cpml.intersect.segment_segment fails to find intersects for some segments

[kromka-chleba]

I'm using CPML's cpml.intersect.segment_segment for finding road intersections in my Minetest mod and I noticed that CPML fails to find intersections for some of them. I compared CPML output with mlib's mlib.segment.getIntersection for the data and mlib finds them correctly.

Data for which CPML fails but mlib works:

Case 1

Seg1: {
	{
		y = -32,
		z = 97,
		x = 448
	},
	{
		y = -32,
		z = 13,
		x = 532
	}
}
Seg2: {
	{
		y = -32,
		z = -12,
		x = 524
	},
	{
		y = -32,
		z = 208,
		x = 524
	}
}
mlib: {
	y = -32,
	z = 21,
	x = 524
}
CPML: nil

Case 2

Seg1: {
	{
		y = -32,
		z = 290,
		x = 688
	},
	{
		y = -32,
		z = 353,
		x = 625
	}
}
Seg2: {
	{
		y = -32,
		z = 208,
		x = 524
	},
	{
		y = -32,
		z = 331,
		x = 647
	}
}
mlib: {
	y = -32,
	z = 331,
	x = 647
}
CPML: nil

Case 3

Seg1: {
	{
		y = -32,
		z = 290,
		x = 688
	},
	{
		y = -32,
		z = 353,
		x = 625
	}
}
Seg2: {
	{
		y = -32,
		z = 331,
		x = 647
	},
	{
		y = -32,
		z = 448,
		x = 647
	}
}
mlib: {
	y = -32,
	z = 331,
	x = 647
}
CPML: nil

Case 4

Seg1: {
	{
		y = -32,
		z = 928,
		x = 489
	},
	{
		y = -32,
		z = 805,
		x = 612
	}
}
Seg2: {
	{
		y = -32,
		z = 810,
		x = 621
	},
	{
		y = -32,
		z = 810,
		x = 448
	}
}
mlib: {
	y = -32,
	z = 810,
	x = 607
}
CPML: nil

[kromka-chleba]

Okay, I did more tests and looks like cpml.intersect.line_line finds the intersection correctly but cpml.intersect.segment_segment fails. The reason behind this is that the latter function expects these segments to be component-wise min and max, which is totally weird because then cpml.intersect.line_line gets not the points of the segments but points with mixed components. Which is 1. incorrect 2. not documented anywhere.

I'll make a PR that fixes this soon, but I guess there are no buses in Gensokyo after all.