shadowmap-pseudo.h

vec4 fragPosLightSpace = lightSpaceMatrix * worldPos;
float visibility = 1.0 - calcShadow(fragPosLightSpace);
vec3 rgb = emissive + (ambient + visibility * (diffuse + specular)) * color;

float calcShadow(vec4 fragPosLightSpace)
{
	vec3 screenSpacePos = fragPosLightSpace.xyz / fragPosLightSpace.w;
	
	float bias = 0.005;
	float fragDepth = screenSpacePos.z - 0.005;
  
        // furthest depth light can reach/see
	float maxDepth = texture(shadowMap, screenSpacePos.xy).r;

         // if frag depth is beyond what light can see,  then it's in shadow
 	return step(minDepth, fragDepth);
}