display : Add wormholeRegion Calculation

For copybit cases we should clear wormhole region
rather than nonwormhole. Adding support to calculate
and clear the same.

Change-Id: Ie85d1b484174199e35f43ce95b30de1fac9c30b2
diff --git a/libqdutils/cb_utils.cpp b/libqdutils/cb_utils.cpp
new file mode 100644
index 0000000..bc7e5b1
--- /dev/null
+++ b/libqdutils/cb_utils.cpp
@@ -0,0 +1,79 @@
+/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
+* Redistribution and use in source and binary forms, with or without
+* * modification, are permitted provided that the following conditions are
+* met:
+*   * Redistributions of source code must retain the above copyrigh
+*     notice, this list of conditions and the following disclaimer
+*   * Redistributions in binary form must reproduce the above
+*     copyright notice, this list of conditions and the following
+*     disclaimer in the documentation and/or other materials provided
+*     with the distribution.
+*   * Neither the name of The Linux Foundation nor the names of its
+*     contributors may be used to endorse or promote products derived
+*     from this software without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+* ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+* * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include "cb_utils.h"
+
+/* get union of two rects into 3rd rect */
+void getUnion(hwc_rect_t& rect1,hwc_rect_t& rect2, hwc_rect_t& irect) {
+    irect.left   = min(rect1.left, rect2.left);
+    irect.top    = min(rect1.top, rect2.top);
+    irect.right  = max(rect1.right, rect2.right);
+    irect.bottom = max(rect1.bottom, rect2.bottom);
+}
+
+using namespace android;
+using namespace qhwc;
+namespace qdutils {
+
+int CBUtils::getuiClearRegion(hwc_display_contents_1_t* list,
+          hwc_rect_t &clearWormholeRect, LayerProp *layerProp) {
+
+    uint32_t last = list->numHwLayers - 1;
+    hwc_rect_t fbFrame = list->hwLayers[last].displayFrame;
+
+    Rect fbFrameRect(fbFrame.left,fbFrame.top,fbFrame.right,fbFrame.bottom);
+    Region wormholeRegion(fbFrameRect);
+
+    for (uint32_t i = 0 ; i < last; i++) {
+        // need to take care only in per pixel blending.
+        // Restrict calculation only for copybit layers.
+        if((list->hwLayers[i].blending != HWC_BLENDING_NONE) ||
+           !(layerProp[i].mFlags & HWC_COPYBIT))
+            continue ;
+        hwc_rect_t displayFrame = list->hwLayers[i].displayFrame;
+        Rect tmpRect(displayFrame.left,displayFrame.top,displayFrame.right,
+        displayFrame.bottom);
+        Region tmpRegion(tmpRect);
+        wormholeRegion.subtractSelf(wormholeRegion.intersect(tmpRegion));
+    }
+    if (wormholeRegion.isEmpty()) {
+        return 0;
+    }
+    //TO DO :- 1. remove union and call clear for each rect.
+    //      :- 2. support swap ract feature.
+    Region::const_iterator it = wormholeRegion.begin();
+    Region::const_iterator const end = wormholeRegion.end();
+    while (it != end) {
+        const Rect& r = *it++;
+        hwc_rect_t tmpWormRect = {r.left,r.top,r.right,r.bottom};
+        getUnion(clearWormholeRect, tmpWormRect, clearWormholeRect);
+
+    }
+    return 1;
+}
+
+}//namespace qdutils