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EnigmA AMIGA RUN 35 (1999)(G.R. Edizioni)(IT)[!][issue 1999-03].iso
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gamma.h
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C/C++ Source or Header
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1997-08-31
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2KB
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90 lines
////////////////////////////////////////////////////////////
//
// GAMMA.H - Gamma Correction Class
//
// Version: 1.03A
//
// History: 94/08/23 - Version 1.00A release.
// 94/12/16 - Version 1.01A release.
// 95/02/05 - Version 1.02A release.
// 95/07/21 - Version 1.02B release.
// 96/02/14 - Version 1.02C release.
// 96/04/01 - Version 1.03A release.
//
// Compilers: Microsoft Visual C/C++ Professional V1.5
// Borland C++ Version 4.5
//
// Author: Ian Ashdown, P.Eng.
// byHeart Software Limited
// 620 Ballantree Road
// West Vancouver, B.C.
// Canada V7S 1W3
// Tel. (604) 922-6148
// Fax. (604) 987-7621
//
// Copyright 1994-1996 byHeart Software Limited
//
// The following source code has been derived from:
//
// Ashdown, I. 1994. Radiosity: A Programmer's
// Perspective. New York, NY: John Wiley & Sons.
//
// It may be freely copied, redistributed, and/or modified
// for personal use ONLY, as long as the copyright notice
// is included with all source code files.
//
////////////////////////////////////////////////////////////
#ifndef _GAMMA_H
#define _GAMMA_H
#include "color.h"
static const int G_Domain = 256; // Input domain
static const int G_Range = 256; // Output range
class Gamma // Gamma correction
{
private:
// Gamma correction lookup table
static BYTE GammaTable[256];
double g_value; // Gamma value
void InitTable()
{
int i; // Loop index
// Calculate gamma correction lookup table entries
for (i = 0; i < G_Domain; i++)
GammaTable[i] = (BYTE) ((double) G_Range *
pow((double) i / (double) G_Domain, 1.0 /
g_value));
}
public:
Gamma( double g = 2.2 )
{
g_value = g;
InitTable();
}
double GetGamma() { return g_value; }
void Correct( ColorRGB &c )
{
c.SetRed(GammaTable[(UBYTE)c.GetRed()]);
c.SetGreen(GammaTable[(UBYTE)c.GetGreen()]);
c.SetBlue(GammaTable[(UBYTE)c.GetBlue()]);
}
void SetGamma( double g )
{
g_value = g;
InitTable();
}
};
#endif