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paysages : Progress on bruneton atmospheric model (WIP).

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git-svn-id: https://subversion.assembla.com/svn/thunderk/paysages@479 b1fd45b6-86a6-48da-8261-f70d1f35bdcc
This commit is contained in:
Michaël Lemaire 2012-12-13 21:33:42 +00:00 committed by ThunderK
parent b765ae2cff
commit d5dddf40e1
4 changed files with 636 additions and 185 deletions
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4
lib_paysages/Makefile
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@ -1,9 +1,9 @@
BUILDMODE = debug
BUILDPATH = ../build/${BUILDMODE}
OBJPATH = ./obj/${BUILDMODE}
SOURCES = $(wildcard *.c atmosphere/*.c terrain/*.c)
SOURCES = $(wildcard *.c atmosphere/*.c terrain/*.c tools/*.c)
OBJECTS = ${SOURCES:%.c=${OBJPATH}/%.o}
HEADERS = $(wildcard *.h atmosphere/*.h terrain/*.h shared/*.h)
HEADERS = $(wildcard *.h atmosphere/*.h terrain/*.h tools/*.h shared/*.h)
RESULT = ${BUILDPATH}/libpaysages.so
LIBS = glib-2.0 gthread-2.0 IL ILU
CC_FLAGS = -Wall -fPIC -DHAVE_GLIB=1

603
lib_paysages/atmosphere/bruneton.c
View file

@ -10,6 +10,9 @@
#include <math.h>
#include <stdlib.h>
#include "../system.h"
#include "../tools/texture.h"
/*********************** Constants ***********************/
#define TRANSMITTANCE_NON_LINEAR
#define INSCATTER_NON_LINEAR
@ -26,29 +29,18 @@ static const double ISun = 100.0;
#define RES_R 32
#define RES_NU 8
#define TRANSMITTANCE_INTEGRAL_SAMPLES 500
/*#define SKY_W 64
#define SKY_H 16*/
#define SKY_W 640
#define SKY_H 160
#define SKY_W 64
#define SKY_H 16
#define TRANSMITTANCE_W 256
#define TRANSMITTANCE_H 64
#define INSCATTER_INTEGRAL_SAMPLES 50
typedef struct
{
int xsize;
int ysize;
Color* data;
} Texture2D;
typedef struct
{
int xsize;
int ysize;
int zsize;
Color* data;
} Texture3D;
Texture2D _transmittanceTexture = {0, 0, 0};
Texture2D _irrDeltaETexture;
Texture3D _inscatterSampler;
Texture2D* _transmittanceTexture = NULL;
Texture2D* _irrDeltaETexture = NULL;
Texture2D* _irradianceTexture = NULL;
Texture3D* _inscatterTexture = NULL;
Texture3D* _deltaSMTexture = NULL;
Texture3D* _deltaSRTexture = NULL;
// Rayleigh
static const double HR = 8.0;
@ -71,11 +63,25 @@ static const vec3 betaMSca = vec3(3e-3);
static const vec3 betaMEx = betaMSca / 0.9;
static const float mieG = 0.65;*/
/*********************** Layer variables ***********************/
static double _r;
static Color _dhdH;
static int _layer;
/*********************** Shader helpers ***********************/
#define step(_a_,_b_) ((_a_) < (_b_) ? 0 : 1)
#define max(_a_,_b_) ((_a_) > (_b_) ? (_a_) : (_b_))
#define min(_a_,_b_) ((_a_) < (_b_) ? (_a_) : (_b_))
#define sign(_a_) ((_a_) < 0.0 ? -1.0 : ((_a_) > 0.0 ? 1.0 : 0.0))
#define mix(_x_,_y_,_a_) ((_x_) * (1.0 - (_a_)) + (_y_) * (_a_))
static inline double min(double a, double b)
{
return a < b ? a : b;
}
static inline double max(double a, double b)
{
return a > b ? a : b;
}
static inline Color vec4mix(Color v1, Color v2, double a)
{
v1.r = mix(v1.r, v2.r, a);
@ -132,22 +138,11 @@ static inline Color vec4(double r, double g, double b, double a)
return result;
}
static Color _texture2D(Texture2D* tex, double x, double y)
{
if (x < 0.0) x = 0.0;
if (x > 1.0) x = 1.0;
if (y < 0.0) y = 0.0;
if (y > 1.0) y = 1.0;
/* TODO Interpolation */
int ix = (int)round(x * ((double)(tex->xsize - 1)) + 0.5);
int iy = (int)round(y * ((double)(tex->ysize - 1)) + 0.5);
return tex->data[iy * tex->xsize + ix];
}
/*********************** Texture manipulation ***********************/
static Color _texture3D(Texture3D* tex, Vector3 p)
static inline Color _texture3D(Texture3D* tex, Vector3 p)
{
/* TODO Interpolation */
return tex->data[(int)(p.z * (tex->zsize - 1)) * tex->ysize * tex->xsize + (int)(p.y * (tex->ysize - 1)) * tex->xsize + (int)(p.x * (tex->xsize - 1))];
return texture3DGetLinear(tex, p.x, p.y, p.z);
}
static Color _texture4D(Texture3D* tex3d, double r, double mu, double muS, double nu)
@ -175,6 +170,8 @@ static Color _texture4D(Texture3D* tex3d, double r, double mu, double muS, doubl
return vec4mix(_texture3D(tex3d, vec3((uNu + uMuS + 1.0) / (double)(RES_NU), uMu, uR)), _texture3D(tex3d, vec3((uNu + uMuS) / (double)(RES_NU), uMu, uR)), lerp);
}
/*********************** Physics functions ***********************/
/* Rayleigh phase function */
static double _phaseFunctionR(double mu)
{
@ -188,7 +185,7 @@ static double _phaseFunctionM(double mu)
}
/* approximated single Mie scattering (cf. approximate Cm in paragraph "Angular precision") */
Color getMie(Color rayMie)
static Color _getMie(Color rayMie)
{
Color result;
@ -218,41 +215,18 @@ static double _opticalDepth(double H, double r, double mu, double d)
return sqrt((6.2831 * H) * r) * exp((Rg - r) / H) * (x + yx - yy);
}
static Texture3D _precomputeInscatterSampler()
{
Texture3D result;
int x, y;
#if 0
result.xsize = 256;
result.ysize = 64;
result.data = malloc(sizeof(Color) * result.xsize * result.ysize); /* TODO free */
for (x = 0; x < result.xsize; x++)
{
for (y = 0; y < result.ysize; y++)
{
double r, muS;
_getTransmittanceRMu((double)x / result.xsize, (double)y / result.ysize, &r, &muS);
double depth1 = _opticalDepthTransmittance(HR, r, muS);
double depth2 = _opticalDepthTransmittance(HM, r, muS);
Color trans;
trans.r = exp(-(betaR.r * depth1 + betaMEx.x * depth2));
trans.g = exp(-(betaR.g * depth1 + betaMEx.y * depth2));
trans.b = exp(-(betaR.b * depth1 + betaMEx.z * depth2));
trans.a = 1.0;
result.data[y * result.xsize + x] = trans; /* Eq (5) */
}
}
#endif
return result;
}
static inline void _getTransmittanceUV(double r, double mu, double* u, double* v)
{
double dr = (r - Rg) / (Rt - Rg);
#ifdef TRANSMITTANCE_NON_LINEAR
*v = sqrt((r - Rg) / (Rt - Rg));
if (dr >= 0.0)
{
*v = sqrt(dr);
}
else
{
*v = 0.0;
}
*u = atan((mu + 0.15) / (1.0 + 0.15) * tan(1.5)) / 1.5;
#else
*v = (r - Rg) / (Rt - Rg);
@ -266,7 +240,32 @@ static Color _transmittance(double r, double mu)
{
double u, v;
_getTransmittanceUV(r, mu, &u, &v);
return _texture2D(&_transmittanceTexture, u, v);
return texture2DGetLinear(_transmittanceTexture, u, v);
}
/* transmittance(=transparency) of atmosphere between x and x0
* assume segment x,x0 not intersecting ground
* d = distance between x and x0, mu=cos(zenith angle of [x,x0) ray at x) */
Color _transmittance3(double r, double mu, double d)
{
Color result, t1, t2;
double r1 = sqrt(r * r + d * d + 2.0 * r * mu * d);
double mu1 = (r * mu + d) / r1;
if (mu > 0.0)
{
t1 = _transmittance(r, mu);
t2 = _transmittance(r1, mu1);
}
else
{
t1 = _transmittance(r1, -mu1);
t2 = _transmittance(r, -mu);
}
result.r = min(t1.r / t2.r, 1.0);
result.g = min(t1.g / t2.g, 1.0);
result.b = min(t1.b / t2.b, 1.0);
result.a = 1.0;
return result;
}
static void _getIrradianceRMuS(double x, double y, double* r, double* muS)
@ -275,42 +274,9 @@ static void _getIrradianceRMuS(double x, double y, double* r, double* muS)
*muS = -0.2 + x * (1.0 + 0.2);
}
static Texture2D _precomputeIrrDeltaETexture()
{
Texture2D result;
int x, y;
result.xsize = SKY_W;
result.ysize = SKY_H;
result.data = malloc(sizeof(Color) * result.xsize * result.ysize); /* TODO free */
/* Irradiance program */
for (x = 0; x < result.xsize; x++)
{
for (y = 0; y < result.ysize; y++)
{
double r, muS, u, v;
Color trans, irr;
_getIrradianceRMuS((double)x / result.xsize, (double)y / result.ysize, &r, &muS);
trans = _transmittance(r, muS);
_getTransmittanceUV(r, muS, &u, &v);
//printf("%d %d -> %f %f -> %f %f %f\n", x, y, u, v, trans.r, trans.g, trans.b);
irr.r = trans.r * max(muS, 0.0);
irr.g = trans.g * max(muS, 0.0);
irr.b = trans.b * max(muS, 0.0);
irr.a = 1.0;
result.data[y * result.xsize + x] = irr;
}
}
return result;
}
/* nearest intersection of ray r,mu with ground or top atmosphere boundary
* mu=cos(ray zenith angle at ray origin) */
static double limit(double r, double mu)
static double _limit(double r, double mu)
{
double dout = -r * mu + sqrt(r * r * (mu * mu - 1.0) + RL * RL);
double delta2 = r * r * (mu * mu - 1.0) + Rg * Rg;
@ -327,7 +293,7 @@ static double limit(double r, double mu)
static double _opticalDepthTransmittance(double H, double r, double mu)
{
double result = 0.0;
double dx = limit(r, mu) / (double)TRANSMITTANCE_INTEGRAL_SAMPLES;
double dx = _limit(r, mu) / (double)TRANSMITTANCE_INTEGRAL_SAMPLES;
double xi = 0.0;
double yi = exp(-(r - Rg) / H);
int i;
@ -352,56 +318,6 @@ static void _getTransmittanceRMu(double x, double y, double* r, double* muS)
#endif
}
static Color _debugSave2D(void* data, int x, int y)
{
Texture2D* tex = (Texture2D*)data;
return tex->data[y * tex->xsize + x];
}
static Texture2D _precomputeTransmittanceTexture()
{
Texture2D result;
int x, y;
result.xsize = 256;
result.ysize = 64;
result.data = malloc(sizeof(Color) * result.xsize * result.ysize); /* TODO free */
for (x = 0; x < result.xsize; x++)
{
for (y = 0; y < result.ysize; y++)
{
double r, muS;
_getTransmittanceRMu((double)x / result.xsize, (double)y / result.ysize, &r, &muS);
double depth1 = _opticalDepthTransmittance(HR, r, muS);
double depth2 = _opticalDepthTransmittance(HM, r, muS);
Color trans;
trans.r = exp(-(betaR.r * depth1 + betaMEx.x * depth2));
trans.g = exp(-(betaR.g * depth1 + betaMEx.y * depth2));
trans.b = exp(-(betaR.b * depth1 + betaMEx.z * depth2));
trans.a = 1.0;
result.data[y * result.xsize + x] = trans; /* Eq (5) */
}
}
return result;
}
void brunetonInit()
{
if (_transmittanceTexture.xsize == 0) /* TEMP */
{
_transmittanceTexture = _precomputeTransmittanceTexture();
_irrDeltaETexture = _precomputeIrrDeltaETexture();
//_inscatterSampler = _precomputeInscatterSampler();
}
/* DEBUG */
systemSavePictureFile("transmittance.png", _debugSave2D, &_transmittanceTexture, _transmittanceTexture.xsize, _transmittanceTexture.ysize);
systemSavePictureFile("irrdeltae.png", _debugSave2D, &_irrDeltaETexture, _irrDeltaETexture.xsize, _irrDeltaETexture.ysize);
exit(1);
}
/* transmittance(=transparency) of atmosphere for ray (r,mu) of length d
(mu=cos(view zenith angle)), intersections with ground ignored
uses analytic formula instead of transmittance texture */
@ -426,8 +342,231 @@ static inline Color _applyInscatter(Color inscatter, Color attmod, Color samp)
return vec4max(inscatter, 0.0);
}
/* transmittance(=transparency) of atmosphere for infinite ray (r,mu)
(mu=cos(view zenith angle)), or zero if ray intersects ground */
static Color _transmittanceWithShadow(double r, double mu)
{
return mu < -sqrt(1.0 - (Rg / r) * (Rg / r)) ? COLOR_BLACK : _transmittance(r, mu);
}
static Color _hdr(Color c1, Color c2, Color c3)
{
Color L = {c1.r + c2.r + c3.r, c1.g + c2.g + c3.g, c1.b + c2.b + c3.b, 1.0};
L.r *= exposure;
L.g *= exposure;
L.b *= exposure;
L.a *= exposure;
L.r = L.r < 1.413 ? pow(L.r * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.r);
L.g = L.g < 1.413 ? pow(L.g * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.g);
L.b = L.b < 1.413 ? pow(L.b * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.b);
return L;
}
static void _getMuMuSNu(double x, double y, double r, Color dhdH, double* mu, double* muS, double* nu)
{
x -= 0.5;
y -= 0.5;
#ifdef INSCATTER_NON_LINEAR
double d;
if (y < (double)(RES_MU) / 2.0)
{
d = 1.0 - y / ((double)(RES_MU) / 2.0 - 1.0);
d = min(max(dhdH.b, d * dhdH.a), dhdH.a * 0.999);
*mu = (Rg * Rg - r * r - d * d) / (2.0 * r * d);
*mu = min(*mu, -sqrt(1.0 - (Rg / r) * (Rg / r)) - 0.001);
}
else
{
double d = (y - (double)(RES_MU) / 2.0) / ((double)(RES_MU) / 2.0 - 1.0);
d = min(max(dhdH.r, d * dhdH.g), dhdH.g * 0.999);
*mu = (Rt * Rt - r * r - d * d) / (2.0 * r * d);
}
*muS = fmod(x, (double)(RES_MU_S)) / ((double)(RES_MU_S) - 1.0);
/* paper formula :
* muS = -(0.6 + log(1.0 - muS * (1.0 - exp(-3.6)))) / 3.0; */
/* better formula */
*muS = tan((2.0 * (*muS) - 1.0 + 0.26) * 1.1) / tan(1.26 * 1.1);
*nu = -1.0 + floor(x / (double)(RES_MU_S)) / ((double)(RES_NU) - 1.0) * 2.0;
#else
mu = -1.0 + 2.0 * y / (float(RES_MU) - 1.0);
muS = mod(x, float(RES_MU_S)) / (float(RES_MU_S) - 1.0);
muS = -0.2 + muS * 1.2;
nu = -1.0 + floor(x / float(RES_MU_S)) / (float(RES_NU) - 1.0) * 2.0;
#endif
}
/*********************** Texture precomputing ***********************/
static Texture2D* _precomputeTransmittanceTexture()
{
Texture2D* result;
int x, y;
result = texture2DCreate(TRANSMITTANCE_W, TRANSMITTANCE_H);
for (x = 0; x < TRANSMITTANCE_W; x++)
{
for (y = 0; y < TRANSMITTANCE_H; y++)
{
double r, muS;
_getTransmittanceRMu((double)x / TRANSMITTANCE_W, (double)y / TRANSMITTANCE_H, &r, &muS);
double depth1 = _opticalDepthTransmittance(HR, r, muS);
double depth2 = _opticalDepthTransmittance(HM, r, muS);
Color trans;
trans.r = exp(-(betaR.r * depth1 + betaMEx.x * depth2));
trans.g = exp(-(betaR.g * depth1 + betaMEx.y * depth2));
trans.b = exp(-(betaR.b * depth1 + betaMEx.z * depth2));
trans.a = 1.0;
texture2DSetPixel(result, x, y, trans); /* Eq (5) */
}
}
return result;
}
static Texture2D* _precomputeIrrDeltaETexture()
{
Texture2D* result;
int x, y;
result = texture2DCreate(SKY_W, SKY_H);
/* Irradiance program */
for (x = 0; x < SKY_W; x++)
{
for (y = 0; y < SKY_H; y++)
{
double r, muS, u, v;
Color trans, irr;
_getIrradianceRMuS((double)x / SKY_W, (double)y / SKY_H, &r, &muS);
trans = _transmittance(r, muS);
_getTransmittanceUV(r, muS, &u, &v);
//printf("%d %d -> %f %f -> %f %f %f\n", x, y, u, v, trans.r, trans.g, trans.b);
irr.r = trans.r * max(muS, 0.0);
irr.g = trans.g * max(muS, 0.0);
irr.b = trans.b * max(muS, 0.0);
irr.a = 1.0;
texture2DSetPixel(result, x, y, irr);
}
}
return result;
}
static void _setLayer(int layer)
{
double r = layer / (RES_R - 1.0);
r = r * r;
r = sqrt(Rg * Rg + r * (Rt * Rt - Rg * Rg)) + (layer == 0 ? 0.01 : (layer == RES_R - 1 ? -0.001 : 0.0));
double dmin = Rt - r;
double dmax = sqrt(r * r - Rg * Rg) + sqrt(Rt * Rt - Rg * Rg);
double dminp = r - Rg;
double dmaxp = sqrt(r * r - Rg * Rg);
_r = r;
_dhdH.r = dmin;
_dhdH.g = dmax;
_dhdH.b = dminp;
_dhdH.a = dmaxp;
_layer = layer;
}
/*********************** inscatter1.glsl ***********************/
static void _integrand1(double r, double mu, double muS, double nu, double t, Color* ray, Color* mie)
{
double ri = sqrt(r * r + t * t + 2.0 * r * mu * t);
double muSi = (nu * t + muS * r) / ri;
ri = max(Rg, ri);
if (muSi >= -sqrt(1.0 - Rg * Rg / (ri * ri)))
{
Color t1, t2;
t1 = _transmittance3(r, mu, t);
t2 = _transmittance(ri, muSi);
double fR = exp(-(ri - Rg) / HR);
double fM = exp(-(ri - Rg) / HM);
ray->r = fR * t1.r * t2.r;
ray->g = fR * t1.g * t2.g;
ray->b = fR * t1.b * t2.b;
mie->r = fM * t1.r * t2.r;
mie->g = fM * t1.g * t2.g;
mie->b = fM * t1.b * t2.b;
}
else
{
ray->r = ray->g = ray->b = 0.0;
mie->r = mie->g = mie->b = 0.0;
}
}
static void _inscatter1(double r, double mu, double muS, double nu, Color* ray, Color* mie)
{
ray->r = ray->g = ray->b = 0.0;
mie->r = mie->g = mie->b = 0.0;
double dx = _limit(r, mu) / (double)(INSCATTER_INTEGRAL_SAMPLES);
double xi = 0.0;
Color rayi;
Color miei;
_integrand1(r, mu, muS, nu, 0.0, &rayi, &miei);
int i;
for (i = 1; i <= INSCATTER_INTEGRAL_SAMPLES; ++i)
{
double xj = (double)(i) * dx;
Color rayj;
Color miej;
_integrand1(r, mu, muS, nu, xj, &rayj, &miej);
ray->r += (rayi.r + rayj.r) / 2.0 * dx;
ray->g += (rayi.g + rayj.g) / 2.0 * dx;
ray->b += (rayi.b + rayj.b) / 2.0 * dx;
mie->r += (miei.r + miej.r) / 2.0 * dx;
mie->g += (miei.g + miej.g) / 2.0 * dx;
mie->b += (miei.b + miej.b) / 2.0 * dx;
xi = xj;
rayi = rayj;
miei = miej;
}
ray->r *= betaR.r;
ray->g *= betaR.g;
ray->b *= betaR.b;
mie->r *= betaMSca.x;
mie->g *= betaMSca.y;
mie->b *= betaMSca.z;
}
static void _inscatter1Prog(Texture3D* tex_rayleigh, Texture3D* tex_mie)
{
int x, y;
for (x = 0; x < RES_MU_S * RES_NU; x++)
{
/*double dx = (double)x / (double)(RES_MU_S * RES_NU);*/
for (y = 0; y < RES_MU; y++)
{
/*double dy = (double)y / (double)(RES_MU);*/
Color ray = COLOR_BLACK;
Color mie = COLOR_BLACK;
double mu, muS, nu;
_getMuMuSNu((double)x + 0.5, (double)y + 0.5, _r, _dhdH, &mu, &muS, &nu);
_inscatter1(_r, mu, muS, nu, &ray, &mie);
/* store separately Rayleigh and Mie contributions, WITHOUT the phase function factor
* (cf "Angular precision") */
texture3DSetPixel(tex_rayleigh, x, y, _layer, ray);
texture3DSetPixel(tex_mie, x, y, _layer, mie);
}
}
/* TODO Iterate texture */
}
/*********************** Final getters ***********************/
/* inscattered light along ray x+tv, when sun in direction s (=S[L]-T(x,x0)S[L]|x0) */
static Color _inscatter(Vector3* _x, double* _t, Vector3 v, Vector3 s, double* _r, double* _mu, Vector3* attenuation)
static Color _getInscatterColor(Vector3* _x, double* _t, Vector3 v, Vector3 s, double* _r, double* _mu, Vector3* attenuation)
{
Color result;
double r = v3Norm(*_x);
@ -453,7 +592,7 @@ static Color _inscatter(Vector3* _x, double* _t, Vector3 v, Vector3 s, double* _
double muS = v3Dot(x, s) / r;
double phaseR = _phaseFunctionR(nu);
double phaseM = _phaseFunctionM(nu);
Color inscatter = vec4max(_texture4D(&_inscatterSampler, r, mu, muS, nu), 0.0);
Color inscatter = vec4max(_texture4D(_inscatterTexture, r, mu, muS, nu), 0.0);
if (t > 0.0)
{
Vector3 x0 = v3Add(x, v3Scale(v, t));
@ -471,7 +610,7 @@ static Color _inscatter(Vector3* _x, double* _t, Vector3 v, Vector3 s, double* _
{
/* computes S[L]-T(x,x0)S[L]|x0 */
Color attmod = {attenuation->x, attenuation->y, attenuation->z, attenuation->x};
Color samp = _texture4D(&_inscatterSampler, r0, mu0, muS0, nu);
Color samp = _texture4D(_inscatterTexture, r0, mu0, muS0, nu);
inscatter = _applyInscatter(inscatter, attmod, samp);
#ifdef FIX
/* avoids imprecision problems near horizon by interpolating between two points above and below horizon */
@ -484,15 +623,15 @@ static Color _inscatter(Vector3* _x, double* _t, Vector3 v, Vector3 s, double* _
mu = muHoriz - EPS;
r0 = sqrt(r * r + t * t + 2.0 * r * t * mu);
mu0 = (r * mu + t) / r0;
Color inScatter0 = _texture4D(&_inscatterSampler, r, mu, muS, nu);
Color inScatter1 = _texture4D(&_inscatterSampler, r0, mu0, muS0, nu);
Color inScatter0 = _texture4D(_inscatterTexture, r, mu, muS, nu);
Color inScatter1 = _texture4D(_inscatterTexture, r0, mu0, muS0, nu);
Color inScatterA = _applyInscatter(inScatter0, attmod, inScatter1);
mu = muHoriz + EPS;
r0 = sqrt(r * r + t * t + 2.0 * r * t * mu);
mu0 = (r * mu + t) / r0;
inScatter0 = _texture4D(&_inscatterSampler, r, mu, muS, nu);
inScatter1 = _texture4D(&_inscatterSampler, r0, mu0, muS0, nu);
inScatter0 = _texture4D(_inscatterTexture, r, mu, muS, nu);
inScatter1 = _texture4D(_inscatterTexture, r0, mu0, muS0, nu);
Color inScatterB = _applyInscatter(inScatter0, attmod, inScatter1);
inscatter = vec4mix(inScatterA, inScatterB, a);
@ -504,7 +643,7 @@ static Color _inscatter(Vector3* _x, double* _t, Vector3 v, Vector3 s, double* _
/* avoids imprecision problems in Mie scattering when sun is below horizon */
inscatter.a *= smoothstep(0.00, 0.02, muS);
#endif
Color mie = getMie(inscatter);
Color mie = _getMie(inscatter);
result.r = inscatter.r * phaseR + mie.r * phaseM;
result.g = inscatter.g * phaseR + mie.g * phaseM;
result.b = inscatter.b * phaseR + mie.b * phaseM;
@ -577,13 +716,6 @@ static Color _inscatter(Vector3* _x, double* _t, Vector3 v, Vector3 s, double* _
return result;
}*/
/* transmittance(=transparency) of atmosphere for infinite ray (r,mu)
(mu=cos(view zenith angle)), or zero if ray intersects ground */
static Color _transmittanceWithShadow(double r, double mu)
{
return mu < -sqrt(1.0 - (Rg / r) * (Rg / r)) ? COLOR_BLACK : _transmittance(r, mu);
}
/* direct sun light for ray x+tv, when sun in direction s (=L0) */
static Color _sunColor(Vector3 x, double t, Vector3 v, Vector3 s, double r, double mu)
{
@ -603,20 +735,125 @@ static Color _sunColor(Vector3 x, double t, Vector3 v, Vector3 s, double r, doub
}
}
static Color _hdr(Color c1, Color c2, Color c3)
/*********************** Public methods ***********************/
void brunetonInit()
{
Color L = {c1.r + c2.r + c3.r, c1.g + c2.g + c3.g, c1.b + c2.b + c3.b, 1.0};
int layer, x, y, z;
L.r *= exposure;
L.g *= exposure;
L.b *= exposure;
L.a *= exposure;
if (_transmittanceTexture == NULL) /* TEMP */
{
/* TODO Deletes */
L.r = L.r < 1.413 ? pow(L.r * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.r);
L.g = L.g < 1.413 ? pow(L.g * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.g);
L.b = L.b < 1.413 ? pow(L.b * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.b);
/* computes transmittance texture T (line 1 in algorithm 4.1) */
_transmittanceTexture = _precomputeTransmittanceTexture();
return L;
/* computes irradiance texture deltaE (line 2 in algorithm 4.1) */
_irrDeltaETexture = _precomputeIrrDeltaETexture();
/* computes single scattering texture deltaS (line 3 in algorithm 4.1)
* Rayleigh and Mie separated in deltaSR + deltaSM */
_deltaSRTexture = texture3DCreate(RES_MU_S * RES_NU, RES_MU, RES_R);
_deltaSMTexture = texture3DCreate(RES_MU_S * RES_NU, RES_MU, RES_R);
for (layer = 0; layer < RES_R; ++layer)
{
printf("%d\n", layer);
_setLayer(layer);
_inscatter1Prog(_deltaSRTexture, _deltaSMTexture);
}
/* copies deltaE into irradiance texture E (line 4 in algorithm 4.1) */
/* ??? all black texture ??? */
/*_irradianceTexture = texture3DCreate(SKY_W, SKY_H);
_copyIrradianceProg(0.0, _irrDeltaETexture);*/
/* copies deltaS into inscatter texture S (line 5 in algorithm 4.1) */
_inscatterTexture = texture3DCreate(RES_MU_S * RES_NU, RES_MU, RES_R);
for (x = 0; x < RES_MU_S * RES_NU; x++)
{
for (y = 0; y < RES_MU; y++)
{
for (z = 0; z < RES_R; z++)
{
Color result = texture3DGetPixel(_deltaSRTexture, x, y, z);
Color mie = texture3DGetPixel(_deltaSMTexture, x, y, z);
result.a = mie.r;
texture3DSetPixel(_inscatterTexture, x, y, z, result);
}
}
}
/* loop for each scattering order (line 6 in algorithm 4.1) */
for (int order = 2; order <= 4; ++order) {
/* computes deltaJ (line 7 in algorithm 4.1) */
/*glFramebufferTextureEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, deltaJTexture, 0);
glViewport(0, 0, RES_MU_S * RES_NU, RES_MU);
glUseProgram(jProg);
glUniform1f(glGetUniformLocation(jProg, "first"), order == 2 ? 1.0 : 0.0);
glUniform1i(glGetUniformLocation(jProg, "transmittanceSampler"), transmittanceUnit);
glUniform1i(glGetUniformLocation(jProg, "deltaESampler"), deltaEUnit);
glUniform1i(glGetUniformLocation(jProg, "deltaSRSampler"), deltaSRUnit);
glUniform1i(glGetUniformLocation(jProg, "deltaSMSampler"), deltaSMUnit);
for (int layer = 0; layer < RES_R; ++layer) {
setLayer(jProg, layer);
drawQuad();
}*/
/* computes deltaE (line 8 in algorithm 4.1) */
/*glFramebufferTextureEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, deltaETexture, 0);
glViewport(0, 0, SKY_W, SKY_H);
glUseProgram(irradianceNProg);
glUniform1f(glGetUniformLocation(irradianceNProg, "first"), order == 2 ? 1.0 : 0.0);
glUniform1i(glGetUniformLocation(irradianceNProg, "transmittanceSampler"), transmittanceUnit);
glUniform1i(glGetUniformLocation(irradianceNProg, "deltaSRSampler"), deltaSRUnit);
glUniform1i(glGetUniformLocation(irradianceNProg, "deltaSMSampler"), deltaSMUnit);
drawQuad();*/
/* computes deltaS (line 9 in algorithm 4.1) */
/*glFramebufferTextureEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, deltaSRTexture, 0);
glViewport(0, 0, RES_MU_S * RES_NU, RES_MU);
glUseProgram(inscatterNProg);
glUniform1f(glGetUniformLocation(inscatterNProg, "first"), order == 2 ? 1.0 : 0.0);
glUniform1i(glGetUniformLocation(inscatterNProg, "transmittanceSampler"), transmittanceUnit);
glUniform1i(glGetUniformLocation(inscatterNProg, "deltaJSampler"), deltaJUnit);
for (int layer = 0; layer < RES_R; ++layer) {
setLayer(inscatterNProg, layer);
drawQuad();
}*/
/*glEnable(GL_BLEND);
glBlendEquationSeparate(GL_FUNC_ADD, GL_FUNC_ADD);
glBlendFuncSeparate(GL_ONE, GL_ONE, GL_ONE, GL_ONE);*/
/* adds deltaE into irradiance texture E (line 10 in algorithm 4.1) */
/*glFramebufferTextureEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, irradianceTexture, 0);
glViewport(0, 0, SKY_W, SKY_H);
glUseProgram(copyIrradianceProg);
glUniform1f(glGetUniformLocation(copyIrradianceProg, "k"), 1.0);
glUniform1i(glGetUniformLocation(copyIrradianceProg, "deltaESampler"), deltaEUnit);
drawQuad();*/
/* adds deltaS into inscatter texture S (line 11 in algorithm 4.1) */
/*glFramebufferTextureEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, inscatterTexture, 0);
glViewport(0, 0, RES_MU_S * RES_NU, RES_MU);
glUseProgram(copyInscatterNProg);
glUniform1i(glGetUniformLocation(copyInscatterNProg, "deltaSSampler"), deltaSRUnit);
for (int layer = 0; layer < RES_R; ++layer) {
setLayer(copyInscatterNProg, layer);
drawQuad();
}
glDisable(GL_BLEND);*/
}
}
/* DEBUG */
texture2DSaveToFile(_transmittanceTexture, "transmittance.png");
texture2DSaveToFile(_irrDeltaETexture, "irrdeltae.png");
texture3DSaveToFile(_deltaSRTexture, "deltasr.png");
texture3DSaveToFile(_deltaSMTexture, "deltasm.png");
texture3DSaveToFile(_inscatterTexture, "inscatter.png");
exit(1);
}
Color brunetonGetSkyColor(AtmosphereDefinition* definition, Vector3 eye, Vector3 direction, Vector3 sun_position)
@ -650,7 +887,7 @@ Color brunetonGetSkyColor(AtmosphereDefinition* definition, Vector3 eye, Vector3
}
Vector3 attenuation;
Color inscatterColor = _inscatter(&x, &t, v, s, &r, &mu, &attenuation); //S[L]-T(x,xs)S[l]|xs
Color inscatterColor = _getInscatterColor(&x, &t, v, s, &r, &mu, &attenuation); //S[L]-T(x,xs)S[l]|xs
/*Color groundColor = _groundColor(x, t, v, s, r, mu, attenuation); //R[L0]+R[L*]*/
Color groundColor = COLOR_BLACK;
Color sunColor = _sunColor(x, t, v, s, r, mu); //L0

179
lib_paysages/tools/texture.c Normal file
View file

@ -0,0 +1,179 @@
#include "texture.h"
#include <assert.h>
#include <math.h>
#include "../system.h"
struct Texture2D
{
int xsize;
int ysize;
Color* data;
};
struct Texture3D
{
int xsize;
int ysize;
int zsize;
Color* data;
};
Texture2D* texture2DCreate(int xsize, int ysize)
{
Texture2D* result;
result = (Texture2D*)malloc(sizeof(Texture2D));
result->xsize = xsize;
result->ysize = ysize;
result->data = malloc(sizeof(Color) * xsize * ysize);
return result;
}
void texture2DDelete(Texture2D* tex)
{
free(tex->data);
free(tex);
}
void texture2DSetPixel(Texture2D* tex, int x, int y, Color col)
{
assert(x >= 0 && x < tex->xsize);
assert(y >= 0 && y < tex->ysize);
tex->data[y * tex->xsize + x] = col;
}
Color texture2DGetPixel(Texture2D* tex, int x, int y)
{
assert(x >= 0 && x < tex->xsize);
assert(y >= 0 && y < tex->ysize);
return tex->data[y * tex->xsize + x];
}
Color texture2DGetNearest(Texture2D* tex, double dx, double dy)
{
if (dx < 0.0) dx = 0.0;
if (dx > 1.0) dx = 1.0;
if (dy < 0.0) dy = 0.0;
if (dy > 1.0) dy = 1.0;
int ix = (int)(dx * (double)(tex->xsize - 1));
int iy = (int)(dy * (double)(tex->ysize - 1));
assert(ix >= 0 && ix < tex->xsize);
assert(iy >= 0 && iy < tex->ysize);
return tex->data[iy * tex->xsize + ix];
}
Color texture2DGetLinear(Texture2D* tex, double dx, double dy)
{
/* TODO */
return texture2DGetNearest(tex, dx, dy);
}
Color texture2DGetCubic(Texture2D* tex, double dx, double dy)
{
/* TODO */
return texture2DGetNearest(tex, dx, dy);
}
void texture2DSaveToFile(Texture2D* tex, const char* filepath)
{
systemSavePictureFile(filepath, (PictureCallbackSavePixel)texture2DGetPixel, tex, tex->xsize, tex->ysize);
}
Texture3D* texture3DCreate(int xsize, int ysize, int zsize)
{
Texture3D* result;
result = (Texture3D*)malloc(sizeof(Texture3D));
result->xsize = xsize;
result->ysize = ysize;
result->zsize = zsize;
result->data = malloc(sizeof(Color) * xsize * ysize * zsize);
return result;
}
void texture3DDelete(Texture3D* tex)
{
free(tex->data);
free(tex);
}
void texture3DSetPixel(Texture3D* tex, int x, int y, int z, Color col)
{
assert(x >= 0 && x < tex->xsize);
assert(y >= 0 && y < tex->ysize);
assert(z >= 0 && z < tex->ysize);
tex->data[z * tex->xsize * tex->ysize + y * tex->xsize + x] = col;
}
Color texture3DGetPixel(Texture3D* tex, int x, int y, int z)
{
assert(x >= 0 && x < tex->xsize);
assert(y >= 0 && y < tex->ysize);
assert(z >= 0 && z < tex->zsize);
return tex->data[z * tex->xsize * tex->ysize + y * tex->xsize + x];
}
Color texture3DGetNearest(Texture3D* tex, double dx, double dy, double dz)
{
if (dx < 0.0) dx = 0.0;
if (dx > 1.0) dx = 1.0;
if (dy < 0.0) dy = 0.0;
if (dy > 1.0) dy = 1.0;
if (dz < 0.0) dz = 0.0;
if (dz > 1.0) dz = 1.0;
int ix = (int)(dx * (double)(tex->xsize - 1));
int iy = (int)(dy * (double)(tex->ysize - 1));
int iz = (int)(dz * (double)(tex->zsize - 1));
assert(ix >= 0 && ix < tex->xsize);
assert(iy >= 0 && iy < tex->ysize);
assert(iz >= 0 && iz < tex->zsize);
return tex->data[iz * tex->xsize * tex->ysize + iy * tex->xsize + ix];
}
Color texture3DGetLinear(Texture3D* tex, double dx, double dy, double dz)
{
/* TODO */
return texture3DGetNearest(tex, dx, dy, dz);
}
Color texture3DGetCubic(Texture3D* tex, double dx, double dy, double dz)
{
/* TODO */
return texture3DGetNearest(tex, dx, dy, dz);
}
static Color _callbackTex3dSave(Texture3D* tex, int x, int y)
{
int z = y / tex->ysize;
y = y % tex->ysize;
assert(x >= 0 && x < tex->xsize);
assert(y >= 0 && y < tex->xsize);
assert(z >= 0 && z < tex->xsize);
return tex->data[z * tex->xsize * tex->ysize + y * tex->xsize + x];
}
void texture3DSaveToFile(Texture3D* tex, const char* filepath)
{
systemSavePictureFile(filepath, (PictureCallbackSavePixel)_callbackTex3dSave, tex, tex->xsize, tex->ysize * tex->zsize);
}

35
lib_paysages/tools/texture.h Normal file
View file

@ -0,0 +1,35 @@
#ifndef _PAYSAGES_TOOLS_TEXTURE_H_
#define _PAYSAGES_TOOLS_TEXTURE_H_
#ifdef __cplusplus
extern "C" {
#endif
#include "../color.h"
typedef struct Texture2D Texture2D;
typedef struct Texture3D Texture3D;
Texture2D* texture2DCreate(int xsize, int ysize);
void texture2DDelete(Texture2D* tex);
void texture2DSetPixel(Texture2D* tex, int x, int y, Color col);
Color texture2DGetPixel(Texture2D* tex, int x, int y);
Color texture2DGetNearest(Texture2D* tex, double dx, double dy);
Color texture2DGetLinear(Texture2D* tex, double dx, double dy);
Color texture2DGetCubic(Texture2D* tex, double dx, double dy);
void texture2DSaveToFile(Texture2D* tex, const char* filepath);
Texture3D* texture3DCreate(int xsize, int ysize, int zsize);
void texture3DDelete(Texture3D* tex);
void texture3DSetPixel(Texture3D* tex, int x, int y, int z, Color col);
Color texture3DGetPixel(Texture3D* tex, int x, int y, int z);
Color texture3DGetNearest(Texture3D* tex, double dx, double dy, double dz);
Color texture3DGetLinear(Texture3D* tex, double dx, double dy, double dz);
Color texture3DGetCubic(Texture3D* tex, double dx, double dy, double dz);
void texture3DSaveToFile(Texture3D* tex, const char* filepath);
#ifdef __cplusplus
}
#endif
#endif