END OF AN ERA, FRACTALFORUMS.COM IS CONTINUED ON FRACTALFORUMS.ORG

float t=0.0;    //total distance
float d=1.0;    //estimated distance
float pd=10.0;//previous estimate
float os=0.0;  //overstep
for(int i=0;i<64;i++){ //march loop
d=DE(ro+rd*t); //get the distance estimate
if(d>os){         //we have NOT stepped over anything
os=d*min(1.0,0.5*d/pd);//calc overstep based on ratio of this step to last
t+=d+os;   //add in the overstep
pd=d;    //save this step length for next calc
}else{ //we HAVE stepped over something
t-=os; //so remove the overstep
pd=100000.0;d=0.1;os=0.0;//and reset so the next overstep will be small
}
if(t>MAX_DIST || d<MIN_DIST)break;
}