197 lines
8.0 KiB
C++

/*
* This file is part of RawTherapee.
*
* Copyright (c) 2004-2010 Gabor Horvath <hgabor@rawtherapee.com>
*
* RawTherapee is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* RawTherapee is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with RawTherapee. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __CURVES_H__
#define __CURVES_H__
#include <glibmm.h>
#include <map>
#include <string>
#include <math.h>
#include <mycurve.h>
#define CURVES_MIN_POLY_POINTS 1000
#define SQR(x) ((x)*(x))
namespace rtengine {
class CurveFactory {
friend class Curve;
protected:
// look-up tables for the standard srgb gamma and its inverse (filled by init())
static int igammatab_srgb[65536];
static int gammatab_srgb[65536];
// look-up tables for the simple exponential gamma
static int gammatab[65536];
// functions calculating the parameters of the contrast curve based on the desired slope at the center
static double solve_upper (double m, double c, double deriv);
static double solve_lower (double m, double c, double deriv);
static double dupper (const double b, const double m, const double c);
static double dlower (const double b, const double m, const double c);
// basic convex function between (0,0) and (1,1). m1 and m2 controls the slope at the start and end point
static inline double basel (double x, double m1, double m2) {
if (x==0.0)
return 0.0;
double k = sqrt ((m1-1.0)*(m1-m2)/2) / (1.0-m2);
double l = (m1-m2) / (1.0-m2) + k;
double lx = log(x);
return m2*x + (1.0-m2)*(2.0 - exp(k*lx))*exp(l*lx);
}
// basic concave function between (0,0) and (1,1). m1 and m2 controls the slope at the start and end point
static inline double baseu (double x, double m1, double m2) {
return 1.0 - basel(1.0-x, m1, m2);
}
// convex curve between (0,0) and (1,1) with slope m at (0,0). hr controls the highlight recovery
static inline double cupper (double x, double m, double hr) {
if (hr>1.0)
return baseu (x, m, 2.0*(hr-1.0)/m);
double x1 = (1.0-hr)/m;
double x2 = x1 + hr;
if (x>=x2) return 1.0;
if (x<x1) return x*m;
return 1.0 - hr + hr*baseu((x-x1)/hr, m, 0);
}
// concave curve between (0,0) and (1,1) with slope m at (1,1). sr controls the shadow recovery
static inline double clower (double x, double m, double sr) {
return 1.0 - cupper(1.0-x, m, sr);
}
// convex curve between (0,0) and (1,1) with slope m at (0,0). hr controls the highlight recovery
static inline double cupper2 (double x, double m, double hr) {
double x1 = (1.0-hr)/m;
double x2 = x1 + hr;
if (x>=x2) return 1.0;
if (x<x1) return x*m;
return 1.0 - hr + hr*baseu((x-x1)/hr, m, 0.3*hr);
}
static inline double clower2 (double x, double m, double sr) {
float x1 = sr/1.5 + 0.00001;
float y1 = 1-(1-x1)*m;
if (x>x1 || sr<0.001)
return 1-(1-x)*m;
else
return y1+m*(x-x1)-(1-m)*SQR(SQR(1-x/x1));
}
// tone curve base. a: slope (from exp.comp.), b: black, D: max. x value (can be>1), hr,sr: highlight,shadow recovery
static inline double basecurve (double x, double a, double b, double D, double hr, double sr) {
if (b<0) {
double m = 0.5;
double slope = 1+b;
double y = -b+m*slope;
if (x>m)
return y + (x - m)*slope;
else
return y*clower2(x/m, slope*m/y, 2.0-sr);
} else {
double slope = a/(1-b);
double m = a*D>1 ? b/a+(0.25)/slope : b+(1-b)/4;
double y = a*D>1 ? 0.25 : (m-b/a)*slope;
if (x<=m)
return b==0 ? x*slope : clower (x/m, slope*m/y, sr) * y;
else if (a*D>1)
return y+(1.0-y)*cupper2((x-m)/(D-m), slope*(D-m)/(1.0-y), hr);
else
return y+(x-m)*slope;
}
}
// brightness curve at point x, only positive amount it supported
static inline double brightnessbase (double x, double amount) {
if (x<0.5)
return x + amount*cupper(2.0*x, 4.5, 0.0)/3.0;
else
return x + amount*cupper(2.0-2.0*x, 1.5, 0.0)/3.0;
}
// brightness curve at point x, positive negative and zero amount are supported
static inline double brightness (double x, double amount) {
if (amount==0)
return x;
else if (amount>0)
return brightnessbase (x, amount);
else
return 1.0 - brightnessbase (1.0-x, -amount);
}
public:
static void init ();
static inline double centercontrast (double x, double b, double m);
// standard srgb gamma and its inverse
static inline double gamma2 (double x) {
return x <= 0.00304 ? x*12.92 : 1.055*exp(log(x)/2.4)-0.055;
}
static inline double igamma2 (double x) {
return x <= 0.03928 ? x/12.92 : exp(log((x+0.055)/1.055)*2.4);
}
// gamma function with adjustable parameters
static inline double gamma (double x, double gamma, double start, double slope, double mul, double add){
return (x <= start ? x*slope : exp(log(x)/gamma)*mul-add);
}
// gamma functions on [0,65535] based on look-up tables
static inline int gamma_srgb (int x) { return gammatab_srgb[x]; }
static inline int gamma (int x) { return gammatab[x]; }
static inline int igamma_srgb (int x) { return igammatab_srgb[x]; }
public:
// static void updateCurve3 (int* curve, int* ohistogram, const std::vector<double>& cpoints, double defmul, double ecomp, int black, double hlcompr, double shcompr, double br, double contr, double gamma_, bool igamma, int skip=1);
static void complexCurve (double ecomp, double black, double hlcompr, double shcompr, double br, double contr, double defmul, double gamma_, bool igamma, const std::vector<double>& curvePoints, unsigned int* histogram, float* hlCurve, float* shCurve, int* outCurve, unsigned int* outBeforeCCurveHistogram, int skip=1);
static void complexsgnCurve (double satclip, double satcompr, double saturation, double colormult, const std::vector<double>& curvePoints, int* outCurve, int skip=1);
};
class Curve {
protected:
int N;
int ppn; // targeted polyline point number
double* x;
double* y;
std::vector<double> poly_x; // X points of the faceted curve
std::vector<double> poly_y; // Y points of the faceted curve
double* ypp;
CurveType kind;
protected:
void spline_cubic_set ();
void NURBS_set ();
static inline double p00 (double x, double prot) { return CurveFactory::clower (x, 2.0, prot); }
static inline double p11 (double x, double prot) { return CurveFactory::cupper (x, 2.0, prot); }
static inline double p01 (double x, double prot) { return x<=0.5 ? CurveFactory::clower (x*2, 2.0, prot)/2.0 : 0.5 + CurveFactory::cupper ((x-0.5)*2, 2.0, prot)/2.0; }
static inline double p10 (double x, double prot) { return x<=0.5 ? CurveFactory::cupper (x*2, 2.0, prot)/2.0 : 0.5 + CurveFactory::clower ((x-0.5)*2, 2.0, prot)/2.0; }
static inline double pfull (double x, double prot, double sh, double hl) { return (1-sh)*(1-hl)*p00(x,prot) + sh*hl*p11(x,prot) + (1-sh)*hl*p01(x,prot) + sh*(1-hl)*p10(x,prot); }
public:
Curve (const std::vector<double>& points, int ppn=CURVES_MIN_POLY_POINTS);
~Curve ();
double getVal (double x);
void getVal (const std::vector<double>& t, std::vector<double>& res);
};
}
#endif