Re : Image resize

SDL Development
1

You can also do it by hand copying pixel per pixel …
But you need to know a little bit of direct access to pixels,
algorithmic, and antialiasing for zoom in.

To give an idea, if you divide an image size by two, you
simply copy pixels with an even x and y coordinate.
This is a very simply example, it is not so straightforward
when the destination size is not an exact divisor of the original size …
(or only the width, not the height and vice versa).

When you make an image bigger, aliasing appear and you need
to apply an antialiasing filter to it (neighbours, gauss, etc.).

If you want to play and learn new things, try doing it by hand, else,
as Andre suggested, use a library having this feature implemented for you,
like SDL_gfx.

Regards

----- Message d’origine ----De : Leo Cabrera
? : A list for developers using the SDL library. (includes SDL-announce)
Envoy? le : Vendredi, 25 Juillet 2008, 15h56mn 58s
Objet : Re: [SDL] Image resize

Use the rotozoom feature of SDL_gfx. :stuck_out_tongue:

Andre Botelho wrote:

is there a fast way to resize images on SDL?

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

  _____________________________________________________________________________

Envoyez avec Yahoo! Mail. Une boite mail plus intelligente http://mail.yahoo.fr

2

i’ve asked it before, but since it is a holiday period, perhaps noone
ready my plea for information :

can anyone give some hint about the situation for multimonitor support
on both mac os X and windows XP ?

we have a project that is going to be rewritten pretty soon, and I
really want to make it a crossplatform, opensource solution this time.
SDL would be a perfect fit, but we really need dual monitor support

can anyone confirm or deny that SDL 1.3 handles full screen dual
monitor applications ?

I would be most grateful !

Jeroen

3

To give you at least some answer…

I know it is planned to support multiple displays (and have a much nicer interface than SDL 1.2 does for many things) on each of the supported platforms (Mac and Windows among those). I can’t say, though, how much of that support is there yet. You might have to just download 1.3 and build a quick test to see if it can handle what you need. The problem is sorting through the header files instead of documentation.

SDL 1.3 Plans (quick Google search):
http://icculus.org/cgi-bin/finger/finger.pl?user=icculus&date=2007-10-07&section=sdl13

Jonny D----------------------------------------

From: jeroen.clarysse at telenet.be
To: sdl at lists.libsdl.org
Date: Mon, 28 Jul 2008 11:57:38 +0200
Subject: [SDL] A desperate call for information on SDL 1.3…

i’ve asked it before, but since it is a holiday period, perhaps noone
ready my plea for information :

can anyone give some hint about the situation for multimonitor support
on both mac os X and windows XP ?

we have a project that is going to be rewritten pretty soon, and I
really want to make it a crossplatform, opensource solution this time.
SDL would be a perfect fit, but we really need dual monitor support

can anyone confirm or deny that SDL 1.3 handles full screen dual
monitor applications ?

I would be most grateful !

Jeroen

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

4

thanks for the info !

i’ve never compiled SDL mysql and i’m a bit scared of such things (not
experienced enough)

is anyone aware of developes actually involved with 1.3 ?On 28 Jul 2008, at 19:27, Jonathan Dearborn wrote:

To give you at least some answer…

I know it is planned to support multiple displays (and have a much
nicer interface than SDL 1.2 does for many things) on each of the
supported platforms (Mac and Windows among those). I can’t say,
though, how much of that support is there yet. You might have to
just download 1.3 and build a quick test to see if it can handle
what you need. The problem is sorting through the header files
instead of documentation.

SDL 1.3 Plans (quick Google search):
http://icculus.org/cgi-bin/finger/finger.pl?user=icculus&date=2007-10-07&section=sdl13

Jonny D

From: @Jeroen_Clarysse
To: sdl at lists.libsdl.org
Date: Mon, 28 Jul 2008 11:57:38 +0200
Subject: [SDL] A desperate call for information on SDL 1.3…

i’ve asked it before, but since it is a holiday period, perhaps noone
ready my plea for information :

can anyone give some hint about the situation for multimonitor
support
on both mac os X and windows XP ?

we have a project that is going to be rewritten pretty soon, and I
really want to make it a crossplatform, opensource solution this
time.
SDL would be a perfect fit, but we really need dual monitor support

can anyone confirm or deny that SDL 1.3 handles full screen dual
monitor applications ?

I would be most grateful !

Jeroen

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

5

Hi,

Don’t be scared! It’s not that traumatic - Google is your friend :slight_smile:

Just build your knowledge step-by-step.

Either get the source from the download page, or from SVN. (svn.tigris.org).

Compilation instructions are in the source tree.

The learning curve is steep, esp on Windows, because of the disconnect
between what you see and what happens (the GUI is a front-end to
command-line tools).

Personally, when I started (10 years ago) using Visual Studio, I found
the options overwhelming (because I didn’t understand them). I found
Linux a much better learning environment, because you have to read
lots of documentation to know what’s going on, for example, compiling a
program with GCC is as simple as:

 gcc source.c

To find out more, you do:

man gcc

You then look at the ‘synopsis’ and you see [-o outfile], so you type

'/-o'

and keep pressing ‘n’ until you get to the full description of -o.

And that’s all there is too it. You just keep doing that, one option at
a time. Anything man can’t tell you, Google can.

Eddy

jeroen clarysse wrote:> thanks for the info !

i’ve never compiled SDL mysql and i’m a bit scared of such things (not
experienced enough)

is anyone aware of developes actually involved with 1.3 ?

On 28 Jul 2008, at 19:27, Jonathan Dearborn wrote:

To give you at least some answer…

I know it is planned to support multiple displays (and have a much
nicer interface than SDL 1.2 does for many things) on each of the
supported platforms (Mac and Windows among those). I can’t say,
though, how much of that support is there yet. You might have to just
download 1.3 and build a quick test to see if it can handle what you
need. The problem is sorting through the header files instead of
documentation.

SDL 1.3 Plans (quick Google search):
http://icculus.org/cgi-bin/finger/finger.pl?user=icculus&date=2007-10-07&section=sdl13

Jonny D

From: jeroen.clarysse at telenet.be
To: sdl at lists.libsdl.org
Date: Mon, 28 Jul 2008 11:57:38 +0200
Subject: [SDL] A desperate call for information on SDL 1.3…

i’ve asked it before, but since it is a holiday period, perhaps noone
ready my plea for information :

can anyone give some hint about the situation for multimonitor support
on both mac os X and windows XP ?

we have a project that is going to be rewritten pretty soon, and I
really want to make it a crossplatform, opensource solution this time.
SDL would be a perfect fit, but we really need dual monitor support

can anyone confirm or deny that SDL 1.3 handles full screen dual
monitor applications ?

I would be most grateful !

Jeroen

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

6

can anyone give some hint about the situation for multimonitor support
on both mac os X and windows XP ?

we have a project that is going to be rewritten pretty soon, and I
really want to make it a crossplatform, opensource solution this time.
SDL would be a perfect fit, but we really need dual monitor support

can anyone confirm or deny that SDL 1.3 handles full screen dual
monitor applications ?

Yes, it is planned, but not yet implemented.

See ya!
-Sam Lantinga, Lead Software Engineer, Blizzard Entertainment