Nicolas Cellier uploaded a new version of Graphics to project The Trunk:
http://source.squeak.org/trunk/Graphics-nice.86.mcz

==================== Summary ====================

Name: Graphics-nice.86
Author: nice
Time: 31 October 2009, 3:13:31 am
UUID: 67835c13-ecca-4ff8-8635-e8f15d789607
Ancestors: Graphics-nice.85

while at arcTan: fix 2 ULP in Float theta
Note that Float theta is in [0,2*pi[ while arcTan: is in [-pi,pi]
(0 at 0) theta leads to pi/2 instead of 0 for new version of arcTan: (pi for old version)
#arcTan: does handle case of negativeZero, #theta doesn't


=============== Diff against Graphics-nice.85 ===============

Item was changed:
  ----- Method: Point>>theta (in category 'polar coordinates') -----
  theta
  	"Answer the angle the receiver makes with origin in radians. right is 0; 
  	down is 90. 
  	Corrected the constants from single precision to 64 Bit precision 
  	and changed the sends in case of overflow to constants HK 2005-07-23"
  
  	| tan theta |
  	x = 0
  		ifTrue: [y >= 0
+ 				ifTrue: [^ 1.5707963267948966 "90.0 degreesToRadians"]
- 				ifTrue: [^ 1.570796326794897 "90.0 degreesToRadians"]
  				ifFalse: [^ 4.71238898038469 "270.0 degreesToRadians"]]
  		ifFalse: 
  			[tan := y asFloat / x asFloat.
  			theta := tan arcTan.
  			x >= 0
  				ifTrue: [y >= 0
  						ifTrue: [^theta]
  						ifFalse: [^"360.0 degreesToRadians" 6.283185307179586 + theta]]
  				ifFalse: [^"180.0 degreesToRadians" 3.141592653589793 + theta]]!