Skip to content

Fix for boundary spinning #8

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
tessprime wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Fix for boundary spinning #8

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Binary file added images/error_type1.png
View file
Open in desktop
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
51 changes: 43 additions & 8 deletions js/verlet-js/verlet.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -44,6 +44,34 @@ Particle.prototype.draw = function(ctx) {
ctx.fill();
}

/**
*
* Computes time of intersection of a particle with a wall
*
* @param {Vec2} line wall's root position
* @param {Vec2} p particle's position
* @param {Vec2} dir walls's direction
* @param {Vec2} v particle's velocity
*/
var intersectionTime = function(wall, p, dir, v) {
if (dir.x != 0) {
var denominator = v.y - dir.y * v.x / dir.x ;
if (denominator == 0) return undefined; // Movement is parallel to wall
var numerator = wall.y + dir.y * (p.x - wall.x) / dir.x - p.y;
return numerator / denominator;
} else {
if (v.x == 0) return undefined; // parallel again
var denominator = v.x;
var numerator = wall.x - p.x;
return numerator / denominator;
}
}

var intersectionPoint = function(wall, p, dir, v) {
var t = intersectionTime(wall, p, dir, v);
return new Vec2(p.x + v.x * t, p.y + v.y * t);
}

var VerletJS = function(width, height, canvas) {
this.width = width;
this.height = height;
Expand All @@ -54,16 +82,24 @@ var VerletJS = function(width, height, canvas) {
this.draggedEntity = null;
this.selectionRadius = 20;
this.highlightColor = "#4f545c";

var v = new Vec2();
this.bounds = function (particle) {
if (particle.pos.y > this.height-1)
particle.pos.y = this.height-1;
v.mutableSet(particle.pos);
v.mutableSub(particle.lastPos);
if (particle.pos.y > this.height-1) {
particle.pos.mutableSet(
intersectionPoint(new Vec2(0,this.height-1), particle.lastPos, new Vec2(1,0), v));
}

if (particle.pos.x < 0)
particle.pos.x = 0;
if (particle.pos.x < 0) {
particle.pos.mutableSet(
intersectionPoint(new Vec2(0,0), particle.pos, new Vec2(0,1), v));
}

if (particle.pos.x > this.width-1)
particle.pos.x = this.width-1;
if (particle.pos.x > this.width-1) {
particle.pos.mutableSet(
intersectionPoint(new Vec2(this.width-1,0), particle.pos, new Vec2(0,1), v));
}
}

var _this = this;
Expand Down Expand Up @@ -227,4 +263,3 @@ VerletJS.prototype.nearestEntity = function() {

return entity;
}