NX: Add configurable callout to external logic to handle display update events

graphics/Kconfig

@@ -56,6 +56,30 @@ config NX_WRITEONLY
 		Automatically defined if NX_LCDDRIVER and LCD_NOGETRUN are
 		defined.
 
+config NX_UPDATE
+	bool "Display update hooks'
+	default n
+	---help---
+		Enable a callout to inform some external module that the display has
+		been updated.  This would be useful in a couple for cases.
+
+		- When a serial LCD is used, but a framebuffer is used to access the
+		  LCD.  In this case, the update callout can be used to refresh the
+		  affected region of the display.
+
+		- When VNC is enabled.  This is case, this callout is necessary to
+		  update the remote frame buffer to match the local framebuffer.
+
+		When this feature is enabled, some external logic must provide this
+		interface:
+
+		  void nx_notify_rectangle(FAR NX_PLANEINFOTYPE *pinfo,
+		                           FAR const struct nxgl_rect_s *rect);
+
+		That is the function that will handle the notification.  It
+		receives the rectangular region that was updated in the provided
+		plane.
+
 menu "Supported Pixel Depths"
 
 config NX_DISABLE_1BPP

graphics/nxbe/nxbe_bitmap.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * graphics/nxbe/nxbe_bitmap.c
  *
- *   Copyright (C) 2008-2009, 2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2012, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -75,8 +75,17 @@ static void nxs_clipcopy(FAR struct nxbe_clipops_s *cops,
                          FAR const struct nxgl_rect_s *rect)
 {
   struct nx_bitmap_s *bminfo = (struct nx_bitmap_s *)cops;
+
+  /* Copy the rectangular region */
+
   plane->copyrectangle(&plane->pinfo, rect, bminfo->src,
                        &bminfo->origin, bminfo->stride);
+
+#ifdef CONFIG_NX_UPDATE
+  /* Notify external logic that the display has been updated */
+
+  nx_notify_rectangle(&plane->pinfo, rect);
+#endif
 }
 
 /****************************************************************************
@@ -153,6 +162,7 @@ void nxbe_bitmap(FAR struct nxbe_window_s *wnd, FAR const struct nxgl_rect_s *de
 
   nxgl_rectintersect(&remaining, &bounds, &wnd->bounds);
   nxgl_rectintersect(&remaining, &remaining, &wnd->be->bkgd.bounds);
+
   if (nxgl_nullrect(&remaining))
     {
       return;
@@ -177,4 +187,3 @@ void nxbe_bitmap(FAR struct nxbe_window_s *wnd, FAR const struct nxgl_rect_s *de
                    &info.cops, &wnd->be->plane[i]);
     }
 }
-

graphics/nxbe/nxbe_fill.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * graphics/nxbe/nxbe_fill.c
  *
- *   Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2011, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 
 #include <nuttx/nx/nxglib.h>
+#include <nuttx/nx/nx.h>
 
 #include "nxbe.h"
 
@@ -71,7 +72,16 @@ static void nxbe_clipfill(FAR struct nxbe_clipops_s *cops,
                         FAR const struct nxgl_rect_s *rect)
 {
   struct nxbe_fill_s *fillinfo = (struct nxbe_fill_s *)cops;
+
+  /* Draw the rectangle */
+    
   plane->fillrectangle(&plane->pinfo, rect, fillinfo->color);
+
+#ifdef CONFIG_NX_UPDATE
+  /* Notify external logic that the display has been updated */
+
+  nx_notify_rectangle(&plane->pinfo, rect);
+#endif
 }
 
 /****************************************************************************

graphics/nxbe/nxbe_filltrapezoid.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * graphics/nxbe/nxbe_filltrapezoid.c
  *
- *   Copyright (C) 2008-2009, 2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2012, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -44,6 +44,18 @@
 
 #include "nxbe.h"
 
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifndef MIN
+#  define MIN(a,b) (((a) < (b)) ? (a) : (b)
+#endif
+
+#ifndef MAX
+#  define MAX(a,b) (((a) > (b)) ? (a) : (b)
+#endif
+
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -73,7 +85,26 @@ static void nxbe_clipfilltrapezoid(FAR struct nxbe_clipops_s *cops,
                                    FAR const struct nxgl_rect_s *rect)
 {
   struct nxbe_filltrap_s *fillinfo = (struct nxbe_filltrap_s *)cops;
+#ifdef CONFIG_NX_UPDATE
+  FAR const struct nxgl_rect_s *update;
+#endif
+
+  /* Draw the trapezond */
+
   plane->filltrapezoid(&plane->pinfo, &fillinfo->trap, rect, fillinfo->color);
+
+#ifdef CONFIG_NX_UPDATE
+  /* Notify external logic that the display has been updated */
+
+  update.pt1.x = MIN(MAX(fillinfo->trap.top.x1, rect->pt1.x),
+                     MAX(fillinfo->trap.bot.x1, rect->pt1.x));
+  update.pt1.y = MAX(fillinfo->trap.top.y, rect->pt1.y);
+  update.pt2.x = MAX(MIN(fillinfo->trap.top.x2, rect->pt2.x),
+                     MIN(fillinfo->trap.bot.x2, rect->pt2.x));
+  update.pt2.y = MIN(fillinfo->trap.bot.y, rect->pt2.y);
+
+  nx_notify_rectangle(&plane->pinfo, &update);
+#endif
 }
 
 /****************************************************************************

graphics/nxbe/nxbe_move.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * graphics/nxbe/nxbe_move.c
  *
- *   Copyright (C) 2008-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2011-2012, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -78,6 +78,9 @@ static void nxbe_clipmovesrc(FAR struct nxbe_clipops_s *cops,
 {
   struct nxbe_move_s *info = (struct nxbe_move_s *)cops;
   struct nxgl_point_s offset;
+#ifdef CONFIG_NX_UPDATE
+  FAR const struct nxgl_rect_s *update;
+#endif
 
   if (info->offset.x != 0 || info->offset.y != 0)
     {
@@ -86,7 +89,20 @@ static void nxbe_clipmovesrc(FAR struct nxbe_clipops_s *cops,
       offset.x = rect->pt1.x + info->offset.x;
       offset.y = rect->pt1.y + info->offset.y;
 
+      /* Move the source rectangle to the destination position */
+
       plane->moverectangle(&plane->pinfo, rect, &offset);
+
+#ifdef CONFIG_NX_UPDATE
+      /* Notify external logic that the display has been updated */
+
+      update.pt1.x = offset.x;
+      update.pt1.y = offset.y;
+      update.pt2.x = rect->pt2.x + info->offset.x;
+      update.pt2.y = rect->pt2.y + info->offset.y;
+
+      nx_notify_rectangle(&plane->pinfo, &update);
+#endif
     }
 }
 

graphics/nxbe/nxbe_setpixel.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * graphics/nxbe/nxbe_setpixel.c
  *
- *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 
 #include <nuttx/nx/nxglib.h>
+#include <nuttx/nx/nx.h>
 
 #include "nxbe.h"
 
@@ -71,7 +72,16 @@ static void nxbe_clipfill(FAR struct nxbe_clipops_s *cops,
                           FAR const struct nxgl_rect_s *rect)
 {
   struct nxbe_setpixel_s *fillinfo = (struct nxbe_setpixel_s *)cops;
+
+  /* Set the pixel */
+  
   plane->setpixel(&plane->pinfo, &rect->pt1, fillinfo->color);
+
+#ifdef CONFIG_NX_UPDATE
+  /* Notify external logic that the display has been updated */
+
+  nx_notify_rectangle(&plane->pinfo, rect);
+#endif
 }
 
 /****************************************************************************
@@ -79,7 +89,7 @@ static void nxbe_clipfill(FAR struct nxbe_clipops_s *cops,
  ****************************************************************************/
 
 /****************************************************************************
- * Name: nxbe_fill
+ * Name: nxbe_setpixel
  *
  * Description:
  *  Fill the specified rectangle in the window with the specified color

include/nuttx/nx/nx.h

@@ -901,6 +901,32 @@ int nx_bitmap(NXWINDOW hwnd, FAR const struct nxgl_rect_s *dest,
               FAR const void *src[CONFIG_NX_NPLANES],
               FAR const struct nxgl_point_s *origin, unsigned int stride);
 
+/****************************************************************************
+ * Name: nx_notify_rectangle
+ *
+ * Description:
+ *   When CONFIG_NX_UPDATE=y, then the graphics system will callout to
+ *   inform some external module that the display has been updated.  This
+ *   would be useful in a couple for cases.
+ *
+ *   - When a serial LCD is used, but a framebuffer is used to access the
+ *     LCD.  In this case, the update callout can be used to refresh the
+ *     affected region of the display.
+ *
+ *   - When VNC is enabled.  This is case, this callout is necessary to
+ *     update the remote frame buffer to match the local framebuffer.
+ *
+ * When this feature is enabled, some external logic must provide this
+ * interface.  This is the function that will handle the notification.  It
+ * receives the rectangular region that was updated on the provided plane.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NX_UPDATE
+void nx_notify_rectangle(FAR NX_PLANEINFOTYPE *pinfo,
+                         FAR const struct nxgl_rect_s *rect);
+#endif
+
 /****************************************************************************
  * Name: nx_kbdin
  *