diff --git a/apps/spline.c b/apps/spline.c
index cd99daf..8f3907e 100644
--- a/apps/spline.c
+++ b/apps/spline.c
@@ -15,11 +15,11 @@
 
 #define _apps_spline_pixmap(spline) ((spline)->widget.window->pixmap)
 
-#define NPT 4
 
 typedef struct _apps_spline {
     twin_widget_t widget;
-    twin_point_t points[NPT];
+    int npt;
+    twin_point_t *points;
     int which;
     twin_fixed_t line_width;
     twin_cap_t cap_style;
@@ -32,28 +32,51 @@ static void _apps_spline_paint(apps_spline_t *spline)
 
     path = twin_path_create();
     twin_path_set_cap_style(path, spline->cap_style);
-    twin_path_move(path, spline->points[0].x, spline->points[0].y);
-    twin_path_curve(path, spline->points[1].x, spline->points[1].y,
-                    spline->points[2].x, spline->points[2].y,
-                    spline->points[3].x, spline->points[3].y);
-    twin_paint_stroke(_apps_spline_pixmap(spline), 0xff404040, path,
-                      spline->line_width);
-    twin_path_set_cap_style(path, TwinCapButt);
-    twin_paint_stroke(_apps_spline_pixmap(spline), 0xffffff00, path,
-                      twin_int_to_fixed(2));
-
-    twin_path_empty(path);
-    twin_path_move(path, spline->points[0].x, spline->points[0].y);
-    twin_path_draw(path, spline->points[1].x, spline->points[1].y);
-    twin_paint_stroke(_apps_spline_pixmap(spline), 0xc08000c0, path,
-                      twin_int_to_fixed(2));
-    twin_path_empty(path);
-    twin_path_move(path, spline->points[3].x, spline->points[3].y);
-    twin_path_draw(path, spline->points[2].x, spline->points[2].y);
-    twin_paint_stroke(_apps_spline_pixmap(spline), 0xc08000c0, path,
-                      twin_int_to_fixed(2));
-    twin_path_empty(path);
-    for (i = 0; i < NPT; i++) {
+    if (spline->npt == 4) {
+        twin_path_move(path, spline->points[0].x, spline->points[0].y);
+        twin_path_curve(path, spline->points[1].x, spline->points[1].y,
+                        spline->points[2].x, spline->points[2].y,
+                        spline->points[3].x, spline->points[3].y);
+        twin_paint_stroke(_apps_spline_pixmap(spline), 0xff404040, path,
+                          spline->line_width);
+        twin_path_set_cap_style(path, TwinCapButt);
+        twin_paint_stroke(_apps_spline_pixmap(spline), 0xffffff00, path,
+                          twin_int_to_fixed(2));
+
+        twin_path_empty(path);
+        twin_path_move(path, spline->points[0].x, spline->points[0].y);
+        twin_path_draw(path, spline->points[1].x, spline->points[1].y);
+        twin_paint_stroke(_apps_spline_pixmap(spline), 0xc08000c0, path,
+                          twin_int_to_fixed(2));
+        twin_path_empty(path);
+        twin_path_move(path, spline->points[3].x, spline->points[3].y);
+        twin_path_draw(path, spline->points[2].x, spline->points[2].y);
+        twin_paint_stroke(_apps_spline_pixmap(spline), 0xc08000c0, path,
+                          twin_int_to_fixed(2));
+        twin_path_empty(path);
+    } else if (spline->npt == 3) {
+        twin_path_move(path, spline->points[0].x, spline->points[0].y);
+        twin_path_quadratic_curve(path, spline->points[1].x,
+                                  spline->points[1].y, spline->points[2].x,
+                                  spline->points[2].y);
+        twin_paint_stroke(_apps_spline_pixmap(spline), 0xff404040, path,
+                          spline->line_width);
+        twin_path_set_cap_style(path, TwinCapButt);
+        twin_paint_stroke(_apps_spline_pixmap(spline), 0xffffff00, path,
+                          twin_int_to_fixed(2));
+        twin_path_empty(path);
+        twin_path_move(path, spline->points[0].x, spline->points[0].y);
+        twin_path_draw(path, spline->points[1].x, spline->points[1].y);
+        twin_paint_stroke(_apps_spline_pixmap(spline), 0xc08000c0, path,
+                          twin_int_to_fixed(2));
+        twin_path_empty(path);
+        twin_path_move(path, spline->points[1].x, spline->points[1].y);
+        twin_path_draw(path, spline->points[2].x, spline->points[2].y);
+        twin_paint_stroke(_apps_spline_pixmap(spline), 0xc08000c0, path,
+                          twin_int_to_fixed(2));
+        twin_path_empty(path);
+    }
+    for (i = 0; i < spline->npt; i++) {
         twin_path_empty(path);
         twin_path_circle(path, spline->points[i].x, spline->points[i].y,
                          twin_int_to_fixed(10));
@@ -81,7 +104,7 @@ static int _apps_spline_hit(apps_spline_t *spline,
 {
     int i;
 
-    for (i = 0; i < NPT; i++)
+    for (i = 0; i < spline->npt; i++)
         if (twin_fixed_abs(x - spline->points[i].x) < spline->line_width / 2 &&
             twin_fixed_abs(y - spline->points[i].y) < spline->line_width / 2)
             return i;
@@ -123,28 +146,40 @@ static twin_dispatch_result_t _apps_spline_dispatch(twin_widget_t *widget,
 
 static void _apps_spline_init(apps_spline_t *spline,
                               twin_box_t *parent,
-                              twin_dispatch_proc_t dispatch)
+                              twin_dispatch_proc_t dispatch,
+                              int npt)
 {
     static const twin_widget_layout_t preferred = {0, 0, 1, 1};
     _twin_widget_init(&spline->widget, parent, 0, preferred, dispatch);
     twin_widget_set(&spline->widget, 0xffffffff);
     spline->line_width = twin_int_to_fixed(100);
     spline->cap_style = TwinCapRound;
-    spline->points[0].x = twin_int_to_fixed(100);
-    spline->points[0].y = twin_int_to_fixed(100);
-    spline->points[1].x = twin_int_to_fixed(300);
-    spline->points[1].y = twin_int_to_fixed(300);
-    spline->points[2].x = twin_int_to_fixed(100);
-    spline->points[2].y = twin_int_to_fixed(300);
-    spline->points[3].x = twin_int_to_fixed(300);
-    spline->points[3].y = twin_int_to_fixed(100);
+    spline->points = calloc(npt, sizeof(twin_point_t));
+    spline->npt = npt;
+    if (npt == 4) {
+        spline->points[0].x = twin_int_to_fixed(100);
+        spline->points[0].y = twin_int_to_fixed(100);
+        spline->points[1].x = twin_int_to_fixed(300);
+        spline->points[1].y = twin_int_to_fixed(300);
+        spline->points[2].x = twin_int_to_fixed(100);
+        spline->points[2].y = twin_int_to_fixed(300);
+        spline->points[3].x = twin_int_to_fixed(300);
+        spline->points[3].y = twin_int_to_fixed(100);
+    } else if (npt == 3) {
+        spline->points[0].x = twin_int_to_fixed(100);
+        spline->points[0].y = twin_int_to_fixed(100);
+        spline->points[1].x = twin_int_to_fixed(200);
+        spline->points[1].y = twin_int_to_fixed(300);
+        spline->points[2].x = twin_int_to_fixed(300);
+        spline->points[2].y = twin_int_to_fixed(100);
+    }
 }
 
-static apps_spline_t *apps_spline_create(twin_box_t *parent)
+static apps_spline_t *apps_spline_create(twin_box_t *parent, int npt)
 {
     apps_spline_t *spline = malloc(sizeof(apps_spline_t));
 
-    _apps_spline_init(spline, parent, _apps_spline_dispatch);
+    _apps_spline_init(spline, parent, _apps_spline_dispatch, npt);
     return spline;
 }
 
@@ -157,7 +192,12 @@ void apps_spline_start(twin_screen_t *screen,
 {
     twin_toplevel_t *toplevel = twin_toplevel_create(
         screen, TWIN_ARGB32, TwinWindowApplication, x, y, w, h, name);
-    apps_spline_t *spline = apps_spline_create(&toplevel->box);
-    (void) spline;
+    apps_spline_t *spline_cubic = apps_spline_create(&toplevel->box, 4);
+    twin_toplevel_t *toplevel2 = twin_toplevel_create(
+        screen, TWIN_ARGB32, TwinWindowApplication, x + 20, y + 20, w, h, name);
+    apps_spline_t *spline_quad = apps_spline_create(&toplevel2->box, 3);
+    (void) spline_cubic;
+    (void) spline_quad;
     twin_toplevel_show(toplevel);
+    twin_toplevel_show(toplevel2);
 }
diff --git a/include/twin.h b/include/twin.h
index 356ccaa..8f7c60f 100644
--- a/include/twin.h
+++ b/include/twin.h
@@ -1061,6 +1061,12 @@ void twin_path_curve(twin_path_t *path,
                      twin_fixed_t x3,
                      twin_fixed_t y3);
 
+void twin_path_quadratic_curve(twin_path_t *path,
+                               twin_fixed_t x1,
+                               twin_fixed_t y1,
+                               twin_fixed_t x2,
+                               twin_fixed_t y2);
+
 /*
  * timeout.c
  */
diff --git a/src/spline.c b/src/spline.c
index 6d1d7f8..e716cfc 100644
--- a/src/spline.c
+++ b/src/spline.c
@@ -164,3 +164,26 @@ void twin_path_curve(twin_path_t *path,
                              _twin_matrix_x(&path->state.matrix, x3, y3),
                              _twin_matrix_y(&path->state.matrix, x3, y3));
 }
+
+void twin_path_quadratic_curve(twin_path_t *path,
+                               twin_fixed_t x1,
+                               twin_fixed_t y1,
+                               twin_fixed_t x2,
+                               twin_fixed_t y2)
+{
+    twin_spoint_t p0 = _twin_path_current_spoint(path);
+    /* Convert quadratic to cubic control point */
+    /* CP1 = P0 + 2/3 * (P1 - P0) */
+    twin_sfixed_t dx1 = twin_fixed_to_sfixed(x1) - p0.x;
+    twin_sfixed_t dy1 = twin_fixed_to_sfixed(y1) - p0.y;
+    twin_sfixed_t cx1 = p0.x + twin_sfixed_mul(dx1, twin_int_to_sfixed(2) / 3);
+    twin_sfixed_t cy1 = p0.y + twin_sfixed_mul(dy1, twin_int_to_sfixed(2) / 3);
+    /* CP2 = P2 + 2/3 * (P1 - P2) */
+    twin_sfixed_t x2s = twin_fixed_to_sfixed(x2);
+    twin_sfixed_t y2s = twin_fixed_to_sfixed(y2);
+    twin_sfixed_t dx2 = twin_fixed_to_sfixed(x1) - x2s;
+    twin_sfixed_t dy2 = twin_fixed_to_sfixed(y1) - y2s;
+    twin_sfixed_t cx2 = x2s + twin_sfixed_mul(dx2, twin_int_to_sfixed(2) / 3);
+    twin_sfixed_t cy2 = y2s + twin_sfixed_mul(dy2, twin_int_to_sfixed(2) / 3);
+    _twin_path_scurve(path, cx1, cy1, cx2, cy2, x2s, y2s);
+}