diff --git a/js/x11/examples/smoketest/trapezoids.js b/js/x11/examples/smoketest/trapezoids.js
new file mode 100644
index 0000000..7361629
--- /dev/null
+++ b/js/x11/examples/smoketest/trapezoids.js
@@ -0,0 +1,125 @@
+var _ = require('underscore');
+var x11 = require('../../lib');
+var Exposure = x11.eventMask.Exposure;
+var PointerMotion = x11.eventMask.PointerMotion;
+var ButtonPress = x11.eventMask.ButtonPress;
+
+var draw;
+
+var useConvo3 = true;
+
+x11.createClient({ debug: true}, function(err, display) {
+
+  var X = display.client;
+  var root = display.screen[0].root;
+
+  var wid = X.AllocID();
+  X.CreateWindow(
+     wid, root,
+     0, 0, 800, 600,
+     0, 0, 0, 0,
+     {
+        eventMask: Exposure|PointerMotion|ButtonPress
+     }
+  );
+  X.MapWindow(wid);
+
+
+  X.require('render', function(err, Render) {
+
+    Render.QueryFilters(console.log);
+
+    var pixMask = X.AllocID();
+    X.CreatePixmap(pixMask, wid, 8, 600, 600);
+    var pictTraps = X.AllocID();
+    Render.CreatePicture(pictTraps, pixMask, Render.a8);
+
+    var pictWin = X.AllocID();
+    Render.CreatePicture(pictWin, wid, Render.rgb24);
+
+    var pictSolid = X.AllocID();
+    r = 0.2; g = 0.2; b = 0.2; a = 1;
+    Render.CreateSolidFill(pictSolid, r, g, b, a);
+
+    var pixBuff = X.AllocID();
+    X.CreatePixmap(pixBuff, wid, 24, 600, 600);
+    var pictBuff = X.AllocID();
+    Render.CreatePicture(pictBuff, pixBuff, Render.rgb24);
+
+    var convo5 = [ 5, 5, 0.0030,    0.0133,    0.0219,    0.0133,    0.0030,
+      0.0133,    0.0596,    0.0983,    0.0596,    0.0133,
+      0.0219,    0.0983,    0.1621,    0.0983,    0.0219,
+      0.0133,    0.0596,    0.0983,    0.0596,    0.0133,
+      0.0030,    0.0133,    0.0219,    0.0133,    0.0030];
+    var convo3 = [3, 3, 0.01, 0.08, 0.01, 0.08, 0.64, 0.08, 0.01, 0.08, 0.01];
+
+    var convo5 = [21, 21].concat(require('./blur-convolution')(21, 11));
+
+    //Render.SetPictureFilter(pictBuff, 'convolution', convo3);
+    //Render.SetPictureFilter(pictTraps, 'convolution', convo3);
+    //Render.SetPictureFilter(pictBuff, 'bilinear', []);
+    Render.SetPictureFilter(pictBuff, 'best', []);
+
+    draw1 = function(x, y) {
+      console.log('draw 1', x, y);
+       var r = 3 + 2*Math.floor(x / 100);
+       var convo = [r, r].concat(require('./blur-convolution')(r, r));
+       Render.SetPictureFilter(pictBuff, 'convolution', convo);
+
+       var a = (x-400)/500;
+       var m = [
+        Math.cos(a), Math.sin(a), 0,
+        -Math.sin(a), Math.cos(a), 0,
+        0, 0, 1
+      ];
+     // Render.SetPictureTransform(pictTraps, m)
+
+      var r, g, b;
+
+      // fill window
+      r = 1; g = 1; b = 1; a = 0.5;
+      Render.FillRectangles(1, pictBuff, [r, g, b, a], [0, 0, 1000, 1000])
+
+      // fill traps
+      r = 0; g = 0; b = 0; a = 0;
+      Render.FillRectangles(1, pictTraps, [r, g, b, a], [0, 0, 1000, 1000])
+
+      Render.AddTraps(pictTraps, 0, 0, [
+        x, 200, y,
+        //150, 200, 50,
+        5, 250, 300,
+        110, 200, 310,
+        50, 150, 500
+      ]);
+
+
+      // (op, src, mask, dst, srcX, srcY, maskX, maskY, dstX, dstY, width, height)
+      //Render.Composite(Render.PictOp.Over, pictSolid, pictTraps, pictWin, 0, 0, 0, 0, 0, 0, 800, 600);
+      //Render.PictOp.Over
+
+      Render.Composite(Render.PictOp.Over, pictSolid, pictTraps, pictBuff, 0, 0, 0, 0, 0, 0, 800, 600);
+      Render.Composite(Render.PictOp.Over, pictBuff, 0, pictWin, 0, 0, 0, 0, 0, 0, 800, 600);
+
+    };
+
+    draw = function(x, y) {
+      var f = _.debounce(function() {
+        draw1(x, y);
+      }, 100);
+      f();
+    };
+
+  });
+
+}).on('error', function(err) {
+   console.log(err);
+}).on('event', function(ev) {
+    //console.log(ev);
+    if (ev.name == 'MotionNotify') {
+      draw(ev.x, ev.y);
+    } else if (ev.name == 'ButtonPress') {
+      useConvo3 = !useConvo3;
+      draw(ev.x, ev.y);
+      //console.log(ev);
+    }
+});