Added a new pad type: trace pads, for antennas and other trace-like elements.

- layer.h (enum pad_type): added pad type pt_trace
- layer.c (pad_type_to_layers, layers_to_pad_type), inst.c (inst_pad):
  "trace" pad instantition and conversion infrastructure
- fpd.y (pad_type), dump.c (print_obj): .fpd file I/O for "trace" pads
- postscript.c (prologue): added Postscript function "horpath" to produce
  horizontal stripes
- postscript.c (hatch): show "trace" pads with horizontal stripes
- gui_style.h (gc_pad_trace), gui_style.c (gc_pad_trace, gui_setup_style),
  gui_inst.c (pad_gc): added visualization of "trace" pads
- gui_status.c (show_pad_type): added "trace" pad type
- README: added description of "trace" pads
- README: added usage examples for the various pad types



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5998 99fdad57-331a-0410-800a-d7fa5415bdb3

layer.c

@@ -1,8 +1,8 @@
 /*
  * layer.c - PCB layers on a pad
  *
- * Written 2009, 2010 by Werner Almesberger
- * Copyright 2009, 2010 by Werner Almesberger
+ * Written 2009-2011 by Werner Almesberger
+ * Copyright 2009-2011 by Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -52,6 +52,9 @@ layer_type pad_type_to_layers(enum pad_type type)
 	case pt_bare:
 		layers |= LAYER_COPPER_TOP | LAYER_MASK_TOP;
 		break;
+	case pt_trace:
+		layers |= LAYER_COPPER_TOP;
+		break;
 	case pt_paste:
 		layers = LAYER_PASTE_TOP;
 		break;
@@ -70,7 +73,9 @@ enum pad_type layers_to_pad_type(layer_type layers)
 	if (layers & LAYER_COPPER_TOP) {
 		if (layers & LAYER_PASTE_TOP)
 			return pt_normal;
-		return pt_bare;
+		if (layers & LAYER_MASK_TOP)
+			return pt_bare;
+		return pt_trace;
 	} else {
 		if (layers & LAYER_PASTE_TOP)
 			return pt_paste;