1 files changed, 85 insertions, 0 deletions
diff --git a/src/images/SkPageFlipper.cpp b/src/images/SkPageFlipper.cpp
new file mode 100644
index 0000000..526ba09
--- /dev/null
+++ b/src/images/SkPageFlipper.cpp
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2008 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 "SkPageFlipper.h"
+
+SkPageFlipper::SkPageFlipper() {
+    fWidth = 0;
+    fHeight = 0;
+    fDirty0 = &fDirty0Storage;
+    fDirty1 = &fDirty1Storage;
+
+    fDirty0->setEmpty();
+    fDirty1->setEmpty();
+}
+
+SkPageFlipper::SkPageFlipper(int width, int height) {
+    fWidth = width;
+    fHeight = height;
+    fDirty0 = &fDirty0Storage;
+    fDirty1 = &fDirty1Storage;
+
+    fDirty0->setRect(0, 0, width, height);
+    fDirty1->setEmpty();
+}
+
+void SkPageFlipper::resize(int width, int height) {
+    fWidth = width;
+    fHeight = height;
+    
+    // this is the opposite of the constructors
+    fDirty1->setRect(0, 0, width, height);
+    fDirty0->setEmpty();
+}
+
+void SkPageFlipper::inval() {
+    fDirty1->setRect(0, 0, fWidth, fHeight);
+}
+
+void SkPageFlipper::inval(const SkIRect& rect) {
+    SkIRect r;
+    r.set(0, 0, fWidth, fHeight);
+    if (r.intersect(rect)) {
+        fDirty1->op(r, SkRegion::kUnion_Op);
+    }
+}
+
+void SkPageFlipper::inval(const SkRegion& rgn) {
+    SkRegion r;
+    r.setRect(0, 0, fWidth, fHeight);
+    if (r.op(rgn, SkRegion::kIntersect_Op)) {
+        fDirty1->op(r, SkRegion::kUnion_Op);
+    }
+}
+
+void SkPageFlipper::inval(const SkRect& rect, bool antialias) {
+    SkIRect r;
+    rect.round(&r);
+    if (antialias) {
+        r.inset(-1, -1);
+    }
+    this->inval(r);
+}
+
+const SkRegion& SkPageFlipper::update(SkRegion* copyBits) {
+    // Copy over anything new from page0 that isn't dirty in page1
+    copyBits->op(*fDirty0, *fDirty1, SkRegion::kDifference_Op);
+    SkTSwap<SkRegion*>(fDirty0, fDirty1);
+    fDirty1->setEmpty();
+    return *fDirty0;
+}
+
+