Calculates the angle (in radians) from a specified point to the coordinate origin as measured from the positive x-axis.

However, I would like to calculate the angle between a set of points other than the origin. Is there any way to do this, and if so, can I get a pointer towards the right track? Thanks in advance! :)

the added code for arcs is below

`// Calculate the angle the current point makes with the circle center int angle = (int) degrees(atan2(y, x)); //int(degrees(atan2(mouseY-(height/2),mouseX-(width/2))));

// draw the circle points as long as they lie in the range specified if (x < y) {

// draw point in range 0 to 45 degrees
if ( -90 + angle >= startAngle &&  -90 + angle <= endAngle) {
  point(centerX + y, centerY - x);
}

//// draw point in range 45 to 90 degrees
if (-angle >= startAngle && -angle <= endAngle) {
  point(centerX + x, centerY - y);
}

//// draw point in range 90 to 135 degrees
if (-180 + angle >= startAngle && -180 + angle <= endAngle) {
  point(centerX - x, centerY - y);
}

//// draw point in range 135 to 180 degrees
if ((-90 + -angle >= (startAngle) && -90 + -angle <= (endAngle))) {
  point(centerX - y, centerY - x);
}

// draw point in range 180 to 225 degrees
if (90 + (angle) >= (startAngle) && 90 + (angle) <= (endAngle)) {
  point(centerX - y, centerY + x);

  System.out.println("angle " + (90 + (angle)));
}

// draw point in range 225 to 270 degrees
if (180 + -angle >= startAngle && 180 + -angle <= endAngle) {
  point(centerX - x, centerY + y);
}

// draw point in range 270 to 315 degrees
if (angle >= startAngle && angle <= endAngle) {
  point(centerX + x, centerY + y);
}

// draw point in range 315 to 360 degrees
if (-angle + 90 >= startAngle && -angle + 90 <= endAngle) {
  point(centerX + y, centerY + x);
}

} } `

float deg = −3.5;

i get this when i try to run this deg as a float ,whats the issue? i have calculated float deg = -144.3; but i cant do −3.5?

processing.app.SketchException: unexpected char: '\'
    at processing.mode.java.JavaBuild.preprocess(JavaBuild.java:386)
    at processing.mode.java.JavaBuild.preprocess(JavaBuild.java:192)
    at processing.mode.java.JavaBuild.build(JavaBuild.java:151)
    at processing.mode.java.JavaBuild.build(JavaBuild.java:130)
    at processing.mode.java.JavaMode.handleRun(JavaMode.java:120)
    at processing.mode.java.JavaEditor$23.run(JavaEditor.java:697)
    at java.lang.Thread.run(Unknown Source)

in a forum i visited looking to learn more about the subject i seen this

π=3.141592653...π=3.141592653... is a constant (it's just a number).

Type this into a calculator and you're done.

To convert radians to degrees: multiply by 180π180π.

To convert degrees to radians: multiply by π180π180.

So −3.5×180π=−200.535228296...−3.5×180π=−200.535228296..., which is
−200.54 ∘
−200.54 ∘
to two decimal places.

which translate into -3.5 \times \frac{180}{\pi}= -200.535228296...

I can do this for quarter squares by saying if (mouseX < 300 & mouseY < 300) { rect ... }

but am unable to work out how to define the triangle from two corners to the centre - shown in my sketch as coloured red.

void draw() {
  background(145,180,70);

  if (mouseX < 300 & mouseY < 300) {
    triangle(0, 0, 0,600, 300,300); // Left
    fill(190,75,90);
    }

    if (mouseX > 300 & mouseY > 300){
    triangle(300, 300, 600,600, 600,0); // Left
    fill(190,75,90); // Right
  }
}

I am trying to work out how to draw a line with a length of 100 at 90 degrees to a line that originates at the centre of a circle.

I know: the angle of the black line from the centre, The x and y coordinates of the start point of the red line (small black circle) The intended length of the red line

I need: The X and Y coordinates of the end point of the red line so that it remains at 90 degrees to the black line and the length remains at 100.

The code for the sketch it:

PVector a = new PVector(0, 0);
PVector b = new PVector(0, 150);
PVector c = new PVector(150, 0);
float angle1, arcangle1;
float tangentAngle;
int smallRadius = 10;
float bigDiam = 400;

void setup() {
  size(500, 500);
  smooth();
  strokeWeight(2);
}

void draw() {
  background(255);
  translate(width/2, height/2);
  noFill();
  ellipse(0, 0, bigDiam, bigDiam);
  fill(255);
  if (dist(b.x, b.y, 0, 0)>((bigDiam/2) - smallRadius/2)) {
    fill(255, 0, 0);
  }

  line(a.x, a.y, b.x, b.y);
  ellipse(a.x, a.y, 20, 20);
  ellipse(b.x, b.y, smallRadius, smallRadius);
  strokeWeight(2);

  b.set(mouseX-width/2, mouseY-height/2, 0);


  angle1 = PVector.angleBetween(b, c);

if (c.y <= b.y) { 
    arcangle1 = angle1;
  } else { 
    arcangle1 = angle1 + 2*(PI-angle1);
  }

  float tDistance = dist(b.x, b.y, 0, 0);

  fill(0);
  ellipse(0, 0, 50, 50);
  fill(255);
  text(degrees(arcangle1), -20, 0);
  fill(0, 0, 0, 50);
  arc(0, 0, bigDiam-150, bigDiam-150, 0, arcangle1, PIE);
  println(degrees(arcangle1));
  stroke(255, 0, 100);
  line(0+(200/tDistance)*(b.x-0), 0+(200/tDistance)*(b.y-0), 0, -(bigDiam/2));
  stroke(0);
  ellipse(0+(200/tDistance)*(b.x-0), 0+(200/tDistance)*(b.y-0), 10, 10);
}

Thanks!

So, i tried converting radians to angles, constrain degrees and convert to radians again. But the result is the same.

a = radians(constrain(degrees(a), 90, 270));

Any clue?

I'd like to be able to display the relative degree position of the joystick cursor, such at at the top of the screen it would show 0 degrees, when in the 3 o'clock position it would be 90 degree, and 6 o'clock would show 180 degrees and a 9 o'clock it would show 270... and so on. I guess the max would be 359 deg after which the bearing would become 0 again. This is relative to the center of the screen, so the Y portion (width) should have no effect on the reading.

I suspect this is fairly trivial to do, but as a Processing noob, my best efforts have failed!