//-----------------------------------------------------------------------------
//
// Sample Name: GammaControl Sample
//
// Copyright (c) 1999-2001 Microsoft Corporation. All rights reserved.
//
//-----------------------------------------------------------------------------
Description
===========
GammaControl demonstrates how to use IDirectDrawGammaControl to adjust
how bright the system displays the DirectDraw surface.
Path
====
Source: DXSDK\Samples\Multimedia\DDraw\GammaControl
Executable: DXSDK\Samples\Multimedia\DDraw\Bin
User's Guide
============
Click the left mouse button to decrease the gamma ramp or the right mouse button
to increase it. Press the ESC key to quit the program.
Programming Notes
=================
For details on how to setup a full-screen DirectDraw app, see the FullScreenMode
sample.
To adjust the gamma, first check to see if the device supports it. Call
IDirectDraw::GetCaps to check if DDCAPS2_PRIMARYGAMMA is set. If it is, then
you can set the gamma ramp by calling IDirectDrawGammaControl::SetGammaRamp.
For simplicity this sample creates a gamma ramp which is linear for all
color components. The ramp runs from 0 at index 0 linearly up to a user
defined number at index 255 for each of the color components. However, the ramp
does not need to be linear.
LGram16
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