Common.glsl so far

common.glsl

vec4 inputGamma( const in vec4 input_rgba ) {

#ifdef GAMMA_INPUT
	vec4 output_rgba = input_rgba;
	output_rgba.xyz * output_rgba.xyz;
	return output_rgba;
#else
	return input_rgba;
#endif

}

vec3 rgbaToNormal( input_rgba, normal_scale ) {

	vec3 output_normal = input_rgba.xyz * 2.0 - 1.0;
	output_normal.xy *= normal_scale;
	output_normal = normalize( output_normal );
	return normalTex;

}

float halfDot( const in vec3 surfaceNormal, const in vec3 lightNormal ) {
	return 0.5 * dot( surfaceNormal, lightNormal ) + 0.5;
}

float lambertDiffuse( const in vec3 surfaceNormal, const in vec3 lightNormal ) {
#ifdef HALF_LAMBERT
	return max( halfDot( surfaceNormal, lightNormal ), 0.0 );
#else
	return max( dot( surfaceNormal, lightNormal ), 0.0 );
#endif
}

float lightDistanceFadeOutAlpha( const in vec3 lightSurfaceDelta, const in float lightDistance ) {
	float alpha = 1.0;
	if ( lightDistance > 0.0 )
		alpha = 1.0 - min( ( length( lightSurfaceDelta ) / lightDistance ), 1.0 );
	return alpha;
}

vec3 schlickCoeff( specularColor, lightNormal, lightHalfNormal ) {
	return specularColor + vec3( 1.0 - specularColor ) * pow( 1.0 - dot( lightNormal, lightHalfNormal ), 5.0 );
}

float specularCoeff( shininessFactor, lightDotNormalHalf, shininess ) {
	return shininessFactor.r * max( pow( lightDotNormalHalf, shininess ), 0.0 );
}

vec3 schlickSpecular( const in vec3 specularColor, const in vec3 surfaceNormal, const in vec3 viewNormal, const in vec3 lightNormal,  const in vec3 shininessFactor, const in float shininess ) {

	vec3 lightHalfNormal = normalize( lightNormal + viewNormal );
	float lightDotNormalHalf = max( dot( normal, lightHalfNormal ), 0.0 );
	float specularWeight = specularCoeff( shininessFactor, lightDotNormalHalf, shininess );
	float specularNormalization = ( shininess + 2.0001 ) / 8.0;

	vec3 schlick = schlickCoeff( specularColor, lightNormal, lightHalfNormal );
				
	return schlick * specularWeight * specularNormalization;
}