Emre's JavaScript Tetris AI Lab

function evaluate(debugmode)
{
	var x,y,i,full,empty,btype,well,blocked,lblock,rblock;

// Intermediate Results
	var HorizontalTransitions = 0;
	var FilledLines = 0;
	var HighestBlock = -1;
	var VerticalTransitions = 0;
	var BlockedCells = 0;
	var Wells = 0;

// Copy to eField, Calculate HorizontalTransitions, FilledLines and HighestBlock
	for(i=y=this.height-1;y>=0;y--)
	{
		btype=1; full=1; empty=1;
		for(x=this.width-1;x>=0;x--)
		{
			if(this.data[x+y*this.width]==0)
				this.efield[x+i*this.width]=0; else empty=!(this.efield[x+i*this.width]=1);
			if(btype!=this.efield[x+i*this.width])
			{
				btype = this.efield[x+i*this.width]; full=0;
				HorizontalTransitions++;
			}
		}
		if(!empty) HighestBlock = -1;
		if(empty && HighestBlock==-1) HighestBlock = this.height-(y+1);

if(!full) i--; else for(x=this.width-1;x>=0;x--) this.efield[x+y*this.width]=0;
		if(!btype) HorizontalTransitions++;
	}
	if(HighestBlock==-1) HighestBlock = this.height;
	FilledLines=i+1;
	HighestBlock -= FilledLines;

// Calculate VerticalTransitions, Wells, BurriedCells
	for(x=0;x<this.width;x++)
	{
		btype=0; blocked=0;
		for(y=(this.height-HighestBlock);y<this.height;y++)
		{
			if(btype!=this.efield[x+y*this.width])
			{
				blocked=1;
				btype=this.efield[x+y*this.width];
				VerticalTransitions++;
			}
			if(blocked&&!this.efield[x+y*this.width])
			{
				BlockedCells++;
			}
			if(x==0) lblock=1; else lblock = this.efield[(x-1)+y*this.width];
			if(x==this.width-1)
				rblock=1; else rblock = this.efield[(x+1)+y*this.width];
			if(lblock&&rblock)
			{
				for(i=y;i<this.height&&(this.efield[x+i*this.width]==0);i++) Wells++;
			}
		}
		if(!btype) VerticalTransitions++;
	}

// Calculate Final Score
	FinalScore =
		(-1.00 * HighestBlock)+
		(-1.00 * HorizontalTransitions)+
		(-1.00 * VerticalTransitions)+
		(-4.00 * BlockedCells)+
		(-0.90 * Wells)+
		( 0.10 * FilledLines);
	return FinalScore;
}

Variables
this.height	Height of the field
this.width	Width of the field
this.data[n]	Element in the field where n is between 0 and width*height