// keyframe interpolation in 2D
// Written June 2006 by Jarek Rossignac
int nr=8;                // number of cars
int snr=nr;
int snrm=snr*128;
car C[] = new car [nr];   // array of cars
car SC[] = new car [snrm];   // array of cars
car ST[] = new car [snrm];   // array of cars
vec I=new vec (1,0);      // basis vector for angle calculations
vec labelD=new vec(-3,2); // offset vector for painting labels on cars
float t=0;                // animation time
int mode=2;               // interpolaiton mode: 0=linear, 1=Bezier, 2=twist
boolean showLabels=true, extra=true, inter=true, tweaked=true, mixed=true, animate=true, showControl=true, showCurve=false;
color control, derived;
int rec=4;
float s = 0.5;
int curve = 0;
float step = 0; float inc=0.5;
float back = 2.0;
float a = PI/6; 


void setup(){ size(800, 800);  colorMode(HSB,60); control=color(0,60,60); derived=color(20,60,30,30); 
   PFont font = loadFont("Courier-14.vlw"); textFont(font, 12);  
   createCars ();
   }

void createCars () {
  for (int i=0; i<nr; i++)  C[i] = new car(width/2+width*0.3*cos(2*PI*i/nr+a)+random(5),height/2+width*0.3*sin(2*PI*i/nr+a)+random(5),0*PI*i/nr+a+random(PI/12),control); 
  for (int i=0; i<snrm; i++) {ST[i] = new car(width/2,height/2,0,derived); SC[i] = new car(width/2,height/2,0,derived); };
  copyCars(); subdivide(); 
  }
   
void draw()   {background (60);  rectMode(CENTER);  
  fill(0); if (tweaked) {if (mixed) text("mixed  b="+int(back*8)+"/8, s="+int(s*8)+"/8",10,20); else text("s="+int(s*8)+"/8",10,20);} else text("simple polyscrew",10,20); 
  if (animate) 
  {step+=inc; if (step>=1.0) {step=0; curve=sn(curve);}; car K = interpolate(SC[curve],step,SC[sn(curve)]); K.paint();}
     else for (int i=0; i<snr; i++) {SC[i].paint();}; 
 if (showControl) { for (int i=0; i<nr; i++) {
      C[i].paint(); 
      if (showLabels) {stroke(0);fill(60); C[i].paintDots(); fill(0); C[i].F.label(str(i),labelD); };
      }; 
    };
  if (showCurve) {stroke(45,40,60); strokeWeight(2); for (int i=0; i<snr; i++) drawTwist(SC[i],SC[sn(i)]); strokeWeight(1);};
  };

void update() {copyCars(); subdivide();  }

void subdivide () { if (mixed) {refine(back); for (int i=0; i<rec-1; i++) refine (s);} else for (int i=0; i<rec; i++) refine (s); }
void refine (float s) {
  for (int i=snr-1; 0<=i; i--) {
    SC[2*i+1].interpolateTwist(SC[i],.5,SC[sn(i)]); 
    SC[2*i+1].col=derived; 
    SC[2*i].setFrom(SC[i]); 
    SC[2*i].col=derived; 
    };
  snr*=2;  
 for (int i=0; i<=snr; i+=1) ST[i].setFrom(SC[i]); 
  if (tweaked) {
     for (int i=1; i<=snr; i+=2) SC[i].setFrom(fourPoint(SC[sp(sp(sp(i)))],SC[sp(i)],SC[sn(i)],SC[sn(sn(sn(i)))])); 
     for (int i=0; i<=snr; i+=2) ST[i].setFrom(Bspline(ST[sp(sp(i))],ST[i],ST[sn(sn(i))])); 
     for (int i=0; i<=snr; i+=1) SC[i].interpolateTwist(ST[i],s,SC[i]); 
     };
  };

   
car fourPoint(car A, car B, car D, car E) {
  car CM=new car();  // CM.paint(); 
  car CN=new car(); // CN.paint();
  car CX=new car(); 
    CM.interpolateTwist(A,9./8.,B); 
    CN.interpolateTwist(E,9./8.,D); 
    CX.interpolateTwist(CN,0.5,CM); CX.col=derived;
  return(CX);
  }
  
car Bspline(car A, car B, car C) {
  car CM=new car();  // CM.paint(); 
  car CN=new car(); // CN.paint();
  car CX=new car(); 
    CM.interpolateTwist(B,0.25,A); 
    CN.interpolateTwist(B,0.25,C); 
    CX.interpolateTwist(CN,0.5,CM); CX.col=derived;
  return(CX);
  }
  
void copyCars() {for (int i=0; i<nr; i++) SC[i].setFrom(C[i]); snr=nr;};
int sn(int j) {  if (j==snr-1) {return (0);}  else {return(j+1);}  };  // next vertex in control loop
int sp(int j) {  if (j==0) {return (snr-1);}  else {return(j-1);}  };  // next vertex in control loop
int in(int j) {  if (j==nr-1) {return (0);}  else {return(j+1);}  };  // next vertex in control loop
int ip(int j) {  if (j==0) {return (nr-1);}  else {return(j-1);}  };  // next vertex in control loop
    
void mousePressed() {boolean found=false; 
  for (int i=nr-1; i>=0; i--) { if (!found) {if(C[i].selected()) { found=true;}; }; };
  if (!found) {  };
  } 
void mouseDragged() { 
  for (int i=0; i<nr; i++) { if(C[i].picked) {C[i].track(); };   };  
  update(); 
  }
void mouseReleased() {
  for (int i=0; i<nr; i++) {C[i].picked=false; C[i].pickedSpeed=false;}; 
  update(); 
  };
  
void keyPressed() { 
   if (key=='.') {rec++; };  
   if (key==',') {rec--; };  
   if (key=='<') {a-=PI/4; println("a="+a*180.0/PI); };  
   if (key=='>') {a+=PI/4; println("a="+a*180.0/PI);};  
   if (key=='c') {showControl=!showControl; };  
   if (key=='d') {};  
   if (key=='p') {showCurve=!showCurve; };  
   if (key=='a') {animate=!animate; curve=0; step=0;};  
   if (key=='s') {tweaked=false;};  
   if (key=='m') {tweaked=true; mixed=true; s=-0.5; back=1.+64349./67224.;};  
   if (key=='M') {tweaked=true; mixed=true; };  
   if (key=='b') {tweaked=true; mixed=false; s=0.0;};  
   if (key=='f') {tweaked=true; mixed=false; s=1.0;};  
   if (key=='j') {tweaked=true; mixed=false; s=0.5;};  
   if (key=='i') {inter=!inter; };  
   if (key=='h') {createCars();};  
   if (key=='S') {saveCars();};  
   if (key=='L') {loadCars();};   
   if (key=='W') {for (int i=0; i<nr; i++)  C[i].write();};
   if (key=='l') {showLabels=!showLabels;}; 
   if (key==CODED) {
     if (keyCode==UP) back+=0.125;
     if (keyCode==DOWN) back-=0.125;
     if (keyCode==RIGHT) s+=0.125; 
     if (keyCode==LEFT)  s-=0.125;  
     }
   update(); print(".");
  }