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Re: [whatwg] Canvas roundedRect

From: Bronislav Klučka <Bronislav.Klucka@bauglir.com>
Date: Thu, 21 Jun 2012 19:51:54 +0200
Message-ID: <4FE35F3A.9060002@bauglir.com>
To: whatwg@lists.whatwg.org
Hi,
So why do ve have rect? 4 lines could do it... simple enough...

Canvas is for immediate raster graphics, SVG for retain vector 
graphics.  The use is a matter of choice, canvas have been used to 
create controls, graphs, diagrams... all could use round rect. But I 
agree, that idea below is not very well thought out.
If we would go for round rect (RR), we need the obility to create RR 
paths and the ability to create each "corner" different - specify x and 
y radiuses for every "corner"

Brona.

On 21.6.2012 19:34, David Dailey wrote:
> It seems to me that the primary use of rounded rectangles is for UI's rather
> than art, and as such, SVG, that supports DOM and events, already has syntax
> for rounded rectangles. I have seen how the<canvas>  folks like to re-invent
> wheels, but the path syntax within canvas already should allow creation of
> line arc line arc sequences, and making things too easy would not appeal to
> the<canvas>  machismo would it?
>
> How many rounded rectangles have you ever seen that don't invite
> mouseclicks? And then do you really want to try to calculate whether or not
> the mouse event is atop one of those thingies, particularly after it has
> been rotated, scaled and skewed?
>
> I'm just not seeing why<canvas>  would need this.
>
> Regards
> David
>
> -----Original Message-----
> From: whatwg-bounces@lists.whatwg.org
> [mailto:whatwg-bounces@lists.whatwg.org] On Behalf Of Igor Trindade Oliveira
> Sent: Thursday, June 21, 2012 12:59 PM
> To: whatwg@lists.whatwg.org
> Subject: [whatwg] Canvas roundedRect
>
> Currently, canvas2d does not have support for rounded rectangles and the web
> developers are implementing rounded rectangles using arcs or bezier
> curves.[1][2] So i propose the addition of two new functions:
>
> void fillRoundedRect(unrestricted double x, unrestricted double y,
> unrestricted double w, unrestricted double h, unrestricted double xRadius,
> unrestricted double yRadius); void strokeRoundedRect(unrestricted double x,
> unrestricted double y, unrestricted double w, unrestricted double h,
> unrestricted double xRadius, unrestricted double yRadius);
>
> Where the xRadius and yRadius arguments specify the radii of the ellipses
> defining the corners of the rounded rectangle.
>
> Additionally, if we know that the path is a rounded rectangle, we can make
> optimizations in the graphics libraries reducing the amount of tesselations.
>
> [1] http://www.scriptol.com/html5/canvas/rounded-rectangle.php
> [2]
> http://www.supercalifrigginawesome.com/Extending-Canvas-to-Draw-Rounded-Rect
> angles
>
>
>

-- 

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          Bronislav Klučka



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Received on Thursday, 21 June 2012 17:52:34 UTC

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