How to rotate a graphic

[Mark Wieder]

Claus-

Saturday, November 14, 2009, 8:45:18 AM, Jan wrote:

> Take a look at the 'fillGradient' property in the Dictionary. It
> is an array of different properties of the gradient which fills your
> graphic.
> Of particular interest are the 'from', 'to and 'via'
> sub-properties, as these designate where the gradient starts and
> ends, and at what angle.

...and nonintuitively, the "from" element is the center of rotation.
Here's a simple routine to turn the graphic gradient clockwise from
horizontal to vertical.

on mouseUp pMouseBtnNo
    local tGradient
    local tFrom, tTo, tVia
    local tLength
    
    put the fillgradient of graphic 1 into tGradient
    put tGradient["from"] into tFrom
    put tGradient["to"] into tTo
    put tGradient["via"] into tVia
    
    -- "from" is the fulcrum : we want to rotate around it

    set the itemdelimiter to comma
    put item 1 of tTo - item 1 of tFrom into tLength
    put item 1 of tFrom into item 1 of tTo
    put item 2 of tFrom + tLength into item 2 of tTo
    
    put item 2 of tVia- item 2 of tFrom into tLength
    put item 2 of tFrom into item 2 of tVia
    put item 1 of tFrom - tLength into item 1 of tVia
    
    put tFrom into tGradient["from"]
    put tTo into tGradient["to"]
    put tVia into tGradient["via"]
    set the fillgradient of graphic 1 to tGradient
end mouseUp

-- 
-Mark Wieder
 mwieder at ahsoftware.net