Canvas line style comments

The spec says: "The lineCap attribute defines the type of endings that 
UAs will place on the end of lines. The three valid values are butt, 
round, and square. The butt value means that the end of each line is a 
flat edge perpendicular to the direction of the line. The round value ..."

That doesn't give any clear "must" requirements for butts. (Nothing else 
defines precisely how lines are to be rendered, so this isn't just a 
statement of a consequence of a specified line-drawing algorithm, so it 
should say "must" here else there won't be any testable requirements for 
lineCap=butt.)


"The miter limit ratio is the maximum allowed ratio of the length of the 
two continuation lines to the line width" is wrong - it's the maximum 
allowed ratio of the miter length to half the line width (e.g. when 
mitering a right angle the critical point is miterLimit=sqrt(2)).


"If the miter length would be exceeded" - s/length/limit ratio/


In the definition of 'miter': s/abuting/abutting/

-- 
Philip Taylor
pjt47@cam.ac.uk

Received on Thursday, 29 May 2008 00:45:51 UTC