diff --git a/src/com/homelinux/holtrop/opengltest/MyRenderer.java b/src/com/homelinux/holtrop/opengltest/MyRenderer.java
index 4cd8f39..e42047c 100644
--- a/src/com/homelinux/holtrop/opengltest/MyRenderer.java
+++ b/src/com/homelinux/holtrop/opengltest/MyRenderer.java
@@ -119,10 +119,10 @@ public class MyRenderer implements GLSurfaceView.Renderer
     public void onSurfaceCreated(GL10 unused, EGLConfig config)
     {
         final float attribs[] = {
-            1, 1,  0.8f, 0.8f, 1,
-            0, 1,  0, 0, 1,
-            0, 0,  0.8f, 0.8f, 1,
-            1, 0,  0, 0, 1
+            0.5f, 0.5f,   0.8f, 0.8f, 1,
+            -0.5f, 0.5f,  0, 0, 1,
+            -0.5f, -0.5f, 0.8f, 0.8f, 1,
+            0.5f, -0.5f,  0, 0, 1
         };
         checkGLError("onSurfaceCreated");
         ByteBuffer bb = ByteBuffer.allocateDirect(attribs.length * 4);
@@ -221,7 +221,8 @@ public class MyRenderer implements GLSurfaceView.Renderer
                 Tile t = m_tiles[x][y];
                 Matrix.setIdentityM(m_modelview, 0);
                 Matrix.translateM(m_modelview, 0,
-                        x - GRID_WIDTH / 2.0f, y - GRID_HEIGHT / 2.0f,
+                        x + 0.5f - GRID_WIDTH / 2.0f,
+                        y + 0.5f - GRID_HEIGHT / 2.0f,
                         -DISTANCE);
                 if (t.flipping)
                 {