// Riermersma's formula
static uint32_t rgb_diff(uint32_t x, uint32_t y)
{
int rm = (R(x)+R(y))/2;
return 2*sqrd(R(x), R(y))
+ 4*sqrd(G(x), G(y))
+ 3*sqrd(B(x), B(y))
+ rm*(sqrd(R(x), R(y))-sqrd(B(x), B(y)))/256;
}
static void
cmd_sd(void)
{
real sd, variance;
int units;
unsigned long qmask, m;
int quantity;
qmask = get_qlist(BIT(Q_DECLINATION));
if (!qmask) return; /* no quantities found - error already reported */
if (qmask == BIT(Q_DEFAULT)) {
default_grade(pcs);
return;
}
sd = read_numeric(fFalse, NULL);
if (sd <= (real)0.0) {
compile_error_skip(-/*Standard deviation must be positive*/48);
return;
}
units = get_units(qmask, fFalse);
if (units == UNITS_NULL) return;
sd *= factor_tab[units];
variance = sqrd(sd);
for (quantity = 0, m = BIT(quantity); m <= qmask; quantity++, m <<= 1)
if (qmask & m) pcs->Var[quantity] = variance;
}
void init_mandel(void)
{
mandel_surf = malloc(sizeof(Pixbuf));
mandel_surf->w = mandel_surf->h = 1024;
mandel_surf->pitch = mandel_surf->w*sizeof(uint8_t);
mandel_surf->bpp = 8;
uint8_t *data = mandel_surf->data = malloc(mandel_surf->w * mandel_surf->h * sizeof(*data));
for(int y=0; y < mandel_surf->h; y++) { // TODO: speed this up (marching squares?)
for(int x=0; x < mandel_surf->w; x++) {
double complex z0 = x*2.0f/mandel_surf->w - 1.5f + (y*2.0f/mandel_surf->h - 1.0f)*I;
double complex z = z0;
// int i=0; while(cabs(z) < 2 && i < 1024) {
int i=0;
while(sqrd(cimag(z))+sqrd(creal(z)) < 4 && i < 128) {
i++;
z = z*z + z0;
}
//n + log2ln(R) – log2ln|z|
float mu = (i + 1 - log2f(logf(cabs(z))));
data[y*mandel_surf->w + x] = 128*log2f(mu*(4.0f/128)+1);
//data[y*mandel_surf->w + x] = (256*log2(i*32.0f/1024+1)/5);
}
}
glPushAttrib(GL_TEXTURE_BIT);
glGenTextures(1, &mandel_tex);
glBindTexture(GL_TEXTURE_2D, mandel_tex);
gluBuild2DMipmaps(GL_TEXTURE_2D, GL_LUMINANCE, mandel_surf->w, mandel_surf->h, GL_LUMINANCE, GL_UNSIGNED_BYTE, mandel_surf->data);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glPopAttrib();
}
static void
default_grade(settings *s)
{
/* Values correspond to those in bcra5.svx */
s->Var[Q_POS] = (real)sqrd(0.05);
s->Var[Q_LENGTH] = (real)sqrd(0.05);
s->Var[Q_COUNT] = (real)sqrd(0.05);
s->Var[Q_DX] = s->Var[Q_DY] = s->Var[Q_DZ] = (real)sqrd(0.05);
s->Var[Q_BEARING] = (real)sqrd(rad(0.5));
s->Var[Q_GRADIENT] = (real)sqrd(rad(0.5));
s->Var[Q_BACKBEARING] = (real)sqrd(rad(0.5));
s->Var[Q_BACKGRADIENT] = (real)sqrd(rad(0.5));
/* SD of plumbed legs (0.25 degrees?) */
s->Var[Q_PLUMB] = (real)sqrd(rad(0.25));
/* SD of level legs (0.25 degrees?) */
s->Var[Q_LEVEL] = (real)sqrd(rad(0.25));
s->Var[Q_DEPTH] = (real)sqrd(0.05);
}
// brightness formula
static uint32_t rgb_diff(uint32_t x, uint32_t y)
{
return 2*sqrd(R(x), R(y))
+ 3*sqrd(G(x), G(y))
+ 1*sqrd(B(x), B(y));
}
