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Drawing Smooth Ovals (Real Studio network user group Mailinglist archive)

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Re: vCards (important for me)   -   Pepe
  Drawing Smooth Ovals   -   John Del Pizzo
   Re: Drawing Smooth Ovals   -   Kevin Ballard
   Re: Drawing Smooth Ovals   -   Joseph J. Strout

Drawing Smooth Ovals
Date: 09.05.02 00:37 (Wed, 08 May 2002 19:37:07 -0400)
From: John Del Pizzo

I'm working on a application that creates custom bubble charts. A bubble
chart (or perceptual map) is like any normal x,y scatter plot except the
that the size of each point is determined by a third value. For example, the
position on the x axis could be determined by a product's price, the y axis
could be a product's quality and the width of the "bubble" could be market
share.

I'm currently drawing into a canvas with filloval. The problem is the edges
of the circle are jagged, not smooth. Are there any tools or techniques I
could use to get a smooth circle?

I'd also be interesting in giving my bubbles a 3d look - similar to what
excel can do when it builds these types of charts. (No, I don't want to
automate excel.)

I appreciate any ideas.

Thanks,

John


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Re: Drawing Smooth Ovals
Date: 09.05.02 00:47 (Wed, 08 May 2002 19:47:33 -0400)
From: Kevin Ballard
On 5/8/02 7:37 PM, "John Del Pizzo" <<email address removed>> wrote:

> I'm currently drawing into a canvas with filloval. The problem is the edges
> of the circle are jagged, not smooth. Are there any tools or techniques I
> could use to get a smooth circle?

Try drawing at 2x or 4x the desired size and scaling down.

Re: Drawing Smooth Ovals
Date: 09.05.02 02:18 (Wed, 8 May 2002 18:18:55 -0700)
From: Joseph J. Strout
At 7:37 PM -0400 5/8/02, John Del Pizzo wrote:

>I'm currently drawing into a canvas with filloval. The problem is the edges
>of the circle are jagged, not smooth. Are there any tools or techniques I
>could use to get a smooth circle?
>
>I'd also be interesting in giving my bubbles a 3d look - similar to what
>excel can do when it builds these types of charts.

Satisfy both desires at once by making a nice 3D shaded bubble in
your favorite paint program, at a size equal to or larger than the
largest bubble you expect to need -- say, 128x128. Then draw this
into your canvas with DrawPicture, using all nine parameters to scale
it to the size you need.

To really do it right, you should use a mask as well as an image, so
the edges can blend smoothly with the background.

Cheers,
- Joe