demotool/shaders/lib/utils.glsl

//! type library


const float PI = 3.1415926535;
const float TAU = 2 * PI;
const float PHI = sqrt( 5 ) * .5 + .5;


// -----------------------------------------------------------------------------

float M_Hash(
	in vec2 p )
{
	p = fract(p * vec2(5.3987, 5.4421));
	p += dot(p.yx, p.xy + vec2(21.5351, 14.3137));
	return fract(p.x * p.y * 95.4307);
}

// -----------------------------------------------------------------------------

float M_Luminosity(
	in vec3 color )
{
	return dot( color , vec3( .299 , .587 , .114 ) );
}

vec3 M_NormalizeColor(
	in vec3 color )
{
	const float l = M_Luminosity( color );
	return l > 0 ? ( color / l ) : vec3( 1 );
}

// -----------------------------------------------------------------------------

float M_Saturate(
	in float x )
{
	return clamp( x , 0 , 1 );
}

float M_LengthSqr(
	in vec3 x )
{
	return dot( x , x );
}

float M_Sqr(
	in float x )
{
	return x * x;
}

vec2 M_Sqr(
	in vec2 x )
{
	return x * x;
}

vec3 M_Sqr(
	in vec3 x )
{
	return x * x;
}

float M_Sign(
	in float x )
{
	return ( x < 0 ) ? -1 : 1;
}

vec2 M_Sign(
	in vec2 v )
{
	return vec2( M_Sign( v.x ) , M_Sign( v.y ) );
}


float M_VecMax(
	in vec2 v )
{
	return max( v.x , v.y );
}

float M_VecMax(
	in vec3 v )
{
	return max( M_VecMax( v.xy ) , v.z );
}

float M_VecMax(
	in vec4 v )
{
	return max( M_VecMax( v.xy ) , M_VecMax( v.zw ) );
}


float M_VecMin(
	in vec2 v )
{
	return min( v.x , v.y );
}

float M_VecMin(
	in vec3 v )
{
	return min( M_VecMin( v.xy ) , v.z );
}

float M_VecMin(
	in vec4 v )
{
	return min( M_VecMin( v.xy ) , M_VecMin( v.zw ) );
}