add overview

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/info/libgamma.texinfo b/info/libgamma.texinfo
index 5100602..9dd2972 100644
--- a/info/libgamma.texinfo
+++ b/info/libgamma.texinfo
@@ -60,6 +60,33 @@ Texts. A copy of the license is included in the section entitled
 @node Overview
 @chapter Overview
 
+@command{libgamma} is a library that aims to
+abstract away the display server when adjusting
+the colours curves for monitors via gamma ramps,
+and to be cross-platform.
+
+@command{libgamma} have support for the X RandR
+(Resize and Rotate) extension, the X VidMode
+extension and under Linux the Direct Rendering
+Manager which lets software work with graphics
+outside of graphical environments. Additionally
+@command{libgamma} have support for Windows
+Graphics Device Interface (Windows GDI) under
+Linux and Quartz using CoreGraphics under OS X.
+However Windows GDI and Quartz/CoreGraphics do
+not receive first-party testing on their target
+platforms but do receive first-party testing
+using a compatibility layer that translates
+the calls to RandR calls.
+
+Furthermore @command{libgamma} provides a dummy
+method that can be used to ignore adjustments
+and can be controlled from a another program to
+pretend like the environment has changed. This
+can be used test how well your software handles
+such events. It can also be configured at runtime
+to use another adjustment method such as RandR.
+
 
 @node GNU Free Documentation License
 @appendix GNU Free Documentation License