hwc: Extend PTOR feature for two layers

- Consider two smallest layers for PTOR feature which uses MDP comp.
- These two layers are rendered on a buffer and are queued to MDP
  to acheive full MDP Composition
- This helps to acheive performance enhancement

Change-Id: I43d9306ff19cd2d7a410c885316523965a44cbd4
diff --git a/libhwcomposer/hwc_copybit.h b/libhwcomposer/hwc_copybit.h
index 3d3d302..99a39c8 100644
--- a/libhwcomposer/hwc_copybit.h
+++ b/libhwcomposer/hwc_copybit.h
@@ -51,11 +51,9 @@
 
     void setReleaseFdSync(int fd);
 
-    bool prepareOverlap(hwc_context_t *ctx, hwc_display_contents_1_t *list,
-                        int overlapIndex);
+    bool prepareOverlap(hwc_context_t *ctx, hwc_display_contents_1_t *list);
 
-    int drawOverlap(hwc_context_t *ctx, hwc_display_contents_1_t *list,
-                    int overlapIndex);
+    int drawOverlap(hwc_context_t *ctx, hwc_display_contents_1_t *list);
 
 private:
     /* cached data */
@@ -87,8 +85,10 @@
     // Helper functions for copybit composition
     int  drawLayerUsingCopybit(hwc_context_t *dev, hwc_layer_1_t *layer,
                           private_handle_t *renderBuffer, bool isFG);
+    // Helper function to draw copybit layer for PTOR comp
     int drawRectUsingCopybit(hwc_context_t *dev, hwc_layer_1_t *layer,
-                          private_handle_t *renderBuffer, hwc_rect_t rect);
+                          private_handle_t *renderBuffer, hwc_rect_t overlap,
+                          hwc_rect_t destRect);
     int fillColorUsingCopybit(hwc_layer_1_t *layer,
                           private_handle_t *renderBuffer);
     bool canUseCopybitForYUV (hwc_context_t *ctx);