Repo created

libs/shaders/GL/transit_circle.fsh.glsl

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+// Warning! Beware to use this shader. "discard" command may significally reduce performance.
+// Unfortunately some CG algorithms cannot be implemented without discarding fragments from depth buffer.
+
+layout (location = 0) in vec3 v_radius;
+layout (location = 1) in vec4 v_color;
+
+layout (location = 0) out vec4 v_FragColor;
+
+const float aaPixelsCount = 2.5;
+
+void main()
+{
+  vec4 finalColor = v_color;
+  float smallRadius = v_radius.z - aaPixelsCount;
+  float stepValue = smoothstep(smallRadius * smallRadius, v_radius.z * v_radius.z,
+                              dot(v_radius.xy, v_radius.xy));
+  finalColor.a = finalColor.a * (1.0 - stepValue);
+  if (finalColor.a < 0.01)
+    discard;
+  v_FragColor = finalColor;
+}