hey, I think it's quite simple but I don't get it.

I want a shape to be moved like that:

float xpos;
float speed = 2;
float diameter = 30;



void setup () {
 size(320, 240);
 smooth ();
 xpos = width / 2;
}

void draw () {
 background (45);


 if (xpos> width - diameter / 2) {
   speed = speed * -1;
 }
 
 if (xpos < diameter / 2) {
   speed = speed * -1;
 }

 xpos = xpos + speed;

 ellipse (xpos, height / 2, diameter, diameter);
}


what I have done looks like that:


color haut = color(250, 183, 130);
color rot = color (242, 63, 92);
color susi = color (218, 184, 92);

float xpos = 0;
float ypos = 0;
float speed = 2;


void setup () {
 size (1000, 750);
 background (0);
 smooth ();
 frameRate (7);

 
 xpos = width / 2;
}



void draw () {  
pushMatrix();
 translate (0,0);
 if (xpos> width ) {

   speed = speed * -1;
 }

 if (xpos < width) {
   speed = speed * -1;
 }

 xpos = xpos + speed;

 //MONSTER1
 koerper_1 ();
 zaehne_1 ();
 linkes_Auge_1 ();
 rechtes_Auge_1 ();
 mund_1 ();
 zaehne_1 ();
 popMatrix ();
}

void koerper_1 () {
 beginShape();
 fill (susi);
 vertex(634, 278);
 bezierVertex (650, 299, 660, 350, 636, 496);
 bezierVertex (626, 480, 704, 479, 749, 452);
 bezierVertex (624, 404, 755, 419, 763, 408);
 bezierVertex (759, 404, 744, 418, 750, 433);
 bezierVertex (731, 454, 713, 465, 675, 473);
 bezierVertex (624, 468, 624, 431, 636, 496);
 bezierVertex (675, 565, 702, 613, 729, 625);
 bezierVertex (729, 628, 712, 630, 649, 598);
 bezierVertex (647, 618, 629, 621, 610, 626);
 bezierVertex (653, 683, 638, 680, 557, 614);
 bezierVertex (505, 549, 527, 512, 563, 451);
 bezierVertex (551, 481, 550, 482, 498, 458);
 bezierVertex (477, 443, 458, 414, 445, 397);
 bezierVertex (431, 386, 438, 422, 463, 462);
 bezierVertex (541, 493, 561, 372, 563, 315);
 bezierVertex ( 566, 275, 634, 278, 634, 278);
 endShape();
}


void linkes_Auge_1 () {
 beginShape ();
 fill (255);
 vertex (580, 330);
 bezierVertex (582, 333,  582, 339, 580, 343);
 bezierVertex (  574, 346, 570, 344, 569, 340 );
 bezierVertex (  569, 336, 575, 329 , 580, 330);
 endShape ();
}


void rechtes_Auge_1 (){
 beginShape ();
 vertex (636, 318);
 bezierVertex (642, 327,639, 336, 633, 339) ;
 bezierVertex (633, 339, 625, 336,  624, 329);
 bezierVertex (628, 320, 632, 318, 636, 318);
 endShape ();
}

void mund_1 (){
 fill (rot);
 beginShape ();
 vertex (581, 364);
 bezierVertex (607, 362,639, 359, 646, 367);
 bezierVertex ( 639, 370 , 621, 369,591, 375 );
 bezierVertex (576, 374, 571, 369,574, 364 );
 endShape (CLOSE);
}


void zaehne_1 () {
 beginShape ();
 vertex (571, 371);
 bezierVertex (577, 369, 583, 372, 587, 368);
 bezierVertex (690, 370, 595, 366, 599, 370);
 bezierVertex (602, 367, 605, 368, 608, 365);
 bezierVertex (612, 367, 617, 364, 619, 367);
 bezierVertex (623, 363, 625, 367, 630, 364);
 bezierVertex (636, 365, 640, 363, 647, 365);
 endShape ();
}




but nothing happens. can anybody out there help me?