Solvespace

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//-----------------------------------------------------------------------------
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// Point rendering shader
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//
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// Copyright 2016 Aleksey Egorov
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//-----------------------------------------------------------------------------
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const float feather = 0.5;
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attribute vec3 pos;
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attribute vec2 loc;
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uniform mat4 modelview;
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uniform mat4 projection;
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uniform float width;
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uniform float pixel;
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void main() {
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    // get camera vectors from modelview matrix
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    vec3 u = vec3(modelview[0].x, modelview[1].x, modelview[2].x);
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    vec3 v = vec3(modelview[0].y, modelview[1].y, modelview[2].y);
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    // calculate point contour extension basis for constant width and caps
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    // calculate point extension width considering antialiasing
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    float ext = width + feather * pixel;
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    // extend point contour
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    vec3 vertex = pos;
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    vertex += ext * loc.x * normalize(u);
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    vertex += ext * loc.y * normalize(v);
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    // transform resulting vertex with modelview and projection matrices
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    gl_Position = projection * modelview * vec4(vertex, 1.0);
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}
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