Line thickness, Anti-aliasing

SDL Development
1

Hi guys,

Does anybody know a fast algorithm for drawing anti-aliased lines of a
variable width for:

straight lines,
ellipses,
curves in general (spline)

… or if there is already some lib out there doing this (integratable
with libsdl).

thanx

  • Lars :slight_smile:
2

Lars Knudsen wrote:

Hi guys,

Does anybody know a fast algorithm for drawing anti-aliased lines of a
variable width for:

straight lines,
ellipses,
curves in general (spline)

… or if there is already some lib out there doing this (integratable
with libsdl).

Hi,

check out SDL_gfx (available from libsdl.org). I don’t know if it does
all of these tasks, though.

Sebastian

3

Thanx, but I’ve checked. The SDL_gfx library only draws lines in a
"single pixel" width :frowning:

Could anyone else tell me if they have some code lying around to do
this? … I’m thinking about “reverse engineering” the engine in Java2D.

  • Lars

Sebastian Beschke wrote:> Lars Knudsen wrote:

Hi guys,

Does anybody know a fast algorithm for drawing anti-aliased lines of
a variable width for:

straight lines,
ellipses,
curves in general (spline)

… or if there is already some lib out there doing this (integratable
with libsdl).

Hi,

check out SDL_gfx (available from libsdl.org). I don’t know if it does
all of these tasks, though.

Sebastian

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

4

You can try antigrain http://www.antigrain.com/ and then blit the image.
Adib.

Lars Knudsen wrote:> Thanx, but I’ve checked. The SDL_gfx library only draws lines in a

“single pixel” width :frowning:

Could anyone else tell me if they have some code lying around to do
this? … I’m thinking about “reverse engineering” the engine in Java2D.

  • Lars

Sebastian Beschke wrote:

Lars Knudsen wrote:

Hi guys,

Does anybody know a fast algorithm for drawing anti-aliased lines of
a variable width for:

straight lines,
ellipses,
curves in general (spline)

… or if there is already some lib out there doing this (integratable
with libsdl).

Hi,

check out SDL_gfx (available from libsdl.org). I don’t know if it does
all of these tasks, though.

Sebastian

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

5

You might look up “Wu Antialiasing” – probably the fastest software-only
anti-aliasing algorithm in existance.

A couple years ago, Andreas Schiffler (sdl at lokigames.com) was looking for
the same thing. I dunno if they still read this list or answer that email
address, but you might try contacting them – I believe they did actually
find or impliment the Wu algorithm for SDL.

  • Silicon> ----- Original Message -----

From: taraben.a@wige-data.de (Adib Taraben)
To:
Sent: Friday, February 20, 2004 3:47 PM
Subject: Re: HELP Please :-). Re: [SDL] Line thickness, Anti-aliasing

You can try antigrain http://www.antigrain.com/ and then blit the image.
Adib.

Lars Knudsen wrote:

Thanx, but I’ve checked. The SDL_gfx library only draws lines in a
"single pixel" width :frowning:

Could anyone else tell me if they have some code lying around to do
this? … I’m thinking about “reverse engineering” the engine in Java2D.

  • Lars

Sebastian Beschke wrote:

Lars Knudsen wrote:

Hi guys,

Does anybody know a fast algorithm for drawing anti-aliased lines of
a variable width for:

straight lines,
ellipses,
curves in general (spline)

… or if there is already some lib out there doing this (integratable
with libsdl).

Hi,

check out SDL_gfx (available from libsdl.org). I don’t know if it does
all of these tasks, though.

Sebastian

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

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