st/patch/alpha.c

20 lines
319 B
C

float
clamp(float value, float lower, float upper) {
if (value < lower)
return lower;
if (value > upper)
return upper;
return value;
}
void
changealpha(const Arg *arg)
{
if ((alpha > 0 && arg->f < 0) || (alpha < 1 && arg->f > 0))
alpha += arg->f;
alpha = clamp(alpha, 0.0, 1.0);
xloadcols();
redraw();
}