// Created by Wisecase2 var clicked = true; var paused = false; var mostr = ""; function Click(){ clicked = true; } function Pause(){ paused = !paused; } window.onload= function() { var box1 = document.getElementById('box1'), box2 = document.getElementById('box2'); var wall = document.getElementById('wall'), wall2 = document.getElementById('wall2'); var ground = document.getElementById('ground'), piece = document.getElementById('piece'); var box1ins = document.getElementById('box1ins'), box2ins = document.getElementById('box2ins'); var pos1 = 160.0, pos2 = 333.999, v1 = 0.0, v2 = -75.0, m1 = 1.0, m2 = 3.0, dt = 1.0/60.0; var status = true, collision = 0, invm1m2 = 1.0/(m1 + m2), m1m2 = m1 - m2, m2m1 = m2 - m1; var collision2 = 0; box1.style.left = pos1 + 'px'; box2.style.left = pos2 + 'px'; box1ins.style.left = (pos1 + 5) + 'px' + 5; box2ins.style.left = (pos2 + 5) + 'px' + 5; wall.style.left = 'px'; wall2.style.left = 'px'; ground.style.left = 'px'; piece.style.left = pos1 + 'px'; function display(id, x){ document.getElementById(id).innerHTML = x; } function graphics(){ box1.style.left = pos1 + 'px'; box2.style.left = pos2 + 'px'; box1ins.style.left = (pos1 + 5) + 'px'; box2ins.style.left = (pos2 + 5) + 'px'; } function time() { var ti = 0.0, tiend = 0.0, count = 0, rest = dt, less = 0.0, dv = 0.0; var massc = document.getElementById("mass"); var mode = document.getElementById("mode").selectedIndex; var modeop = document.getElementById("mode").options; var ope = modeop[mode].index; switch(ope){ case 0: mostr = "Max = 8, mass block2 = 10^(2*(input - 1))"; break; case 1: mostr = "Mass block2 = cot(pi/(2*input))^2"; break; case 2: mostr = "Mass block2 = input"; break; } function reset(){ pos1 = 160.0; pos2 = 333.999; v1 = 0.0; v2 = -75.0; rest = 0.0; status = true; collision = 0; collision2 = 0; } var setinput = document.getElementById("mass"); if(setinput){ setinput.addEventListener("keyup", function(event) { if (event.keyCode === 13) { event.preventDefault(); clicked = true; } }); } function reset2(val, op){ reset(); switch(op){ case 0: if(val.value > 8){ m2 = Math.pow(10.0, 2.0*(8.0 - 1.0)); document.getElementById('mass').value = '8'; }else{ m2 = Math.pow(10.0, 2.0*(val.value - 1.0)); } break; case 1: m2 = 1.0/Math.tan(Math.PI/(2.0*val.value)); m2 *= m2; break; case 2: m2 = val.value*1.0; break; } invm1m2 = 1.0/(m1 + m2); m1m2 = m1 - m2; m2m1 = m2 - m1; } if(!paused){ //document.getElementById("set").onclick = function() {reset2(massc, modeop[mode].index)}; if(clicked){ reset2(massc, ope); clicked = false; } while(count < 1000000000 && rest > 0.0){ //max 8 digits of Pi if(status){ ti = -(pos1 - pos2 + 60.0)/(v1 - v2); if(ti < 0) ti = 0.02; }else{ ti = -(pos1 - 20.0)/v1; if(v1 === 0.0 || ti < 0) ti = 0.02; } tiend = (334.0 - pos2)/v2; if(v2 === 0.0 || tiend < 0) tiend = 0.02; if((ti <= rest) && (ti < tiend)){ pos1 += ti*v1; pos2 += ti*v2; if(status){ var v1F = (v1*(m1m2) + 2.0*m2*v2)*invm1m2; var v2F = (v2*(m2m1) + 2.0*m1*v1)*invm1m2; v1 = v1F; v2 = v2F; collision++; status = false; }else{ v1 = -v1; collision2++; status = true; } rest -= ti; }else if(tiend <= rest){ reset(); break; }else{ break; } count++; //prevents infinite loop } pos1 += rest*v1; pos2 += rest*v2; graphics(); display('disp1',mostr + "
Blocks collisions: "+collision+"
" + "All collisions: "+(collision + collision2)+"
" + " π = " + Math.PI); display('disp2', "Block1 Mass = " + m1 + "
Block2 Mass = " + m2 + "
Block1 Vel: "+v1+"
Block2 Vel: "+v2 + "
Block1 Pos: "+ pos1+ "
Block2 Pos: "+ pos2) } } setInterval(time, 16); };

Box collusions