//these are just the rendering controls, using the tickbox, turn them on and off how you want
muscles = false;
skeleton = false;
outline = true;
//this turns wave muscles on or off
wave = false;

//verlet integration 2d

//how many points you have on the stage;  points should have instances ball1, ball2, ball3 etc.
point_no = 17;

//this creates an array containing x, y, oldx, and oldy posiitions for each point
points = new Array();
for(i=1;i<point_no+1;i++){
points[i] = {x:_root["ball"+i]._x, y:_root["ball"+i]._y, x2:_root["ball"+i]._x, y2:_root["ball"+i]._y};
}

//iterations is how many times calculations are repeated per frame, should be >4 for best results but depends on what kind of
//object it is
iterations = 4;

//universal gravity
gravity = 0.4

//on enter frame call each function
function onEnterFrame(){
//clear drawing after frame
_root.clear();
// carry out main functions;
verlet();
render();
constraints();
ai();
keys();
}

//the verlet function pretty much moves the points by the difference of the previous two points
verlet = function(){
//for each particle
for(i=1;i<point_no+1;i++){
//store initial point
tempx = points[i].x
tempy = points[i].y
//verlet integration
points[i].x += points[i].x - points[i].x2
points[i].y += points[i].y - points[i].y2 + gravity
//store previous point
points[i].x2 = tempx;
points[i].y2 = tempy;
}
}

//this controls where each particle is allowed to go
constraints = function(){
//for each particle carry out distance and boundary functions
for(it=0;it<iterations;it++){
distance();
boundaries();
}
}
//this function connects each particle/point with either a solid line (constrain) or a spring (muscle);
distance = function(){
//torso
muscle(1, 2, 68);
constrain(2, 3, 60);
//chest triangle
constrain(4, 7, 65);
constrain(4, 3, 95);
constrain(7, 3, 95);
//hip triangle
constrain(10, 13, 65);
constrain(10, 2, 95);
constrain(13, 2, 95);
//waist muscles;
muscle(4, 10, 100);
muscle(7, 13, 100);
//neck muscles;
muscle(4, 1, 70);
muscle(7, 1, 70);
muscle(3, 1, 128);
muscle(13, 1, 200);
muscle(10, 1, 200);
//left arm;
constrain(4, 5, 60);
constrain(5, 6, 50);
muscle(1, 5, 130);
muscle(4, 6, 110);
//right arm;
constrain(7, 8, 60);
constrain(8, 9, 50);
muscle(1, 8, 130);
muscle(7, 9, 110);
//left leg;
constrain(10, 11, 85);
constrain(11, 12, 80);
muscle(10, 12, 165);
muscle(3, 10, 40);
//right leg;
constrain(13, 14, 85);
constrain(14, 15, 80);
muscle(13, 15, 165);
muscle(3, 13, 40);
//leg width;
muscle(12, 15, 90);
muscle(11, 14, 100);
muscle(2, 15, 280);
muscle(2, 12, 280);
//feet;
constrain(12, 16, 30);
constrain(15, 17, 30);
muscle(16, 11, 100);
muscle(17, 14, 100);
muscle(17, 16, 170);
//arms up;, the wave function only occurs on clicks
if(wave == true){
muscle(9, 13, 220);
muscle(6, 10, 220);
muscle(15, 9, 350);
muscle(12, 6, 350);
}
}
//edge of the world and friction
boundaries = function(){
for(i=1;i<point_no+1;i++){
if(points[i].x > 540) (points[i].x = 540)
if(points[i].x < 0) (points[i].x = 0)
if(points[i].y > 400){
//friction depends on the normal force ie penetration depth...
depth = points[i].y-400
points[i].x -= depth*(points[i].x-points[i].x2)/10
points[i].y = 400;
}
//move the balls to the positions
_root["ball"+i]._x = points[i].x
_root["ball"+i]._y = points[i].y
}
//position head movie clip (you'll need one of these on the stage);
head._x = ball1._x
head._y = ball1._y
}
//the constrain function
constrain = function(point, target, distance){
r = distance;
dx = points[point].x-points[target].x
dy = points[point].y-points[target].y
d1 = Math.round(Math.sqrt(dx*dx + dy*dy))
d2 = 0.5*(d1-r)/d1
dx = dx*d2;
dy = dy*d2;
points[target].x += dx; points[target].y += dy;
points[point].x -= dx; points[point].y -= dy
if(skeleton==true){
_root.lineStyle(2, 0xFF0000);
_root.moveTo(points[target].x, points[target].y);
_root.lineTo(points[point].x, points[point].y);
}
}
//the muscle function;
muscle = function(point, target, distance){
r = distance;
dx = points[point].x-points[target].x
dy = points[point].y-points[target].y
d1 = Math.round(Math.sqrt(dx*dx + dy*dy))
d2 = 0.05*(d1-r)/d1
dx = dx*d2;
dy = dy*d2;
points[target].x += dx; points[target].y += dy;
points[point].x -= dx; points[point].y -= dy;
if(muscles==true){
_root.lineStyle(2, 0x0000FF);
_root.moveTo(points[target].x, points[target].y);
_root.lineTo(points[point].x, points[point].y);
}
}
//control with the keys
keys = function(){
for(i=1;i<point_no+1;i++){
if(Key.isDown(Key.RIGHT)) points[i].x += gravity*2
if(Key.isDown(Key.LEFT)) points[i].x -= gravity*2
if(Key.isDown(Key.UP)) points[i].y -= gravity*2
if(Key.isDown(Key.DOWN)) points[i].y += gravity*2
}
}
//render it
render = function(){
if(outline==true){
_root.lineStyle(10, 0x000000, 100);
_root.moveTo(ball1._x, ball1._y);
_root.lineTo((ball4._x+ball7._x)/2, (ball4._y+ball7._y)/2);
_root.moveTo(ball4._x, ball4._y);
_root.beginFill(0x000000, 100);
_root.curveTo((ball2._x+ball3._x)/2, (ball2._y+ball3._y)/2, (ball10._x+ball11._x)/2, (ball10._y+ball11._y)/2);
_root.curveTo((ball10._x+ball13._x)/2, (ball10._y+ball13._y)/2, (ball13._x+ball14._x)/2, (ball13._y+ball14._y)/2);
_root.curveTo((ball2._x+ball3._x)/2, (ball2._y+ball3._y)/2, ball7._x, ball7._y);
_root.lineTo(ball4._x, ball4._y);
_root.endFill();
_root.lineTo(ball5._x, ball5._y);
_root.lineTo(ball6._x, ball6._y);
_root.moveTo(ball7._x, ball7._y);
_root.lineTo(ball8._x, ball8._y);
_root.lineTo(ball9._x, ball9._y);
_root.moveTo((ball10._x+ball11._x)/2, (ball10._y+ball11._y)/2);
_root.lineTo(ball11._x, ball11._y);
_root.lineTo(ball12._x, ball12._y);
_root.lineTo(ball16._x, ball16._y);
_root.moveTo((ball13._x+ball14._x)/2, (ball13._y+ball14._y)/2);
_root.lineTo(ball14._x, ball14._y);
_root.lineTo(ball15._x, ball15._y);
_root.lineTo(ball17._x, ball17._y);
}
}
//control the wave function;
_root.onMouseDown = function(){
wave = true;
}
_root.onMouseUp = function(){
wave = false;
}