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
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
//-----------------------------------------------------------------------------
// Outline rendering shader
//
// Copyright 2016 Aleksey Egorov
//-----------------------------------------------------------------------------
const int EMPHASIZED_AND_CONTOUR = 0;
const int EMPHASIZED_WITHOUT_CONTOUR = 1;
const int CONTOUR_ONLY = 2;
const float feather = 0.5;
attribute vec3 pos;
attribute vec4 loc;
attribute vec3 tgt;
attribute vec3 nol;
attribute vec3 nor;
uniform mat4 modelview;
uniform mat4 projection;
uniform float width;
uniform float pixel;
uniform int mode;
varying vec3 fragLoc;
void main() {
// get camera direction from modelview matrix
vec3 dir = vec3(modelview[0].z, modelview[1].z, modelview[2].z);
// perform outline visibility test
float ldot = dot(nol, dir);
float rdot = dot(nor, dir);
bool isOutline = (ldot > -1e-6) == (rdot < 1e-6) ||
(rdot > -1e-6) == (ldot < 1e-6);
bool isTagged = loc.w > 0.5;
float visible = float((mode == CONTOUR_ONLY && isOutline) ||
(mode == EMPHASIZED_AND_CONTOUR && (isOutline || isTagged)) ||
(mode == EMPHASIZED_WITHOUT_CONTOUR && isTagged && !isOutline));
// calculate line contour extension basis for constant width and caps
vec3 norm = normalize(cross(tgt, dir));
norm = normalize(norm - dir * dot(dir, norm));
vec3 perp = normalize(cross(dir, norm));
// calculate line extension width considering antialiasing
float ext = (width + feather * pixel) * visible;
// extend line contour
vec3 vertex = pos;
vertex += ext * loc.x * normalize(perp);
vertex += ext * loc.y * normalize(norm);
// write fragment location for calculating caps and antialiasing
fragLoc = vec3(loc);
// transform resulting vertex with modelview and projection matrices
gl_Position = projection * modelview * vec4(vertex, 1.0);
}
|
