Skip to content
Related Articles

Related Articles

p5.js | constrain() Function

View Discussion
Improve Article
Save Article
  • Last Updated : 25 Mar, 2020
View Discussion
Improve Article
Save Article

The constrain() function in p5.js is used to constrain a number between a given minimum and maximum limit.

Syntax:

constrain( n, low, high )

Parameters: This function accept three parameters as mentioned above and described below:

  • n: It is a number which denotes the value that has to be constrained.
  • low: It is a number which denotes the minimum limit to which the number is constrained.
  • high: It is a number which denotes the maximum limit to which the number is constrained.

Return Value: It returns a number with the constrained value.

The example below illustrates the constrain() function in p5.js:

Example 1:




function setup() {
  createCanvas(650, 200);
  textSize(20);
   
  inputElemA = createInput(10);
  inputElemA.position(30, 40);
   
  inputElemB = createInput(100);
  inputElemB.position(30, 60);
   
  sliderElem = createSlider(-100, 100, 50, 1);
  sliderElem.position(30, 120);
}
   
function draw() {
  clear();
  text("Enter two values between which the "
    + "number would be constrained", 20, 20);
  text("Move the slider to observe the effects"
    + " of the constrain() function", 20, 100);
   
  // Convert the string value to a number value
  inputValA = Number(inputElemA.value());
  inputValB = Number(inputElemB.value());
  sliderVal = sliderElem.value();
   
  text("The slider value is: " + sliderVal, 20, 160);
   
  // Display the constrained value
  text("The constrained value is: "
        + constrain(sliderVal, inputValA,
        inputValB), 20, 180);
}


Output:
constrain-slider

Example 2:




function setup() {
  createCanvas(600, 350);
  textSize(20);
   
}
   
function draw() {
  clear();
  text("Move the pointer to see the effect "
        + "of constrain() in the square", 20, 30);
  text("White circle represents unconstrained"
        + " mouse", 20, 50);
  text("Red circle represents mouse constrained"
        + " to box dimensions", 20, 70);
   
  noFill();
  square(100, 100, 200);
   
  circle(mouseX, mouseY, 40);
   
  // Constrain the mouse x and y position
  constrainedMouseX = constrain(mouseX, 100, 300);
  constrainedMouseY = constrain(mouseY, 100, 300);
   
  fill('red');
  circle(constrainedMouseX, constrainedMouseY, 20);
}


Output:
constrain-box-dimensions

Online editor: https://editor.p5js.org/

Environment Setup: https://www.geeksforgeeks.org/p5-js-soundfile-object-installation-and-methods/

Reference: https://p5js.org/reference/#/p5/constrain


My Personal Notes arrow_drop_up
Recommended Articles
Page :

Start Your Coding Journey Now!