1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
// ----------------------------------------------------------------------------
// Copyright (c) 2014, Nicolas P. Rougier. All Rights Reserved.
// Distributed under the (new) BSD License.
// ----------------------------------------------------------------------------
/* ---------------------------------------------------------
Computes the signed distance from a line
Parameters:
-----------
p0, p1: Points describing the line
p: Point to measure distance from
Return:
-------
Signed distance
--------------------------------------------------------- */
float line_distance(vec2 p, vec2 p1, vec2 p2) {
vec2 center = (p1 + p2) * 0.5;
float len = length(p2 - p1);
vec2 dir = (p2 - p1) / len;
vec2 rel_p = p - center;
return dot(rel_p, vec2(dir.y, -dir.x));
}
|
