doc fixes

gears.scad

@@ -196,8 +196,11 @@ function _inherit_gear_thickness(thickness,dflt=10) =
 //   which you compute with {{gear_dist()}}, is a complex calculation that depends on the profile shifts of both meshing gears.  This means that profile shifting
 //   can also be used to fine tune the spacing between gears.  When the gear has many teeth a negative profile shift may
 //   be able to bring the gears slightly closer together, while still avoiding undercutting.
-//   Profile shifting also changes the effective pressure angle of the gear engagement.  
+//   Profile shifting also changes the effective pressure angle of the gear engagement.
-//   .
+// Figure(2D,Med,NoAxes): The green gear is a 7 tooth gear without profile shifting.  In yellow is the same gear, profile shifted.  Note that the teeth too longer narrow at their base.  Also note that the effective root circle has a larger radius, and the teeth are also longer.
+//   spur_gear2d(mod=5, teeth=7);
+//   color("green")spur_gear2d(mod=5, teeth=7, profile_shift=0);
+// Continues:
 //   The minimum number of teeth to avoid undercutting is 17 for a pressure angle of 20, but it is 32 for a pressure
 //   angle of 14.5 degrees.  It can be computed as `2/(sin(alpha))^2` where `alpha` is the pressure angle.
 //   By default, the gear modules produce corrected gears.  You can override this by specifying the profile shift

masks2d.scad

@@ -44,7 +44,7 @@ function _inset_corner(corner, mask_angle, inset, excess, flat_top) =
 //   As a 2D mask, this is designed to be differenced away from the edge of a shape that with its corner at the origin and one edge on the X+ axis and the other mask_angle degrees counterclockwise from the X+ axis.  
 //   If called as a function, returns a 2D path of the outline of the mask shape.
 //   .
-//  The roundover can be specified by radius, diameter, height, cut, or joint length.
+//   The roundover can be specified by radius, diameter, height, cut, or joint length.
 //   ![Types of Roundovers](images/rounding/section-types-of-roundovers_fig1.png)
 //   If you need roundings to agree on edges of different mask_angle, e.g. to round the base of a prismoid, then you need all of the
 //   masks used to have the same height.  (Note that it may appear that matching joint would also work, but it does not because the joint distances are measured
@@ -67,7 +67,7 @@ function _inset_corner(corner, mask_angle, inset, excess, flat_top) =
 //   anchor = Translate so anchor point is at origin (0,0,0).  See [anchor](attachments.scad#subsection-anchor).  Default: `CENTER`
 //   spin = Rotate this many degrees around the Z axis after anchor.  See [spin](attachments.scad#subsection-spin).  Default: `0`
 // Side Effects:
-//  Tags the children with "remove" (and hence sets `$tag`) if no tag is already set.
+//   Tags the children with "remove" (and hence sets `$tag`) if no tag is already set.
 //
 // Example(2D): 2D Roundover Mask by Radius
 //   mask2d_roundover(r=10);
@@ -858,7 +858,6 @@ function mask2d_dovetail(edge, angle, slope, shelf=0, inset=0, mask_angle=90, ex
 //   mask2d_ogee(pattern, [excess], ...) [ATTAHCMENTS];
 // Usage: As Function
 //   path = mask2d_ogee(pattern, [excess], ...);
-//
 // Description:
 //   Creates a 2D Ogee mask shape that is useful for extruding into a 3D mask for a 90° edge.
 //   Conversely, you can use that same extruded shape to make an interior ogee decoration between two walls at a 90º angle.
@@ -885,7 +884,7 @@ function mask2d_dovetail(edge, angle, slope, shelf=0, inset=0, mask_angle=90, ex
 //   spin = Rotate this many degrees around the Z axis after anchor.  See [spin](attachments.scad#subsection-spin).  Default: `0`
 //
 // Side Effects:
-//  Tags the children with "remove" (and hence sets `$tag`) if no tag is already set.
+//   Tags the children with "remove" (and hence sets `$tag`) if no tag is already set.
 //
 // Example(2D): 2D Ogee Mask
 //   mask2d_ogee([