- the set of layers of a pad is now maintained in the instance, so that we can

make adjustments when removing layers provided by specialized pads
- gui_inst.c: moved gc construction from gui_draw_pad and gui_draw_rpad to
  shared pad_gc
- layer.h: new home of all definitions related to pads and layers
- layer.c: 
- overlap.c: functions to test for overlaps of pad shapes (in progress)



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5634 99fdad57-331a-0410-800a-d7fa5415bdb3

layer.c

@@ -0,0 +1,56 @@
+/*
+ * layer.c - PCB layers on a pad
+ *
+ * Written 2009 by Werner Almesberger
+ * Copyright 2009 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#include <stdlib.h>
+
+#include "layer.h"
+
+
+layer_type pad_type_to_layers(enum pad_type type)
+{
+	layer_type layers = 0;
+
+	switch (type) {
+	case pt_normal:
+		layers = LAYER_PASTE;
+		/* fall through */
+	case pt_bare:
+		layers |= LAYER_COPPER | LAYER_MASK;
+		break;
+	case pt_paste:
+		layers = LAYER_PASTE;
+		break;
+	case pt_mask:
+		layers = LAYER_MASK;
+		break;
+	default:
+		abort();
+	}
+	return layers;
+}
+
+
+enum pad_type layers_to_pad_type(layer_type layers)
+{
+	if (layers & LAYER_COPPER) {
+		if (layers & LAYER_PASTE)
+			return pt_normal;
+		return pt_bare;
+	} else {
+		if (layers & LAYER_PASTE)
+			return pt_paste;
+		if (layers & LAYER_MASK)
+			return pt_mask;
+		abort();
+	}
+}