paysages3d/lib_paysages/sky.c

446 lines
14 KiB
C
Raw Normal View History

#include "sky.h"
#include <stdlib.h>
#include <math.h>
#include "shared/types.h"
#include "color.h"
#include "clouds.h"
#include "euclid.h"
#include "lighting.h"
#include "render.h"
#include "tools.h"
#define SPHERE_SIZE 1000.0
void skyInit()
{
}
void skyQuit()
{
}
void skySave(PackStream* stream, SkyDefinition* definition)
{
packWriteDouble(stream, &definition->daytime);
colorGradationSave(stream, definition->sun_color);
packWriteDouble(stream, &definition->sun_radius);
packWriteDouble(stream, &definition->sun_halo_size);
curveSave(stream, definition->sun_halo_profile);
colorGradationSave(stream, definition->zenith_color);
colorGradationSave(stream, definition->haze_color);
packWriteDouble(stream, &definition->haze_height);
packWriteDouble(stream, &definition->haze_smoothing);
}
void skyLoad(PackStream* stream, SkyDefinition* definition)
{
packReadDouble(stream, &definition->daytime);
colorGradationLoad(stream, definition->sun_color);
packReadDouble(stream, &definition->sun_radius);
packReadDouble(stream, &definition->sun_halo_size);
curveLoad(stream, definition->sun_halo_profile);
colorGradationLoad(stream, definition->zenith_color);
colorGradationLoad(stream, definition->haze_color);
packReadDouble(stream, &definition->haze_height);
packReadDouble(stream, &definition->haze_smoothing);
skyValidateDefinition(definition);
}
SkyDefinition skyCreateDefinition()
{
SkyDefinition def;
def.daytime = 0.0;
def.sun_color = colorGradationCreate();
def.sun_radius = 1.0;
def.sun_halo_size = 0.0;
def.sun_halo_profile = curveCreate();
def.zenith_color = colorGradationCreate();
def.haze_color = colorGradationCreate();
def.haze_height = 0.0;
def.haze_smoothing = 0.0;
skyValidateDefinition(&def);
return def;
}
void skyDeleteDefinition(SkyDefinition* definition)
{
curveDelete(definition->sun_halo_profile);
colorGradationDelete(definition->sun_color);
colorGradationDelete(definition->zenith_color);
colorGradationDelete(definition->haze_color);
}
void skyCopyDefinition(SkyDefinition* source, SkyDefinition* destination)
{
destination->daytime = source->daytime;
destination->sun_radius = source->sun_radius;
destination->sun_halo_size = source->sun_halo_size;
destination->haze_height = source->haze_height;
destination->haze_smoothing = source->haze_smoothing;
curveCopy(source->sun_halo_profile, destination->sun_halo_profile);
colorGradationCopy(source->sun_color, destination->sun_color);
colorGradationCopy(source->zenith_color, destination->zenith_color);
colorGradationCopy(source->haze_color, destination->haze_color);
colorGradationCopy(source->_sky_gradation, destination->_sky_gradation);
}
void skyValidateDefinition(SkyDefinition* definition)
{
Color zenith, haze;
zenith = colorGradationGet(definition->zenith_color, definition->daytime);
haze = colorGradationGet(definition->haze_color, definition->daytime);
definition->_sky_gradation = colorGradationCreate();
colorGradationQuickAdd(definition->_sky_gradation, 0.0, &haze);
colorGradationQuickAdd(definition->_sky_gradation, definition->haze_height - definition->haze_smoothing, &haze);
colorGradationQuickAdd(definition->_sky_gradation, definition->haze_height, &zenith);
colorGradationQuickAdd(definition->_sky_gradation, 1.0, &zenith);
}
int skyGetLights(SkyDefinition* sky, LightDefinition* lights, int max_lights)
{
double sun_angle;
Vector3 sun_direction;
int nblights = 0;
sun_angle = (sky->daytime + 0.75) * M_PI * 2.0;
sun_direction.x = cos(sun_angle);
sun_direction.y = sin(sun_angle);
sun_direction.z = 0.0;
/* TODO Night lights */
if (max_lights > 0)
{
/* Light from the sun */
lights[0].direction = v3Scale(sun_direction, -1.0);
lights[0].color = colorGradationGet(sky->sun_color, sky->daytime);
lights[0].reflection = 1.0;
lights[0].filtered = 1;
lights[0].masked = 1;
lights[0].amplitude = 0.0;
nblights = 1;
if (max_lights > 1)
{
/* Skydome lighting */
lights[1].direction.x = 0.0;
lights[1].direction.y = -1.0;
lights[1].direction.z = 0.0;
lights[1].color = colorGradationGet(sky->zenith_color, sky->daytime);
lights[1].color.r *= 0.6;
lights[1].color.g *= 0.6;
lights[1].color.b *= 0.6;
lights[1].reflection = 0.0;
lights[1].filtered = 1;
lights[1].masked = 0;
lights[1].amplitude = M_PI / 2.0;
nblights = 2;
}
}
return nblights;
}
static inline double _angleBetween(double thetav, double phiv, double theta, double phi)
{
double cospsi = sin(thetav) * sin(theta) * cos(phi-phiv) + cos(thetav) * cos(theta);
if (cospsi > 1.0) return 0.0;
if (cospsi < -1.0) return M_PI;
return acos(cospsi);
}
static inline double _perezFunction(double A, double B, double C, double D, double E, double Theta, double Gamma)
{
double cosGamma = cos(Gamma);
return (1.0 + A * exp(B / cos(Theta))) * (1.0 + C * exp(D * Gamma) + E * cosGamma * cosGamma);
}
typedef struct
{
double x;
double y;
double Y;
} ColorxyY;
/* Distribution coefficients for the luminance(Y) distribution function */
static double YDC[5][2] = { { 0.1787, - 1.4630},
{-0.3554, 0.4275},
{-0.0227, 5.3251},
{ 0.1206, - 2.5771},
{-0.0670, 0.3703} };
/* Distribution coefficients for the x distribution function */
static double xDC[5][2] = { {-0.0193, -0.2592},
{-0.0665, 0.0008},
{-0.0004, 0.2125},
{-0.0641, -0.8989},
{-0.0033, 0.0452} };
/* Distribution coefficients for the y distribution function */
static double yDC[5][2] = { {-0.0167, -0.2608},
{-0.0950, 0.0092},
{-0.0079, 0.2102},
{-0.0441, -1.6537},
{-0.0109, 0.0529} };
/* Zenith x value */
static double xZC[3][4] = { {0.00166, -0.00375, 0.00209, 0},
{-0.02903, 0.06377, -0.03203, 0.00394},
{0.11693, -0.21196, 0.06052, 0.25886} };
/* Zenith y value */
static double yZC[3][4] = { { 0.00275, -0.00610, 0.00317, 0},
{-0.04214, 0.08970, -0.04153, 0.00516},
{0.15346, -0.26756, 0.06670, 0.26688} };
static double _distribution(double A, double B, double C, double D, double E, double Theta, double Gamma, double ThetaSun)
{
double f0 = _perezFunction(A,B,C,D,E,Theta,Gamma);
double f1 = _perezFunction(A,B,C,D,E,0,ThetaSun);
return(f0/f1);
}
static double _chromaticity( double ZC[3][4], double ThetaSun, double turbidity)
{
double t1 = ThetaSun;
double t2 = t1*t1;
double t3 = t2 * t1;
double c = (ZC[0][0]*t3 + ZC[0][1]*t2 + ZC[0][2]*t1 + ZC[0][3])* turbidity * turbidity +
(ZC[1][0]*t3 + ZC[1][1]*t2 + ZC[1][2]*t1 + ZC[1][3])* turbidity +
(ZC[2][0]*t3 + ZC[2][1]*t2 + ZC[2][2]*t1 + ZC[2][3]);
return c;
}
static Color _toColor(ColorxyY src)
{
double X, Y, Z;
Color dest;
/* Convert to XYZ space */
X = src.x * (src.Y / src.y);
Y = src.Y;
Z = (1.0 - src.x - src.y)* (src.Y/src.y);
/* Convert to RGB */
dest.r = 3.240479 * X - 1.537150 * Y - 0.498535 * Z;
dest.g = - 0.969256 * X + 1.875991 * Y + 0.041556 * Z;
dest.b = 0.055648 * X - 0.204043 * Y + 1.057311 * Z;
dest.a = 1.0;
return dest;
}
static Color _preethamApproximate(SkyDefinition* definition, double theta, double phi)
{
double thetaSun;
double phiSun;
double gamma;
double turbidity = 3.0;
ColorxyY skycolor;
ColorxyY Zenith;
double A,B,C,D,E;
double d,chi;
/* Handle angles */
if (definition->daytime <= 0.5)
{
if (definition->daytime <= 0.25)
{
thetaSun = M_PI / 2.0 - 0.00001;
}
else
{
thetaSun = M_PI - definition->daytime * 2.0 * M_PI;
}
phiSun = 0.0;
}
else
{
if (definition->daytime >= 0.75)
{
thetaSun = M_PI / 2.0 - 0.00001;
}
else
{
thetaSun = (definition->daytime - 0.5) * 2.0 * M_PI;
}
phiSun = M_PI;
}
gamma = _angleBetween(theta, phi, thetaSun, phiSun);
/* Zenith luminance */
chi = (4.0/9.0 - turbidity/120.0)*(M_PI - 2*thetaSun);
Zenith.Y = (4.0453*turbidity - 4.9710)*tan(chi) - 0.2155*turbidity + 2.4192;
if (Zenith.Y < 0.0) Zenith.Y = -Zenith.Y;
A = YDC[0][0]*turbidity + YDC[0][1];
B = YDC[1][0]*turbidity + YDC[1][1];
C = YDC[2][0]*turbidity + YDC[2][1];
D = YDC[3][0]*turbidity + YDC[3][1];
E = YDC[4][0]*turbidity + YDC[4][1];
/* Sky luminance */
d = _distribution(A, B, C, D, E, theta, gamma, thetaSun);
skycolor.Y = Zenith.Y * d;
/* Zenith x */
Zenith.x = _chromaticity( xZC, thetaSun, turbidity );
A = xDC[0][0]*turbidity + xDC[0][1];
B = xDC[1][0]*turbidity + xDC[1][1];
C = xDC[2][0]*turbidity + xDC[2][1];
D = xDC[3][0]*turbidity + xDC[3][1];
E = xDC[4][0]*turbidity + xDC[4][1];
/* Sky x */
d = _distribution(A, B, C, D, E, theta, gamma, thetaSun);
skycolor.x = Zenith.x * d;
/* Zenith y */
Zenith.y = _chromaticity( yZC, thetaSun, turbidity );
A = yDC[0][0]*turbidity + yDC[0][1];
B = yDC[1][0]*turbidity + yDC[1][1];
C = yDC[2][0]*turbidity + yDC[2][1];
D = yDC[3][0]*turbidity + yDC[3][1];
E = yDC[4][0]*turbidity + yDC[4][1];
/* Sky y */
d = _distribution(A, B, C, D, E, theta, gamma, thetaSun);
skycolor.y = Zenith.y * d;
/* Small hack on luminance value */
//skycolor.Y = 1 - exp(-(1.0/25.0) * skycolor.Y);
return _toColor(skycolor);
}
Color skyGetColor(SkyDefinition* definition, Renderer* renderer, Vector3 eye, Vector3 look)
{
double dist;
Vector3 sun_position;
Color sun_color, sky_color;
sun_position = skyGetSunDirection(definition);
look = v3Normalize(look);
dist = v3Norm(v3Sub(look, sun_position));
sky_color = _preethamApproximate(definition, M_PI/2.0 - asin(look.y), acos(v3Dot(look, sun_position)));
if (dist < definition->sun_radius + definition->sun_halo_size)
{
sun_color = colorGradationGet(definition->sun_color, definition->daytime);
if (dist <= definition->sun_radius)
{
return sun_color;
}
else
{
dist = (dist - definition->sun_radius) / definition->sun_halo_size;
sun_color.a = curveGetValue(definition->sun_halo_profile, dist);
colorMask(&sky_color, &sun_color);
return sky_color;
}
}
else
{
return sky_color;
}
}
static Color _postProcessFragment(Renderer* renderer, Vector3 location, void* data)
{
Vector3 direction;
Color result;
SkyDefinition* definition;
definition = (SkyDefinition*)data;
direction = v3Sub(location, renderer->camera_location);
result = skyGetColor(definition, renderer, renderer->camera_location, v3Normalize(direction));
result = renderer->applyClouds(renderer, result, renderer->camera_location, v3Add(renderer->camera_location, v3Scale(direction, 10.0)));
return result;
}
void skyRender(SkyDefinition* definition, Renderer* renderer)
{
int res_i, res_j;
int i, j;
double step_i, step_j;
double current_i, current_j;
Vector3 vertex1, vertex2, vertex3, vertex4;
Vector3 direction;
res_i = renderer->render_quality * 40;
res_j = renderer->render_quality * 20;
step_i = M_PI * 2.0 / (double)res_i;
step_j = M_PI / (double)res_j;
for (j = 0; j < res_j; j++)
{
if (!renderer->addRenderProgress(renderer, 0.0))
{
return;
}
current_j = (double)(j - res_j / 2) * step_j;
for (i = 0; i < res_i; i++)
{
current_i = (double)i * step_i;
direction.x = SPHERE_SIZE * cos(current_i) * cos(current_j);
direction.y = SPHERE_SIZE * sin(current_j);
direction.z = SPHERE_SIZE * sin(current_i) * cos(current_j);
vertex1 = v3Add(renderer->camera_location, direction);
direction.x = SPHERE_SIZE * cos(current_i + step_i) * cos(current_j);
direction.y = SPHERE_SIZE * sin(current_j);
direction.z = SPHERE_SIZE * sin(current_i + step_i) * cos(current_j);
vertex2 = v3Add(renderer->camera_location, direction);
direction.x = SPHERE_SIZE * cos(current_i + step_i) * cos(current_j + step_j);
direction.y = SPHERE_SIZE * sin(current_j + step_j);
direction.z = SPHERE_SIZE * sin(current_i + step_i) * cos(current_j + step_j);
vertex3 = v3Add(renderer->camera_location, direction);
direction.x = SPHERE_SIZE * cos(current_i) * cos(current_j + step_j);
direction.y = SPHERE_SIZE * sin(current_j + step_j);
direction.z = SPHERE_SIZE * sin(current_i) * cos(current_j + step_j);
vertex4 = v3Add(renderer->camera_location, direction);
/* TODO Triangles at poles */
renderer->pushQuad(renderer, vertex1, vertex4, vertex3, vertex2, _postProcessFragment, definition);
}
}
}
Vector3 skyGetSunDirection(SkyDefinition* definition)
{
Vector3 result;
double sun_angle = (definition->daytime + 0.75) * M_PI * 2.0;
result.x = cos(sun_angle);
result.y = sin(sun_angle);
result.z = 0.0;
return result;
}
Color skyGetSunColor(SkyDefinition* definition)
{
return colorGradationGet(definition->sun_color, definition->daytime);
}
Color skyGetZenithColor(SkyDefinition* definition)
{
return colorGradationGet(definition->zenith_color, definition->daytime);
}