uniform sampler2D tex;
uniform vec3 fog_color, grid_color;

varying vec3 vpos;

void main()
{
	vec3 texel = texture2D(tex, gl_TexCoord[0].st).xyz;
	vec3 color = pow(texel * grid_color, vec3(0.75)) * 2.0;

	float dist = abs(vpos.z);
	float fog = 1.0 - exp(-dist * 0.11);

	float t = clamp(fog, 0.0, 1.0);
	gl_FragColor.xyz = mix(color, fog_color, t);
	gl_FragColor.a = 1.0;
}