Resilient Image Library (ResIL) version 1.7.9 Readme, Notes and Quick Use
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<DZA[afk]> ResIL song: "la la la, a cross-platform image library utilizing a
           simple syntax to load, save, convert, manipulate, filter and display
           a variety of images with ease, la la la"


What is it?
-----------

ResIL is an Open Source image library whose distribution is done under the
terms of the GNU LGPL license. See the COPYING file for more details.
It was created as an updated fork of DevIL. Like DevIL, ResIL offers you a 
simple way to implement loading, manipulating, filtering, converting, 
displaying, saving from/to several different image formats in your own project.


Where can I find it?
--------------------

ResIL can be found at http://openil.sourceforge.net


How do I build and install the 3 libraries ?
-----------------------------------------

*nix    users should read README.unix
VisualC users should read README.win
Cygwin  users should read README.cygwin
MacOSX  users should read README.macosx

PS: *nix stands for GNU/Linux, *BSD, SunOS/Solaris and perhaps some more.
 

More Extensive Documentation
----------------------------

This file is only a quick guide to point you to more detailed information on
how to use ResIL.  More extensive documentation can currently be found on the
ResIL site at http://openil.sf.net and in the /Docs directory in a normal
install.


Why the hell another image library?
-----------------------------------

I have never seen an image library that can do everything ResIL does.  Sure,
various different libraries can do part of what ResIL can do as well or even
better, but I wanted a simple to use library that encompassed all of these
features.  I also wanted an extremely portable image library that could be used
from a variety of languages and utilized the OpenGL syntax.


Basic Readme
------------

Most anything stated in this document applies to ResIL as well as ResILU and
ResILUT, unless otherwise stated. (This file is best viewed with word wrap on.)


Errors:
-------

All errors generated inside ResIL, along with illegal parameters passed to
ResIL functions are caught and passed to ilSetError(), an internal library
function.  The calling program can call ilGetError() to get the value of the
error generated.  Error types are defined in il.h, using the 0x501 - 0x5FF
range.  ilGetError() will return 0 (IL_NO_ERROR) if no error has occurred.


Basic Usage:
------

This demonstrates loading an image through ResIL for OpenGL. Don't forget to 
call ilInit before you before you do anything:

#include <IL/il.h>
#include <IL/ilu.h>
#include <IL/ilut.h>

...

ILuint ResILError;


ilInit();

ResILError = ilGetError();

if (ResILError != IL_NO_ERROR) {
  printf ("ResIL Error (ilInit: %s\n", iluGetErrorString (ResILError));
  exit (2);
}

....

ILuint ResILID;


ilGenImages(1, &ResILID);
ilBindImage(ResILID);
ilLoadImage("default1.tga");  // Loads into the current bound image
ResILError = ilGetError();

if (ResILError != IL_NO_ERROR) {
  printf ("ResIL Error (ilLoadImage: %s\n", iluGetErrorString (ResILError));
  exit (2);
}

....

ilutRenderer(IL_OPENGL);  // Switch the renderer

....

GLuint openglID, openglError;


openglID   = ilutGLBindTexImage(); // This generates the texture for you
ResILError = ilGetError();

if (ResILError != IL_NO_ERROR) {
  printf ("Error: %s\n", iluGetErrorString (ResILError));
  exit (2);
}

if (openglError != GL_NO_ERROR) {
  printf ("Opengl Error (ilutGLBindTexImage): %s\n", gluGetErrorString (openglError));
  exit (2);
}



// Make sure to close the image when you are done with it (though ResIL
// automatically deletes them when the program exits):

glDeleteTextures(1, &openglID);
ilDeleteImages  (1, &ResILID);


More Examples:
---------

The TestIL project is included to test features of ResIL.

ResIL includes a project called GLTest.  This is a simple test of ResIL's
capabilities.  All it does it load any image and displays it in a window
created by FreeGlut, which is available on http://freeglut.sourceforge.net. It
is also included to let the user have an idea of what the library can really
be used for.

Several other test projects are included to test support with various display
APIs.  The WindowsTest project is a basic image program that only runs in
Windows right now but showcases several of ResIL's features through various
menus.

If you want more in-depth tutorials, you can find them on
http://openil.sf.net, or they may be in your installation under the /examples
directory.  Documents are also available in the /docs directory.


Additional Reading
------------------

All image formats used in ResIL have corresponding documents on
http://www.wotsit.org, under the Graphics Files section.  These documents
proved invaluable for the creation of this library when there was no library
already available for that image format.


Legalese
--------

All contents of this file are intellectual property of Denton Woods,
copyright 2001-2008.
