[cairo] Disabling antialiased shape drawing

Bill Spitzak spitzak at d2.com
Sun Aug 7 17:55:44 PDT 2005

Robert O'Callahan wrote:
> On Sun, 2005-08-07 at 16:08 -0700, Bill Spitzak wrote:
>>It certainly seems to me that a single API will work for this.
>>It looks like people want exactly three things:
>>1. Antialiasing of some form. This is the default state of Cairo.
>>2. Supersampling for antialiasing is ok, but partial pixel coverage is 
>>not. The result will look like #1 or #3 depending on the driver.
>>3. Need to emulate old graphics. No supersampling or antialiasing is wanted.
>>Looks like 3 constants to me.
> I don't think so. Supersampling is something you want on at most a
> per-surface basis. But I want to be able to control antialiasing
> per-drawing-operation; applications knowing that certain drawing
> operations will not form seams can use coverage antialiasing for those
> operations. For example, text glyphs will almost always fall into this
> category. Rounded border corners can also fall into this category.

True. In fact in earlier posts I said I would prefer the ability to turn 
off antialiasing *per edge* of a shape.

However I think you missed what I wanted. Even if it is turned on/off 
per drawing, there is a desire for "supersampling is ok, but 
antialiasing by partial transparency is not". Thus the ability to 
specify this to whatever call turns antialiasing on/off is a good idea.

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