void trace_update_extents(DNATrace *t, int *x0p, int *xnp) {
int ind, pos, x1, fw, cfw, new_x1;
int min = 999999;
int max = -999999;
int x0 = *x0p, xn = *xnp;
int new_x0, new_xn;
if (t->Ned <= 0)
return;
if (x0 < 0) x0 = 0;
if (x0 >= t->read->NPoints) x0 = t->read->NPoints-1;
x1 = x0 + xn < t->read->NPoints ? x0+xn : t->read->NPoints - 1;
x1 = t->tracePos[x1] + 1;
if (x1 >= t->read->NBases) x1--;
x1 = t->read->basePos[x1];
ind = t->tracePosE[x0]; /* Index of first base on screen */
fw = t->font_width/2 + 1;
cfw = t->conf_font_width;
while (ind < t->read->NBases && (pos = trace_get_pos(t, ind)) <= x1) {
pos = point_to_pixel(t, pos) - fw;
if (pos < min)
min = pos;
if (pos + cfw > max)
max = pos + cfw;
ind++;
}
new_x0 = (int)pixel_to_point(t, min-cfw/2-1);
new_xn = (int)pixel_to_point(t, max+cfw/2+1) - new_x0;
x1 = x0 + xn;
new_x1 = new_x0 + new_xn;
x0 = MIN(x0, new_x0);
x1 = MAX(x1, new_x1);
xn = x1 - x0;
if (x0 < 0) {
xn += x0;
x0 = 0;
}
if (x0 + xn > t->read->NPoints)
xn = t->read->NPoints - x0;
*x0p = x0;
*xnp = xn;
}
int pixel_to_base(DNATrace *tracePtr, int pixel, int allow_end) {
int cur, nearest, dist, t;
int pos = pixel_to_point(tracePtr, pixel - tracePtr->borderWidth - 1);
if (pos < 0)
pos = 0;
if (pos >= tracePtr->read->NPoints)
pos = tracePtr->read->NPoints -1;
nearest = tracePtr->tracePosE[pos];
if (!allow_end) {
while (nearest < tracePtr->Ned- 1) {
nearest++;
if (tracePtr->edPos[nearest])
break;
}
} else {
while (nearest < tracePtr->Ned) {
nearest++;
if (tracePtr->edPos[nearest])
break;
}
}
dist = trace_get_pos(tracePtr, nearest) - pos;
if (dist < 0)
dist = 9999;
cur = nearest;
do {
cur--;
if (cur >= 0) {
t = trace_get_pos(tracePtr, cur) - pos;
if (t <= 0)
t = 9999;
if (t < dist) {
dist = t;
nearest = cur;
}
}
} while (cur >= 0 && t != 9999);
return nearest;
}
void mandelbrot_get_point(FRACTAL *fractal, int px, int py, double *zx, double *zy, double *cx, double *cy)
{
*zx = 0.0;
*zy = 0.0;
pixel_to_point(fractal->window, px, py, cx, cy);
}
