Fire_Emitter.osl

// GLSL code by unknown
// OSL compiled, ported 4 vector to floats - By Mads Drøschler
// 5.6.2018
// License CC3.0

float fract(float x)
{
	return x - floor(x);
}

vector fract(vector x)
{
	return x - floor(x);
}


float Snoise(vector uv, float res)
{
	vector s = vector(1e0, 1e2, 1e3);
	uv *= res;
	vector uv0 = floor(mod(uv, res))*s;
	vector uv1 = floor(mod(uv+vector(1.), res))*s;
	vector f = fract(uv); 
	f = f*f*(3.0-2.0*f);
	float a =  uv0[0]+uv0[1]+uv0[2];
	float b =  uv1[0]+uv0[1]+uv0[2];
	float c =  uv0[0]+uv1[1]+uv0[2];
	float d =  uv1[0]+uv1[1]+uv0[2];
	float ra = fract(sin(a*1e-1)*1e3);
	float rb = fract(sin(b*1e-1)*1e3);
	float rc = fract(sin(c*1e-1)*1e3);
	float rd = fract(sin(d*1e-1)*1e3);
	float r0 = mix(mix(ra, rb, f[0]), mix(rc, rd, f[0]), f[1]);
	float raa = fract(sin((a + uv1[2] - uv0[2])*1e-1)*1e3);
	float rbb = fract(sin((b + uv1[2] - uv0[2])*1e-1)*1e3);
	float rcc = fract(sin((c + uv1[2] - uv0[2])*1e-1)*1e3);
	float rdd = fract(sin((d + uv1[2] - uv0[2])*1e-1)*1e3);
	float r1 = mix(mix(raa, rbb, f[0]), mix(rcc, rdd, f[0]), f[1]);
	
	return mix(r0, r1, f[2])*2.-1.;
}

shader Fire_Emitter
( 

	point Po = P,
	float Time = 1.0,
	output vector Out = 0,
)
{
	vector p = Po;
    p[0] *= 1.0;
	float Color = 3.0 - (5.*length(2.*p));
	vector coord = vector(atan2(p[0],p[1])/(2*M_PI)+.5, length(p)*.4, .5);
	
	for(int i = 1; i <= 8; i++)
{
		float power = pow(2.0, float(i));
		Color += (1.5 / power) * Snoise(coord + vector(0.,-Time*.05, Time*.01), power*16.);
}
	Out = vector( Color, pow(max(Color,0.),2.)*0.4, pow(max(Color,0.),3.)*0.15);
}