# bmoren / p5.collide2D

A collision detection library for 2D geometry in p5.js
JavaScript

## Latest commit

`better attribution`
Latest commit 6a63a06 May 9, 2020

## Files

Type Name Latest commit message Commit time
Failed to load latest commit information. README.md May 9, 2020 p5.collide2d.js Nov 28, 2018 p5.collide2d.min.js Nov 28, 2018 p5collide2d.png Feb 5, 2016

# p5.collide2D #### A 2d collision detection library for p5.js

p5.collide2D provides tools for calculating collision detection for 2D geometry with p5.js.

p5.collide2D contains some versions of, and references to, the functions in Jeffrey Thompson's Collision Detection Book. His code is CC BY-NC-SA 4.0, so, this is too! I highly, highly, reccomend reading his book to better understand all of the details involved in collision detection. Implementing this library into your code will be much easier and more efficent after reading it!

It's an incredible resource for this kind of work! – http://www.jeffreythompson.org/collision-detection/ p5.collide2D assumes the default p5.js rectMode(CORNER) and ellipseMode(CENTER)

All p5.collide2D functions return `true` if the specified geometry is colliding and `false` if they are not.

## p5.collide2D examples & documentation

#### collideDebug()

###### collideDebug(debugMode, size, color)

Enables collision debug mode. Draws an ellipse at the collision point between objects on screen where applicable and calculable.

```function setup() {
collideDebug(true);
}```

#### collidePointPoint()

###### collidePointPoint(x, y, x2, y2, [buffer])

Point to point collision with an optional buffer zone.

```//basic 2D example
var hit = false;
function draw() {
background(255);
ellipse(100,100,1,1); //change to 10,10px size for buffer example
ellipse(mouseX,mouseY,1,1); //change to 10,10px size for buffer example

//no buffer zone, most standard example
hit = collidePointPoint(100,100,mouseX,mouseY)

//buffer of 10 px
//hit = collidePointPoint(100,100,mouseX,mouseY,10)

print("colliding? " + hit);
}```

#### collidePointCircle()

###### collidePointCircle(pointX, pointY, circleX, circleY, diameter)

point to circle collision in 2D. Assumes ellipseMode(CENTER);

```var hit = false;
function draw() {
background(255);
ellipse(200,200,100,100);
point(mouseX,mouseY);

hit = collidePointCircle(mouseX,mouseY,200,200,100)

print("colliding? " + hit);

}```

#### collidePointEllipse()

###### collidePointEllipse(pointX, pointY, ellipseX, ellipseY, ellipseWidth, ellipseHeight )

point ellipse collision. It takes the point, the centre of the ellipse, the major and the minor axes (diameters). ```let hit = false;
function draw(){
background(255);
ellipse(200,200,50,150);
point(mouseX,mouseY);

hit = collidePointEllipse(mouseX,mouseY,200,200,50,150)

print("colliding? " + hit);
}```

#### collidePointRect()

###### collidePointRect(pointX, pointY, x, y, width, height)

point to rect collision in 2D. Assumes rectMode(CORNER);

```var hit = false;
function draw() {
background(255);
rect(200,200,100,150);

hit = collidePointRect(mouseX,mouseY,200,200,100,150);

print("colliding? " + hit);

}```

#### collidePointLine()

###### collidePointLine(pointX, pointY, x, y, x2, y2, [buffer])

point to line collision in 2D, includes and optional buffer which expands the hit zone on the line (default buffer is 0.1).

```var hit = false;
function draw(){
background(255);
line(200,300,100,150);
point(mouseX,mouseY);

//collide point line using the optional buffer with a 0.5 value
hit = collidePointLine(mouseX,mouseY,200,300,100,150, 0.5);

print("colliding? " + hit);
}```

#### collidePointArc()

###### collidePointArc(pointX, pointY, arcCenterX, arcCenterY, arcRadius, arcRotationAngle, arcAngle, [buffer])

Point to Arc collision in 2D. ```var ARC_RADIUS = 100;
var ARC_ANGLE = Math.PI/3;
var ROTATION_ANGLE = -Math.PI / 4;
var hit = false;
function draw() {
background(220);
push();
// translate to center of canvas
translate(width / 2, height / 2);
// rotate by some angle
rotate(ROTATION_ANGLE);
fill(color(180, 220, 210));
stroke(10);
pop();
point(mouseX, mouseY);
hit = collidePointArc(mouseX, mouseY, width / 2, height / 2, ARC_RADIUS, ROTATION_ANGLE, ARC_ANGLE);

print("colliding? " + hit);
}```

#### collideCircleCircle()

###### collideCircleCircle(circleX, circleY,circleDiameter, circleX2, circleY2, circleDiameter2)

circle to circle collision in 2D. Assumes ellipseMode(CENTER);

```var hit = false;
function draw() {
background(255);
ellipse(200,200,100,100);
ellipse(mouseX,mouseY,150,150);

hit = collideCircleCircle(mouseX,mouseY,150,200,200,100)

print("colliding? " + hit);

}```

#### collideRectRect()

###### collideRectRect(x, y, width, height, x2, y2, width2, height2 )

rect rect collision in 2D. Assumes rectMode(CORNER);

```var hit = false;
function draw() {
background(255);
rect(200,200,100,150);
rect(mouseX,mouseY,50,75);

hit = collideRectRect(200,200,100,150,mouseX,mouseY,50,75);

print("colliding? " + hit);

}```

#### collideRectCircle()

###### collideRectCircle(x1, y1, width1, height1, cx, cy, diameter)

rect circle collision in 2D. Assumes rectMode(CORNER) && ellipseMode(CENTER);

```var hit = false;
function draw() {
background(255);
rect(200,200,100,150);
ellipse(mouseX,mouseY,100,100);

hit = collideRectCircle(200,200,100,150,mouseX,mouseY,100);

print("colliding? " + hit);
}```

#### collideLineLine()

###### collideLineLine(x1, y1, x2, y2, x3, y3, x4, y4, [calcIntersection])

line to line collision in 2D. Takes an optional boolean parameter which calculates the intersection point. If enabled it will return an object containing the x,y position of the collision intersection. If no intersection occurs, it will return an object containing x,y values as false. Has a debug mode.

```//basic example
var hit = false;
function draw(){
background(255);
line(200,300,100,150);
line(mouseX,mouseY,350,50);
hit = collideLineLine(200,300,100,150,mouseX,mouseY,350,50);

print("colliding? " + hit);
}```
```//Return an object containing the x,y position of the intersection using the optional calcIntersection boolean
var hit = false;
function draw(){
background(255);
line(200,300,100,150);
line(mouseX,mouseY,350,50);

hit = collideLineLine(200,300,100,150,mouseX,mouseY,350,50,true);

print("X-intersection:" + hit.x);
print("Y-intersection:" + hit.y);
}```

#### collideLineCircle()

###### collideLineCircle(x1, y1, x2, y2, cx, cy, diameter)

point to circle collision in 2D. Has a debug mode.

```var hit = false;
function draw(){
background(255);
line(200,300,100,150);
ellipse(mouseX,mouseY,50,50);
hit = collideLineCircle(200,300,100,150,mouseX,mouseY,50);

print("colliding? " + hit);

}```

#### collideLineRect()

###### collideLineRect(x1, y1, x2, y2, rx, ry, rw, rh, [calcIntersection])

Line to Rectangle collision in 2d. Takes and optional boolean parameter which calculates the intersection points. If enables it will return an object containing objects of the top,left,bottom,right X,Y intersection positions. If no intersection occurs, it will return an object containing x,y values as false. Has a debug mode.

```//basic example
var hit = false;
function draw() {
background(255);
rect(200,300,100,150);
line(mouseX,mouseY,350,50);

hit = collideLineRect(mouseX,mouseY,350,50,200,300,100,150);

print("colliding? " + hit);
}```
```//Return an object containing the x,y position of the bottom intersection of the rect using the optional calcIntersection boolean.
var hit = false;
function draw() {
background(255);
rect(200,300,100,150);
line(mouseX,mouseY,350,50);

hit = collideLineRect(mouseX,mouseY,350,50,200,300,100,150,true);

//retruned object contains top,right,bottom,left objects which each contain x,y values.
print("bottomX: " + hit.bottom.x);
print("bottomY: " + hit.bottom.y);
print("topX: " + hit.top.x);
print("topY: " + hit.top.y);
print("leftX: " + hit.left.x);
print("leftY: " + hit.left.y);
print("rightX: " + hit.right.x);
print("rightY: " + hit.right.y);
}```

#### collidePointPoly()

###### collidePointPoly(pointX,pointY,vectorArray)

Point to Poly Collision in 2D. Takes a point x,y and an array of p5.Vector points which contain the x,y positions of the polygon. This function works with x-sided polygons, and "collapsed" polygons where a single polygon shape overlaps itself.

```var hit = false;
var poly = []; //store the vertices for our polygon
function setup() {
createCanvas(500,500);
poly = createVector(123,231);     // set X/Y positions
poly = createVector(10,111);
poly = createVector(20,23);
poly = createVector(390,33);
}

function draw() {
background(255);

//draw the polygon from the created Vectors above.
beginShape();
for(i=0; i < poly.length; i++){
vertex(poly[i].x,poly[i].y);
}
endShape(CLOSE);

ellipse(mouseX,mouseY,10,10); //put a small ellipse on our point.

hit = collidePointPoly(mouseX,mouseY,poly); //3rd parameter is an array of vertices.

print("colliding? " + hit);
}```

#### collideCirclePoly()

###### collideCirclePoly(x,y,diameter,vectorArray, [interiorCollision])

Circle to Poly Collision in 2D. Takes a circle x,y,diameter and an array of p5.Vector points which contain the x,y positions of the polygon. This function works with x-sided polygons, and "collapsed" polygons where a single polygon shape overlaps itself. Takes an optional 5th 'true' boolean parameter which enables the collision detection if the circle is wholly inside the polygon. The interior detection is off by default to save evaluating all of the edges of the polygon a second time. Has a debug mode.

```var hit = false;
var poly = [];
function setup() {
createCanvas(windowWidth,windowHeight);
collideDebug(true)
poly = createVector(123,231);     // set X/Y position
poly = createVector(10,111);
poly = createVector(20,23);
poly = createVector(390,33);
}

function draw() {
background(255);

//draw the polygon from the created Vectors above.
beginShape();
for(i=0; i < poly.length; i++){
vertex(poly[i].x,poly[i].y);
}
endShape(CLOSE);

ellipse(mouseX,mouseY,45,45);

hit = collideCirclePoly(mouseX,mouseY,45,poly);
//enable the hit detection if the circle is wholly inside the polygon
// hit = collideCirclePoly(mouseX,mouseY,45,poly,true);

print("colliding? " + hit);
}```

#### collideRectPoly()

###### collideRectPoly(x,y,width,height,vectorArray, [interiorCollision])

Rect to Poly Collision in 2D. Takes a rect x,y,width,height and an array of p5.Vector points which contain the x,y positions of the polygon. This function works with x-sided polygons, and "collapsed" polygons where a single polygon shape overlaps itself. Takes an optional 6th 'true' boolean parameter which enables the collision detection if the rect is wholly inside the polygon. The interior detection is off by default to save evaluating all of the edges of the polygon a second time. Has a debug mode.

```var hit = false;
var poly = [];
function setup() {
createCanvas(windowWidth,windowHeight);
collideDebug(true)
poly = createVector(323,431);     // set X/Y position
poly = createVector(210,311);
poly = createVector(220,223);
poly = createVector(590,233);
}

function draw() {
background(255);
push()
beginShape();
//draw the polygon from the created Vectors above.
for(i=0; i < poly.length; i++){
vertex(poly[i].x,poly[i].y);
}
endShape(CLOSE);

rect(mouseX,mouseY,45,100);

hit = collideRectPoly(mouseX,mouseY,45,100,poly);
//enable the hit detection if the circle is wholly inside the polygon
// hit = collideRectPoly(mouseX,mouseY,45,100,poly,true);

print("colliding? " + hit);
}```

#### collideLinePoly()

###### collideLinePoly(x1, y1, x2, y2, vertices)

Line to Poly Collision in 2D. Takes a line x,y,x2,y2 and an array of p5.Vector points which contain the x,y positions of the polygon. This function works with x-sided polygons, and "collapsed" polygons where a single polygon shape overlaps itself. Has a debug mode.

```var hit = false;
var poly = new Array(16);
function setup() {
createCanvas(windowWidth,windowHeight);
collideDebug(true)

//generate a 16 sided polygon
var angle = TWO_PI / poly.length;
for (var i=0; i<poly.length; i++) {
var a = angle * i;
var x = 300 + cos(a) * 100;
var y = 200 + sin(a) * 100;
poly[i] = createVector(x,y);
}
}
function draw() {
background(255);
beginShape();
//draw the polygon from the created Vectors above.
for(i=0; i < poly.length; i++){
vertex(poly[i].x,poly[i].y);
}
endShape(CLOSE);

line(10,10,mouseX,mouseY);

hit = collideLinePoly(mouseX,mouseY,45,100,poly);

print("colliding? " + hit);
}```

#### collidePolyPoly()

###### collidePolyPoly(polygon1, polygon2, [interiorCollision])

Polygon to Polygon Collision in 2D. Takes a 2 arrays of p5.Vector points which contain the x,y positions of the polygons. This function works with x-sided polygons, and "collapsed" polygons where a single polygon shape overlaps itself. Takes an optional 3rd 'true' boolean parameter which enables the collision detection if the polygon is wholly inside the other polygon. The interior detection is off by default to save evaluating all of the edges of the polygon a second time. Has a debug mode.

```//example adapted from Jeffrey Thompson
var hit = false;
var poly = new Array(8);
var randomPoly = []
function setup() {
createCanvas(windowWidth,windowHeight);
collideDebug(true) //enable debug mode

//generate a uniform sided polygon
var angle = TWO_PI / poly.length;
for (var i=0; i<poly.length; i++) {
var a = angle * i;
var x = 300 + cos(a) * 100;
var y = 200 + sin(a) * 100;
poly[i] = createVector(x,y);
}

// create a random polygon
var a = 0;
var i = 0;
while (a < 360) {
var x = cos(radians(a)) * random(30,50);
var y = sin(radians(a)) * random(30,50);
randomPoly[i] = createVector(x,y);
a += random(15, 40);
i += 1;
}
}
function draw() {
background(255);
// update random polygon to mouse position
var mouse = createVector(mouseX, mouseY);
var diff = mouse.sub(randomPoly);

for (i=0; i < randomPoly.length; i++) {
}

beginShape();
//draw the polygon from the created Vectors above.
for(i=0; i < poly.length; i++){
vertex(poly[i].x,poly[i].y);
}
endShape(CLOSE);
beginShape();
for(i=0; i < randomPoly.length; i++){
vertex(randomPoly[i].x,randomPoly[i].y);
}
endShape(CLOSE);

hit = collidePolyPoly(poly,randomPoly,true);
print("colliding? " + hit);

}```

#### collidePointTriangle()

###### collidePointTriangle(px, py, x1, y1, x2, y2, x3, y3)

Point to Triangle collision in 2D. You could use collidePointPoly() to do this as well, but this is more efficient.

```var hit = false;
function draw() {
background(255);
triangle(300,200,350,300,250,300)
ellipse(mouseX,mouseY,10,10);

hit = collidePointTriangle(mouseX,mouseY, 300,200,350,300,250,300)
print("colliding? " + hit)
}```

#### collide 2Dprimitive Triangle

To collide any primitive shape into a triangle, use the corresponding primitive shape with a 3 sided polygon as your triangle. note: you will have to define your triangle using p5.Vector, see example below.

```var hit = false;
var triPoly = []
function setup() {
createCanvas(windowWidth,windowHeight);
collideDebug(true)

triPoly = createVector(300,200);
triPoly = createVector(350,300);
triPoly = createVector(250,300);
}

function draw() {
background(255);

//we could for loop over the tyiPoly array to draw it with a begin/endShape, but this is easier :)
triangle(300,200,350,300,250,300)
ellipse(mouseX,mouseY,45,45);

hit = collideCirclePoly(mouseX,mouseY,45, triPoly)

print("colliding? " + hit)
}```
You can’t perform that action at this time.