClipType = kWideOpen_ClipType;
+        } else {
+            fClipType = kClipStack_ClipType;
+            fClip.fClipStack.fStack = SkRef(clipStack);
+            if (origin) {
+                fClip.fClipStack.fOrigin = *origin;
+            } else {
+                fClip.fClipStack.fOrigin.setZero();
+            }
+        }
+    }
+
+    const SkIRect& irect() const {
+        SkASSERT(kIRect_ClipType == fClipType);
+        return fClip.fIRect;
+    }
+
+    void reset() {
+        if (kClipStack_ClipType == fClipType) {
+            fClip.fClipStack.fStack->unref();
+            fClip.fClipStack.fStack = NULL;
+        }
+        fClipType = kWideOpen_ClipType;
+    }
+
+    const SkIPoint& origin() const {
+        SkASSERT(kClipStack_ClipType == fClipType);
+        return fClip.fClipStack.fOrigin;
+    }
+
+    bool isWideOpen(const SkRect& rect) const {
+        return (kWideOpen_ClipType == fClipType) ||
+               (kClipStack_ClipType == fClipType && this->clipStack()->isWideOpen()) ||
+               (kIRect_ClipType == fClipType && this->irect().contains(rect));
+    }
+
+    bool isWideOpen(const SkIRect& rect) const {
+        return (kWideOpen_ClipType == fClipType) ||
+               (kClipStack_ClipType == fClipType && this->clipStack()->isWideOpen()) ||
+               (kIRect_ClipType == fClipType && this->irect().contains(rect));
+    }
+
+    bool isWideOpen() const {
+        return (kWideOpen_ClipType == fClipType) ||
+               (kClipStack_ClipType == fClipType && this->clipStack()->isWideOpen());
+    }
+
+    void getConservativeBounds(const GrSurface* surface,
+                               SkIRect* devResult,
+                               bool* isIntersectionOfRects = NULL) const {
+        this->getConservativeBounds(surface->width(), surface->height(),
+                                    devResult, isIntersectionOfRects);
+    }
+
+    void getConservativeBounds(int width, int height,
+                               SkIRect* devResult,
+                               bool* isIntersectionOfRects = NULL) const;
+
+    static const GrClip& WideOpen() {
+        static GrClip clip;
+        return clip;
+    }
+
+    enum ClipType {
+        kClipStack_ClipType,
+        kWideOpen_ClipType,
+        kIRect_ClipType,
+    };
+
+    ClipType clipType() const { return fClipType; }
+
+private:
+    union Clip {
+        struct ClipStack {
+            const SkClipStack* fStack;
+            SkIPoint fOrigin;
+        } fClipStack;
+        SkIRect fIRect;
+    } fClip;
+
+    ClipType fClipType;
+};
+
+#endif
diff --git a/include/gpu/GrClipData.h b/include/gpu/GrClipData.h
deleted file mode 100644
index bb7101d8a6..0000000000
--- a/include/gpu/GrClipData.h
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * Copyright 2010 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef GrClip_DEFINED
-#define GrClip_DEFINED
-
-#include "SkClipStack.h"
-#include "GrSurface.h"
-
-struct SkIRect;
-
-/**
- * GrClipData encapsulates the information required to construct the clip
- * masks. 'fOrigin' is only non-zero when saveLayer has been called
- * with an offset bounding box. The clips in 'fClipStack' are in
- * device coordinates (i.e., they have been translated by -fOrigin w.r.t.
- * the canvas' device coordinates).
- */
-class GrClipData : SkNoncopyable {
-public:
-    SkAutoTUnref<const SkClipStack>  fClipStack;
-    SkIPoint                         fOrigin;
-
-    GrClipData()
-        : fClipStack(NULL) {
-        fOrigin.setZero();
-    }
-
-    bool operator==(const GrClipData& other) const {
-        if (fOrigin != other.fOrigin) {
-            return false;
-        }
-
-        if (fClipStack && other.fClipStack) {
-            return *fClipStack == *other.fClipStack;
-        }
-
-        return fClipStack == other.fClipStack;
-    }
-
-    bool operator!=(const GrClipData& other) const {
-        return !(*this == other);
-    }
-
-    void getConservativeBounds(const GrSurface* surface,
-                               SkIRect* devResult,
-                               bool* isIntersectionOfRects = NULL) const {
-        this->getConservativeBounds(surface->width(), surface->height(),
-                                    devResult, isIntersectionOfRects);
-    }
-
-    void getConservativeBounds(int width, int height,
-                               SkIRect* devResult,
-                               bool* isIntersectionOfRects = NULL) const;
-};
-
-#endif
diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index 846cd0f111..2433b89189 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -8,7 +8,7 @@
 #ifndef GrContext_DEFINED
 #define GrContext_DEFINED
 
-#include "GrClipData.h"
+#include "GrClip.h"
 #include "GrColor.h"
 #include "GrPaint.h"
 #include "GrPathRendererChain.h"
@@ -367,13 +367,13 @@ public:
      * Gets the current clip.
      * @return the current clip.
      */
-    const GrClipData* getClip() const { return fClip; }
+    const GrClip* getClip() const { return fClip; }
 
     /**
      * Sets the clip.
      * @param clipData  the clip to set.
      */
-    void setClip(const GrClipData* clipData) { fClip = clipData; }
+    void setClip(const GrClip* clipData) { fClip = clipData; }
 
     ///////////////////////////////////////////////////////////////////////////
     // Draws
@@ -680,7 +680,7 @@ public:
         AutoClip(GrContext* context, InitialClip SkDEBUGCODE(initialState))
         : fContext(context) {
             SkASSERT(kWideOpen_InitialClip == initialState);
-            fNewClipData.fClipStack.reset(SkRef(&fNewClipStack));
+            fNewClipData.setClipStack(&fNewClipStack);
 
             fOldClip = context->getClip();
             context->setClip(&fNewClipData);
@@ -689,7 +689,7 @@ public:
         AutoClip(GrContext* context, const SkRect& newClipRect)
         : fContext(context)
         , fNewClipStack(newClipRect) {
-            fNewClipData.fClipStack.reset(SkRef(&fNewClipStack));
+            fNewClipData.setClipStack(&fNewClipStack);
 
             fOldClip = fContext->getClip();
             fContext->setClip(&fNewClipData);
@@ -702,10 +702,10 @@ public:
         }
     private:
         GrContext*        fContext;
-        const GrClipData* fOldClip;
+        const GrClip* fOldClip;
 
         SkClipStack       fNewClipStack;
-        GrClipData        fNewClipData;
+        GrClip        fNewClipData;
     };
 
     class AutoWideOpenIdentityDraw {
@@ -761,7 +761,7 @@ public:
 
 private:
     GrGpu*                          fGpu;
-    const GrClipData*               fClip;  // TODO: make this ref counted
+    const GrClip*                   fClip;
 
     GrResourceCache*                fResourceCache;
     GrFontCache*                    fFontCache;