// 3D Cube Rotation// http://www.speich.net/computer/moztesting/3d.htm// Created by Simon Speichvar Q = new Array();var MTrans = new Array();  // transformation matrixvar MQube = new Array();  // position information of qubevar I = new Array();      // entity matrixvar Origin = new Object();var Testing = new Object();var LoopTimer;var DisplArea = new Object();DisplArea.Width = 300;DisplArea.Height = 300;function DrawLine(From, To) {  var x1 = From.V[0];  var x2 = To.V[0];  var y1 = From.V[1];  var y2 = To.V[1];  var dx = Math.abs(x2 - x1);  var dy = Math.abs(y2 - y1);  var x = x1;  var y = y1;  var IncX1, IncY1;  var IncX2, IncY2;    var Den;  var Num;  var NumAdd;  var NumPix;  if (x2 >= x1) {  IncX1 = 1; IncX2 = 1;  }  else { IncX1 = -1; IncX2 = -1; }  if (y2 >= y1)  {  IncY1 = 1; IncY2 = 1; }  else { IncY1 = -1; IncY2 = -1; }  if (dx >= dy) {    IncX1 = 0;    IncY2 = 0;    Den = dx;    Num = dx / 2;    NumAdd = dy;    NumPix = dx;  }  else {    IncX2 = 0;    IncY1 = 0;    Den = dy;    Num = dy / 2;    NumAdd = dx;    NumPix = dy;  }  NumPix = Math.round(Q.LastPx + NumPix);  var i = Q.LastPx;  for (; i < NumPix; i++) {    Num += NumAdd;    if (Num >= Den) {      Num -= Den;      x += IncX1;      y += IncY1;    }    x += IncX2;    y += IncY2;  }  Q.LastPx = NumPix;}function CalcCross(V0, V1) {  var Cross = new Array();  Cross[0] = V0[1]*V1[2] - V0[2]*V1[1];  Cross[1] = V0[2]*V1[0] - V0[0]*V1[2];  Cross[2] = V0[0]*V1[1] - V0[1]*V1[0];  return Cross;}function CalcNormal(V0, V1, V2) {  var A = new Array();   var B = new Array();   for (var i = 0; i < 3; i++) {    A[i] = V0[i] - V1[i];    B[i] = V2[i] - V1[i];  }  A = CalcCross(A, B);  var Length = Math.sqrt(A[0]*A[0] + A[1]*A[1] + A[2]*A[2]);   for (var i = 0; i < 3; i++) A[i] = A[i] / Length;  A[3] = 1;  return A;}function CreateP(X,Y,Z) {  this.V = [X,Y,Z,1];}// multiplies two matricesfunction MMulti(M1, M2) {  var M = [[],[],[],[]];  var i = 0;  var j = 0;  for (; i < 4; i++) {    j = 0;    for (; j < 4; j++) M[i][j] = M1[i][0] * M2[0][j] + M1[i][1] * M2[1][j] + M1[i][2] * M2[2][j] + M1[i][3] * M2[3][j];  }  return M;}//multiplies matrix with vectorfunction VMulti(M, V) {  var Vect = new Array();  var i = 0;  for (;i < 4; i++) Vect[i] = M[i][0] * V[0] + M[i][1] * V[1] + M[i][2] * V[2] + M[i][3] * V[3];  return Vect;}function VMulti2(M, V) {  var Vect = new Array();  var i = 0;  for (;i < 3; i++) Vect[i] = M[i][0] * V[0] + M[i][1] * V[1] + M[i][2] * V[2];  return Vect;}// add to matricesfunction MAdd(M1, M2) {  var M = [[],[],[],[]];  var i = 0;  var j = 0;  for (; i < 4; i++) {    j = 0;    for (; j < 4; j++) M[i][j] = M1[i][j] + M2[i][j];  }  return M;}function Translate(M, Dx, Dy, Dz) {  var T = [  [1,0,0,Dx],  [0,1,0,Dy],  [0,0,1,Dz],  [0,0,0,1]  ];  return MMulti(T, M);}function RotateX(M, Phi) {  var a = Phi;  a *= Math.PI / 180;  var Cos = Math.cos(a);  var Sin = Math.sin(a);  var R = [  [1,0,0,0],  [0,Cos,-Sin,0],  [0,Sin,Cos,0],  [0,0,0,1]  ];  return MMulti(R, M);}function RotateY(M, Phi) {  var a = Phi;  a *= Math.PI / 180;  var Cos = Math.cos(a);  var Sin = Math.sin(a);  var R = [  [Cos,0,Sin,0],  [0,1,0,0],  [-Sin,0,Cos,0],  [0,0,0,1]  ];  return MMulti(R, M);}function RotateZ(M, Phi) {  var a = Phi;  a *= Math.PI / 180;  var Cos = Math.cos(a);  var Sin = Math.sin(a);  var R = [  [Cos,-Sin,0,0],  [Sin,Cos,0,0],  [0,0,1,0],     [0,0,0,1]  ];  return MMulti(R, M);}function DrawQube() {  // calc current normals  var CurN = new Array();  var i = 5;  Q.LastPx = 0;  for (; i > -1; i--) CurN[i] = VMulti2(MQube, Q.Normal[i]);  if (CurN[0][2] < 0) {    if (!Q.Line[0]) { DrawLine(Q[0], Q[1]); Q.Line[0] = true; };    if (!Q.Line[1]) { DrawLine(Q[1], Q[2]); Q.Line[1] = true; };    if (!Q.Line[2]) { DrawLine(Q[2], Q[3]); Q.Line[2] = true; };    if (!Q.Line[3]) { DrawLine(Q[3], Q[0]); Q.Line[3] = true; };  }  if (CurN[1][2] < 0) {    if (!Q.Line[2]) { DrawLine(Q[3], Q[2]); Q.Line[2] = true; };    if (!Q.Line[9]) { DrawLine(Q[2], Q[6]); Q.Line[9] = true; };    if (!Q.Line[6]) { DrawLine(Q[6], Q[7]); Q.Line[6] = true; };    if (!Q.Line[10]) { DrawLine(Q[7], Q[3]); Q.Line[10] = true; };  }  if (CurN[2][2] < 0) {    if (!Q.Line[4]) { DrawLine(Q[4], Q[5]); Q.Line[4] = true; };    if (!Q.Line[5]) { DrawLine(Q[5], Q[6]); Q.Line[5] = true; };    if (!Q.Line[6]) { DrawLine(Q[6], Q[7]); Q.Line[6] = true; };    if (!Q.Line[7]) { DrawLine(Q[7], Q[4]); Q.Line[7] = true; };  }  if (CurN[3][2] < 0) {    if (!Q.Line[4]) { DrawLine(Q[4], Q[5]); Q.Line[4] = true; };    if (!Q.Line[8]) { DrawLine(Q[5], Q[1]); Q.Line[8] = true; };    if (!Q.Line[0]) { DrawLine(Q[1], Q[0]); Q.Line[0] = true; };    if (!Q.Line[11]) { DrawLine(Q[0], Q[4]); Q.Line[11] = true; };  }  if (CurN[4][2] < 0) {    if (!Q.Line[11]) { DrawLine(Q[4], Q[0]); Q.Line[11] = true; };    if (!Q.Line[3]) { DrawLine(Q[0], Q[3]); Q.Line[3] = true; };    if (!Q.Line[10]) { DrawLine(Q[3], Q[7]); Q.Line[10] = true; };    if (!Q.Line[7]) { DrawLine(Q[7], Q[4]); Q.Line[7] = true; };  }  if (CurN[5][2] < 0) {    if (!Q.Line[8]) { DrawLine(Q[1], Q[5]); Q.Line[8] = true; };    if (!Q.Line[5]) { DrawLine(Q[5], Q[6]); Q.Line[5] = true; };    if (!Q.Line[9]) { DrawLine(Q[6], Q[2]); Q.Line[9] = true; };    if (!Q.Line[1]) { DrawLine(Q[2], Q[1]); Q.Line[1] = true; };  }  Q.Line = [false,false,false,false,false,false,false,false,false,false,false,false];  Q.LastPx = 0;}function Loop() {  if (Testing.LoopCount > Testing.LoopMax) return;  var TestingStr = String(Testing.LoopCount);  while (TestingStr.length < 3) TestingStr = "0" + TestingStr;  MTrans = Translate(I, -Q[8].V[0], -Q[8].V[1], -Q[8].V[2]);  MTrans = RotateX(MTrans, 1);  MTrans = RotateY(MTrans, 3);  MTrans = RotateZ(MTrans, 5);  MTrans = Translate(MTrans, Q[8].V[0], Q[8].V[1], Q[8].V[2]);  MQube = MMulti(MTrans, MQube);  var i = 8;  for (; i > -1; i--) {    Q[i].V = VMulti(MTrans, Q[i].V);  }  DrawQube();  Testing.LoopCount++;  Loop();}function Init(CubeSize) {  // init/reset vars  Origin.V = [150,150,20,1];  Testing.LoopCount = 0;  Testing.LoopMax = 50;  Testing.TimeMax = 0;  Testing.TimeAvg = 0;  Testing.TimeMin = 0;  Testing.TimeTemp = 0;  Testing.TimeTotal = 0;  Testing.Init = false;  // transformation matrix  MTrans = [  [1,0,0,0],  [0,1,0,0],  [0,0,1,0],  [0,0,0,1]  ];    // position information of qube  MQube = [  [1,0,0,0],  [0,1,0,0],  [0,0,1,0],  [0,0,0,1]  ];    // entity matrix  I = [  [1,0,0,0],  [0,1,0,0],  [0,0,1,0],  [0,0,0,1]  ];    // create qube  Q[0] = new CreateP(-CubeSize,-CubeSize, CubeSize);  Q[1] = new CreateP(-CubeSize, CubeSize, CubeSize);  Q[2] = new CreateP( CubeSize, CubeSize, CubeSize);  Q[3] = new CreateP( CubeSize,-CubeSize, CubeSize);  Q[4] = new CreateP(-CubeSize,-CubeSize,-CubeSize);  Q[5] = new CreateP(-CubeSize, CubeSize,-CubeSize);  Q[6] = new CreateP( CubeSize, CubeSize,-CubeSize);  Q[7] = new CreateP( CubeSize,-CubeSize,-CubeSize);    // center of gravity  Q[8] = new CreateP(0, 0, 0);    // anti-clockwise edge check  Q.Edge = [[0,1,2],[3,2,6],[7,6,5],[4,5,1],[4,0,3],[1,5,6]];    // calculate squad normals  Q.Normal = new Array();  for (var i = 0; i < Q.Edge.length; i++) Q.Normal[i] = CalcNormal(Q[Q.Edge[i][0]].V, Q[Q.Edge[i][1]].V, Q[Q.Edge[i][2]].V);    // line drawn ?  Q.Line = [false,false,false,false,false,false,false,false,false,false,false,false];    // create line pixels  Q.NumPx = 9 * 2 * CubeSize;  for (var i = 0; i < Q.NumPx; i++) CreateP(0,0,0);    MTrans = Translate(MTrans, Origin.V[0], Origin.V[1], Origin.V[2]);  MQube = MMulti(MTrans, MQube);  var i = 0;  for (; i < 9; i++) {    Q[i].V = VMulti(MTrans, Q[i].V);  }  DrawQube();  Testing.Init = true;  Loop();}for ( var i = 20; i <= 160; i *= 2 ) {  Init(i);}Q = null;MTrans = null;MQube = null;I = null;Origin = null;Testing = null;LoopTime = null;DisplArea = null;