--- fract/mandelzoom.cgi	2001/02/25 05:49:07	1.2
+++ fract/mandelzoom.cgi	2001/02/25 22:54:25	1.5
@@ -3,19 +3,24 @@
 import cgi, Image, ImageDraw, sys, math
 from string import atoi, atof
 
+# This is to get backtrace output
 sys.stderr = sys.stdout
 
+# Uncomment this to get the backtrace more readable
+#print "Content-Type: text/plain"
+#print ""
+
 form= cgi.FieldStorage()
 
 # Image size
 if form.has_key('width'):
     width= atoi(form['width'].value)
 else:
-    width= 570
+    width= 480
 if form.has_key('height'):
     height= atoi(form['height'].value)
 else:
-    height= 570
+    height= 480
 
 xmax, ymax = width-1, height-1          # Coordinate maximums
 
@@ -33,7 +38,7 @@
 if form.has_key('diag'):
     diag= atof(form['diag'].value)
 else:
-    diag= math.sqrt(8)
+    diag= math.sqrt(32) # sqrt(4**2 + 4**2)
 
 debug= form.has_key('debug')
 
@@ -42,9 +47,6 @@
 else:
     maxiter= 270
 
-#print "Content-Type: text/plain"
-#print ""
-
 # If type!=image, then output an HTML page, not an image
 if not (form.has_key('type') and form['type'].value == "image"):
     print """Content-Type: text/html
@@ -67,7 +69,7 @@
     else:
         ds=""
     if form.has_key('zoom'):
-        zoom=atoi(form['zoom'].value)
+        zoom=atof(form['zoom'].value)
         diag=diag/zoom
     else:
         # If no zoom provided, don't actually zoom
@@ -76,15 +78,20 @@
     print 'ALIGN=BOTTOM HEIGHT="%s"' % (str(height)),
     print 'WIDTH="%s"><P>' % (str(width))
     print 'Zoom: <SELECT NAME="zoom">'
-    for zv in [-5, -3, -2, 1, 2, 3, 5]:
+    for zv in [1.0/5, 1.0/3, 1.0/2, 1.0/1.5, 1.0, 1.5, 2.0, 3.0, 5.0]:
         print '<OPTION',
-        if zv==zoom:
+        if str(zv)==str(zoom):
             print 'SELECTED',
         print 'VALUE="%s"' % (str(zv))
-        if zv < 0:
-            print '>÷%s' % (str(-zv))
+        if zv == 1:
+            print '>Pan'
+        elif zv < 1:
+            if int(1/zv) == 1/zv:
+                print '>Out ÷%s' % (str(int(1/zv)))
+            else:
+                print '>Out ÷%s' % (str(1/zv))
         else:
-            print '>×%s' % (str(zv))
+            print '>In ×%s' % (str(zv))
     print '</SELECT>'
     print """Width: <INPUT TYPE=TEXT NAME="width" MAXLENGTH="4" SIZE="3"
     VALUE="%s">
@@ -92,21 +99,35 @@
     VALUE="%s">
     Iterations: <INPUT TYPE=TEXT NAME="iter" MAXLENGTH="4" SIZE="3"
     VALUE="%s">
-    Debug mode: <INPUT TYPE=CHECKBOX NAME="debug" """ % (str(width), str(height), str(maxiter))
+    Debug mode: <INPUT TYPE=CHECKBOX NAME="debug" """ % (str(width), str(height), str(maxiter)),
     if debug:
         print 'CHECKED>'
     else:
         print '>'
-    for key in form.keys():
-        if key not in ["zoom", "type", "debug", "image.x", "image.y", "iter", "height", "width"]:
-            print '<INPUT TYPE=HIDDEN NAME="%s" VALUE="%s">' % (key, form[key].value)
+    print '<INPUT TYPE=SUBMIT VALUE="Apply">'
+    for var in (("diag", diag), ("cx", cx), ("cy", cy)):
+        print '<INPUT TYPE=HIDDEN NAME="%s" VALUE="%s">' % var
     print '<INPUT TYPE=HIDDEN NAME=type VALUE="html">'
 
     print """</FORM>
 </BODY></HTML>"""
     sys.exit(0)
 
-c1, c2 = (-2+2j), (2-2j)                # Corner coordinates
+# Figure out c1 and c2 from width, height, diag, cx, and cy.
+# Diagonal in pixels
+diagp= math.sqrt(width**2 + height**2)
+# Scale between pixels and coordinates
+scale= diagp/diag
+x= (width/2.0)/scale
+y= (height/2.0)/scale
+
+c1= cx - x + cy - y * (0+1j)
+c2= cx + x + cy + y * (0+1j)
+
+#print width, height, diag, cx, cy, diagp, scale, x, y, c1, c2
+#sys.exit(0)
+
+#c1, c2 = (-2+2j), (2-2j)                # Corner coordinates
 
 # Force c1 to be upper left and c2 to be lower right
 c1, c2= complex(min(c1.real, c2.real), max(c1.imag, c2.imag)), \