Parallax Corrected Cubemaps?

[stgatilov 1255]

I have a question about shader.

How does this work and why is it needed:

    //---------------------------------------------------------
	// Tone Map to convert HDR values to range 0.0 - 1.0
	//---------------------------------------------------------
	draw_Color.xyz = color.xyz / (color.xyz + vec3(1.0));

 

[cabalistic 795]

I copied that from the original cubemap reflection shader, no clue about its origin or purpose. To be honest, I forgot about that line, or I would have tried to see what it looks like without it