mat3forplaskjs.js

//Mat3 for Plask
//Add your plask.js

////////Change your plask.js makeSetter and add exports.Mat3//////////////

  function makeSetter(type, loc) {
    switch (type) {
      case gl.BOOL:  // NOTE: bool could be set with 1i or 1f.
      case gl.INT:
      case gl.SAMPLER_2D:
      case gl.SAMPLER_CUBE:
        return function(value) {
          gl.uniform1i(loc, value);
          return this;
        };
      case gl.FLOAT:
        return function(value) {
          gl.uniform1f(loc, value);
          return this;
        };
      case gl.FLOAT_VEC2:
        return function(v) {
          gl.uniform2f(loc, v.x, v.y);
        };
      case gl.FLOAT_VEC3:
        return function(v) {
          gl.uniform3f(loc, v.x, v.y, v.z);
        };
      case gl.FLOAT_VEC4:
        return function(v) {
          gl.uniform4f(loc, v.x, v.y, v.z, v.w);
        };
      case gl.FLOAT_MAT3:///add
        return function(mat3) {
          gl.uniformMatrix3fv(loc, false, mat3.toFloat32Array());
        };
      case gl.FLOAT_MAT4:
        return function(mat4) {
          gl.uniformMatrix4fv(loc, false, mat4.toFloat32Array());
        };
      default:
        break;
    }
///////////////////////////////////////////////////////////////////
exports.Mat3 = Mat3;
///////////////////////////////////////////////////////////////////




///////////////////////////////////////////////////////////////////
//   3x3 matrix
//   a11 a12 a13
//   a21 a22 a23
//   a31 a32 a33
///////////////////////////////////////////////////////////////////

function Mat3() {
  this.reset();
}

// Set the full 9 elements of the 3x3 matrix, arguments in row major order.
// The elements are specified in row major order.
Mat3.prototype.set3x3r = function(a11, a12, a13, a21, a22, a23,a31, a32, a33) {
  this.a11 = a11; this.a12 = a12; this.a13 = a13;
  this.a21 = a21; this.a22 = a22; this.a23 = a23;
  this.a31 = a31; this.a32 = a32; this.a33 = a33; 

  return this;
};

// Reset the transform to the identity matrix.
Mat3.prototype.reset = function() {
  this.set3x3r(1, 0, 0,
               0, 1, 0, 
               0, 0, 1 );

  return this;
};

// Transpose the matrix, rows become columns and columns become rows.
Mat3.prototype.transpose = function() {
  var a11 = this.a11, a12 = this.a12, a13 = this.a13,
      a21 = this.a21, a22 = this.a22, a23 = this.a23,
      a31 = this.a31, a32 = this.a32, a33 = this.a33;

  this.a11 = a11; this.a12 = a21; this.a13 = a31;
  this.a21 = a12; this.a22 = a22; this.a23 = a32;
  this.a31 = a13; this.a32 = a23; this.a33 = a33;

  return this;
};


Mat3.prototype.dup = function() {
  var m = new Mat3();  // TODO(deanm): This could be better.
  m.set3x3r(this.a11, this.a12, this.a13,
            this.a21, this.a22, this.a23,
            this.a31, this.a32, this.a33);
  return m;
};

Mat3.prototype.toFloat32Array = function() {
  return new Float32Array([this.a11, this.a21, this.a31,
                           this.a12, this.a22, this.a32,
                           this.a13, this.a23, this.a33]);
};

Mat3.prototype.toMat4 = function(){
 var m = new Mat4;
 m.set4x4r(this.a11, this.a12, this.a13, 0,
           this.a21, this.a22, this.a23, 0,
           this.a31, this.a32, this.a33, 0,
           0,        0,        0,        1);
 return m;
};

Mat3.prototype.debugString = function() {
  var s = [this.a11, this.a12, this.a13,
           this.a21, this.a22, this.a23,
           this.a31, this.a32, this.a33,];
  var row_lengths = [0, 0, 0];
  for (var i = 0; i < 9; ++i) {
    s[i] += '';  // Stringify.
    var len = s[i].length;
    var row = i & 2;
    if (row_lengths[row] < len)
      row_lengths[row] = len;
  }

  var out = '';
  for (var i = 0; i < 9; ++i) {
    var len = s[i].length;
    var row_len = row_lengths[i & 2];
    var num_spaces = row_len - len;
    while (num_spaces--) out += ' ';
    out += s[i] + ((i & 2) === 2 ? '\n' : '  ');
  }

  return out;
};


///////////////////////////////////////////////////////////////////
//add Mat4 methods
///////////////////////////////////////////////////////////////////

////toMat3

Mat4.prototype.toMat3 = function(){
 var m = new Mat3;
 m.set3x3r(this.a11, this.a12, this.a13,
           this.a21, this.a22, this.a23,
           this.a31, this.a32, this.a33);
 return m;
};


////toInverseMat3 

Mat4.prototype.toInverseMat3 = function () {
  var m = new Mat3;
  var  x11 = this.a11,  x12 = this.a12,  x13 = this.a13,
       x21 = this.a21,  x22 = this.a22,  x23 = this.a23,
       x31 = this.a31,  x32 = this.a32,  x33 = this.a33;

  var   b11 = x22 * x33 - x23 * x32,
        b12 = x32 * x13 - x33 * x12,
        b13 = x12 * x23 - x13 * x22,
        b21 = x23 * x31 - x21 * x33,
        b22 = x33 * x11 - x31 * x13,
        b23 = x13 * x21 - x11 * x23,
        b31 = x21 * x32 - x22 * x31,
        b32 = x31 * x12 - x32 * x11,
        b33 = x11 * x22 - x12 * x21;

  var det = x11 * b11 + x21 * b12 + x31 * b13;
  var invdet;
  
  if (!det){
  return console.log('det is zero');
  }
  else{
  invdet = 1 / det;
  m.set3x3r(b11 * invdet,
            b12 * invdet,
            b13 * invdet,
            b21 * invdet,
            b22 * invdet,
            b23 * invdet,
            b31 * invdet,
            b32 * invdet,
            b33 * invdet);
  return m;
  }
};

//////////////////////////////////////////////////////////////////////