I got this website with a bg that as you move you mouse around it lights up part of the bg depending on where your mouse it. I was wondering if there was a way to make that light spot bob around on its own. Here is a codepen with the JS: https://codepen.io/anon/pen/MGoxNr
I hope thats enough to see what its doing
Here is a live website using this: http://www.crimson-moon.com/
If you need to see it.
function onDocumentMouseMove(event) {
mouseX = ( event.clientX - windowHalfX ) * 10;
mouseY = ( event.clientY - windowHalfY ) * -10;
}
Remove onDocumentMouseMove and set some interval, where you set X, Y on circle with some radius. Set some incrementing varible, and depending on it, calculate X,Y position on circle.
x0, y0 - center of circle
r - circle radius
a - angle
x = x0 + r*cos(a)
y = y0 + r*sin(a)
changing angle x, y will change.
Related
I'm building a p5js donut chart, but I'm struggling to show the data labels in the middle. I think I have managed to get the boundaries right for it, but how would match the angle that I'm in? Or is there a way of matching just through the colours?
https://i.stack.imgur.com/enTBo.png
I have started by trying to match the boundaries of the chart to the pointer, which I managed to do using mouseX and mouseY. Any suggestions, please?
if(mouseX >= width / 2 - width * 0.2 && mouseY >= height / 2 - width * 0.2
&& mouseX <= width / 2 + width * 0.2 && mouseY <= height / 2 + width * 0.2)
{
//console.log("YAY!!! I'm inside the pie chart!!!");
}
else
{
textSize(14);
text('Hover over to see the labels', width / 2, height / 2);
}
};
[1]: https://i.stack.imgur.com/enTBo.png
While you could theoretically use the get() function to check the color of the pixel under the mouse cursor and correlate that with one of the entries in your dataset, I think you would be much better off doing the math to determine which segment the mouse is currently over. And conveniently p5.js provides helper functions that make it very easy.
In the example you showed you are only checking if the mouse cursor is in a rectangular region. But in reality you want to check if the mouse cursor is within a circle. To do this you can use the dist(x1, y1, x2, y2) function. Once you've established that the mouse cursor is over your pie chart, you'll want to determine which segment it is over. This can be done by finding the angle between a line draw from the center of the chart to the right (or whichever direction is where you started drawing the wedges), and a line drawn from the center of the chart to the mouse cursor. This can be accomplished using the angleBetween() function of p5.Vector.
Here's a working example:
const colors = ['red', 'green', 'blue'];
const thickness = 40;
let segments = {
foo: 34,
bar: 55,
baz: 89
};
let radius = 80, centerX, centerY;
function setup() {
createCanvas(windowWidth, windowHeight);
noFill();
strokeWeight(thickness);
strokeCap(SQUARE);
ellipseMode(RADIUS);
textAlign(CENTER, CENTER);
textSize(20);
centerX = width / 2;
centerY = height / 2;
}
function draw() {
background(200);
let keys = Object.keys(segments);
let total = keys.map(k => segments[k]).reduce((v, s) => v + s, 0);
let start = 0;
// Check the mouse distance and angle
let mouseDist = dist(centerX, centerY, mouseX, mouseY);
// Find the angle between a vector pointing to the right, and the vector
// pointing from the center of the window to the current mouse position.
let mouseAngle =
createVector(1, 0).angleBetween(
createVector(mouseX - centerX, mouseY - centerY)
);
// Counter clockwise angles will be negative 0 to PI, switch them to be from
// PI to TWO_PI
if (mouseAngle < 0) {
mouseAngle += TWO_PI;
}
for (let i = 0; i < keys.length; i++) {
stroke(colors[i]);
let angle = segments[keys[i]] / total * TWO_PI;
arc(centerX, centerY, radius, radius, start, start + angle);
// Check mouse pos
if (mouseDist > radius - thickness / 2 &&
mouseDist < radius + thickness / 2) {
if (mouseAngle > start && mouseAngle < start + angle) {
// If the mouse is the correct distance from the center to be hovering over
// our "donut" and the angle to the mouse cursor is in the range for the
// current slice, display the slice information
push();
noStroke();
fill(colors[i]);
text(`${keys[i]}: ${segments[keys[i]]}`, centerX, centerY);
pop();
}
}
start += angle;
}
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.3.1/p5.js"></script>
I think I know the source of the problem was that #thenewbie experienced: it is the p5 library being used. I was using the p5.min.js and experiencing the same problem. Once I started using the full p5.js library, the issue was resolved and #Paul's script worked.
Here is a link I came across while researching this which put me onto the solution:
https://github.com/processing/p5.js/issues/3973
Thanks Paul for the clear explanations and code above.
I'm writing a simple computer animation, which is a line that rotates around a fixed point at the center of that line. The amount of rotation is based on a gradient noise algorithm (OpenSimplex noise). The line has an origin [x,y] and a nr of the animation frame. These three values plugged into OpenSimplex noise give a rotation value. This part is working perfectly.
The problem is I want to make the line appear to follow the mouse cursor, depending on how far the mouse cursor is from the line. The cursor has coordinates [mx, my] (which change for every frame of animation). I can easily rotate the line and point straight towards the cursor. But I'm having difficulties factoring in the distance. To clarify; the line is rotation on the gradient noise and the mouse cursor alters that rotation to make the line (at [x, y]) point at [mx, my].
Also, the line has an 180 degree identity, so the closest end should point towards the mouse.
Basically what I'm doing now is taking "rotation line" plus "rotation mouse". If it is between 90 and 270 deg the back of the line is closest to the cursor, otherwise the front (for simplicity this is not included in the example code below). So I then take the difference, factor in the distance and substract or add it to the rotation of the line. And this works fairly well except for some artifacts.
let r = OpenSimplexNoise(x, y, frame); // gives current original rotation
let frame = 68; // whichever frame
let x = 60; // some fixed coordinate of line
let y = 60; // some fixed coordinate of line
let mouseX = 10; // changes when the mouse moves
let mouseY = 10; // changes when the mouse moves
let mouseRadius = 200;
let width = 100;
let height = 1;
function distance (x, y, cx, cy) {
return Math.sqrt((x - cx) * (x - cx) + (y - cy) * (y - cy));
}
function angle (x1, y1, x2, y2) {
let dx = x1 - x2;
let dy = y1 - y2;
return 360 + (Math.atan2(dy, dx) * 180 / Math.PI);
}
if (distance(x, y, mouseX, mouseY) <= mouseRadius) {
let dist = distance(x, y, mouseX, mouseY);
let mouseR = angle(x, y, mouseX, mouseY) % 360;
let near = (mouseRadius - dist) / mouseRadius;
let far = 1 - near;
r = (r * far + near * mouseR) % 360;
}
// r now includes mouse
A live version:
https://jsfiddle.net/Ruudt/56pk2wd1/1/
The problem lies in the cases where the mouse passes from being left to right of perpendicular to the (original rotation) line. Here the calculation will nominate the other end as "closests", then calculate the distance and apply this to the rotation. This results in the line jumping from pointing slightly left of the cursor to right of the cursor (or vice versa).
Is there a way to fix this?
I've made an image to illustrate the situation.
The red line represents the line using only the rotation of the gradient noise
The black line is the line that also includes mouse position
the blue arc is the mouse rotation value (right end is origin)
line rotation:
I've looked for help of first player rotation on three.js for a while but most of the answers are outdated with functions which currently don't exist in the updated library.
I'm trying to make my code run so that the camera will rotate around it's own axis according to the position of the mouse on the screen.
The current rotation code is:
var scale = 10;
function viewKeys(){
document.addEventListener("mousemove", MouseMove, true);
function MouseMove(event) {
mouseX = event.clientX - divOffsetWidth;
mouseY = event.clientY - divOffsetHeight;
}
}
divOffset variables make the mouse positions read relative to the center of the HTML div.
function viewAnimate(){
camera.rotation.x = -((3/2)*(Math.PI*mouseY)) / (scale);
camera.rotation.y = -(2*(Math.PI*mouseX)) / (scale);
}
The viewKeys() function is called in the init() function and the viewAnimate() function is called within the animate() function.
Currently the code can rotate normally when the camera's position is (0,0,0) but if I move to a different position it looks as if the camera is rotating relative to the whole environment's axis.
I am aware that there are lots of control librarys for three.js but I would like to understand how to be able to rotate something on its own axis myself.
How do you suppose I change the rotation so that it works correctly?
If you want to rotate the camera yourself via the mouse, you will have to understand how Euler rotations work in three.js. See this answer.
One way to implement what you want is by using a pattern like so:
var scale = 1;
var mouseX = 0;
var mouseY = 0;
camera.rotation.order = "YXZ"; // this is not the default
document.addEventListener( "mousemove", mouseMove, false );
function mouseMove( event ) {
mouseX = - ( event.clientX / renderer.domElement.clientWidth ) * 2 + 1;
mouseY = - ( event.clientY / renderer.domElement.clientHeight ) * 2 + 1;
camera.rotation.x = mouseY / scale;
camera.rotation.y = mouseX / scale;
}
I agree with you that experimenting with this would be a good learning experience.
three.js r.89
i have a problem at setting a new mouse position. I have an Object which is moving and rotating free in a Space and following the position of the pointerlocked cursor. Targetposition is a Vector3 positioned behind the object. Now i want to make an Animation which moves the object in the opposite direction by rotating it smoothly. So I disable my mouseListener and rotate the object with the given Three.js functions. But after I enable my listener the targetPosition turns back to the mouse position and makes the move useless. So now i want to calculate the mouse Position for my new Targetposition after the animation. How can i do that ?
The function for the 3D mouse coordinates looks something like this:
enter code here
mouseY = Math.max(-85, Math.min(70, -mouseY));
phi = THREE.Math.degToRad(90 + mouseY);
theta = THREE.Math.degToRad(mouseX);
targetPosition.x = object.position.x + 100 * Math.sin(phi) * Math.cos(theta);
targetPosition.y = object.position.y + 100 * Math.cos(phi);
targetPosition.z = object.position.z + 100 * Math.sin(phi) * Math.sin(theta);
object.lookAt(targetPosition);
im working on a 2d canvas game. i have a player circle and some circles (random in size and position). i made the random circles move around an random x.y point. this means i have to radii. one is the radius from the rotationpoint to the middlepoint of the "bubble" and the other ist die radius of the bubble itself.
what i need is the collision between playercircle und the bubbles. i know how to create circle to circle collisondetction with pythagorean theorem and it works quite well. However there is a problem:
right now the collision works for the random x and y point + the radius (from rotationpoint) but not for the bubble itself.
what i tryed is to store the x and y of the rotationpoint + the radius to the middlepoint of the bubble into a variable to use them in collision. it works quite fine. if i console.log these x and y points they give me the changing x and ys from the middlepoint of the bubble.
my problem now is that if if substract these point from the playercircle x and y i didnt work with the right collision. so obviously im missing somethig and right now i am at a dead end.
i made a fiddle to show you, the function for the collision is on line 170, variablenames BubbleX and BubbleY. The .counter to animate the around the neg. or positiv:
http://jsfiddle.net/CLrPx/1/ (you need to use the console to the if there is a collision or not)
function collideBubbles(c1, c2) {
// moving/rotation xPos and yPos
var bubbleX = c2.xPos + Math.cos(c2.counter / 100) * c2.radius; // actual x and y pos. from bubble!
var bubbleY = c2.yPos + Math.cos(c2.counter / 100) * c2.radius;
//console.log('bubbleX: ' + bubbleX);
//console.log('bubbleY: ' + bubbleY);
var dx = c1.xPos - bubbleX; // change with pos from actual bubble!
var dy = c1.yPos - bubbleY; // change with pos from actual bubble!
var distance = c1.radius + c2.bubbleRadius
// Pytagorean Theorem
return (dx * dx + dy * dy <= distance * distance);
}