Fix numerous errors in trapezoid rendering and wide line drawing algorithms

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3840 42af7a65-404d-4744-a932-0658087f49c3

16 files changed, 1094 insertions, 56 deletions

diff --git a/apps/ChangeLog.txt b/apps/ChangeLog.txt
index 3acea4076..61be7e0db 100755
--- a/apps/ChangeLog.txt
+++ b/apps/ChangeLog.txt
@@ -93,3 +93,6 @@
 	  memory.
 
 6.8 2011-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
+
+	* apps/examples/nxlines:  Added a test for NX line drawing capabilities.
+
diff --git a/apps/examples/Makefile b/apps/examples/Makefile
index f5ab34a1c..f8cbd4384 100644
--- a/apps/examples/Makefile
+++ b/apps/examples/Makefile
@@ -38,9 +38,9 @@
 # Sub-directories
 
 SUBDIRS = buttons dhcpd ftpc hello helloxx hidkbd igmp mm mount nettest \
-	  nsh null nx nxffs nxflat nxhello nximage nxtext ostest pashello pipe \
-	  poll rgmp romfs sendmail serloop thttpd udp uip usbserial usbstorage \
-	  wget wlan
+	  nsh null nx nxffs nxflat nxhello nximage nxlines nxtext ostest pashello \
+	  pipe poll rgmp romfs sendmail serloop thttpd udp uip usbserial \
+	  usbstorage wget wlan
 
 # Sub-directories that might need context setup
 
@@ -55,6 +55,9 @@ endif
 ifeq ($(CONFIG_EXAMPLES_NXIMAGE_BUILTIN),y)
 CNTXTDIRS +=  nximage
 endif
+ifeq ($(CONFIG_EXAMPLES_LINES_BUILTIN),y)
+CNTXTDIRS +=  nxlines
+endif
 ifeq ($(CONFIG_EXAMPLES_NXTEXT_BUILTIN),y)
 CNTXTDIRS +=  nxtext
 endif
diff --git a/apps/examples/README.txt b/apps/examples/README.txt
index 06e84ce45..b155a3ab2 100644
--- a/apps/examples/README.txt
+++ b/apps/examples/README.txt
@@ -406,6 +406,40 @@ examples/nximage
     NOTE: As of this writing, most of the pixel depth, scaling options, and
     combinations thereof  have not been tested.
 
+examplex/nxlines
+^^^^^^^^^^^^^^^^
+
+  A very simple graphics example that just exercised the NX line drawing
+  logic.
+
+  The following configuration options can be selected:
+
+    CONFIG_EXAMPLES_NXLINES_BUILTIN -- Build the NXLINES example as a "built-in"
+      that can be executed from the NSH command line    
+    CONFIG_EXAMPLES_NXLINES_VPLANE -- The plane to select from the frame-
+      buffer driver for use in the test.  Default: 0
+    CONFIG_EXAMPLES_NXLINES_DEVNO - The LCD device to select from the LCD
+      driver for use in the test: Default: 0
+    CONFIG_EXAMPLES_NXLINES_BGCOLOR -- The color of the background.  Default
+      depends on CONFIG_EXAMPLES_NXLINES_BPP.
+    CONFIG_EXAMPLES_NXLINES_LINEWIDTH - Selects the width of the lines in
+      pixels (default: 16)
+    CONFIG_EXAMPLES_NXLINES_LINECOLOR -- The color of the lines drawn in the
+      background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP.
+    CONFIG_EXAMPLES_NXLINES_BPP -- Pixels per pixel to use.  Valid options
+      include 2, 4, 8, 16, 24, and 32.  Default is 16.
+    CONFIG_EXAMPLES_NXLINES_EXTERNINIT - The driver for the graphics device on
+      this platform requires some unusual initialization.  This is the
+      for, for example, SPI LCD/OLED devices.  If this configuration is
+      selected, then the platform code must provide an LCD initialization
+      function with a prototype like:
+
+      #ifdef CONFIG_NX_LCDDRIVER
+      FAR struct lcd_dev_s *up_nxdrvinit(unsigned int devno);
+      #else
+      FAR struct fb_vtable_s *up_nxdrvinit(unsigned int devno);
+      #endif
+
 examples/nxtext
 ^^^^^^^^^^^^^^^
 
diff --git a/apps/examples/nxlines/Makefile b/apps/examples/nxlines/Makefile
new file mode 100644
index 000000000..0c865c42d
--- /dev/null
+++ b/apps/examples/nxlines/Makefile
@@ -0,0 +1,105 @@
+############################################################################
+# apps/examples/nxlines/Makefile
+#
+#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. 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.
+# 3. Neither the name NuttX 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 BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE 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 $(TOPDIR)/.config
+-include $(TOPDIR)/Make.defs
+include $(APPDIR)/Make.defs
+
+# NuttX NX Graphics Example.
+
+ASRCS		=
+CSRCS		= nxlines_main.c nxlines_bkgd.c
+
+AOBJS		= $(ASRCS:.S=$(OBJEXT))
+COBJS		= $(CSRCS:.c=$(OBJEXT))
+
+SRCS		= $(ASRCS) $(CSRCS)
+OBJS		= $(AOBJS) $(COBJS)
+
+ifeq ($(WINTOOL),y)
+  BIN		= "${shell cygpath -w  $(APPDIR)/libapps$(LIBEXT)}"
+else
+  BIN		= "$(APPDIR)/libapps$(LIBEXT)"
+endif
+
+ROOTDEPPATH	= --dep-path .
+
+# NXLINES built-in application info
+
+APPNAME		= nxlines
+PRIORITY	= SCHED_PRIORITY_DEFAULT
+STACKSIZE	= 2048
+
+# Common build
+
+VPATH		= 
+
+all: .built
+.PHONY: context clean depend distclean
+
+$(AOBJS): %$(OBJEXT): %.S
+	$(call ASSEMBLE, $<, $@)
+
+$(COBJS): %$(OBJEXT): %.c
+	$(call COMPILE, $<, $@)
+
+.built: $(OBJS)
+	@( for obj in $(OBJS) ; do \
+		$(call ARCHIVE, $(BIN), $${obj}); \
+	done ; )
+	@touch .built
+
+.context:
+ifeq ($(CONFIG_EXAMPLES_NXLINES_BUILTIN),y)
+	$(call REGISTER,$(APPNAME),$(PRIORITY),$(STACKSIZE),$(APPNAME)_main)
+	@touch $@
+endif
+
+context: .context
+
+.depend: Makefile $(SRCS)
+	@$(MKDEP) $(ROOTDEPPATH) $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
+	@touch $@
+
+depend: .depend
+
+clean:
+	@rm -f *.o *~ .*.swp .built
+	$(call CLEAN)
+
+distclean: clean
+	@rm -f Make.dep .depend
+
+-include Make.dep
diff --git a/apps/examples/nxlines/nxlines.h b/apps/examples/nxlines/nxlines.h
new file mode 100644
index 000000000..d4b255485
--- /dev/null
+++ b/apps/examples/nxlines/nxlines.h
@@ -0,0 +1,173 @@
+/****************************************************************************
+ * examples/nxlines/nxlines.h
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name NuttX 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 BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE 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.
+ *
+ ****************************************************************************/
+
+#ifndef __APPS_EXAMPLES_NXLINES_NXLINES_H
+#define __APPS_EXAMPLES_NXLINES_NXLINES_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <semaphore.h>
+
+#include <nuttx/nx/nxglib.h>
+#include <nuttx/nx/nx.h>
+#include <nuttx/rgbcolors.h>
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/* Configuration ************************************************************/
+
+#ifndef CONFIG_NX
+#  error "NX is not enabled (CONFIG_NX)"
+#endif
+
+#ifndef CONFIG_EXAMPLES_NXLINES_VPLANE
+#    define CONFIG_EXAMPLES_NXLINES_VPLANE 0
+#endif
+
+#ifndef CONFIG_EXAMPLES_NXLINES_BPP
+#  define CONFIG_EXAMPLES_NXLINES_BPP 16
+#endif
+
+#ifndef CONFIG_EXAMPLES_NXLINES_BGCOLOR
+#  if CONFIG_EXAMPLES_NXLINES_BPP == 24 || CONFIG_EXAMPLES_NXLINES_BPP == 32
+#    define CONFIG_EXAMPLES_NXLINES_BGCOLOR RGB24_DARKGREEN
+#  elif CONFIG_EXAMPLES_NXLINES_BPP == 16
+#    define CONFIG_EXAMPLES_NXLINES_BGCOLOR RGB16_DARKGREEN
+#  else
+#    define CONFIG_EXAMPLES_NXLINES_BGCOLOR RGB8_DARKGREEN
+# endif
+#endif
+
+#ifndef CONFIG_EXAMPLES_NXLINES_LINEWIDTH
+#  define CONFIG_EXAMPLES_NXLINES_LINEWIDTH 16
+#endif
+
+#ifndef CONFIG_EXAMPLES_NXLINES_LINECOLOR
+#  if CONFIG_EXAMPLES_NXLINES_BPP == 24 || CONFIG_EXAMPLES_NXLINES_BPP == 32
+#    define CONFIG_EXAMPLES_NXLINES_LINECOLOR RGB24_YELLOW
+#  elif CONFIG_EXAMPLES_NXLINES_BPP == 16
+#    define CONFIG_EXAMPLES_NXLINES_LINECOLOR RGB16_YELLOW
+#  else
+#    define CONFIG_EXAMPLES_NXLINES_LINECOLOR RGB8_YELLOW
+# endif
+#endif
+
+/* Debug ********************************************************************/
+
+#ifdef CONFIG_CPP_HAVE_VARARGS
+#  ifdef CONFIG_DEBUG
+#    define message(...) lib_lowprintf(__VA_ARGS__)
+#    define msgflush()
+#  else
+#    define message(...) printf(__VA_ARGS__)
+#    define msgflush() fflush(stdout)
+#  endif
+#else
+#  ifdef CONFIG_DEBUG
+#    define message lib_lowprintf
+#    define msgflush()
+#  else
+#    define message printf
+#    define msgflush() fflush(stdout)
+#  endif
+#endif
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+enum exitcode_e
+{
+  NXEXIT_SUCCESS = 0,
+  NXEXIT_EXTINITIALIZE,
+  NXEXIT_FBINITIALIZE,
+  NXEXIT_FBGETVPLANE,
+  NXEXIT_LCDINITIALIZE,
+  NXEXIT_LCDGETDEV,
+  NXEXIT_NXOPEN,
+  NXEXIT_NXREQUESTBKGD,
+  NXEXIT_NXSETBGCOLOR
+};
+
+struct nxlines_data_s
+{
+  /* The NX handles */
+
+  NXHANDLE hnx;
+  NXHANDLE hbkgd;
+
+  /* The screen resolution */
+
+  nxgl_coord_t xres;
+  nxgl_coord_t yres;
+
+  volatile bool havepos;
+  sem_t sem;
+  volatile int code;
+};
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/* NXLINES state data */
+
+extern struct nxlines_data_s g_nxlines;
+
+/* NX callback vtables */
+
+extern const struct nx_callback_s g_bgcb;
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef CONFIG_EXAMPLES_NXLINES_EXTERNINIT
+extern FAR NX_DRIVERTYPE *up_nxdrvinit(unsigned int devno);
+#endif
+
+/* Background window interfaces */
+
+extern void nxlinex_test(NXWINDOW hwnd);
+
+#endif /* __APPS_EXAMPLES_NXLINES_NXLINES_H */
diff --git a/apps/examples/nxlines/nxlines_bkgd.c b/apps/examples/nxlines/nxlines_bkgd.c
new file mode 100644
index 000000000..d7666ee48
--- /dev/null
+++ b/apps/examples/nxlines/nxlines_bkgd.c
@@ -0,0 +1,271 @@
+/****************************************************************************
+ * examples/nxlines/nxlines_bkgd.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name NuttX 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 BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <debug.h>
+#include <fixedmath.h>
+
+#include <nuttx/nx/nx.h>
+#include <nuttx/nx/nxglib.h>
+
+#include "nxlines.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+#ifndef MIN
+#  define MIN(a,b) (a < b ? a : b)
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static void nxlines_redraw(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
+                        bool morem, FAR void *arg);
+static void nxlines_position(NXWINDOW hwnd, FAR const struct nxgl_size_s *size,
+                          FAR const struct nxgl_point_s *pos,
+                          FAR const struct nxgl_rect_s *bounds,
+                          FAR void *arg);
+#ifdef CONFIG_NX_MOUSE
+static void nxlines_mousein(NXWINDOW hwnd, FAR const struct nxgl_point_s *pos,
+                         uint8_t buttons, FAR void *arg);
+#endif
+
+#ifdef CONFIG_NX_KBD
+static void nxlines_kbdin(NXWINDOW hwnd, uint8_t nch, FAR const uint8_t *ch,
+                       FAR void *arg);
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* Background window call table */
+
+const struct nx_callback_s g_bgcb =
+{
+  nxlines_redraw,   /* redraw */
+  nxlines_position  /* position */
+#ifdef CONFIG_NX_MOUSE
+  , nxlines_mousein /* mousein */
+#endif
+#ifdef CONFIG_NX_KBD
+  , nxlines_kbdin   /* my kbdin */
+#endif
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxlines_redraw
+ ****************************************************************************/
+
+static void nxlines_redraw(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
+                        bool more, FAR void *arg)
+{
+  gvdbg("hwnd=%p rect={(%d,%d),(%d,%d)} more=%s\n",
+         hwnd, rect->pt1.x, rect->pt1.y, rect->pt2.x, rect->pt2.y,
+         more ? "true" : "false");
+}
+
+/****************************************************************************
+ * Name: nxlines_position
+ ****************************************************************************/
+
+static void nxlines_position(NXWINDOW hwnd, FAR const struct nxgl_size_s *size,
+                          FAR const struct nxgl_point_s *pos,
+                          FAR const struct nxgl_rect_s *bounds,
+                          FAR void *arg)
+{
+  /* Report the position */
+
+  gvdbg("hwnd=%p size=(%d,%d) pos=(%d,%d) bounds={(%d,%d),(%d,%d)}\n",
+        hwnd, size->w, size->h, pos->x, pos->y,
+        bounds->pt1.x, bounds->pt1.y, bounds->pt2.x, bounds->pt2.y);
+
+  /* Have we picked off the window bounds yet? */
+
+  if (!g_nxlines.havepos)
+    {
+      /* Save the background window handle */
+
+      g_nxlines.hbkgd = hwnd;
+
+      /* Save the window limits */
+
+      g_nxlines.xres = bounds->pt2.x + 1;
+      g_nxlines.yres = bounds->pt2.y + 1;
+
+      g_nxlines.havepos = true;
+      sem_post(&g_nxlines.sem);
+      gvdbg("Have xres=%d yres=%d\n", g_nxlines.xres, g_nxlines.yres);
+    }
+}
+
+/****************************************************************************
+ * Name: nxlines_mousein
+ ****************************************************************************/
+
+#ifdef CONFIG_NX_MOUSE
+static void nxlines_mousein(NXWINDOW hwnd, FAR const struct nxgl_point_s *pos,
+                         uint8_t buttons, FAR void *arg)
+{
+  message("nxlines_mousein: hwnd=%p pos=(%d,%d) button=%02x\n",
+          hwnd,  pos->x, pos->y, buttons);
+}
+#endif
+
+/****************************************************************************
+ * Name: nxlines_kbdin
+ ****************************************************************************/
+
+#ifdef CONFIG_NX_KBD
+static void nxlines_kbdin(NXWINDOW hwnd, uint8_t nch, FAR const uint8_t *ch,
+                       FAR void *arg)
+{
+  gvdbg("hwnd=%p nch=%d\n", hwnd, nch);
+
+   /* In this example, there is no keyboard so a keyboard event is not
+    * expected.
+    */
+
+   message("nxlines_kbdin: Unexpected keyboard callback\n");
+}
+#endif
+
+ /****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxlinex_test
+ *
+ * Description:
+ *   Print "Hello, World!" in the center of the display.
+ *
+ ****************************************************************************/
+
+void nxlinex_test(NXWINDOW hwnd)
+{
+  struct nxgl_vector_s vector;
+  struct nxgl_vector_s previous;
+  nxgl_mxpixel_t color[CONFIG_NX_NPLANES];
+  nxgl_coord_t xcenter;
+  nxgl_coord_t ycenter;
+  nxgl_coord_t radius;
+  nxgl_coord_t halfx;
+  nxgl_coord_t halfy;
+  b16_t angle;
+  int ret;
+
+  /* Get the radius and center of the circle */
+
+  radius  = MIN(g_nxlines.yres, g_nxlines.xres) >> 1;
+  xcenter = g_nxlines.xres >> 1;
+  ycenter = g_nxlines.yres >> 1;
+
+  angle = 0;
+  previous.pt1.x = xcenter;
+  previous.pt1.y = ycenter;
+  previous.pt2.x = xcenter;
+  previous.pt2.y = ycenter;
+
+  for (;;)
+    {
+       /* Determine the position of the line on this pass */
+
+       halfx = b16toi(b16muli(b16sin(angle), radius));
+       halfy = b16toi(b16muli(b16cos(angle), radius));
+
+       vector.pt1.x = xcenter + halfx;
+       vector.pt1.y = ycenter + halfy;
+       vector.pt2.x = xcenter - halfx;
+       vector.pt2.y = ycenter - halfy;
+
+       message("Angle: %04x vector: (%d,%d)->(%d,%d)\n",
+               angle, vector.pt1.x, vector.pt1.y, vector.pt2.x, vector.pt2.y);
+
+       /* Clear the previous line */
+
+       color[0] = CONFIG_EXAMPLES_NXLINES_BGCOLOR;
+       ret = nx_drawline((NXWINDOW)hwnd, &previous, CONFIG_EXAMPLES_NXLINES_LINEWIDTH, color);
+       if (ret < 0)
+         {
+           message("nxlinex_test: nx_drawline failed clearing: %d\n", ret);
+         }
+
+       /* Draw the new line */
+
+       color[0] = CONFIG_EXAMPLES_NXLINES_LINECOLOR;
+       ret = nx_drawline((NXWINDOW)hwnd, &vector, CONFIG_EXAMPLES_NXLINES_LINEWIDTH, color);
+       if (ret < 0)
+         {
+           message("nxlinex_test: nx_drawline failed clearing: %d\n", ret);
+         }
+
+       /* Set up for the next time throught the loop then sleep for a bit. */
+
+       angle += b16PI / 16;                      /* 32 angular positions in full circle */
+       if (angle > (31 *  (2 * b16PI) / 16))     /* Wrap back to zero.. allowing for slop */
+         {
+           angle = 0;
+         }
+
+       memcpy(&previous, &vector, sizeof(struct nxgl_vector_s));
+       usleep(500*1000);
+    }
+}
diff --git a/apps/examples/nxlines/nxlines_main.c b/apps/examples/nxlines/nxlines_main.c
new file mode 100644
index 000000000..551642a24
--- /dev/null
+++ b/apps/examples/nxlines/nxlines_main.c
@@ -0,0 +1,280 @@
+/****************************************************************************
+ * examples/nxlines/nxlines_main.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name NuttX 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 BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <time.h>
+#include <string.h>
+#include <sched.h>
+#include <errno.h>
+#include <debug.h>
+
+#ifdef CONFIG_NX_LCDDRIVER
+#  include <nuttx/lcd/lcd.h>
+#else
+#  include <nuttx/fb.h>
+#endif
+
+#include <nuttx/arch.h>
+#include <nuttx/nx/nx.h>
+#include <nuttx/nx/nxglib.h>
+
+#include "nxlines.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Configuration ************************************************************/
+/* If not specified, assume that the hardware supports one video plane */
+
+#ifndef CONFIG_EXAMPLES_NXLINES_VPLANE
+#  define CONFIG_EXAMPLES_NXLINES_VPLANE 0
+#endif
+
+/* If not specified, assume that the hardware supports one LCD device */
+
+#ifndef CONFIG_EXAMPLES_NXLINES_DEVNO
+#  define CONFIG_EXAMPLES_NXLINES_DEVNO 0
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+struct nxlines_data_s g_nxlines =
+{
+  NULL,          /* hnx */
+  NULL,          /* hbkgd */
+  0,             /* xres */
+  0,             /* yres */
+  false,         /* havpos */
+  { 0 },         /* sem */
+  NXEXIT_SUCCESS /* exit code */
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxlines_initialize
+ ****************************************************************************/
+
+static inline int nxlines_initialize(void)
+{
+  FAR NX_DRIVERTYPE *dev;
+
+#if defined(CONFIG_EXAMPLES_NXLINES_EXTERNINIT)
+  /* Use external graphics driver initialization */
+
+  message("nxlines_initialize: Initializing external graphics device\n");
+  dev = up_nxdrvinit(CONFIG_EXAMPLES_NXLINES_DEVNO);
+  if (!dev)
+    {
+      message("nxlines_initialize: up_nxdrvinit failed, devno=%d\n",
+              CONFIG_EXAMPLES_NXLINES_DEVNO);
+      g_nxlines.code = NXEXIT_EXTINITIALIZE;
+      return ERROR;
+    }
+
+#elif defined(CONFIG_NX_LCDDRIVER)
+  int ret;
+
+  /* Initialize the LCD device */
+
+  message("nxlines_initialize: Initializing LCD\n");
+  ret = up_lcdinitialize();
+  if (ret < 0)
+    {
+      message("nxlines_initialize: up_lcdinitialize failed: %d\n", -ret);
+      g_nxlines.code = NXEXIT_LCDINITIALIZE;
+      return ERROR;
+    }
+
+  /* Get the device instance */
+
+  dev = up_lcdgetdev(CONFIG_EXAMPLES_NXLINES_DEVNO);
+  if (!dev)
+    {
+      message("nxlines_initialize: up_lcdgetdev failed, devno=%d\n", CONFIG_EXAMPLES_NXLINES_DEVNO);
+      g_nxlines.code = NXEXIT_LCDGETDEV;
+      return ERROR;
+    }
+
+  /* Turn the LCD on at 75% power */
+
+  (void)dev->setpower(dev, ((3*CONFIG_LCD_MAXPOWER + 3)/4));
+#else
+  int ret;
+
+  /* Initialize the frame buffer device */
+
+  message("nxlines_initialize: Initializing framebuffer\n");
+  ret = up_fbinitialize();
+  if (ret < 0)
+    {
+      message("nxlines_initialize: up_fbinitialize failed: %d\n", -ret);
+      g_nxlines.code = NXEXIT_FBINITIALIZE;
+      return ERROR;
+    }
+
+  dev = up_fbgetvplane(CONFIG_EXAMPLES_NXLINES_VPLANE);
+  if (!dev)
+    {
+      message("nxlines_initialize: up_fbgetvplane failed, vplane=%d\n", CONFIG_EXAMPLES_NXLINES_VPLANE);
+      g_nxlines.code = NXEXIT_FBGETVPLANE;
+      return ERROR;
+    }
+#endif
+
+  /* Then open NX */
+
+  message("nxlines_initialize: Open NX\n");
+  g_nxlines.hnx = nx_open(dev);
+  if (!g_nxlines.hnx)
+    {
+      message("nxlines_initialize: nx_open failed: %d\n", errno);
+      g_nxlines.code = NXEXIT_NXOPEN;
+      return ERROR;
+    }
+  return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: user_start/nxlines_main
+ ****************************************************************************/
+
+#ifdef CONFIG_EXAMPLES_NXLINES_BUILTIN
+#  define MAIN_NAME nxlines_main
+#  define MAIN_NAME_STRING "nxlines_main"
+#else
+#  define MAIN_NAME user_start
+#  define MAIN_NAME_STRING "user_start"
+#endif
+
+int MAIN_NAME(int argc, char *argv[])
+{
+  nxgl_mxpixel_t color;
+  int ret;
+
+  /* Initialize NX */
+
+  ret = nxlines_initialize();
+  message(MAIN_NAME_STRING ": NX handle=%p\n", g_nxlines.hnx);
+  if (!g_nxlines.hnx || ret < 0)
+    {
+      message(MAIN_NAME_STRING ": Failed to get NX handle: %d\n", errno);
+      g_nxlines.code = NXEXIT_NXOPEN;
+      goto errout;
+    }
+
+  /* Set the background to the configured background color */
+
+  message(MAIN_NAME_STRING ": Set background color=%d\n",
+          CONFIG_EXAMPLES_NXLINES_BGCOLOR);
+
+  color = CONFIG_EXAMPLES_NXLINES_BGCOLOR;
+  ret = nx_setbgcolor(g_nxlines.hnx, &color);
+  if (ret < 0)
+    {
+      message(MAIN_NAME_STRING ": nx_setbgcolor failed: %d\n", errno);
+      g_nxlines.code = NXEXIT_NXSETBGCOLOR;
+      goto errout_with_nx;
+    }
+
+  /* Get the background window */
+
+  ret = nx_requestbkgd(g_nxlines.hnx, &g_bgcb, NULL);
+  if (ret < 0)
+    {
+      message(MAIN_NAME_STRING ": nx_setbgcolor failed: %d\n", errno);
+      g_nxlines.code = NXEXIT_NXREQUESTBKGD;
+      goto errout_with_nx;
+    }
+
+  /* Wait until we have the screen resolution.  We'll have this immediately
+   * unless we are dealing with the NX server.
+   */
+
+  while (!g_nxlines.havepos)
+    {
+      (void)sem_wait(&g_nxlines.sem);
+    }
+  message(MAIN_NAME_STRING ": Screen resolution (%d,%d)\n", g_nxlines.xres, g_nxlines.yres);
+
+  /* Now, say perform the lines (these test does not return so the remaining
+   * logic is cosmetic). 
+   */
+
+  nxlinex_test(g_nxlines.hbkgd);
+
+  /* Release background */
+
+  (void)nx_releasebkgd(g_nxlines.hbkgd);
+
+  /* Close NX */
+
+errout_with_nx:
+  message(MAIN_NAME_STRING ": Close NX\n");
+  nx_close(g_nxlines.hnx);
+errout:
+  return g_nxlines.code;
+}
diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index fe9e22961..b663b8f55 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -1971,4 +1971,4 @@
 	* arch/arm/src/lpc17xx/chip.h:  Fix some chip memory configuration errors
 	  for the LPC1764, LPC1756, and LPC1754 (submitted by Li Zhuoy (Lzzy))
 	* arch/arm/src/lpc17xx/lpc17_can.h:  Revised CAN driver submitted by
-	   Li Zhuoy (Lzzy).
+	   Li Zhuoy (Lzzy).  The driver now supports both CAN1 and CAN2.
diff --git a/nuttx/configs/sim/nx/defconfig b/nuttx/configs/sim/nx/defconfig
index d4688ea49..9859e74c5 100644
--- a/nuttx/configs/sim/nx/defconfig
+++ b/nuttx/configs/sim/nx/defconfig
@@ -525,6 +525,38 @@ CONFIG_EXAMPLES_NX_SERVERPRIO=120
 CONFIG_EXAMPLES_NX_NOTIFYSIGNO=4
 
 #
+# Settings for examples/nxlines
+#
+# CONFIG_EXAMPLES_NXLINES_BUILTIN -- Build the NXLINES example as a "built-in"
+#   that can be executed from the NSH command line
+# CONFIG_EXAMPLES_NXLINES_VPLANE -- The plane to select from the frame-
+#   buffer driver for use in the test.  Default: 0
+# CONFIG_EXAMPLES_NXLINES_DEVNO - The LCD device to select from the LCD
+#   driver for use in the test: Default: 0
+# CONFIG_EXAMPLES_NXLINES_BGCOLOR -- The color of the background.  Default
+#   depends on CONFIG_EXAMPLES_NXLINES_BPP.
+# CONFIG_EXAMPLES_NXLINES_LINEWIDTH - Selects the width of the lines in
+#   pixels (default: 16)
+# CONFIG_EXAMPLES_NXLINES_LINECOLOR -- The color of the lines drawn in the
+#   background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP.
+# CONFIG_EXAMPLES_NXLINES_BPP -- Pixels per pixel to use.  Valid options
+#   include 2, 4, 8, 16, 24, and 32.  Default is 16.
+# CONFIG_EXAMPLES_NXLINES_EXTERNINIT - The driver for the graphics device on
+#   this platform requires some unusual initialization.  This is the
+#   for, for example, SPI LCD/OLED devices.  If this configuration is
+#   selected, then the platform code must provide an LCD initialization
+#   function.
+#
+CONFIG_EXAMPLES_NXLINES_BUILTIN=n
+CONFIG_EXAMPLES_NXLINES_VPLANE=0
+CONFIG_EXAMPLES_NXLINES_DEVNO=0
+#CONFIG_EXAMPLES_NXLINES_BGCOLOR=
+CONFIG_EXAMPLES_NXLINES_LINEWIDTH=16
+#CONFIG_EXAMPLES_NXLINES_LINECOLOR=
+CONFIG_EXAMPLES_NXLINES_BPP=CONFIG_SIM_FBBPP
+CONFIG_EXAMPLES_NXLINES_EXTERNINIT=n
+
+#
 # Settings for examples/mount
 CONFIG_EXAMPLES_MOUNT_DEVNAME="/dev/ram0"
 #CONFIG_EXAMPLES_MOUNT_NSECTORS=2048
diff --git a/nuttx/configs/stm3210e-eval/nsh2/defconfig b/nuttx/configs/stm3210e-eval/nsh2/defconfig
index 3d51891a5..987127cfd 100644
--- a/nuttx/configs/stm3210e-eval/nsh2/defconfig
+++ b/nuttx/configs/stm3210e-eval/nsh2/defconfig
@@ -1133,6 +1133,38 @@ CONFIG_EXAMPLES_NXIMAGE_YSCALE2p0=n
 CONFIG_EXAMPLES_NXIMAGE_EXTERNINIT=n
 
 #
+# Settings for examples/nxlines
+#
+# CONFIG_EXAMPLES_NXLINES_BUILTIN -- Build the NXLINES example as a "built-in"
+#   that can be executed from the NSH command line
+# CONFIG_EXAMPLES_NXLINES_VPLANE -- The plane to select from the frame-
+#   buffer driver for use in the test.  Default: 0
+# CONFIG_EXAMPLES_NXLINES_DEVNO - The LCD device to select from the LCD
+#   driver for use in the test: Default: 0
+# CONFIG_EXAMPLES_NXLINES_BGCOLOR -- The color of the background.  Default
+#   depends on CONFIG_EXAMPLES_NXLINES_BPP.
+# CONFIG_EXAMPLES_NXLINES_LINEWIDTH - Selects the width of the lines in
+#   pixels (default: 16)
+# CONFIG_EXAMPLES_NXLINES_LINECOLOR -- The color of the lines drawn in the
+#   background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP.
+# CONFIG_EXAMPLES_NXLINES_BPP -- Pixels per pixel to use.  Valid options
+#   include 2, 4, 8, 16, 24, and 32.  Default is 16.
+# CONFIG_EXAMPLES_NXLINES_EXTERNINIT - The driver for the graphics device on
+#   this platform requires some unusual initialization.  This is the
+#   for, for example, SPI LCD/OLED devices.  If this configuration is
+#   selected, then the platform code must provide an LCD initialization
+#   function.
+#
+CONFIG_EXAMPLES_NXLINES_BUILTIN=n
+CONFIG_EXAMPLES_NXLINES_VPLANE=0
+CONFIG_EXAMPLES_NXLINES_DEVNO=0
+CONFIG_EXAMPLES_NXLINES_BGCOLOR=0x0320
+CONFIG_EXAMPLES_NXLINES_LINEWIDTH=16
+CONFIG_EXAMPLES_NXLINES_LINECOLOR=0xffe0
+CONFIG_EXAMPLES_NXLINES_BPP=16
+CONFIG_EXAMPLES_NXLINES_EXTERNINIT=n
+
+#
 # Settings for examples/usbstorage
 #
 # CONFIG_EXAMPLES_USBSTRG_BUILTIN
diff --git a/nuttx/configs/stm3210e-eval/nx/defconfig b/nuttx/configs/stm3210e-eval/nx/defconfig
index 2a6c2846d..894f569f5 100644
--- a/nuttx/configs/stm3210e-eval/nx/defconfig
+++ b/nuttx/configs/stm3210e-eval/nx/defconfig
@@ -1084,6 +1084,38 @@ CONFIG_EXAMPLES_NXIMAGE_YSCALE2p0=n
 CONFIG_EXAMPLES_NXIMAGE_EXTERNINIT=n
 
 #
+# Settings for examples/nxlines
+#
+# CONFIG_EXAMPLES_NXLINES_BUILTIN -- Build the NXLINES example as a "built-in"
+#   that can be executed from the NSH command line
+# CONFIG_EXAMPLES_NXLINES_VPLANE -- The plane to select from the frame-
+#   buffer driver for use in the test.  Default: 0
+# CONFIG_EXAMPLES_NXLINES_DEVNO - The LCD device to select from the LCD
+#   driver for use in the test: Default: 0
+# CONFIG_EXAMPLES_NXLINES_BGCOLOR -- The color of the background.  Default
+#   depends on CONFIG_EXAMPLES_NXLINES_BPP.
+# CONFIG_EXAMPLES_NXLINES_LINEWIDTH - Selects the width of the lines in
+#   pixels (default: 16)
+# CONFIG_EXAMPLES_NXLINES_LINECOLOR -- The color of the lines drawn in the
+#   background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP.
+# CONFIG_EXAMPLES_NXLINES_BPP -- Pixels per pixel to use.  Valid options
+#   include 2, 4, 8, 16, 24, and 32.  Default is 16.
+# CONFIG_EXAMPLES_NXLINES_EXTERNINIT - The driver for the graphics device on
+#   this platform requires some unusual initialization.  This is the
+#   for, for example, SPI LCD/OLED devices.  If this configuration is
+#   selected, then the platform code must provide an LCD initialization
+#   function.
+#
+CONFIG_EXAMPLES_NXLINES_BUILTIN=n
+CONFIG_EXAMPLES_NXLINES_VPLANE=0
+CONFIG_EXAMPLES_NXLINES_DEVNO=0
+CONFIG_EXAMPLES_NXLINES_BGCOLOR=0x0320
+CONFIG_EXAMPLES_NXLINES_LINEWIDTH=16
+CONFIG_EXAMPLES_NXLINES_LINECOLOR=0xffe0
+CONFIG_EXAMPLES_NXLINES_BPP=16
+CONFIG_EXAMPLES_NXLINES_EXTERNINIT=n
+
+#
 # Stack and heap information
 #
 # CONFIG_BOOT_RUNFROMFLASH - Some configurations support XIP
diff --git a/nuttx/configs/stm3210e-eval/nxtext/defconfig b/nuttx/configs/stm3210e-eval/nxtext/defconfig
index ca7597656..dc66b0fa8 100644
--- a/nuttx/configs/stm3210e-eval/nxtext/defconfig
+++ b/nuttx/configs/stm3210e-eval/nxtext/defconfig
@@ -1110,7 +1110,7 @@ CONFIG_EXAMPLES_NXTEXT_NOTIFYSIGNO=4
 # Settings for examples/nximage
 #
 # CONFIG_EXAMPLES_NXIMAGE_BUILTIN -- Build the NXIMAGE example as a "built-in"
-#   that can be executed from the NSH command line    
+#   that can be executed from the NSH command line
 # CONFIG_EXAMPLES_NXIMAGE_VPLANE -- The plane to select from the frame-
 #   buffer driver for use in the test.  Default: 0
 # CONFIG_EXAMPLES_NXIMAGE_DEVNO - The LCD device to select from the LCD
@@ -1144,6 +1144,38 @@ CONFIG_EXAMPLES_NXIMAGE_YSCALE2p0=n
 CONFIG_EXAMPLES_NXIMAGE_EXTERNINIT=n
 
 #
+# Settings for examples/nxlines
+#
+# CONFIG_EXAMPLES_NXLINES_BUILTIN -- Build the NXLINES example as a "built-in"
+#   that can be executed from the NSH command line
+# CONFIG_EXAMPLES_NXLINES_VPLANE -- The plane to select from the frame-
+#   buffer driver for use in the test.  Default: 0
+# CONFIG_EXAMPLES_NXLINES_DEVNO - The LCD device to select from the LCD
+#   driver for use in the test: Default: 0
+# CONFIG_EXAMPLES_NXLINES_BGCOLOR -- The color of the background.  Default
+#   depends on CONFIG_EXAMPLES_NXLINES_BPP.
+# CONFIG_EXAMPLES_NXLINES_LINEWIDTH - Selects the width of the lines in
+#   pixels (default: 16)
+# CONFIG_EXAMPLES_NXLINES_LINECOLOR -- The color of the lines drawn in the
+#   background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP.
+# CONFIG_EXAMPLES_NXLINES_BPP -- Pixels per pixel to use.  Valid options
+#   include 2, 4, 8, 16, 24, and 32.  Default is 16.
+# CONFIG_EXAMPLES_NXLINES_EXTERNINIT - The driver for the graphics device on
+#   this platform requires some unusual initialization.  This is the
+#   for, for example, SPI LCD/OLED devices.  If this configuration is
+#   selected, then the platform code must provide an LCD initialization
+#   function.
+#
+CONFIG_EXAMPLES_NXLINES_BUILTIN=n
+CONFIG_EXAMPLES_NXLINES_VPLANE=0
+CONFIG_EXAMPLES_NXLINES_DEVNO=0
+CONFIG_EXAMPLES_NXLINES_BGCOLOR=0x0320
+CONFIG_EXAMPLES_NXLINES_LINEWIDTH=16
+CONFIG_EXAMPLES_NXLINES_LINECOLOR=0xffe0
+CONFIG_EXAMPLES_NXLINES_BPP=16
+CONFIG_EXAMPLES_NXLINES_EXTERNINIT=n
+
+#
 # Stack and heap information
 #
 # CONFIG_BOOT_RUNFROMFLASH - Some configurations support XIP
diff --git a/nuttx/graphics/nxglib/fb/nxglib_filltrapezoid.c b/nuttx/graphics/nxglib/fb/nxglib_filltrapezoid.c
index 2f16b58ed..4f0c2f072 100644
--- a/nuttx/graphics/nxglib/fb/nxglib_filltrapezoid.c
+++ b/nuttx/graphics/nxglib/fb/nxglib_filltrapezoid.c
@@ -115,8 +115,8 @@ void NXGL_FUNCNAME(nxgl_filltrapezoid,NXGLIB_SUFFIX)(
 
   /* Get the top run position and the number of rows to draw */
 
-  x1 = trap->top.x1;
-  x2 = trap->top.x2;
+  x1    = trap->top.x1;
+  x2    = trap->top.x2;
 
   /* Calculate the number of rows to render */
 
@@ -133,6 +133,15 @@ void NXGL_FUNCNAME(nxgl_filltrapezoid,NXGLIB_SUFFIX)(
 
   if (y1 < bounds->pt1.y)
     {
+      /* Is the entire trapezoid "above" the clipping window? */
+
+      if (y2 < bounds->pt1.y)
+        {
+          /* Yes.. then do nothing */
+
+          return;
+        }
+
       /* Calculate the x values for the new top run */
 
       int dy = bounds->pt1.y - y1;
@@ -147,6 +156,15 @@ void NXGL_FUNCNAME(nxgl_filltrapezoid,NXGLIB_SUFFIX)(
 
   if (y2 > bounds->pt2.y)
     {
+      /* Is the entire trapezoid "below" the clipping window? */
+
+      if (y1 > bounds->pt2.y)
+        {
+          /* Yes.. then do nothing */
+
+          return;
+        }
+
       /* Clip and re-calculate the number of rows to render */
 
       y2     = bounds->pt2.y;
diff --git a/nuttx/graphics/nxglib/lcd/nxglib_filltrapezoid.c b/nuttx/graphics/nxglib/lcd/nxglib_filltrapezoid.c
index 0c8611088..970bbf829 100644
--- a/nuttx/graphics/nxglib/lcd/nxglib_filltrapezoid.c
+++ b/nuttx/graphics/nxglib/lcd/nxglib_filltrapezoid.c
@@ -124,14 +124,23 @@ void NXGL_FUNCNAME(nxgl_filltrapezoid,NXGLIB_SUFFIX)
 
   /* Calculate the slope of the left and right side of the trapezoid */
 
-  dy    = boty - topy;
-  dx1dy = b16divi((botx1 - topx1), dy);
-  dx2dy = b16divi((botx2 - topx2), dy);
+  dy     = boty - topy;
+  dx1dy  = b16divi((botx1 - topx1), dy);
+  dx2dy  = b16divi((botx2 - topx2), dy);
 
   /* Perform vertical clipping */
 
   if (topy < bounds->pt1.y)
     {
+      /* Is the entire trapezoid "above" the clipping window? */
+
+      if (boty < bounds->pt1.y)
+        {
+          /* Yes.. then do nothing */
+
+          return;
+        }
+
       /* Calculate the x values for the new top run */
 
       dy      = bounds->pt1.y - topy;
@@ -145,6 +154,15 @@ void NXGL_FUNCNAME(nxgl_filltrapezoid,NXGLIB_SUFFIX)
 
   if (boty > bounds->pt2.y)
     {
+      /* Is the entire trapezoid "below" the clipping window? */
+
+      if (topy > bounds->pt2.y)
+        {
+          /* Yes.. then do nothing */
+
+          return;
+        }
+
       /* Calculate the x values for the new bottom run */
 
       dy      = boty - bounds->pt2.y;
diff --git a/nuttx/graphics/nxglib/nxglib_runoffset.c b/nuttx/graphics/nxglib/nxglib_runoffset.c
index 31d0dd163..f66d73674 100644
--- a/nuttx/graphics/nxglib/nxglib_runoffset.c
+++ b/nuttx/graphics/nxglib/nxglib_runoffset.c
@@ -70,7 +70,7 @@
  * Name: nxgl_runoffset
  *
  * Description:
- *   Offset the run position by the specified dx, dy values.
+ *   Offset the run position by the specified (integer) dx, dy values.
  *
  ****************************************************************************/
 
@@ -79,7 +79,7 @@ void nxgl_runoffset(FAR struct nxgl_run_s *dest,
                     nxgl_coord_t dx, nxgl_coord_t dy)
 {
   b16_t b16dx = itob16(dx);
-  dest->x1  += b16dx;
-  dest->x2  += b16dx;
-  dest->y   += dy;
+  dest->x1    = src->x1 + b16dx;
+  dest->x2    = src->x2 + b16dx;
+  dest->y     = src->y  + dy;
 }
diff --git a/nuttx/graphics/nxglib/nxglib_splitline.c b/nuttx/graphics/nxglib/nxglib_splitline.c
index 7be9cc115..eb2906e3f 100644
--- a/nuttx/graphics/nxglib/nxglib_splitline.c
+++ b/nuttx/graphics/nxglib/nxglib_splitline.c
@@ -112,15 +112,16 @@ int nxgl_splitline(FAR struct nxgl_vector_s *vector,
                    nxgl_coord_t linewidth)
 {
   struct nxgl_vector_s line;
-  struct nxgl_point_s pt;
   nxgl_coord_t iheight;
   nxgl_coord_t iwidth;
+  nxgl_coord_t iy;
   nxgl_coord_t triheight;
-  nxgl_coord_t adjwidth;
-  nxgl_coord_t xoffset;
-  nxgl_coord_t halfoffset;
   nxgl_coord_t halfheight;
+  b16_t adjwidth;
+  b16_t xoffset;
+  b16_t halfoffset;
   b16_t angle;
+  b16_t b16x;
 
   /* First, check the linewidth */
 
@@ -226,13 +227,17 @@ int nxgl_splitline(FAR struct nxgl_vector_s *vector,
 
   angle        = b16atan2(itob16(iheight), itob16(iwidth));
   triheight    = b16toi(linewidth * b16cos(angle));
-  adjwidth     = b16toi(b16divb16(itob16(linewidth), b16sin(angle)));
-  xoffset      = (linewidth * linewidth + (adjwidth >> 1)) / adjwidth;
+  adjwidth     = b16divb16(itob16(linewidth), b16sin(angle));
+  xoffset      = itob16(linewidth * linewidth);
+  xoffset      = b16divb16(xoffset, adjwidth);
 
   halfoffset   = (xoffset   >> 1);
   halfheight   = (triheight >> 1);
 
-  /* Return the top triangle (if there is one) */
+  /* Return the top triangle (if there is one).  NOTE that the horizontal
+   * (z) positions are represented with 16 bits of fraction.  The vertical
+   * (y) positions, on the other hand, are integer.
+   */
 
   if (triheight > 0)
     {
@@ -240,53 +245,53 @@ int nxgl_splitline(FAR struct nxgl_vector_s *vector,
         {
           /* Line is going "south east" */
 
-          pt.x = line.pt1.x - halfoffset;
-          pt.y = line.pt1.y + halfheight;
+          b16x = itob16(line.pt1.x) - halfoffset;
+          iy   = line.pt1.y + halfheight;
 
-          traps[0].top.x1 = pt.x + xoffset;
+          traps[0].top.x1 = b16x + xoffset;
           traps[0].top.x2 = traps[0].top.x1;
-          traps[0].top.y  = pt.y - triheight + 1;
-          traps[0].bot.x1 = pt.x;
-          traps[0].bot.x2 = pt.x + adjwidth - 1;
-          traps[0].bot.y  = pt.y;
-
-          pt.x = line.pt2.x + halfoffset;
-          pt.y = line.pt2.y - halfheight;
-
-          traps[2].top.x1 = pt.x - adjwidth + 1;
-          traps[2].top.x2 = pt.x;
-          traps[2].top.y  = pt.y;
-          traps[2].bot.x1 = pt.x - xoffset;
+          traps[0].top.y  = iy - triheight + 1;
+          traps[0].bot.x1 = b16x;
+          traps[0].bot.x2 = b16x + adjwidth - b16ONE;
+          traps[0].bot.y  = iy;
+
+          b16x = itob16(line.pt2.x) + halfoffset;
+          iy   = itob16(line.pt2.y) - halfheight;
+
+          traps[2].top.x1 = b16x - adjwidth + b16ONE;
+          traps[2].top.x2 = b16x;
+          traps[2].top.y  = iy;
+          traps[2].bot.x1 = b16x - xoffset;
           traps[2].bot.x2 = traps[2].bot.x1;
-          traps[2].bot.y  = pt.y + triheight - 1;
+          traps[2].bot.y  = iy + triheight - 1;
         }
       else
         {
           /* Line is going "south west" */
 
-          pt.x = line.pt1.x + halfoffset;
-          pt.y = line.pt1.y + halfheight;
+          b16x = itob16(line.pt1.x) + halfoffset;
+          iy   = itob16(line.pt1.y) + halfheight;
 
-          traps[0].top.x1 = pt.x - xoffset;
+          traps[0].top.x1 = b16x - xoffset;
           traps[0].top.x2 = traps[0].top.x1;
-          traps[0].top.y  = pt.y - triheight + 1;
-          traps[0].bot.x1 = pt.x - adjwidth + 1;
-          traps[0].bot.x2 = pt.x;
-          traps[0].bot.y  = pt.y;
-
-          pt.x = line.pt2.x - halfoffset;
-          pt.y = line.pt2.y - halfheight;
-
-          traps[2].top.x1 = pt.x;
-          traps[2].top.x2 = pt.x + adjwidth - 1;
-          traps[2].top.y  = pt.y;
-          traps[2].bot.x1 = pt.x + xoffset;
+          traps[0].top.y  = iy - triheight + 1;
+          traps[0].bot.x1 = b16x - adjwidth + b16ONE;
+          traps[0].bot.x2 = b16x;
+          traps[0].bot.y  = iy;
+
+          b16x = itob16(line.pt2.x) - halfoffset;
+          iy   = itob16(line.pt2.y) - halfheight;
+
+          traps[2].top.x1 = b16x;
+          traps[2].top.x2 = b16x + adjwidth - b16ONE;
+          traps[2].top.y  = iy;
+          traps[2].bot.x1 = b16x + xoffset;
           traps[2].bot.x2 = traps[2].bot.x1;
-          traps[2].bot.y  = pt.y + triheight - 1;
+          traps[2].bot.y  = iy + triheight - 1;
         }
 
       /* The center parallelogram is the horizontal edge of each triangle.
-       * Note the minor inefficency: that horizontal edge is drawn twice.
+       * Note the minor inefficency: that horizontal edges are drawn twice.
        */
 
       traps[1].top.x1 = traps[0].bot.x1;
@@ -304,11 +309,11 @@ int nxgl_splitline(FAR struct nxgl_vector_s *vector,
    * bottom.  Just return the center parallelogram.
    */
 
-  traps[1].top.x1 = line.pt1.x - halfoffset;
+  traps[1].top.x1 = itob16(line.pt1.x) - halfoffset;
   traps[1].top.x2 = traps[1].top.x1 + adjwidth - 1;
   traps[1].top.y  = line.pt1.y;
  
-  traps[1].bot.x1 = line.pt2.x - halfoffset;
+  traps[1].bot.x1 = itob16(line.pt2.x) -  halfoffset;
   traps[1].bot.x2 = traps[1].bot.x1 + adjwidth - 1;
   traps[1].bot.y  = line.pt2.y;
   return 1;