Index: graphics.awk
===================================================================
--- graphics.awk	(revision 20748)
+++ graphics.awk	(revision 20749)
@@ -14,72 +14,23 @@
 	}
 }
 
-# spiral from x,y pos, and inradius does nothing
-function a_spiral(xcen ,ycen, radius, inradius, turns, deg_offset)
+# Archimedean spirals
+function a_spiral(xcen ,ycen, radius, inradius, turns, sides, phase)
 {
-	x = xcen
-	y = ycen
-	angle = turns * 2 * 3.141592654
-	phi  = deg_to_rad(deg_offset)
-	factor = 24
-	interval = angle*factor
-	theta = 0
-	for (i=0 ; i <  interval+0; i++ ){
-		theta += 1/factor
-		message("theta is: " theta)
-		message("interval is: " interval)
-		xn = x + (theta*radius)/(interval)*cos(theta + phi)
-		yn = y + (theta*radius)/(interval)*sin(theta + phi)
-		ddraft("line from " x "," y " to " xn "," yn )
-		x = xn
-		y = yn
+	if (sides+0 < 3){
+		message ("must have 3 or more sides")
+		return 0
 	}
-}
-
-# function for spirals defined with annular ring and # of turns
-function spiral_by_turns(xcen ,ycen, radius, inradius, turns, deg_offset,xrad,yrad)
-{
 	x = xcen
 	y = ycen
-	phi  = deg_to_rad(deg_offset)
-	factor = 24
-	theta = 0 
-	if (xrad == ""){
-		xrad = 1
-	}
-	if (yrad == ""){
-		yrad = 1
-	}
-	if (inradius > 0 ){
-		if (inradius == radius){
-			message ("inradius cannot be equal to radius")
-			return 0
-		}
-		annular_turns = turns
-		full_turns = turns*radius/(radius-inradius) 
-		offset = (full_turns - annular_turns) * 2 *3.141592654 
-	}
-	else {
-		annular_turns = 0
-		full_turns = turns
-		offset = 0
-	}
-	angle = full_turns * 2 * 3.141592654
-	interval = angle*factor
-	message ("xrad:" xrad)
-	spiral_length = 0
-	for (i= 0 ; i <  interval -1 ; i++ ){
-		theta += 1/factor
-		if (theta < offset){
-			ignore = 1	
-		}
-		else if (theta >= offset){
-			ignore = 0
-			}
-			message("ignore is: " ignore)
-		xn = x + xrad*(theta*radius)/(interval)*cos(theta + phi)
-		yn = y + yrad*(theta*radius)/(interval)*sin(theta + phi)
-		if (!ignore){ 
+	steps = sides * turns
+	phi  = deg_to_rad(phase)
+	for (i=0 ; i <= steps; i++ ){
+		r =  inradius + (i*(radius - inradius))/steps
+		angle = 2 * 3.141592654 * i/sides
+		xn = xcen + r * cos(angle + phi)
+		yn = ycen + r * sin(angle + phi)
+		if ( i > 0) {
 			ddraft("line from " x "," y " to " xn "," yn )
 			spiral_length += sqrt((xn-x)^2 + (yn-y)^2) 
 		}
@@ -87,17 +38,11 @@
 		y = yn
 	}
 	message("spiral length is: " spiral_length)
+	spiral_length = 0
 }
 
-# spiral defined with spiral_length instead of # of turns
-function spiral_by_length(xcen ,ycen, radius, inradius, spiral_length, deg_offset)
-{
-
-}
-
 function drawpoly(xcen,ycen, sides, side_length, circumradius,rot_angle) # side_length, rot_deg, apothem, circumradius)
 {
-	# setups
 	pi = 3.141592654
 	segment_angle =  2*3.14159264/sides
 	message("segment angle is: " segment_angle )
@@ -135,7 +80,9 @@
 		x = xn
 		y = yn
 	}
-	if ( xcen - (xsum/sides) < 1 ){
+	if ( xcen - circumradius < 1 || ycen - circumradius < 1 ){
+		message("xcen: " xcen)
+		message("xsum/sides: " xsum/sides)
 		return 0
 	}
 	for (i in xvert){ 	
@@ -157,7 +104,6 @@
 
 BEGIN {
 	fgw_func_reg("rules")
-	fgw_func_reg("spiral_by_turns")
-	fgw_func_reg("spiral_by_length")
+	fgw_func_reg("a_spiral")
 	fgw_func_reg("drawpoly")
 }