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
|
uniform mat4 ModelViewProjectionMatrix;
uniform vec2 Viewport;
layout(points) in;
layout(triangle_strip, max_vertices = 4) out;
in vec4 finalColor[1];
in float finalThickness[1];
out vec4 mColor;
out vec2 mTexCoord;
/* project 3d point to 2d on screen space */
vec2 toScreenSpace(vec4 vertex)
{
return vec2(vertex.xy / vertex.w) * Viewport;
}
void main(void)
{
vec4 P0 = gl_in[0].gl_Position;
vec2 sp0 = toScreenSpace(P0);
float size = finalThickness[0];
/* generate the triangle strip */
mTexCoord = vec2(0, 1);
mColor = finalColor[0];
gl_Position = vec4(vec2(sp0.x - size, sp0.y + size) / Viewport, 0, 1.0);
EmitVertex();
mTexCoord = vec2(0, 0);
mColor = finalColor[0];
gl_Position = vec4(vec2(sp0.x - size, sp0.y - size) / Viewport, 0, 1.0);
EmitVertex();
mTexCoord = vec2(1, 1);
mColor = finalColor[0];
gl_Position = vec4(vec2(sp0.x + size, sp0.y + size) / Viewport, 0, 1.0);
EmitVertex();
mTexCoord = vec2(1, 0);
mColor = finalColor[0];
gl_Position = vec4(vec2(sp0.x + size, sp0.y - size) / Viewport, 0, 1.0);
EmitVertex();
EndPrimitive();
}
|
