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Strange BUG ?!? (Read 427 times)
mattjakob
Strange BUG ?!?
May 3rd, 2007, 10:34am  
Hi.
I'm sorry to post all this code (pretty useless).
I just made this little program to understand drawing splines and automatically adjust their joint (made them 2-continuous).

If I try to comment the call to grid_lines() in draw() and lauch it after the first clic it frezes and crashes.

To use it simply click and drag to see a preview of the control point, then release. Click again for another spline.
Press any key on the keyboard to try to "optimize" it.
(note: try to make a couple of splines close to continuity and other with cups joints...)

Sorry for the errors, but im so tireeeed !
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&&----------------------------------&& aittaM ~ Jakob&&
 
mattjakob
Re: Strange BUG ?!?
Reply #1 - May 3rd, 2007, 10:36am  
Code:

/****************** COPYRIGHT MATTIA JAKOB DAL POZZO ******************
					  [M ~ J]
	 May 2007 - Simple program to draw continuos bezier curves
	 mattjakob [at] gmail [dot] com
 **********************************************************************/


float[][] p = new float[201][4];  //array containing the points
boolean[] opt = new boolean[201]; //array containing the status (optimized or not) of the 'knots' (a 'knot' is the first starting point of each curve
int gridSize;			   //size of each grid cell
int curves = 1;			 //amount of curves
boolean ren;			    //decides whether to stop updatin the scene (in order to display the points being optimized with different colours)


void setup()
{
  size(500, 500);
  p[1][1] = 250;
  p[1][2] = 250;
  smooth();
  ren = true;
  frameRate(10);
}



void draw()
{
  
  if(ren) //if 'true' updates the scene otherwise maintains the current buffer --> drawing from other functions is possible because there's no more a 'clear display' call
  {
    background(255);
    
    
    /************** BUG: try to comment grid_lines() *************/
    
    grid_lines();
    
    /**************************** BUG ****************************/

    fill(255);
    stroke(0);
    ellipse(width/2, height/2, gridSize * 4/10, gridSize * 4/10);  //the first point is drawn by default at the center of the screen

    //DRAWING GEOMETRY FOR EACH CURVE
    for(int c = 1; c <= curves - 1; c++)  //straight lines connecting vertices and control points
    {
	noFill();
	stroke(180);
	beginShape(LINES);
	vertex(p[c*3 - 2][1], p[c*3 - 2][2]);		//c*3 - 2	 FIRST VERTEX
	vertex(p[c*3 - 2 + 1][1], p[c*3 - 2 + 1][2]);    //c*3 - 2 + 1   FIRST CONTROL POINT
	vertex(p[c*3 - 2 + 1][1], p[c*3 - 2 + 1][2]);    //c*3 - 2 + 2   SECOND CONTROL POINT
	vertex(p[c*3 - 2 + 2][1], p[c*3 - 2 + 2][2]);    //c*3 - 2 + 3   LAST VERTEX
	vertex(p[c*3 - 2 + 2][1], p[c*3 - 2 + 2][2]);    //the parameter 'c' indicates the current curve
	vertex(p[c*3 - 2 + 3][1], p[c*3 - 2 + 3][2]);
	endShape();

	stroke(90);  //bezier drawing
	strokeWeight(2);
	beginShape();
	vertex(p[c*3 - 2][1], p[c*3 - 2][2]);
	bezierVertex(p[c*3 - 2 + 1][1], p[c*3 - 2 + 1][2], p[c*3 - 2 + 2][1], p[c*3 - 2 + 2][2], p[c*3 - 2 + 3][1], p[c*3 - 2 + 3][2]);
	endShape();
	strokeWeight(1);

	fill(255);  //a contour is drawn for each vertex/control point
	for(int i = 0; i <= 3; i++)
	{
	  stroke(i/3f * 255);
	  fill(255);
	  ellipse(p[c*3 - 2 + i][1], p[c*3 - 2 + i][2], gridSize * 3/10, gridSize * 3/10);
	}
	
	if(! opt[c] && c != 1)  //if a 'knot' is marked as 'false' in opt[] it means it has not bee optimized and thus there's no continuiti in that joint. Red marks display this situation
	{
	  noFill();
	  stroke(255, 0, 0);
	  ellipse(p[c*3 - 2][1], p[c*3 - 2][2], gridSize * 5/10, gridSize * 5/10);
	  fill(255);
	  stroke(0, 0, 0);
	  ellipse(p[c*3 - 2][1], p[c*3 - 2][2], gridSize * 3/10, gridSize * 3/10);
	}

    }
    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  }
}



//GENERATES A SERIES OF VALID POINT FOR A BEZIER SEGMENT
void genCurve(float xP, float yP, int zP, int xC, int yC)
{
  print("CURVE #" + curves + " with center of rotation in quadrant (Y X) ");

  fill(255,0,0);
  ellipse(xC, yC, 5, 5);
  fill(255);

  float Dx, Dy, Dz, zC;
  Dx = Dy = Dz = zC = 0;
  Dx = xP - xC;
  Dy = yP - yC;


  while(Dz == 0)
  {
    zC = zP + int(round(random(-gridSize * 2, gridSize * 2)));
    Dz = zP - zC;
  }
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&&----------------------------------&& aittaM ~ Jakob&&
 
mattjakob
Re: Strange BUG ?!?
Reply #2 - May 3rd, 2007, 10:36am  
Code:


  float Ap1 = atan(Dy/Dx);	//Ap1 is the angle made by P1
  float A1 = 0;		     //A1 is a 'world' angle


  if(Dy > 0 && Dx > 0)	    //cases to calculate the correct A1 angle... see the 'quadrant' during runtime in the terminal
  {
    A1 = Ap1;
    println("+ +");
  }
  if(Dy > 0 && Dx < 0)
  {
    A1 = radians(180) + Ap1;
    println("+ -");
  }
  if(Dy < 0 && Dx < 0)
  {
    A1 = radians(180) + Ap1;
    println("- -");
  }
  if(Dy < 0 && Dx > 0)
  {
    A1 = Ap1;
    println("- +");
  }


  float rad = sqrt(sq(Dx) + sq(Dy));
  println("rad: " + rad);
  println("ap : " + degrees(Ap1));
  println("a  : " + degrees(A1));


  for(int i = 0; i <= 3; i++)
  {
    p[(curves*3 - 2) + i][1] = xC + (rad * cos(A1 + (i * Ap1)));	//writes found point coordinates in p[][]
    p[(curves*3 - 2) + i][2] = yC + (rad * sin(A1 + (i * Ap1)));
    p[(curves*3 - 2) + i][3] = 0;

    stroke(200);
    line(xC, yC, p[(curves*3 - 2) + i][1], p[(curves*3 - 2) + i][2]);  //useful when draggin the mouse: due to refresh it allows to have a sort of interactive preview
  }



}


void mouseDragged()
{
  genCurve(p[curves*3 - 2][1], p[curves*3 - 2][2] , 0, mouseX, mouseY);  //when dragging (hold + mmove) the mouse generates parameters for the curve segment
}

void grid_lines()
{
  stroke(230);
  gridSize = width / 20;
  for(int i = 0; i<= width; i = i + gridSize)
  {
    line(i,0,i,height);
  }
  for(int i = 0; i<= height; i = i + gridSize)
  {
    line(0,i,width,i);
  }
}


//FIRST OPTIMIZATION FOR NON-CUSP JOINTS
void optim()
{
  println();
  println();
  float p1X, p1Y, p2X, p2Y, cX, cY, d1, d2, dp, ncX, ncY;
  ncX = ncY = 0;
  for(int i = 2; i <= curves - 1; i++)
  {

    p1X = p[i*3 - 2 +1][1];
    p1Y = p[i*3 - 2 +1][2];
    p2X = p[i*3 - 2 -1][1];
    p2Y = p[i*3 - 2 -1][2];
    cX = p[i*3 - 2][1];
    cY = p[i*3 - 2][2];

    d1 = dist(p1X,p1Y,cX,cY);
    d2 = dist(p2X,p2Y,cX,cY);
    dp = dist(p1X,p1Y,p2X,p2Y);

    if((d1+d2)/dp * 100 < 140)
    {
	fill(255,0,0);
	ellipse(p1X, p1Y, 5,5);
	fill(0,255,0);
	ellipse(p2X, p2Y, 5,5);
	fill(255,0,255);
	ellipse(((p1X + p2X) / 2), ((p1Y + p2Y) / 2), 7,7);

	ncX = (p1X + p2X) / 2;    //the correct point of joint between the two curves is collinear with the control points (cp)
	ncY = (p1Y + p2Y) / 2;    //and is placed halfway between cp1 and cp2
	p[i*3 - 2][1] = ncX;	//updates the array containing the points
	p[i*3 - 2][2] = ncY;
	
	opt[i] = true;		//since this joint now is continuous it's status is updated
	
	println("CURVE #" + i + "optimized with °1°");
    }
  }
  ren = true;
}


void keyPressed()
{
  ren = false;		    //to activate the First optimization the user has to press a key. 'ren' becomes false so that 
  optim();			  //drawing() does not overwrite the screen with a clean display --> in this way it is possible for optim()
}				     //to add some drawing

void mouseReleased()	    //if the mouse is released it means the user has decided a final position for its curve (previsualized while dragging)
{
  curves++;
}
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&&----------------------------------&& aittaM ~ Jakob&&
 
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