void setup(){
  int imWidth = 352;
  int imHeight = 288;
  int cAmt = imWidth*imHeight;
 
  size(imWidth, imHeight);
  //noLoop();
 }
 	
 	

String lines[] = loadStrings("http://imagine-it.org/cs576/args.txt");
int loadStage = 0;

String cmd = lines[0];
String cmdList[] = split(cmd);

String imFilename = cmdList[0];
     int imWidth = 352;
  int imHeight = 288;
  int qLevel = int(cmdList[1]);
  int numCoeff = int(cmdList[2]);
  int cAmt = imWidth*imHeight;
  
int[] rs = new int[cAmt];
int[] gs = new int[cAmt];
int[] bs = new int[cAmt];
int N = 8;
int bX=0;
int zigZag[] = {1,2,6,7,15,16,28,29,3,5,8,14,17,27,30,43,4,9,13,18,26,31,42,44,10,12,19,25,32,41,45,54,11,20,24,33,40,46,53,55,21,23,34,39,47,52,56,61,22,35,38,48,51,57,60,62,36,37,49,50,58,59,63,64};
        float[] rCoeffBuffer = new float[N*N];
        float[] gCoeffBuffer = new float[N*N];
        float[] bCoeffBuffer = new float[N*N];

        int[] channelNew = new int[imWidth*imHeight];
          int blocksW = imWidth/N;
        int blocksH = imHeight/N;
        
void draw(){
   if(loadStage==0){
     fill(0,0,0);
    rect(0,0, imWidth, imHeight);

     fill(204, 102, 0);
  PFont font;
  font = loadFont("Alba-18.vlw"); 
  textFont(font, 18); 
  text( ("Type 'y' if you want to DCT " + imFilename + "\nwith quantization " + qLevel + " and " + numCoeff + " coefficients"), 20, 100);
   } else if(loadStage==1){

// open a file and read its binary data 
byte b[] = loadBytes(imFilename); 
 
// get each value, from 0 to 255 
for (int i = 0; i < cAmt; i++) { 
  int a = b[i] & 0xff; 
  rs[i]= a;
}
for (int i = cAmt; i < (cAmt*2); i++) { 
  int a = b[i] & 0xff; 
  gs[i-cAmt]= a;
} 
for (int i = (cAmt*2); i < (cAmt*3); i++) { 
  int a = b[i] & 0xff; 
  bs[i-(cAmt*2)]= a;
} 

println("Done reading image in");
     fill(0,0,0);
    rect(0,0, imWidth, imHeight);
     fill(204, 102, 0);
  PFont font;
  font = loadFont("Alba-18.vlw"); 
  textFont(font, 18); 
  text( ( imFilename + " is loaded, \n now computing DCT"), 100, 100);
    println(blocksW);
    println(blocksH);
  loadStage=2;
   } else if(loadStage==2){
  
	if( bX<blocksW) {
            println("Doing blocks for bX= " + bX);
	for(int bY=0; bY<blocksH; bY++){
                
		for(int u=0; u < N; u++){
			for(int v=0; v < N; v++){
				// FORWARD
				float rSum = 0;
                                float gSum = 0;
                                float bSum = 0;                                
				for(int x=bX*N; x<(bX*N+N); x++){
					for(int y=bY*N; y<(bY*N+N); y++){
						float cosU = cos( ((2.0*x + 1) * u * PI)/16.0);
						float cosV = cos( ((2.0*y + 1) * v * PI)/16.0);
						//echo "cos U: ".cosU.", cos V: ".cosV."\n";
						rSum += rs[x+(y)*imWidth] * cosU * cosV;
                                                gSum += gs[x+(y)*imWidth] * cosU * cosV;
                                                bSum += bs[x+(y)*imWidth] * cosU * cosV;
						//echo channel[x*N+y]." ";
						}
				}
				
				//echo "sum:".sum."\n";
				float cU = 1.0;
				float cV = 1.0;
				if(u==0) cU = 1.0/sqrt(2.0);
				if(v==0) cV = 1.0/sqrt(2.0);
				rCoeffBuffer[u*N+v] = round((.25 * cU * cV * rSum)/pow(2,qLevel));
                                gCoeffBuffer[u*N+v] = round((.25 * cU * cV * gSum)/pow(2,qLevel));
                                bCoeffBuffer[u*N+v] = round((.25 * cU * cV * bSum)/pow(2,qLevel));
				//echo coeffBuffer[u*N+v]."\n";
			}
		}
	
	for(int x=bX*N; x<(bX*N+N); x++){
		for(int y=bY*N; y<(bY*N+N); y++){
			float rSum = 0;
			float gSum = 0;
			float bSum = 0;
			for(int u=0; u < N; u++){
				for(int v=0; v < N; v++){
                                        if(zigZag[u+v*N]<=numCoeff) {
					float cU = 1.0;
					float cV = 1.0;
					if(u==0) cU = 1.0/sqrt(2.0);
					if(v==0) cV = 1.0/sqrt(2.0);
					float cosU = cos( ((2.0*x + 1) * u * PI)/16.0);
					float cosV = cos( ((2.0*y + 1) * v * PI)/16.0);
					rSum += cU * cV * rCoeffBuffer[u*N+v]*pow(2,qLevel) * cosU * cosV;
                                        gSum += cU * cV * gCoeffBuffer[u*N+v]*pow(2,qLevel) * cosU * cosV;
                                        bSum += cU * cV * bCoeffBuffer[u*N+v]*pow(2,qLevel) * cosU * cosV;
                                        }
				}
			}

                        color black = color(int(.25 * rSum), int(.25 * gSum), int(.25 * bSum));
                        set(x, y, black);
		}
	}
	}
	}
        bX++;
   }
}

void keyPressed() {
  if(key == 'y'){
    loadStage = 1;
    bX=0;
  }
  redraw();
}