OpenSpace/modules/digitaluniverse/shaders/points_gs.glsl

/*****************************************************************************************
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 * OpenSpace                                                                             *
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 * Copyright (c) 2014 - 2017                                                             *
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#version __CONTEXT__

layout(points) in;
//layout(points, max_vertices = 13) out;
layout(line_strip, max_vertices = 13) out;

in float vs_screenSpaceDepth[];
in float vs_scaleFactor[];
in vec4 colorMap[]

uniform int sides;

out float gs_screenSpaceDepth;

const float PI = 3.1415926;

void main()
{
    gs_screenSpaceDepth = vs_screenSpaceDepth[0];
    
    for (int i = 0; i <= sides; i++) {
        // Angle between each side in radians
        float ang = PI * 2.0 / float(sides) * i;

        // Offset from center of point (0.3 to accomodate for aspect ratio)
        //vec4 offset = vec4(cos(ang) * 0.003, -sin(ang) * 0.004, 0.0, 0.0);
        //gl_Position = gl_in[0].gl_Position + offset;

        vec4 offset = vec4(cos(ang) * gl_in[0].gl_Position[0], -sin(ang) * gl_in[0].gl_Position[1],
                            gl_in[0].gl_Position[2] , gl_in[0].gl_Position[3]);
        gl_Position = offset;
        
        EmitVertex();
    }
    
    //gl_Position = gl_in[0].gl_Position;// + offset;
    //EmitVertex();

    EndPrimitive();
}