Separate interface definition and implementation of Snapshot

The Snapshot class is getting complicated enough that its implementation
should now live in a separate .cpp file. This will become particularly
useful when support for clip regions and paths will be added later on.

Change-Id: I050fac5683a9f7a0ff2f7a6beec3dd28aa5eb0d8

1 files changed, 154 insertions, 0 deletions

diff --git a/libs/hwui/Snapshot.cpp b/libs/hwui/Snapshot.cpp
new file mode 100644
index 0000000..a85362d
--- /dev/null
+++ b/libs/hwui/Snapshot.cpp
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Snapshot.h"
+
+#include <SkCanvas.h>
+
+namespace android {
+namespace uirenderer {
+
+///////////////////////////////////////////////////////////////////////////////
+// Constructors
+///////////////////////////////////////////////////////////////////////////////
+
+Snapshot::Snapshot(): flags(0), previous(NULL), layer(NULL), fbo(0),
+        invisible(false), empty(false) {
+
+    transform = &mTransformRoot;
+    clipRect = &mClipRectRoot;
+    region = NULL;
+}
+
+/**
+ * Copies the specified snapshot/ The specified snapshot is stored as
+ * the previous snapshot.
+ */
+Snapshot::Snapshot(const sp<Snapshot>& s, int saveFlags):
+        flags(0), previous(s), layer(NULL), fbo(s->fbo),
+        invisible(s->invisible), empty(false),
+        viewport(s->viewport), height(s->height) {
+
+    if (saveFlags & SkCanvas::kMatrix_SaveFlag) {
+        mTransformRoot.load(*s->transform);
+        transform = &mTransformRoot;
+    } else {
+        transform = s->transform;
+    }
+
+    if (saveFlags & SkCanvas::kClip_SaveFlag) {
+        mClipRectRoot.set(*s->clipRect);
+        clipRect = &mClipRectRoot;
+    } else {
+        clipRect = s->clipRect;
+    }
+
+    if (s->flags & Snapshot::kFlagFboTarget) {
+        flags |= Snapshot::kFlagFboTarget;
+        region = s->region;
+    } else {
+        region = NULL;
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Clipping
+///////////////////////////////////////////////////////////////////////////////
+
+bool Snapshot::clip(float left, float top, float right, float bottom, SkRegion::Op op) {
+    Rect r(left, top, right, bottom);
+    transform->mapRect(r);
+    return clipTransformed(r, op);
+}
+
+bool Snapshot::clipTransformed(const Rect& r, SkRegion::Op op) {
+    bool clipped = false;
+
+    // NOTE: The unimplemented operations require support for regions
+    // Supporting regions would require using a stencil buffer instead
+    // of the scissor. The stencil buffer itself is not too expensive
+    // (memory cost excluded) but on fillrate limited devices, managing
+    // the stencil might have a negative impact on the framerate.
+    switch (op) {
+        case SkRegion::kDifference_Op:
+            break;
+        case SkRegion::kIntersect_Op:
+            clipped = clipRect->intersect(r);
+            if (!clipped) {
+                clipRect->setEmpty();
+                clipped = true;
+            }
+            break;
+        case SkRegion::kUnion_Op:
+            clipped = clipRect->unionWith(r);
+            break;
+        case SkRegion::kXOR_Op:
+            break;
+        case SkRegion::kReverseDifference_Op:
+            break;
+        case SkRegion::kReplace_Op:
+            clipRect->set(r);
+            clipped = true;
+            break;
+    }
+
+    if (clipped) {
+        flags |= Snapshot::kFlagClipSet;
+    }
+
+    return clipped;
+}
+
+void Snapshot::setClip(float left, float top, float right, float bottom) {
+    clipRect->set(left, top, right, bottom);
+    flags |= Snapshot::kFlagClipSet;
+}
+
+const Rect& Snapshot::getLocalClip() {
+    mat4 inverse;
+    inverse.loadInverse(*transform);
+
+    mLocalClip.set(*clipRect);
+    inverse.mapRect(mLocalClip);
+
+    return mLocalClip;
+}
+
+void Snapshot::resetClip(float left, float top, float right, float bottom) {
+    clipRect = &mClipRectRoot;
+    clipRect->set(left, top, right, bottom);
+    flags |= Snapshot::kFlagClipSet;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Transforms
+///////////////////////////////////////////////////////////////////////////////
+
+void Snapshot::resetTransform(float x, float y, float z) {
+    transform = &mTransformRoot;
+    transform->loadTranslate(x, y, z);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Queries
+///////////////////////////////////////////////////////////////////////////////
+
+bool Snapshot::isIgnored() const {
+    return invisible || empty;
+}
+
+}; // namespace uirenderer
+}; // namespace android