gzdoom-gles/wadsrc/static/shaders_gles/glsl/material_normal.fp

vec3 lightContribution(int i, vec3 normal)
{
	vec4 lightpos = lights[i];
	vec4 lightcolor = lights[i+1];
	vec4 lightspot1 = lights[i+2];
	vec4 lightspot2 = lights[i+3];

	float lightdistance = distance(lightpos.xyz, pixelpos.xyz);
	
	//if (lightpos.w < lightdistance)
	//	return vec3(0.0); // Early out lights touching surface but not this fragment

	vec3 lightdir = normalize(lightpos.xyz - pixelpos.xyz);
	float dotprod = dot(normal, lightdir);

	//if (dotprod < -0.0001) return vec3(0.0);	// light hits from the backside. This can happen with full sector light lists and must be rejected for all cases. Note that this can cause precision issues.
	
	float attenuation = clamp((lightpos.w - lightdistance) / lightpos.w, 0.0, 1.0);


	// NOTE, all spot light stuff gone
	return lightcolor.rgb * attenuation;

/* 
	if (lightspot1.w == 1.0)
		attenuation *= spotLightAttenuation(lightpos, lightspot1.xyz, lightspot2.x, lightspot2.y);

	if (lightcolor.a < 0.0) // Sign bit is the attenuated light flag
	{
		attenuation *= clamp(dotprod, 0.0, 1.0);
	}

	

	if (attenuation > 0.0) // Skip shadow map test if possible
	{
		attenuation *= shadowAttenuation(lightpos, lightcolor.a);
		return lightcolor.rgb * attenuation;
	}
	else
	{
		return vec3(0.0);
	}
*/
}

vec3 ProcessMaterialLight(Material material, vec3 color)
{
	vec4 dynlight = uDynLightColor;
	vec3 normal = material.Normal;

#if (DEF_DYNAMIC_LIGHTS_MOD == 1)
	// modulated lights
	for(int i=uLightRange.x; i<uLightRange.y; i+=4)
	{
		dynlight.rgb += lightContribution(i, normal);
	}
#endif

#if (DEF_DYNAMIC_LIGHTS_SUB == 1)
	// subtractive lights
	for(int i=uLightRange.y; i<uLightRange.z; i+=4) 
	{
		dynlight.rgb -= lightContribution(i, normal);
	}
#endif
	
	vec3 frag = material.Base.rgb * clamp(color + desaturate(dynlight).rgb, 0.0, 1.4);
	
#if (DEF_DYNAMIC_LIGHTS_ADD == 1)
		vec4 addlight = vec4(0.0,0.0,0.0,0.0);
				
		// additive lights
		for(int i=uLightRange.z; i<uLightRange.w; i+=4)
		{
			addlight.rgb += lightContribution(i, normal);
		}

		frag = clamp(frag + desaturate(addlight).rgb, 0.0, 1.0);
#endif
 
	return frag;
}