//Your implicit function with x[0], x[1], and x[2] variables.
//The bounding box is [-20, 20]^3
//Please write with C form.

//The code will be included to function "EvaluateFunction" 
//in class "OurImplicitFunction".

//If you want to add a new function, 
//please edit class "OurImplicitFunction", sorry.

/*********** Example ****************/

float x1 = x[0];
float y1 = x[1];
float z1 = x[2];

float tar = (y1+15.0f)/15.0f;
x1 /= tar*tar;
z1 /= tar*tar;

double angle = 4*PI*y1/30.0f;
float xt = x1*cos(angle) + z1*sin(angle);
float yt = y1;
float zt = -x1*sin(angle) + z1*cos(angle);

float rect = R_int(R_int(3 - fabs(xt), 15 - fabs(yt)), 1 - fabs(zt));
float rect3 = 4 - xt*xt - (yt-5)*(yt-5)/4;

x1 = x[0];
y1 = x[1];
z1 = x[2];

tar = (y1+14)/10;
x1 /= tar*tar;
z1 /= tar*tar;
	
float sphere = 5 - x1*x1 - (y1+10)*(y1+10) - z1*z1;
	
float f1 = R_int(rect, -rect3);
float f2 = sphere;

return R_uni(f1, f2) + 100/(1+(f1/2)*(f1/2)+(f2/2)*(f2/2));