blob: 2bd71e977c17277e835659c1606b8188323261da (
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
|
#version 330 core
#extension GL_ARB_enhanced_layouts : enable
#extension GL_ARB_shading_language_420pack : enable
const int maxv = 128;
const int maxarcs = (maxv / 2) - 1;
const int minarcs = 10;
const float tau = radians(360);
const float scale = 150;
uniform ivec4 viewPort;
in vec3 centre[];
in float size[];
layout(points) in;
layout(triangle_strip, max_vertices = maxv) out;
out vec3 geo_centre;
void
doSeg(float arc, vec2 radius)
{
gl_Position = gl_in[0].gl_Position;
geo_centre = centre[0];
EmitVertex();
const vec2 off = vec2(cos(arc), sin(arc)) * radius;
gl_Position.xy = gl_in[0].gl_Position.xy + off;
geo_centre = centre[0];
EmitVertex();
}
void
main()
{
const vec2 display = viewPort.zw;
const vec2 ratio = vec2(1, display.x / display.y);
const vec2 radius = (size[0] * ratio * scale) / gl_in[0].gl_Position.w;
const float step = tau / clamp(radius.x, minarcs, maxarcs);
for (float arc = 0; arc < tau; arc += step) {
doSeg(arc, radius);
}
doSeg(tau, radius);
EndPrimitive();
}
|
