DisplayList draw operation reordering

bug:8037003

The reordering enables similar operations to draw together, minimizing the
OpenGL state change operations that go inbetween draws. Eventually, multiple
complete canvas draw operations will be merged (into a single glDrawArrays call,
for example)

Reorders DisplayList draw operations when:

-They can move backwards in the command stream to be after similar
operations without violating draw ordering

-The OpenGLRenderer is in a simple, replayable state (no complex clip,
or filter/shadow etc)

Also adds two system properties to control the deferral/reordering:
    "debug.hwui.disable_draw_defer"
    "debug.hwui.disable_draw_reorder"
which can be set to "true" to control the display list manipulation

Change-Id: I5e89f3cb0ea2d2afd3e15c64d7f32b8406777a32
diff --git a/libs/hwui/DeferredDisplayList.h b/libs/hwui/DeferredDisplayList.h
new file mode 100644
index 0000000..4fcb297
--- /dev/null
+++ b/libs/hwui/DeferredDisplayList.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#ifndef ANDROID_HWUI_DEFERRED_DISPLAY_LIST_H
+#define ANDROID_HWUI_DEFERRED_DISPLAY_LIST_H
+
+#include <utils/Errors.h>
+#include <utils/Vector.h>
+
+#include "Matrix.h"
+#include "Rect.h"
+
+namespace android {
+namespace uirenderer {
+
+class DrawOp;
+class DrawOpBatch;
+class OpenGLRenderer;
+class SkiaShader;
+
+class DeferredDisplayList {
+public:
+    DeferredDisplayList() { clear(); }
+    ~DeferredDisplayList() { clear(); }
+
+    enum OpBatchId {
+        kOpBatch_None = -1, // Don't batch
+        kOpBatch_Bitmap,
+        kOpBatch_Patch,
+        kOpBatch_AlphaVertices,
+        kOpBatch_Vertices,
+        kOpBatch_AlphaMaskTexture,
+        kOpBatch_Text,
+        kOpBatch_ColorText,
+
+        kOpBatch_Count, // Add other batch ids before this
+    };
+
+    bool isEmpty() { return mBatches.isEmpty(); }
+
+    /**
+     * Plays back all of the draw ops recorded into batches to the renderer.
+     * Adjusts the state of the renderer as necessary, and restores it when complete
+     */
+    status_t flush(OpenGLRenderer& renderer, Rect& dirty, int32_t flags,
+            uint32_t level);
+
+    /**
+     * Add a draw op into the DeferredDisplayList, reordering as needed (for performance) if
+     * disallowReorder is false, respecting draw order when overlaps occur
+     */
+    void add(DrawOp* op, bool disallowReorder);
+
+private:
+    void clear();
+
+
+    Vector<DrawOpBatch*> mBatches;
+    int mBatchIndices[kOpBatch_Count];
+};
+
+}; // namespace uirenderer
+}; // namespace android
+
+#endif // ANDROID_HWUI_DEFERRED_DISPLAY_LIST_H