--- a/doodle/dia/grid_layer.d	Sun Aug 30 22:14:01 2009 +0930
+++ b/doodle/dia/grid_layer.d	Sun Aug 30 23:36:31 2009 +0930
@@ -22,6 +22,7 @@
 
     this(in string name) {
         super(name);
+        mZoomValid = false;
     }
 
     // Layer overrides:
@@ -36,8 +37,12 @@
                        in Rectangle model_damage, scope Context model_cr) const {
         assert(mZoomValid);
 
+        double xx = 1.0, yy = 1.0;
+        model_cr.userToDeviceDistance(xx, yy);
+
         model_cr.save(); {
-            model_cr.setLineWidth(1.0);
+            model_cr.setSourceRgba(0.0, 0.0, 0.0, 0.3);
+            model_cr.setLineWidth(0.5);
 
             {
                 // vertical grid lines
@@ -47,7 +52,13 @@
 
                 for (;;) {
                     line(model_cr, x, y0, x, y1);
-                    model_cr.stroke();
+
+                    // Ensure 1 pixel wide FIXME is this naughty? We are sneaking
+                    // through cairo to mix model and pixel coordinates...
+                    model_cr.save(); {
+                        model_cr.scale(1.0 / xx, 1.0 / yy);
+                        model_cr.stroke();
+                    } model_cr.restore();
 
                     if (x > model_damage.max_corner.x) {
                         break;
@@ -65,7 +76,11 @@
 
                 for (;;) {
                     line(model_cr, x0, y, x1, y);
-                    model_cr.stroke();
+
+                    model_cr.save(); {
+                        model_cr.scale(1.0 / xx, 1.0 / yy);
+                        model_cr.stroke();
+                    } model_cr.restore();
 
                     if (y > model_damage.max_corner.y) {
                         break;
@@ -75,20 +90,20 @@
                 }
             }
         } model_cr.restore();
-
-
-        //double start_x = modf(damage.min_corner.x, zoom);
     }
 
     // Grid overrides:
 
-    void zoom_changed(double zoom) {
+    override void zoom_changed(double zoom) {
         mZoom = zoom;
         mZoomValid = true;
-        mSpacing = 20.0;        // mm
+
+        // FIXME compute spacing properly
+        mSpacing = 10.0 / mZoom;        // mm
     }
 
-    bool snap(in Point a, out Point b) const {
+    // FIXME use inout parameter?
+    override bool snap(in Point a, out Point b) const {
         b = a;
         return false;
     }