demotool/shaders/lib/utils.glsl

30 lines
590 B
GLSL

//! type library
const float PI = 3.14159265;
// -----------------------------------------------------------------------------
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 );
}