diff --git a/ChangeLog b/ChangeLog
index 1e2c2732ab..c4350e2440 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2019,5 +2019,6 @@
 	* arch/arm/src/kinetis/kinetis_sdhc.c: SDHC driver for Kinetis parts.
 	  Initially check-in is just a crude port of the STM32 SDIO driver.
 	  Much more is needed.
-
+	* graphics/, include/nuttx/nx:  Add new NX interfaces for drawing
+  	  circles -- both circular outlines and filled circles.
 
diff --git a/Documentation/NXGraphicsSubsystem.html b/Documentation/NXGraphicsSubsystem.html
index 9b8c84c341..121301030a 100644
--- a/Documentation/NXGraphicsSubsystem.html
+++ b/Documentation/NXGraphicsSubsystem.html
@@ -817,7 +817,7 @@ int nxgl_splitline(FAR struct nxgl_vector_s *vector, FAR struct nxgl_trapezoid_s
 <h3>2.2.20 <a name="nxglcirclepts"><code>nxgl_circlepts</code></a></h3>
 <ul><pre>
 #include &lt;nuttx/nx/nxglib.h&gt;
-void nxgl_circlepts(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
+void nxgl_circlepts(FAR const struct nxgl_point_s *center, nxgl_coord_t radius,
                     FAR struct nxgl_point_s *circle);
 </pre></ul>
 <p>
@@ -843,7 +843,7 @@ void nxgl_circlepts(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
 <h3>2.2.21 <a name="nxglcircletraps"><code>nxgl_circletraps</code></a></h3>
 <ul><pre>
 #include &lt;nuttx/nx/nxglib.h&gt;
-oid nxgl_circletraps(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
+oid nxgl_circletraps(FAR const struct nxgl_point_s *center, nxgl_coord_t radius,
                      FAR struct nxgl_trapezoid_s *circle);
 </pre></ul>
 <p>
@@ -1750,7 +1750,7 @@ int nx_drawline(NXWINDOW hwnd, FAR struct nxgl_vector_s *vector,
 #include &lt;nuttx/nx/nxglib.h&gt;
 #include &lt;nuttx/nx/nx.h&gt;
 
-int nx_drawcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
+int nx_drawcircle(NXWINDOW hwnd, FAR const struct nxgl_point_s *center,
                   nxgl_coord_t radius, nxgl_coord_t width,
                   nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 </pre></ul>
@@ -1786,7 +1786,7 @@ int nx_drawcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
 #include &lt;nuttx/nx/nxglib.h&gt;
 #include &lt;nuttx/nx/nx.h&gt;
 
-int nx_fillcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
+int nx_fillcircle(NXWINDOW hwnd, FAR const struct nxgl_point_s *center,
                   nxgl_coord_t radius, nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 </pre></ul>
 <p>
@@ -2336,7 +2336,7 @@ int nxtk_drawlinewindow(NXTKWINDOW hfwnd, FAR struct nxgl_vector_s *vector,
 #include &lt;nuttx/nx/nxglib.h&gt;
 #include &lt;nuttx/nx/nxtk.h&gt;
 
-int nxtk_drawcirclewindow(NXTKWINDOW hfwnd, FAR struct nxgl_point_s *center,
+int nxtk_drawcirclewindow(NXTKWINDOW hfwnd, FAR const struct nxgl_point_s *center,
                           nxgl_coord_t radius, nxgl_coord_t width,
                           nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 </pre></ul>
@@ -2372,7 +2372,7 @@ int nxtk_drawcirclewindow(NXTKWINDOW hfwnd, FAR struct nxgl_point_s *center,
 #include &lt;nuttx/nx/nxglib.h&gt;
 #include &lt;nuttx/nx/nxtk.h&gt;
 
-int nxtk_fillcirclewindow(NXWINDOW hfwnd, FAR struct nxgl_point_s *center,
+int nxtk_fillcirclewindow(NXWINDOW hfwnd, FAR const struct nxgl_point_s *center,
                           nxgl_coord_t radius, nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 </pre></ul>
 <p>
@@ -2648,7 +2648,7 @@ int nxtk_drawlinetoolbar(NXTKWINDOW hfwnd, FAR struct nxgl_vector_s *vector,
 #include &lt;nuttx/nx/nxglib.h&gt;
 #include &lt;nuttx/nx/nxtk.h&gt;
 
-int nxtk_drawcircletoolbar(NXTKWINDOW hfwnd, FAR struct nxgl_point_s *center,
+int nxtk_drawcircletoolbar(NXTKWINDOW hfwnd, FAR const struct nxgl_point_s *center,
                            nxgl_coord_t radius, nxgl_coord_t width,
                            nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 </pre></ul>
@@ -2684,7 +2684,7 @@ int nxtk_drawcircletoolbar(NXTKWINDOW hfwnd, FAR struct nxgl_point_s *center,
 #include &lt;nuttx/nx/nxglib.h&gt;
 #include &lt;nuttx/nx/nxtk.h&gt;
 
-int nxtk_fillcircletoolbar(NXWINDOW hfwnd, FAR struct nxgl_point_s *center,
+int nxtk_fillcircletoolbar(NXWINDOW hfwnd, FAR const struct nxgl_point_s *center,
                            nxgl_coord_t radius, nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 </pre></ul>
 <p>
diff --git a/TODO b/TODO
index 1c868f9b1a..acab46733f 100644
--- a/TODO
+++ b/TODO
@@ -1348,3 +1348,20 @@ o Other Applications & Tests (apps/examples/)
                the artifact is larger.
   Status:      Open
   Priority:    Medium.
+
+  Description:  examples/nxlines.  There is an error in the line rendering
+                on the 24th step (270 degrees).  At that point, the
+                calculated position is just a bit from being horizontal.
+                Using configuration configs/stm3210e-eval/nxlines, I see:
+
+                  sin: ffff0000 cos: ffffffed radius: 76 halfx: -76 halfy: -1
+
+                And the resulting almost horizontal line:
+                
+                   vector: (44,159)->(196,161)
+
+                is rendered incorrectly every time around. Looks like logic
+                in nxgl_splitlines malfunctioned.
+
+  Status:       Open
+  Priority:     Medium/High
\ No newline at end of file
diff --git a/configs/sim/nx/defconfig b/configs/sim/nx/defconfig
index 9859e74c5a..3dfd3e820f 100644
--- a/configs/sim/nx/defconfig
+++ b/configs/sim/nx/defconfig
@@ -537,8 +537,17 @@ CONFIG_EXAMPLES_NX_NOTIFYSIGNO=4
 #   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_LINECOLOR -- The color of the central lines drawn
+#   in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
+# CONFIG_EXAMPLES_NXLINES_BORDERWIDTH -- The width of the circular border
+#   drawn in the background window. (default: 4).
+# CONFIG_EXAMPLES_NXLINES_BORDERCOLOR -- The color of the circular border
+#   drawn in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
+# CONFIG_EXAMPLES_NXLINES_CIRCLECOLOR -- The color of the circular region
+#   filled in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
 # 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
diff --git a/configs/stm3210e-eval/nsh2/defconfig b/configs/stm3210e-eval/nsh2/defconfig
index 987127cfdd..d496698868 100644
--- a/configs/stm3210e-eval/nsh2/defconfig
+++ b/configs/stm3210e-eval/nsh2/defconfig
@@ -1145,8 +1145,17 @@ CONFIG_EXAMPLES_NXIMAGE_EXTERNINIT=n
 #   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_LINECOLOR -- The color of the central lines drawn
+#   in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
+# CONFIG_EXAMPLES_NXLINES_BORDERWIDTH -- The width of the circular border
+#   drawn in the background window. (default: 4).
+# CONFIG_EXAMPLES_NXLINES_BORDERCOLOR -- The color of the circular border
+#   drawn in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
+# CONFIG_EXAMPLES_NXLINES_CIRCLECOLOR -- The color of the circular region
+#   filled in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
 # 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
@@ -1161,6 +1170,9 @@ CONFIG_EXAMPLES_NXLINES_DEVNO=0
 CONFIG_EXAMPLES_NXLINES_BGCOLOR=0x0320
 CONFIG_EXAMPLES_NXLINES_LINEWIDTH=16
 CONFIG_EXAMPLES_NXLINES_LINECOLOR=0xffe0
+CONFIG_EXAMPLES_NXLINES_BORDERWIDTH=4
+CONFIG_EXAMPLES_NXLINES_BORDERCOLOR=0xffe0
+CONFIG_EXAMPLES_NXLINES_CIRCLECOLOR=0xf7bb
 CONFIG_EXAMPLES_NXLINES_BPP=16
 CONFIG_EXAMPLES_NXLINES_EXTERNINIT=n
 
diff --git a/configs/stm3210e-eval/nxlines/defconfig b/configs/stm3210e-eval/nxlines/defconfig
index af7c1b7d00..6a9ea3979a 100644
--- a/configs/stm3210e-eval/nxlines/defconfig
+++ b/configs/stm3210e-eval/nxlines/defconfig
@@ -1156,8 +1156,17 @@ CONFIG_EXAMPLES_NXIMAGE_EXTERNINIT=n
 #   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_LINECOLOR -- The color of the central lines drawn
+#   in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
+# CONFIG_EXAMPLES_NXLINES_BORDERWIDTH -- The width of the circular border
+#   drawn in the background window. (default: 4).
+# CONFIG_EXAMPLES_NXLINES_BORDERCOLOR -- The color of the circular border
+#   drawn in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
+# CONFIG_EXAMPLES_NXLINES_CIRCLECOLOR -- The color of the circular region
+#   filled in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
 # 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
@@ -1172,6 +1181,9 @@ CONFIG_EXAMPLES_NXLINES_DEVNO=0
 CONFIG_EXAMPLES_NXLINES_BGCOLOR=0x0320
 CONFIG_EXAMPLES_NXLINES_LINEWIDTH=16
 CONFIG_EXAMPLES_NXLINES_LINECOLOR=0xffe0
+CONFIG_EXAMPLES_NXLINES_BORDERWIDTH=4
+CONFIG_EXAMPLES_NXLINES_BORDERCOLOR=0xffe0
+CONFIG_EXAMPLES_NXLINES_CIRCLECOLOR=0xf7bb
 CONFIG_EXAMPLES_NXLINES_BPP=16
 CONFIG_EXAMPLES_NXLINES_EXTERNINIT=n
 
diff --git a/configs/stm3210e-eval/nxtext/defconfig b/configs/stm3210e-eval/nxtext/defconfig
index dc66b0fa8b..d48637a1b6 100644
--- a/configs/stm3210e-eval/nxtext/defconfig
+++ b/configs/stm3210e-eval/nxtext/defconfig
@@ -1156,8 +1156,17 @@ CONFIG_EXAMPLES_NXIMAGE_EXTERNINIT=n
 #   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_LINECOLOR -- The color of the central lines drawn
+#   in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
+# CONFIG_EXAMPLES_NXLINES_BORDERWIDTH -- The width of the circular border
+#   drawn in the background window. (default: 4).
+# CONFIG_EXAMPLES_NXLINES_BORDERCOLOR -- The color of the circular border
+#   drawn in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
+# CONFIG_EXAMPLES_NXLINES_CIRCLECOLOR -- The color of the circular region
+#   filled in the background window. Default depends on CONFIG_EXAMPLES_NXLINES_BPP
+#   (there really is no meaningful default).
 # 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
@@ -1172,6 +1181,9 @@ CONFIG_EXAMPLES_NXLINES_DEVNO=0
 CONFIG_EXAMPLES_NXLINES_BGCOLOR=0x0320
 CONFIG_EXAMPLES_NXLINES_LINEWIDTH=16
 CONFIG_EXAMPLES_NXLINES_LINECOLOR=0xffe0
+CONFIG_EXAMPLES_NXLINES_BORDERWIDTH=4
+CONFIG_EXAMPLES_NXLINES_BORDERCOLOR=0xffe0
+CONFIG_EXAMPLES_NXLINES_CIRCLECOLOR=0xf7bb
 CONFIG_EXAMPLES_NXLINES_BPP=16
 CONFIG_EXAMPLES_NXLINES_EXTERNINIT=n
 
diff --git a/graphics/nxglib/nxglib_circlepts.c b/graphics/nxglib/nxglib_circlepts.c
index 46ebe32911..a6d59280d7 100644
--- a/graphics/nxglib/nxglib_circlepts.c
+++ b/graphics/nxglib/nxglib_circlepts.c
@@ -116,7 +116,7 @@
  *
  ****************************************************************************/
 
-void nxgl_circlepts(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
+void nxgl_circlepts(FAR const struct nxgl_point_s *center, nxgl_coord_t radius,
                     FAR struct nxgl_point_s *circle)
 {
   nxgl_coord_t xoffs;
diff --git a/graphics/nxglib/nxglib_circletraps.c b/graphics/nxglib/nxglib_circletraps.c
index 9c9a93cec9..7c2cd1d7b5 100644
--- a/graphics/nxglib/nxglib_circletraps.c
+++ b/graphics/nxglib/nxglib_circletraps.c
@@ -95,7 +95,7 @@
  *
  ****************************************************************************/
 
-void nxgl_circletraps(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
+void nxgl_circletraps(FAR const struct nxgl_point_s *center, nxgl_coord_t radius,
                       FAR struct nxgl_trapezoid_s *circle)
 {
   nxgl_coord_t xoffs;
@@ -103,11 +103,11 @@ void nxgl_circletraps(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
 
   circle[0].top.x1      = itob16(center->x);
   circle[0].top.x2      = circle[0].top.x1;
-  circle[0].top.y       = center->y + radius;
+  circle[0].top.y       = center->y - radius;
 
   circle[7].bot.x1      = circle[0].top.x1;
   circle[7].bot.x2      = circle[0].top.x1;
-  circle[7].bot.y       = center->y - radius;
+  circle[7].bot.y       = center->y + radius;
 
   circle[3].bot.x1      = itob16(center->x - radius);
   circle[3].bot.x2      = itob16(center->x + radius);
@@ -124,7 +124,7 @@ void nxgl_circletraps(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
 
   circle[2].bot.x1      = itob16(center->x - xoffs);
   circle[2].bot.x2      = itob16(center->x + xoffs);
-  circle[2].bot.y       = center->y + yoffs;
+  circle[2].bot.y       = center->y - yoffs;
 
   circle[3].top.x1      = circle[2].bot.x1;
   circle[3].top.x2      = circle[2].bot.x2;
@@ -132,7 +132,7 @@ void nxgl_circletraps(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
 
   circle[4].bot.x1      = circle[2].bot.x1;
   circle[4].bot.x2      = circle[2].bot.x2;
-  circle[4].bot.y       = center->y - yoffs;
+  circle[4].bot.y       = center->y + yoffs;
 
   circle[5].top.x1      = circle[4].bot.x1;
   circle[5].top.x2      = circle[4].bot.x2;
@@ -140,7 +140,7 @@ void nxgl_circletraps(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
 
   circle[0].bot.x1      = itob16(center->x - yoffs);
   circle[0].bot.x2      = itob16(center->x + yoffs);
-  circle[0].bot.y       = center->y + xoffs;
+  circle[0].bot.y       = center->y - xoffs;
 
   circle[1].top.x1      = circle[0].bot.x1;
   circle[1].top.x2      = circle[0].bot.x2;
@@ -148,7 +148,7 @@ void nxgl_circletraps(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
 
   circle[6].bot.x1      = circle[1].top.x1;
   circle[6].bot.x2      = circle[1].top.x2;
-  circle[6].bot.y       = center->y - xoffs;
+  circle[6].bot.y       = center->y + xoffs;
 
   circle[7].top.x1      = circle[6].bot.x1;
   circle[7].top.x2      = circle[6].bot.x2;
@@ -160,7 +160,7 @@ void nxgl_circletraps(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
 
   circle[1].bot.x1      = itob16(center->x - xoffs);
   circle[1].bot.x2      = itob16(center->x + xoffs);
-  circle[1].bot.y       = center->y + xoffs;
+  circle[1].bot.y       = center->y - xoffs;
 
   circle[2].top.x1      = circle[1].bot.x1;
   circle[2].top.x2      = circle[1].bot.x2;
@@ -168,7 +168,7 @@ void nxgl_circletraps(FAR struct nxgl_point_s *center, nxgl_coord_t radius,
   
   circle[5].bot.x1      = circle[1].bot.x1;
   circle[5].bot.x2      = circle[1].bot.x2;
-  circle[5].bot.y       = center->y - xoffs;
+  circle[5].bot.y       = center->y + xoffs;
 
   circle[6].top.x1      = circle[5].bot.x1;
   circle[6].top.x2      = circle[5].bot.x2;
diff --git a/graphics/nxmu/nx_drawcircle.c b/graphics/nxmu/nx_drawcircle.c
index 5403ee9ef7..5a0780e1a0 100644
--- a/graphics/nxmu/nx_drawcircle.c
+++ b/graphics/nxmu/nx_drawcircle.c
@@ -107,7 +107,7 @@
  *
  ****************************************************************************/
 
-int nx_drawcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
+int nx_drawcircle(NXWINDOW hwnd, FAR const struct nxgl_point_s *center,
                   nxgl_coord_t radius, nxgl_coord_t width,
                   nxgl_mxpixel_t color[CONFIG_NX_NPLANES])
 {
diff --git a/graphics/nxmu/nx_fillcircle.c b/graphics/nxmu/nx_fillcircle.c
index dc4115782a..bfc1dc9e39 100644
--- a/graphics/nxmu/nx_fillcircle.c
+++ b/graphics/nxmu/nx_fillcircle.c
@@ -89,7 +89,7 @@
  *
  ****************************************************************************/
 
-int nx_fillcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
+int nx_fillcircle(NXWINDOW hwnd, FAR const struct nxgl_point_s *center,
                   nxgl_coord_t radius, nxgl_mxpixel_t color[CONFIG_NX_NPLANES])
 {
   FAR struct nxgl_trapezoid_s traps[NCIRCLE_TRAPS];
diff --git a/graphics/nxsu/nx_drawcircle.c b/graphics/nxsu/nx_drawcircle.c
index 741886bc88..8d5c124549 100644
--- a/graphics/nxsu/nx_drawcircle.c
+++ b/graphics/nxsu/nx_drawcircle.c
@@ -107,7 +107,7 @@
  *
  ****************************************************************************/
 
-int nx_drawcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
+int nx_drawcircle(NXWINDOW hwnd, FAR const struct nxgl_point_s *center,
                   nxgl_coord_t radius, nxgl_coord_t width,
                   nxgl_mxpixel_t color[CONFIG_NX_NPLANES])
 {
diff --git a/graphics/nxsu/nx_fillcircle.c b/graphics/nxsu/nx_fillcircle.c
index 9a89c332e4..12c47f80a1 100644
--- a/graphics/nxsu/nx_fillcircle.c
+++ b/graphics/nxsu/nx_fillcircle.c
@@ -89,7 +89,7 @@
  *
  ****************************************************************************/
 
-int nx_fillcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
+int nx_fillcircle(NXWINDOW hwnd, FAR const struct nxgl_point_s *center,
                   nxgl_coord_t radius, nxgl_mxpixel_t color[CONFIG_NX_NPLANES])
 {
   FAR struct nxgl_trapezoid_s traps[NCIRCLE_TRAPS];
diff --git a/graphics/nxtk/nxtk_drawcircletoolbar.c b/graphics/nxtk/nxtk_drawcircletoolbar.c
index 558b3413b3..e9d9ca8ffb 100644
--- a/graphics/nxtk/nxtk_drawcircletoolbar.c
+++ b/graphics/nxtk/nxtk_drawcircletoolbar.c
@@ -107,7 +107,7 @@
  *
  ****************************************************************************/
 
-int nxtk_drawcircletoolbar(NXTKWINDOW hfwnd, FAR struct nxgl_point_s *center,
+int nxtk_drawcircletoolbar(NXTKWINDOW hfwnd, FAR const struct nxgl_point_s *center,
                            nxgl_coord_t radius, nxgl_coord_t width,
                            nxgl_mxpixel_t color[CONFIG_NX_NPLANES])
 {
diff --git a/graphics/nxtk/nxtk_drawcirclewindow.c b/graphics/nxtk/nxtk_drawcirclewindow.c
index d4bd79a301..f70c1c3515 100644
--- a/graphics/nxtk/nxtk_drawcirclewindow.c
+++ b/graphics/nxtk/nxtk_drawcirclewindow.c
@@ -107,7 +107,7 @@
  *
  ****************************************************************************/
 
-int nxtk_drawcirclewindow(NXTKWINDOW hfwnd, FAR struct nxgl_point_s *center,
+int nxtk_drawcirclewindow(NXTKWINDOW hfwnd, FAR const struct nxgl_point_s *center,
                           nxgl_coord_t radius, nxgl_coord_t width,
                           nxgl_mxpixel_t color[CONFIG_NX_NPLANES])
 {
diff --git a/graphics/nxtk/nxtk_fillcircletoolbar.c b/graphics/nxtk/nxtk_fillcircletoolbar.c
index d2e7e5ecbe..d0bb09edd2 100644
--- a/graphics/nxtk/nxtk_fillcircletoolbar.c
+++ b/graphics/nxtk/nxtk_fillcircletoolbar.c
@@ -89,7 +89,7 @@
  *
  ****************************************************************************/
 
-int nxtk_fillcircletoolbar(NXWINDOW hfwnd, FAR struct nxgl_point_s *center,
+int nxtk_fillcircletoolbar(NXWINDOW hfwnd, FAR const struct nxgl_point_s *center,
                            nxgl_coord_t radius,
                            nxgl_mxpixel_t color[CONFIG_NX_NPLANES])
 {
diff --git a/graphics/nxtk/nxtk_fillcirclewindow.c b/graphics/nxtk/nxtk_fillcirclewindow.c
index 4fc7fef644..34c9458650 100644
--- a/graphics/nxtk/nxtk_fillcirclewindow.c
+++ b/graphics/nxtk/nxtk_fillcirclewindow.c
@@ -89,7 +89,7 @@
  *
  ****************************************************************************/
 
-int nxtk_fillcirclewindow(NXWINDOW hfwnd, FAR struct nxgl_point_s *center,
+int nxtk_fillcirclewindow(NXWINDOW hfwnd, FAR const struct nxgl_point_s *center,
                           nxgl_coord_t radius,
                           nxgl_mxpixel_t color[CONFIG_NX_NPLANES])
 {
diff --git a/include/nuttx/nx/nx.h b/include/nuttx/nx/nx.h
index 6912d5552f..1c705e5aa4 100644
--- a/include/nuttx/nx/nx.h
+++ b/include/nuttx/nx/nx.h
@@ -651,7 +651,7 @@ EXTERN int nx_drawline(NXWINDOW hwnd, FAR struct nxgl_vector_s *vector,
  *
  ****************************************************************************/
 
-EXTERN int nx_drawcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
+EXTERN int nx_drawcircle(NXWINDOW hwnd, FAR const struct nxgl_point_s *center,
                          nxgl_coord_t radius, nxgl_coord_t width,
                          nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 
@@ -672,7 +672,7 @@ EXTERN int nx_drawcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
  *
  ****************************************************************************/
 
-EXTERN int nx_fillcircle(NXWINDOW hwnd, FAR struct nxgl_point_s *center,
+EXTERN int nx_fillcircle(NXWINDOW hwnd, FAR const struct nxgl_point_s *center,
                          nxgl_coord_t radius,
                          nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 
diff --git a/include/nuttx/nx/nxglib.h b/include/nuttx/nx/nxglib.h
index 06c9eb383a..95b33772bd 100644
--- a/include/nuttx/nx/nxglib.h
+++ b/include/nuttx/nx/nxglib.h
@@ -650,7 +650,7 @@ EXTERN int nxgl_splitline(FAR struct nxgl_vector_s *vector,
  *
  ****************************************************************************/
 
-EXTERN void nxgl_circlepts(FAR struct nxgl_point_s *center,
+EXTERN void nxgl_circlepts(FAR const struct nxgl_point_s *center,
                            nxgl_coord_t radius,
                            FAR struct nxgl_point_s *circle);
 
@@ -672,7 +672,7 @@ EXTERN void nxgl_circlepts(FAR struct nxgl_point_s *center,
  *
  ****************************************************************************/
 
-EXTERN void nxgl_circletraps(FAR struct nxgl_point_s *center,
+EXTERN void nxgl_circletraps(FAR const struct nxgl_point_s *center,
                              nxgl_coord_t radius,
                              FAR struct nxgl_trapezoid_s *circle);
 
diff --git a/include/nuttx/nx/nxtk.h b/include/nuttx/nx/nxtk.h
index 6a288c37a8..0e066359af 100644
--- a/include/nuttx/nx/nxtk.h
+++ b/include/nuttx/nx/nxtk.h
@@ -283,7 +283,7 @@ EXTERN int nxtk_drawlinewindow(NXTKWINDOW hfwnd,
  ****************************************************************************/
 
 EXTERN int nxtk_drawcirclewindow(NXTKWINDOW hfwnd,
-                                 FAR struct nxgl_point_s *center,
+                                 FAR const struct nxgl_point_s *center,
                                  nxgl_coord_t radius, nxgl_coord_t width,
                                  nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 
@@ -305,7 +305,7 @@ EXTERN int nxtk_drawcirclewindow(NXTKWINDOW hfwnd,
  ****************************************************************************/
 
 EXTERN int nxtk_fillcirclewindow(NXWINDOW hfwnd,
-                                 FAR struct nxgl_point_s *center,
+                                 FAR const struct nxgl_point_s *center,
                                  nxgl_coord_t radius,
                                  nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 
@@ -478,7 +478,7 @@ EXTERN int nxtk_drawlinetoolbar(NXTKWINDOW hfwnd,
  ****************************************************************************/
 
 EXTERN int nxtk_drawcircletoolbar(NXTKWINDOW hfwnd,
-                                  FAR struct nxgl_point_s *center,
+                                  FAR const struct nxgl_point_s *center,
                                   nxgl_coord_t radius, nxgl_coord_t width,
                                   nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
 
@@ -500,7 +500,7 @@ EXTERN int nxtk_drawcircletoolbar(NXTKWINDOW hfwnd,
  ****************************************************************************/
 
 EXTERN int nxtk_fillcircletoolbar(NXWINDOW hfwnd,
-                                  FAR struct nxgl_point_s *center,
+                                  FAR const struct nxgl_point_s *center,
                                   nxgl_coord_t radius,
                                   nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);