Hi!

I am a Processing newbie and I would like to ask you for your advice.
I have written a program that emulates one of the early computer art drawings, basically drawing bundles lines with different lengths and orientations using random numbers. Now I would like to make this static drawing interactive, in a way that every time that the user passes over a certain line with the mouse it will play a sound.

The problem is that I can not figure out how to recognize a single line with the mouse, since what I use to draw lines is the only the line() function.

Thanks a lot!

First of all, thanks a lot for the detailed explanation. You are right, it sounds like an easy task but actually is rather complex... I am trying to create, along with each line, a rectangle with the same starting point, same length, angle and minimum width, so I expect I can check the mouse rollover. Anyway, I would really like to see more of your idea, I'm sure it'll be more then helpful.

This is the basic code that creates the lines, no mouse interaction considered:

void setup()
{  
 size(600, 700);
 background(250);
 
 // Variables initialization
 float i = 0, x0 = 0, y0 = 0, alfa0 = 0, L0 = 0, t = 0,
 n = 0, j = 0, x = 0, y = 0,
 beta = 0, alfa = 0, a = 0, b = 0, Dt = 0, Da = 0, Db = 0, Dbeta = 0,
 Px = 0, Py = 0, Qx = 0, Qy = 0;
 int c = 0;
 // Collection of Brushes
 int[][] brushes = {{0, 0, 0, 1}, // Black Thin Stroke
                   {0, 0, 0, 2}, // Black Thick Stroke
                   {207, 118, 38, 2}}; // Orange Thick Stroke
 
 for (i = 1; i <= random(5, 20); i++){ // Control of the number of carriers i
   c = int(random(0, 3)); // Random index for the brushes matrix
   // Initial parameters of one carrier (a straight line)
   x0 = random(0.4 * width, 0.8 * width); // Origin point A0(x0, y0)
   y0 = random(0.5 * height, 0.7 * height);
   alfa0 = random(-PI, PI); // Angle(in radians)
   L0 = random(0.4 * width, 0.6 * width); // Length
   // Lenghts "a" and "b" of the first line (divided in two segments) of the bundle over the carrier.
   // They have the same angle "beta".
   a = random(0.2 * L0, 0.7 * L0);
   b = random(0.2 * L0, 0.7 * L0);
   beta = random(-PI, PI);
   n = random(5, 30); // Number of lines in the bundle
   t = 0; // First point in the carrier
   
   for (j = 0; j <= n ; j += 1){ // Bundle of lines
     t = t + Dt; // Next point in the carrier
     x = x0 + t * L0 * cos(alfa0); // Point (x,y)
     y = y0 + t * L0 * sin(alfa0);
     // Calculation of the parameters of the lines "a" and "b"
     a = a + Da;
     b = b + Db;
     beta = beta + Dbeta; // Next angle of "a" and "b" over the carrier
     alfa = PI - alfa0 - beta; // Next angle of "a" and "b" over the coordinates origin
     // P: ending point of "a"
     Px = x0 + t * L0 * cos(alfa0) + b * (- cos(alfa));
     Py = y0 + t * L0 * sin(alfa0) + b * (sin(alfa));
     // Q: ending point of "b"
     Qx = x0 + t * L0 * cos(alfa0) + a * (cos(alfa));
     Qy = y0 + t * L0 * sin(alfa0) + a * (- sin(alfa));
     
     smooth();
     strokeWeight(brushes[c][3]);
     stroke(brushes[c][0], brushes[c][1], brushes[c][2]);
     line(x, y, Px, Py); // Paint line a
     line(x, y, Qx, Qy); // Paint line b
     // Random diferentials -> Next point
     Dt = random(0, 0.04);
     Dbeta = random(-0.05 * PI, 0.05 * PI);
     Da = random(- 0.2 * a, 0.2 * a);
     Db = random (- 0.2 * b, 0.2 * b);
   }
 }
}

maybe this helps. pointInsideLine

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