blob: e7632fcad15282d34ad8b95a46ff6fbe8e9b5136 (
plain)
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
|
// Draw "fancy" wireframe, displaying front-facing, back-facing and
// silhouette lines differently.
// Mike Erwin, April 2015
// After working with this shader a while, convinced we should make
// separate shaders for perpective & ortho. (Oct 2016)
// Due to perspective, the line segment's endpoints might disagree on
// whether the adjacent faces are front facing. This geometry shader
// decides which edge type to use if endpoints disagree.
uniform mat4 ProjectionMatrix;
uniform bool drawFront = true;
uniform bool drawBack = true;
uniform bool drawSilhouette = true;
uniform vec4 frontColor;
uniform vec4 backColor;
uniform vec4 silhouetteColor;
layout(lines) in;
layout(line_strip, max_vertices = 2) out;
in vec4 MV_pos[];
in float edgeClass[];
flat out vec4 finalColor;
void emitLine(vec4 color)
{
gl_Position = ProjectionMatrix * MV_pos[0];
EmitVertex();
gl_Position = ProjectionMatrix * MV_pos[1];
finalColor = color;
EmitVertex();
EndPrimitive();
}
void main()
{
float finalEdgeClass = max(edgeClass[0], edgeClass[1]);
if (finalEdgeClass > 0.0f) {
// front-facing edge
if (drawFront)
emitLine(frontColor);
}
else if (finalEdgeClass < 0.0f) {
// back-facing edge
if (drawBack)
emitLine(backColor);
}
else {
// exactly one face is front-facing, silhouette edge
if (drawSilhouette)
emitLine(silhouetteColor);
}
}
|