Changed default for fill pitch (equal to cell's bbox w/h). Updated doc.

src/drc/drc/built-in-macros/_drc_layer.rb

@@ -4287,9 +4287,10 @@ CODE
     #
     # Without a reference point given, the lower left corner of the fill pattern's bounding box will be used
     # as the reference point. The reference point will also defined the footprint of the fill cell - more precisely
-    # the lower left corner. The fill cell's foot print is taken to be a rectangle having the horizontal and vertical
-    # step pitch for width and height respectively. The dimension can be changed however so that the fill cells
-    # can overlap or there can be spacing between the cells. To change the dimensions use the "dim" method.
+    # the lower left corner. When step vectors are given, the fill cell's footprint is taken to be a rectangle
+    # having the horizontal and vertical step pitch for width and height respectively. This way the fill cells 
+    # will be arrange seamlessly. However, the cell's dimensions can be changed, so that the fill cells
+    # can overlap or there is a space between the cells. To change the dimensions use the "dim" method.
     #
     # The following example specifies a fill cell with an active area of -0.5 .. 1.5 in both directions
     # (2 micron width and height). With these dimensions the fill cell's footprint is independent of the
@@ -4329,7 +4330,7 @@ CODE
     end
 
     # %DRC%
-    # @name fill
+    # @name fill_with_left
     # @brief Fills the region with regular pattern of shapes
     # @synopsis layer.fill_with_left([ options ])
     #
@@ -4390,10 +4391,10 @@ CODE
       end
 
       if !row_step
-        row_step = RBA::DVector::new(pattern.bbox.width, 0)
+        row_step = RBA::DVector::new(pattern.default_xpitch, 0)
       end
       if !column_step
-        column_step = RBA::DVector::new(0, pattern.bbox.height)
+        column_step = RBA::DVector::new(0, pattern.default_ypitch)
       end
 
       dbu_trans = RBA::VCplxTrans::new(1.0 / @engine.dbu)

src/drc/drc/built-in-macros/_drc_tags.rb

@@ -207,6 +207,14 @@ module DRC
       RBA::DBox::new(o, o + d)
     end
 
+    def default_xpitch
+      @dim ? @dim.x : self.bbox.width
+    end
+
+    def default_ypitch
+      @dim ? @dim.y : self.bbox.height
+    end
+
     def _computed_origin
       b = self.bbox
       return b.empty? ? RBA::DPoint::new : b.p1

src/lay/lay/doc/about/drc_ref_layer.xml

@@ -1027,6 +1027,101 @@ The following images show the effect of the extents method:
 <keyword name="fill"/>
 <p>Usage:</p>
 <ul>
+<li><tt>layer.fill([ options ])</tt></li>
+</ul>
+<p>
+This method will attempt to fill the polygons of the layer with a regular pattern
+of shapes.
+</p><p>
+The fill function currently is not available in deep mode.
+</p><p>
+Options are:
+<ul>
+<li><b>hstep(x) </b>or <b>hstep(x, y) </b>: specifies the horizontal step pitch of the pattern. x must be 
+a positive value. A vertical displacement component can be specified too, which results in a skewed pattern. </li>
+<li><b>vstep(y) </b>or <b>vstep(x, y) </b>: specifies the vertical step pitch of the pattern. y must be 
+a positive value. A horizontal displacement component can be specified too, which results in a skewed pattern. </li>
+<li><b>origin(x, y) </b>: specifies a fixed point to align the pattern with. This point specifies the location
+of the reference point for one pattern cell. </li>
+<li><b>auto_origin </b>: lets the algorithm choose the origin. This may result is a slightly better fill coverage
+as the algorithm is able to determine a pattern origin per fill island. </li>
+<li><b>fill_pattern(..) </b>: specifies the fill pattern. </li>
+</ul>
+</p><p>
+"fill_pattern" generates a fill pattern object. This object is used for configuring the fill pattern
+content. Fill pattern need to be named. The name will be used for generating the fill cell.
+</p><p>
+To provide a fill pattern, create a fill pattern object and add shapes to it. The following example creates
+a fill pattern named "FILL_CELL" and adds a 1x1 micron box on layer 1/0:
+</p><p>
+<pre>
+p = fill_pattern("FILL_CELL")
+p.shape(1, 0, box(0.0, 0.0, 1.0, 1.0))
+</pre>
+</p><p>
+See <a href="/about/drc_ref_global.xml#box">box</a> for details about the box specification. You can also add paths or polygons with <a href="/about/drc_ref_global.xml#path">path</a> or <a href="/about/drc_ref_global.xml#polygon">polygon</a>.
+</p><p>
+A more compact way of writing this is:
+</p><p>
+<pre>
+p = fill_pattern("FILL_CELL").shape(1, 0, box(0.0, 0.0, 1.0, 1.0))
+</pre>
+</p><p>
+The fill pattern can be given a reference point which is used for placing the pattern. The reference point
+is the one which is aligned with the pattern origin. The following code will assign (-0.5, -0.5) as the reference
+point for the 1x1 micron rectangle. Hence the reference point is a little below and left of the rectangle which 
+in turn shifts the rectangle fill pattern to the right and up:
+</p><p>
+<pre>
+p = fill_pattern("FILL_CELL")
+p.shape(1, 0, box(0.0, 0.0, 1.0, 1.0))
+p.origin(-0.5, -0.5)
+</pre>
+</p><p>
+Without a reference point given, the lower left corner of the fill pattern's bounding box will be used
+as the reference point. The reference point will also defined the footprint of the fill cell - more precisely
+the lower left corner. When step vectors are given, the fill cell's footprint is taken to be a rectangle
+having the horizontal and vertical step pitch for width and height respectively. This way the fill cells 
+will be arrange seamlessly. However, the cell's dimensions can be changed, so that the fill cells
+can overlap or there is a space between the cells. To change the dimensions use the "dim" method.
+</p><p>
+The following example specifies a fill cell with an active area of -0.5 .. 1.5 in both directions
+(2 micron width and height). With these dimensions the fill cell's footprint is independent of the
+step pitch:
+</p><p>
+<pre>
+p = fill_pattern("FILL_CELL")
+p.shape(1, 0, box(0.0, 0.0, 1.0, 1.0))
+p.origin(-0.5, -0.5)
+p.dim(2.0, 2.0)
+</pre>
+</p><p>
+With these ingredients will can use the fill function. The first example fills the polygons
+of "to_fill" with an orthogonal pattern of 1x1 micron rectangles with a pitch of 2 microns:
+</p><p>
+<pre>
+pattern = fill_pattern("FILL_CELL").shape(1, 0, box(0.0, 0.0, 1.0, 1.0)).origin(-0.5, -0.5)
+to_fill.fill(pattern, hstep(2.0), vstep(2.0))
+</pre>
+</p><p>
+This second example will create a skewed fill pattern in auto-origin mode:
+</p><p>
+<pre>
+pattern = fill_pattern("FILL_CELL").shape(1, 0, box(0.0, 0.0, 1.0, 1.0)).origin(-0.5, -0.5)
+to_fill.fill(pattern, hstep(2.0, 1.0), vstep(-1.0, 2.0), auto_origin)
+</pre>
+</p><p>
+The fill function can only work with a target layout for output. 
+It will not work for report output.
+</p><p>
+The layers generated by the fill cells is only available for input later in the 
+script if the output layout is identical to the input layouts.
+If you need the area missed by the fill function, try <a href="#fill_with_left">fill_with_left</a>.
+</p>
+<a name="fill_with_left"/><h2>"fill_with_left" - Fills the region with regular pattern of shapes</h2>
+<keyword name="fill_with_left"/>
+<p>Usage:</p>
+<ul>
 <li><tt>layer.fill_with_left([ options ])</tt></li>
 </ul>
 <p>