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/**
* @file llatmosphere.h
* @brief LLAtmosphere class
*
* $LicenseInfo:firstyear=2018&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2018, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#ifndef LL_ATMOSPHERE_H
#define LL_ATMOSPHERE_H
#include "llglheaders.h"
#include "llgltexture.h"
// An atmosphere layer of width 'width' (in m), and whose density is defined as
// 'exp_term' * exp('exp_scale' * h) + 'linear_term' * h + 'constant_term',
// clamped to [0,1], and where h is the altitude (in m). 'exp_term' and
// 'constant_term' are unitless, while 'exp_scale' and 'linear_term' are in
// m^-1.
class DensityLayer {
public:
DensityLayer()
: width(0.0f)
, exp_term(0.0f)
, exp_scale(0.0f)
, linear_term(0.0f)
, constant_term(0.0f)
{
}
DensityLayer(float width, float exp_term, float exp_scale, float linear_term, float constant_term)
: width(width)
, exp_term(exp_term)
, exp_scale(exp_scale)
, linear_term(linear_term)
, constant_term(constant_term)
{
}
bool operator==(const DensityLayer& rhs) const
{
if (width != rhs.width)
{
return false;
}
if (exp_term != rhs.exp_term)
{
return false;
}
if (exp_scale != rhs.exp_scale)
{
return false;
}
if (linear_term != rhs.linear_term)
{
return false;
}
if (constant_term != rhs.constant_term)
{
return false;
}
return true;
}
float width = 1024.0f;
float exp_term = 1.0f;
float exp_scale = 1.0f;
float linear_term = 1.0f;
float constant_term = 0.0f;
};
typedef std::vector<DensityLayer> DensityProfile;
class AtmosphericModelSettings
{
public:
AtmosphericModelSettings();
AtmosphericModelSettings(
DensityProfile& rayleighProfile,
DensityProfile& mieProfile,
DensityProfile& absorptionProfile);
AtmosphericModelSettings(
F32 skyBottomRadius,
F32 skyTopRadius,
DensityProfile& rayleighProfile,
DensityProfile& mieProfile,
DensityProfile& absorptionProfile,
F32 sunArcRadians,
F32 mieAniso);
bool operator==(const AtmosphericModelSettings& rhs) const;
F32 m_skyBottomRadius;
F32 m_skyTopRadius;
DensityProfile m_rayleighProfile;
DensityProfile m_mieProfile;
DensityProfile m_absorptionProfile;
F32 m_sunArcRadians;
F32 m_mieAnisotropy;
};
class LLAtmosphere
{
public:
LLAtmosphere();
~LLAtmosphere();
static void initClass();
static void cleanupClass();
const LLAtmosphere& operator=(const LLAtmosphere& rhs)
{
LL_ERRS() << "Illegal operation!" << LL_ENDL;
return *this;
}
LLGLTexture* getTransmittance();
LLGLTexture* getScattering();
LLGLTexture* getMieScattering();
LLGLTexture* getIlluminance();
bool configureAtmosphericModel(AtmosphericModelSettings& settings);
protected:
LLAtmosphere(const LLAtmosphere& rhs)
{
*this = rhs;
}
LLPointer<LLGLTexture> m_transmittance;
LLPointer<LLGLTexture> m_scattering;
LLPointer<LLGLTexture> m_mie_scatter_texture;
LLPointer<LLGLTexture> m_illuminance;
std::vector<double> m_wavelengths;
std::vector<double> m_solar_irradiance;
std::vector<double> m_rayleigh_scattering;
std::vector<double> m_mie_scattering;
std::vector<double> m_mie_extinction;
std::vector<double> m_absorption_extinction;
std::vector<double> m_ground_albedo;
AtmosphericModelSettings m_settings;
};
extern LLAtmosphere* gAtmosphere;
#endif // LL_ATMOSPHERE_H
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