static float
_bilinear_interpolate(float ll, float lr, float rl, float rr, float lambda1, float lambda2)
{
float il = _lerp(ll, rl, lambda1);
float ir = _lerp(lr, rr, lambda1);
return _lerp(il,ir,lambda2);
}
static void _get_split_vertex(vertex &v_ret, const vertex &va, const vertex &vb, float y) {
float ly = (y - va.y) / (vb.y - va.y);
v_ret.x = _lerp(va.x, vb.x, ly);
v_ret.y = y;
v_ret.z = _lerp(va.z, vb.z, ly);
v_ret.w = 1;
v_ret.r = _lerp(va.r, vb.r, ly);
v_ret.g = _lerp(va.g, vb.g, ly);
v_ret.b = _lerp(va.b, vb.b, ly);
v_ret.a = _lerp(va.a, vb.a, ly);
v_ret.u = _lerp(va.u, vb.u, ly);
v_ret.v = _lerp(va.v, vb.v, ly);
}
//-----------------------------------------------------------------------
double Noise3D::_noise(double x, double y, double z)
{
int X = (int)floor(x) & 255;
int Y = (int)floor(y) & 255;
int Z = (int)floor(z) & 255;
x -= floor(x);
y -= floor(y);
z -= floor(z);
double u = _fade(x);
double v = _fade(y);
double w = _fade(z);
int A = p[X ]+Y, AA = p[A]+Z, AB = p[A+1]+Z;
int B = p[X+1]+Y, BA = p[B]+Z, BB = p[B+1]+Z;
double lrp = _lerp(w, _lerp(v, _lerp(u, _grad(p[AA], x, y, z),
_grad(p[BA], x-1, y, z)),
_lerp(u, _grad(p[AB], x, y-1, z),
_grad(p[BB], x-1, y-1, z))),
_lerp(v, _lerp(u, _grad(p[AA+1], x, y , z-1),
_grad(p[BA+1], x-1, y, z-1)),
_lerp(u, _grad(p[AB+1], x, y-1, z-1),
_grad(p[BB+1], x-1, y-1, z-1))));
return Ogre::Math::Abs((Ogre::Real)lrp); // Use absolute value, because lrp in between [-1, 1]
}
G_GNUC_PURE
guint32 turbulencePixel(Geom::Point const &p) const {
int wrapx = _wrapx, wrapy = _wrapy, wrapw = _wrapw, wraph = _wraph;
double pixel[4];
double x = p[Geom::X] * _baseFreq[Geom::X];
double y = p[Geom::Y] * _baseFreq[Geom::Y];
double ratio = 1.0;
for (int k = 0; k < 4; ++k)
pixel[k] = 0.0;
for(int octave = 0; octave < _octaves; ++octave)
{
double tx = x + PerlinOffset;
double bx = floor(tx);
double rx0 = tx - bx, rx1 = rx0 - 1.0;
int bx0 = bx, bx1 = bx0 + 1;
double ty = y + PerlinOffset;
double by = floor(ty);
double ry0 = ty - by, ry1 = ry0 - 1.0;
int by0 = by, by1 = by0 + 1;
if (_stitchTiles) {
if (bx0 >= wrapx) bx0 -= wrapw;
if (bx1 >= wrapx) bx1 -= wrapw;
if (by0 >= wrapy) by0 -= wraph;
if (by1 >= wrapy) by1 -= wraph;
}
bx0 &= BMask;
bx1 &= BMask;
by0 &= BMask;
by1 &= BMask;
int i = _latticeSelector[bx0];
int j = _latticeSelector[bx1];
int b00 = _latticeSelector[i + by0];
int b01 = _latticeSelector[i + by1];
int b10 = _latticeSelector[j + by0];
int b11 = _latticeSelector[j + by1];
double sx = _scurve(rx0);
double sy = _scurve(ry0);
double result[4];
// channel numbering: R=0, G=1, B=2, A=3
for (int k = 0; k < 4; ++k) {
double const *qxa = _gradient[b00][k];
double const *qxb = _gradient[b10][k];
double a = _lerp(sx, rx0 * qxa[0] + ry0 * qxa[1],
rx1 * qxb[0] + ry0 * qxb[1]);
double const *qya = _gradient[b01][k];
double const *qyb = _gradient[b11][k];
double b = _lerp(sx, rx0 * qya[0] + ry1 * qya[1],
rx1 * qyb[0] + ry1 * qyb[1]);
result[k] = _lerp(sy, a, b);
}
if (_fractalnoise) {
for (int k = 0; k < 4; ++k)
pixel[k] += result[k] / ratio;
} else {
for (int k = 0; k < 4; ++k)
pixel[k] += fabs(result[k]) / ratio;
}
x *= 2;
y *= 2;
ratio *= 2;
if(_stitchTiles)
{
// Update stitch values. Subtracting PerlinOffset before the multiplication and
// adding it afterward simplifies to subtracting it once.
wrapw *= 2;
wraph *= 2;
wrapx = wrapx*2 - PerlinOffset;
wrapy = wrapy*2 - PerlinOffset;
}
}
if (_fractalnoise) {
guint32 r = CLAMP_D_TO_U8((pixel[0]*255.0 + 255.0) / 2);
guint32 g = CLAMP_D_TO_U8((pixel[1]*255.0 + 255.0) / 2);
guint32 b = CLAMP_D_TO_U8((pixel[2]*255.0 + 255.0) / 2);
guint32 a = CLAMP_D_TO_U8((pixel[3]*255.0 + 255.0) / 2);
r = premul_alpha(r, a);
g = premul_alpha(g, a);
b = premul_alpha(b, a);
ASSEMBLE_ARGB32(pxout, a,r,g,b);
return pxout;
} else {
guint32 r = CLAMP_D_TO_U8(pixel[0]*255.0);
guint32 g = CLAMP_D_TO_U8(pixel[1]*255.0);
guint32 b = CLAMP_D_TO_U8(pixel[2]*255.0);
guint32 a = CLAMP_D_TO_U8(pixel[3]*255.0);
r = premul_alpha(r, a);
g = premul_alpha(g, a);
b = premul_alpha(b, a);
ASSEMBLE_ARGB32(pxout, a,r,g,b);
return pxout;
}
}
int
wind_file_get_wind(wind_file_t* file, float lat, float lon, float height,
float* windu, float *windv, float *uvar, float *vvar)
{
// we use static variables to 'cache' the last left and right lat/longs
// and heights so that we can avoid searching the axes if necessary
static int have_valid_latlon_cache = 0;
static int have_valid_pressure_cache = 0;
static unsigned int left_lat_idx, right_lat_idx;
static unsigned int left_lon_idx, right_lon_idx;
static unsigned int left_pr_idx, right_pr_idx;
static float left_lat, right_lat;
static float left_lon, right_lon;
int i;
float left_height, right_height;
float lat_lambda, lon_lambda, pr_lambda;
assert(file);
assert(windu && windv);
// canonicalise the longitude
lon = _canonicalise_longitude(lon);
// by default, return nothing in case of error.
*windu = *windv = 0.f;
// see if the cache is indeed valid
if(have_valid_latlon_cache)
{
if((left_lat > lat) ||
(right_lat < lat) ||
!_longitude_is_left_of(left_lon, lon) ||
!_longitude_is_left_of(lon, right_lon))
{
have_valid_latlon_cache = 0;
}
}
// if we have no cached grid locations, look for them.
if(!have_valid_latlon_cache)
{
// look for latitude along second axis
if(!_wind_file_axis_find_value(file->axes[1], lat,
_float_is_left_of, &left_lat_idx, &right_lat_idx))
{
fprintf(stderr, "ERROR: Latitude %f is not covered by file.\n", lat);
return 0;
}
left_lat = file->axes[1]->values[left_lat_idx];
right_lat = file->axes[1]->values[right_lat_idx];
// look for longitude along third axis
if(!_wind_file_axis_find_value(file->axes[2], lon,
_longitude_is_left_of, &left_lon_idx, &right_lon_idx))
{
fprintf(stderr, "ERROR: Longitude %f is not covered by file.\n", lon);
return 0;
}
left_lon = file->axes[2]->values[left_lon_idx];
right_lon = file->axes[2]->values[right_lon_idx];
if(verbosity > 1)
fprintf(stderr, "INFO: Moved to latitude/longitude "
"cell (%f,%f)-(%f,%f)\n",
left_lat, left_lon, right_lat, right_lon);
have_valid_latlon_cache = 1;
}
// compute the normalised lat/lon co-ordinate within the cell we're in.
if(left_lat_idx != right_lat_idx)
lat_lambda = (lat - left_lat) / (right_lat - left_lat);
else
lat_lambda = 0.5f;
if(left_lon_idx != right_lon_idx)
lon_lambda = _longitude_distance(lon, left_lon)
/ _longitude_distance(right_lon, left_lon);
else
lon_lambda = 0.5f;
// munge the lambdas into the right range. Numerical approximations can nudge them
// ~1e-08 either side sometimes.
lat_lambda = (lat_lambda < 0.f) ? 0.f : lat_lambda;
lat_lambda = (lat_lambda > 1.f) ? 1.f : lat_lambda;
lon_lambda = (lon_lambda < 0.f) ? 0.f : lon_lambda;
lon_lambda = (lon_lambda > 1.f) ? 1.f : lon_lambda;
// use this normalised co-ordinate to check the left and right heights
if(have_valid_pressure_cache)
{
float ll_height, lr_height, rl_height, rr_height;
// left
ll_height = _wind_file_get_height(file, left_lat_idx, left_lon_idx, left_pr_idx);
lr_height = _wind_file_get_height(file, left_lat_idx, right_lon_idx, left_pr_idx);
rl_height = _wind_file_get_height(file, right_lat_idx, left_lon_idx, left_pr_idx);
rr_height = _wind_file_get_height(file, right_lat_idx, right_lon_idx, left_pr_idx);
left_height = _bilinear_interpolate(ll_height, lr_height, rl_height, rr_height,
lat_lambda, lon_lambda);
// if the leftmost height is too small and we can go lower...
if((left_height > height) && (left_pr_idx > 0))
have_valid_pressure_cache = 0;
// right
ll_height = _wind_file_get_height(file, left_lat_idx, left_lon_idx, right_pr_idx);
lr_height = _wind_file_get_height(file, left_lat_idx, right_lon_idx, right_pr_idx);
rl_height = _wind_file_get_height(file, right_lat_idx, left_lon_idx, right_pr_idx);
rr_height = _wind_file_get_height(file, right_lat_idx, right_lon_idx, right_pr_idx);
right_height = _bilinear_interpolate(ll_height, lr_height, rl_height, rr_height,
lat_lambda, lon_lambda);
// if the rightmost height is too small and we can go higher...
if((right_height < height) && (right_pr_idx < file->axes[0]->n_values-1))
have_valid_pressure_cache = 0;
}
// if our height cache is out of whack, find a better cell.
if(!have_valid_pressure_cache)
{
// search along all heights to find what pressure level we're at
left_pr_idx = right_pr_idx = file->axes[0]->n_values;
left_height = right_height = -1.f;
for(i=0; i<file->axes[0]->n_values; ++i)
{
// get heights for each corner of our lat/lon cell.
float ll_height = _wind_file_get_height(file,
left_lat_idx, left_lon_idx, i);
float lr_height = _wind_file_get_height(file,
left_lat_idx, right_lon_idx, i);
float rl_height = _wind_file_get_height(file,
right_lat_idx, left_lon_idx, i);
float rr_height = _wind_file_get_height(file,
right_lat_idx, right_lon_idx, i);
// interpolate within our cell.
float interp_height = _bilinear_interpolate(
ll_height, lr_height, rl_height, rr_height,
lat_lambda, lon_lambda);
if((interp_height <= height) &&
((interp_height >= left_height) ||
(left_pr_idx == file->axes[0]->n_values)))
{
left_pr_idx = i;
left_height = interp_height;
}
if((interp_height >= height) &&
((interp_height <= right_height) ||
(right_pr_idx == file->axes[0]->n_values)))
{
right_pr_idx = i;
right_height = interp_height;
}
}
if(left_pr_idx == file->axes[0]->n_values)
{
left_pr_idx = right_pr_idx;
if(verbosity > 0)
fprintf(stderr, "WARN: Moved to %.2fm, below height where we "
"have data. "
"Assuming we're at %.fmb or approx. %.2fm.\n",
height,
file->axes[0]->values[left_pr_idx],
_wind_file_get_height(file,
left_lat_idx, left_lon_idx, left_pr_idx));
}
if(right_pr_idx == file->axes[0]->n_values)
{
right_pr_idx = left_pr_idx;
if(verbosity > 0)
fprintf(stderr, "WARN: Moved to %.2fm, above height where we "
"have data. "
"Assuming we're at %.fmb or approx. %.2fm.\n",
height,
file->axes[0]->values[right_pr_idx],
_wind_file_get_height(file,
left_lat_idx, left_lon_idx, right_pr_idx));
}
if((left_pr_idx == file->axes[0]->n_values) ||
(right_pr_idx == file->axes[0]->n_values))
{
fprintf(stderr, "ERROR: Moved to a totally stupid height (%f). "
"Giving up!\n", height);
return 0;
}
if(verbosity > 1)
fprintf(stderr, "INFO: Moved to pressure cell (%.fmb, %.fmb)\n",
file->axes[0]->values[left_pr_idx],
file->axes[0]->values[right_pr_idx]);
have_valid_pressure_cache = 1;
}
// compute the normalised pressure co-ordinate within the cell we're in.
if(left_pr_idx != right_pr_idx)
pr_lambda = (height - left_height) / (right_height - left_height);
else
pr_lambda = 0.5f;
// pr_lambda might be outside of the range [0,1] depending on if we went
// above or below our data, munge it appropriately.
pr_lambda = (pr_lambda < 0.f) ? 0.f : pr_lambda;
pr_lambda = (pr_lambda > 1.f) ? 1.f : pr_lambda;
assert(lat_lambda >= 0.f);
assert(lon_lambda >= 0.f);
assert(pr_lambda >= 0.f);
assert(lat_lambda <= 1.f);
assert(lon_lambda <= 1.f);
assert(pr_lambda <= 1.f);
// By this point we have left/right co-ordinates which describe the
// latitude, longitude and pressure boundaries of our data cell along
// with normalised co-ordinates within it. We can now actually find
// some data...
//
// We compute the lerped u and v along with the neighbourhood mean and
// square mean to calculate the neighbourhood variance.
{
float llu, lru, rlu, rru;
float llv, lrv, rlv, rrv;
float lowu, lowv, highu, highv;
float umean = 0.f;
float usqmean = 0.f;
float vmean = 0.f;
float vsqmean = 0.f;
// let's get the wind u and v for the lower lat/lon cell
_wind_file_get_wind_raw(file,
left_lat_idx, left_lon_idx, left_pr_idx, &llu, &llv);
_wind_file_get_wind_raw(file,
left_lat_idx, right_lon_idx, left_pr_idx, &lru, &lrv);
_wind_file_get_wind_raw(file,
right_lat_idx, left_lon_idx, left_pr_idx, &rlu, &rlv);
_wind_file_get_wind_raw(file,
right_lat_idx, right_lon_idx, left_pr_idx, &rru, &rrv);
lowu = _bilinear_interpolate(llu, lru, rlu, rru, lat_lambda, lon_lambda);
lowv = _bilinear_interpolate(llv, lrv, rlv, rrv, lat_lambda, lon_lambda);
umean = llu + lru + rlu + rru;
vmean = llv + lrv + rlv + rrv;
usqmean = llu*llu + lru*lru + rlu*rlu + rru*rru;
vsqmean = llv*llv + lrv*lrv + rlv*rlv + rrv*rrv;
/*
lowusq = _bilinear_interpolate(llu*llu, lru*lru, rlu*rlu, rru*rru,
lat_lambda, lon_lambda);
lowvsq = _bilinear_interpolate(llv*llv, lrv*lrv, rlv*rlv, rrv*rrv,
lat_lambda, lon_lambda);
*/
// let's get the wind u and v for the upper lat/lon cell
_wind_file_get_wind_raw(file,
left_lat_idx, left_lon_idx, right_pr_idx, &llu, &llv);
_wind_file_get_wind_raw(file,
left_lat_idx, right_lon_idx, right_pr_idx, &lru, &lrv);
_wind_file_get_wind_raw(file,
right_lat_idx, left_lon_idx, right_pr_idx, &rlu, &rlv);
_wind_file_get_wind_raw(file,
right_lat_idx, right_lon_idx, right_pr_idx, &rru, &rrv);
highu = _bilinear_interpolate(llu, lru, rlu, rru, lat_lambda, lon_lambda);
highv = _bilinear_interpolate(llv, lrv, rlv, rrv, lat_lambda, lon_lambda);
umean += llu + lru + rlu + rru;
vmean += llv + lrv + rlv + rrv;
usqmean += llu*llu + lru*lru + rlu*rlu + rru*rru;
vsqmean += llv*llv + lrv*lrv + rlv*rlv + rrv*rrv;
/*
highusq = _bilinear_interpolate(llu*llu, lru*lru, rlu*rlu, rru*rru,
lat_lambda, lon_lambda);
highvsq = _bilinear_interpolate(llv*llv, lrv*lrv, rlv*rlv, rrv*rrv,
lat_lambda, lon_lambda);
*/
*windu = _lerp(lowu, highu, pr_lambda);
*windv = _lerp(lowv, highv, pr_lambda);
// We will calculate the variance by making use of the fact
// that the lerping is effectively a weighted mean or
// expectation and that
// var = E[X^2] - E[X]^2.
//
// In effect this calculates the instantaneous variance by considering the
// contributions from the cube surrounding the point in question.
// This is highly cunning and, on the face of it, not entirely wrong.
umean *= 0.125f; usqmean *= 0.125f;
vmean *= 0.125f; vsqmean *= 0.125f;
*uvar = usqmean - umean * umean;
*vvar = vsqmean - vmean * vmean;
}
return 1;
}
static void _smooth_draw_triangle_flat_bottom(vertex &v0, vertex &v1, vertex &v2) {
if (v0.y == v1.y) {
_swap_vertex(v0, v2);
}
else if (v0.y == v2.y) {
_swap_vertex(v0, v1);
}
if (v1.x > v2.x) {
_swap_vertex(v1, v2);
}
int x0 = v0.x;
int y0 = v0.y;
int x1 = v1.x;
int y1 = v1.y;
int x2 = v2.x;
int y2 = v2.y;
float xs = x0;
float xe = x0;
int y_end = (y1 > y2) ? y1 : y2;
float y_dis = y_end - y0;
float crs = v0.r;
float cre = v0.r;
float cgs = v0.g;
float cge = v0.g;
float cbs = v0.b;
float cbe = v0.b;
float cas = v0.a;
float cae = v0.a;
float tus = v0.u;
float tue = v0.u;
float tvs = v0.v;
float tve = v0.v;
float ds = v0.z;
float de = v0.z;
bool texturing = (tus != -1 && tvs != -1);
color c;
for (int y = y0; y < y_end; y++) {
float ly = ((float)y - y0) / y_dis;
xs = _lerp(x0, x1, ly);
xe = _lerp(x0, x2, ly);
crs = _lerp(v0.r, v1.r, ly);
cre = _lerp(v0.r, v2.r, ly);
cgs = _lerp(v0.g, v1.g, ly);
cge = _lerp(v0.g, v2.g, ly);
cbs = _lerp(v0.b, v1.b, ly);
cbe = _lerp(v0.b, v2.b, ly);
cas = _lerp(v0.a, v1.a, ly);
cae = _lerp(v0.a, v2.a, ly);
if (texturing) {
tus = _lerp(v0.u, v1.u, ly);
tue = _lerp(v0.u, v2.u, ly);
tvs = _lerp(v0.v, v1.v, ly);
tve = _lerp(v0.v, v2.v, ly);
}
ds = _lerp(v0.z, v1.z, ly);
de = _lerp(v0.z, v2.z, ly);
float x_dis = xe - xs;
for (int x = xs; x < xe; x++) {
float lx = ((float)x - xs) / x_dis;
float d = _lerp(ds, de, lx);
if (!depth_buffer::get_instance()->d_test(x, y, d)) {
continue;
}
if (!texturing) {
c.r = _lerp(crs, cre, lx);
c.g = _lerp(cgs, cge, lx);
c.b = _lerp(cbs, cbe, lx);
c.a = _lerp(cas, cae, lx);
}
else {
float u = _lerp(tus, tue, lx);
float v = _lerp(tvs, tve, lx);
c = texture::get_instance()->sampling(u, v);
}
color_buffer::get_intance()->write_color(x, y, c);
}
}
}
