#version 330

uniform vec3 color;
uniform sampler2D map;
uniform float opacity;

uniform int fogType;
uniform vec3 fogColor;
uniform float fogDensity;
uniform float fogNear;
uniform float fogFar;
uniform float alphaTest;

in vec2 vUV;
layout(location = 0) out vec4 fragColor;

void main() {
	vec4 texture = texture( map, vUV );

	if ( texture.a < alphaTest ) discard;

	fragColor = vec4( color * texture.xyz, texture.a * opacity );

	if ( fogType > 0 ) {
		float depth = gl_FragCoord.z / gl_FragCoord.w;
		float fogFactor = 0.0;

		if ( fogType == 1 ) {
			fogFactor = smoothstep( fogNear, fogFar, depth );
		} else {
			const float LOG2 = 1.442695;
			float fogFactor = exp2( - fogDensity * fogDensity * depth * depth * LOG2 );
			fogFactor = 1.0 - clamp( fogFactor, 0.0, 1.0 );
		}

		fragColor = mix( fragColor, vec4( fogColor, fragColor.w ), fogFactor );
	}
}