1 files changed, 105 insertions, 0 deletions
diff --git a/libs/hwui/DamageAccumulator.cpp b/libs/hwui/DamageAccumulator.cpp
new file mode 100644
index 0000000..8aa8c92
--- /dev/null
+++ b/libs/hwui/DamageAccumulator.cpp
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+#define LOG_TAG "DamageAccumulator"
+
+#include "DamageAccumulator.h"
+
+#include <cutils/log.h>
+
+#include "RenderNode.h"
+#include "utils/MathUtils.h"
+
+namespace android {
+namespace uirenderer {
+
+struct DirtyStack {
+    const RenderNode* node;
+    // When this frame is pop'd, this rect is mapped through the above transform
+    // and applied to the previous (aka parent) frame
+    SkRect pendingDirty;
+    DirtyStack* prev;
+    DirtyStack* next;
+};
+
+DamageAccumulator::DamageAccumulator() {
+    mHead = (DirtyStack*) mAllocator.alloc(sizeof(DirtyStack));
+    memset(mHead, 0, sizeof(DirtyStack));
+    // Create a root that we will not pop off
+    mHead->prev = mHead;
+}
+
+void DamageAccumulator::pushNode(const RenderNode* node) {
+    if (!mHead->next) {
+        DirtyStack* nextFrame = (DirtyStack*) mAllocator.alloc(sizeof(DirtyStack));
+        nextFrame->next = 0;
+        nextFrame->prev = mHead;
+        mHead->next = nextFrame;
+    }
+    mHead = mHead->next;
+    mHead->node = node;
+    mHead->pendingDirty.setEmpty();
+}
+
+void DamageAccumulator::popNode() {
+    LOG_ALWAYS_FATAL_IF(mHead->prev == mHead, "Cannot pop the root frame!");
+    DirtyStack* dirtyFrame = mHead;
+    mHead = mHead->prev;
+    if (!dirtyFrame->pendingDirty.isEmpty()) {
+        SkRect mappedDirty;
+        const RenderProperties& props = dirtyFrame->node->properties();
+        const SkMatrix* transform = props.getTransformMatrix();
+        if (transform && !transform->isIdentity()) {
+            transform->mapRect(&mappedDirty, dirtyFrame->pendingDirty);
+        } else {
+            mappedDirty = dirtyFrame->pendingDirty;
+        }
+        if (CC_LIKELY(mHead->node)) {
+            const RenderProperties& parentProps = mHead->node->properties();
+            mappedDirty.offset(props.getLeft() - parentProps.getScrollX(),
+                    props.getTop() - parentProps.getScrollY());
+            if (props.getClipToBounds()) {
+                if (!mappedDirty.intersect(0, 0, parentProps.getWidth(), parentProps.getHeight())) {
+                    mappedDirty.setEmpty();
+                }
+            }
+            if (CC_UNLIKELY(!MathUtils::isZero(props.getTranslationZ()))) {
+                // TODO: Can we better bound the shadow damage area? For now
+                // match the old damageShadowReceiver() path and just dirty
+                // the entire parent bounds
+                mappedDirty.join(0, 0, parentProps.getWidth(), parentProps.getHeight());
+            }
+        } else {
+            mappedDirty.offset(props.getLeft(), props.getTop());
+        }
+        dirty(mappedDirty.fLeft, mappedDirty.fTop, mappedDirty.fRight, mappedDirty.fBottom);
+    }
+}
+
+void DamageAccumulator::dirty(float left, float top, float right, float bottom) {
+    mHead->pendingDirty.join(left, top, right, bottom);
+}
+
+void DamageAccumulator::finish(SkRect* totalDirty) {
+    LOG_ALWAYS_FATAL_IF(mHead->prev != mHead, "Cannot finish, mismatched push/pop calls! %p vs. %p", mHead->prev, mHead);
+    // Root node never has a transform, so this is the fully mapped dirty rect
+    *totalDirty = mHead->pendingDirty;
+    totalDirty->roundOut();
+    mHead->pendingDirty.setEmpty();
+}
+
+} /* namespace uirenderer */
+} /* namespace android */