librw/src/gl/shaders/header.frag

#ifdef USE_UBOS
layout(std140) uniform State
{
	vec2 u_alphaRef;
	vec4  u_fogData;
	vec4  u_fogColor;
};
#else
uniform vec2 u_alphaRef;

uniform vec4  u_fogData;
uniform vec4  u_fogColor;
#endif

#define u_fogStart (u_fogData.x)
#define u_fogEnd (u_fogData.y)
#define u_fogRange (u_fogData.z)
#define u_fogDisable (u_fogData.w)

#ifndef GL2
out vec4 fragColor;
#endif

void DoAlphaTest(float a)
{
	if(a < u_alphaRef.x || a >= u_alphaRef.y)
		discard;
}