gistfile1.pde

// benchmark to see if right-shift is faster than floor( / ).
// this is to quickly find which grid-element a location belongs to.
// test is in 1D only.
 
void draw ()
{
    //setup
    int grid = 3;
    float gridP = pow(2,grid);  // 16 >> 4 == 16 / 2^4
    
    float rnd = random(1000);
    int fInt=0, fInt2=0;
    
    // using right-shifting
    long ts = System.currentTimeMillis();
    for (int i=0; i< 20000; i++)
        fInt = ((int)rnd) >> grid;
    float ts1 = (System.currentTimeMillis()-ts)/1000.0;
    
    // using floor
    ts = System.currentTimeMillis();
    for (int i=0; i< 20000; i++)
        fInt2 = floor(rnd / gridP);
    float ts2 = (System.currentTimeMillis()-ts)/1000.0;
    
    // results
    println( rnd + "	shift: " + fInt +  "	" + ts1 );
    println( rnd + "	floor: " + fInt2 + "	" + ts2 );
    println( "" );
}