Add ToT WebGL conformance tests : part 8

conformance/more/util.js

+/*
+Utilities for the OpenGL ES 2.0 HTML Canvas context
+*/
+
+/*
+** Copyright (c) 2012 The Khronos Group Inc.
+**
+** Permission is hereby granted, free of charge, to any person obtaining a
+** copy of this software and/or associated documentation files (the
+** "Materials"), to deal in the Materials without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Materials, and to
+** permit persons to whom the Materials are furnished to do so, subject to
+** the following conditions:
+**
+** The above copyright notice and this permission notice shall be included
+** in all copies or substantial portions of the Materials.
+**
+** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+*/
+
+function loadTexture(gl, elem, mipmaps) {
+  var tex = gl.createTexture();
+  gl.bindTexture(gl.TEXTURE_2D, tex);
+  gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, elem);
+  if (mipmaps != false)
+    gl.generateMipmap(gl.TEXTURE_2D);
+  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
+  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
+  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
+  if (mipmaps)
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_LINEAR);
+  else
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
+  return tex;
+}
+
+function getShader(gl, id) {
+  var shaderScript = document.getElementById(id);
+  if (!shaderScript) {
+    throw(new Error("No shader element with id: "+id));
+  }
+
+  var str = "";
+  var k = shaderScript.firstChild;
+  while (k) {
+    if (k.nodeType == 3)
+      str += k.textContent;
+    k = k.nextSibling;
+  }
+
+  var shader;
+  if (shaderScript.type == "x-shader/x-fragment") {
+    shader = gl.createShader(gl.FRAGMENT_SHADER);
+  } else if (shaderScript.type == "x-shader/x-vertex") {
+    shader = gl.createShader(gl.VERTEX_SHADER);
+  } else {
+    throw(new Error("Unknown shader type "+shaderScript.type));
+  }
+
+  gl.shaderSource(shader, str);
+  gl.compileShader(shader);
+
+  if (gl.getShaderParameter(shader, gl.COMPILE_STATUS) != 1) {
+    var ilog = gl.getShaderInfoLog(shader);
+    gl.deleteShader(shader);
+    throw(new Error("Failed to compile shader "+shaderScript.id + ", Shader info log: " + ilog));
+  }
+  return shader;
+}
+
+function loadShaderArray(gl, shaders) {
+  var id = gl.createProgram();
+  var shaderObjs = [];
+  for (var i=0; i<shaders.length; ++i) {
+    try {
+      var sh = getShader(gl, shaders[i]);
+      shaderObjs.push(sh);
+      gl.attachShader(id, sh);
+    } catch (e) {
+      var pr = {program: id, shaders: shaderObjs};
+      deleteShader(gl, pr);
+      throw (e);
+    }
+  }
+  var prog = {program: id, shaders: shaderObjs};
+  gl.linkProgram(id);
+  gl.validateProgram(id);
+  if (gl.getProgramParameter(id, gl.LINK_STATUS) != 1) {
+    deleteShader(gl,prog);
+    throw(new Error("Failed to link shader"));
+  }
+  if (gl.getProgramParameter(id, gl.VALIDATE_STATUS) != 1) {
+    deleteShader(gl,prog);
+    throw(new Error("Failed to validate shader"));
+  }
+  return prog;
+}
+function loadShader(gl) {
+  var sh = [];
+  for (var i=1; i<arguments.length; ++i)
+    sh.push(arguments[i]);
+  return loadShaderArray(gl, sh);
+}
+
+function deleteShader(gl, sh) {
+  gl.useProgram(null);
+  sh.shaders.forEach(function(s){
+    gl.detachShader(sh.program, s);
+    gl.deleteShader(s);
+  });
+  gl.deleteProgram(sh.program);
+}
+
+function getGLErrorAsString(ctx, err) {
+  if (err === ctx.NO_ERROR) {
+    return "NO_ERROR";
+  }
+  for (var name in ctx) {
+    if (ctx[name] === err) {
+      return name;
+    }
+  }
+  return err.toString();
+}
+
+function checkError(gl, msg) {
+  var e = gl.getError();
+  if (e != gl.NO_ERROR) {
+    log("Error " + getGLErrorAsString(gl, e) + " at " + msg);
+  }
+  return e;
+}
+
+function throwError(gl, msg) {
+  var e = gl.getError();
+  if (e != 0) {
+    throw(new Error("Error " + getGLErrorAsString(gl, e) + " at " + msg));
+  }
+}
+
+Math.cot = function(z) { return 1.0 / Math.tan(z); }
+
+/*
+  Matrix utilities, using the OpenGL element order where
+  the last 4 elements are the translation column.
+
+  Uses flat arrays as matrices for performance.
+
+  Most operations have in-place variants to avoid allocating temporary matrices.
+
+  Naming logic:
+    Matrix.method operates on a 4x4 Matrix and returns a new Matrix.
+    Matrix.method3x3 operates on a 3x3 Matrix and returns a new Matrix. Not all operations have a 3x3 version (as 3x3 is usually only used for the normal matrix: Matrix.transpose3x3(Matrix.inverseTo3x3(mat4x4)))
+    Matrix.method[3x3]InPlace(args, target) stores its result in the target matrix.
+
+    Matrix.scale([sx, sy, sz]) -- non-uniform scale by vector
+    Matrix.scale1(s)           -- uniform scale by scalar
+    Matrix.scale3(sx, sy, sz)  -- non-uniform scale by scalars
+
+    Ditto for translate.
+*/
+Matrix = {
+  identity : [
+    1.0, 0.0, 0.0, 0.0,
+    0.0, 1.0, 0.0, 0.0,
+    0.0, 0.0, 1.0, 0.0,
+    0.0, 0.0, 0.0, 1.0
+  ],
+
+  newIdentity : function() {
+    return [
+      1.0, 0.0, 0.0, 0.0,
+      0.0, 1.0, 0.0, 0.0,
+      0.0, 0.0, 1.0, 0.0,
+      0.0, 0.0, 0.0, 1.0
+    ];
+  },
+
+  newIdentity3x3 : function() {
+    return [
+      1.0, 0.0, 0.0,
+      0.0, 1.0, 0.0,
+      0.0, 0.0, 1.0
+    ];
+  },
+
+  copyMatrix : function(src, dst) {
+    for (var i=0; i<16; i++) dst[i] = src[i];
+    return dst;
+  },
+
+  to3x3 : function(m) {
+    return [
+      m[0], m[1], m[2],
+      m[4], m[5], m[6],
+      m[8], m[9], m[10]
+    ];
+  },
+
+  // orthonormal matrix inverse
+  inverseON : function(m) {
+    var n = this.transpose4x4(m);
+    var t = [m[12], m[13], m[14]];
+    n[3] = n[7] = n[11] = 0;
+    n[12] = -Vec3.dot([n[0], n[4], n[8]], t);
+    n[13] = -Vec3.dot([n[1], n[5], n[9]], t);
+    n[14] = -Vec3.dot([n[2], n[6], n[10]], t);
+    return n;
+  },
+
+  inverseTo3x3 : function(m) {
+    return this.inverse4x4to3x3InPlace(m, this.newIdentity3x3());
+  },
+
+  inverseTo3x3InPlace : function(m,n) {
+    var a11 = m[10]*m[5]-m[6]*m[9],
+        a21 = -m[10]*m[1]+m[2]*m[9],
+        a31 = m[6]*m[1]-m[2]*m[5],
+        a12 = -m[10]*m[4]+m[6]*m[8],
+        a22 = m[10]*m[0]-m[2]*m[8],
+        a32 = -m[6]*m[0]+m[2]*m[4],
+        a13 = m[9]*m[4]-m[5]*m[8],
+        a23 = -m[9]*m[0]+m[1]*m[8],
+        a33 = m[5]*m[0]-m[1]*m[4];
+    var det = m[0]*(a11) + m[1]*(a12) + m[2]*(a13);
+    if (det == 0) // no inverse
+      return [1,0,0,0,1,0,0,0,1];
+    var idet = 1 / det;
+    n[0] = idet*a11;
+    n[1] = idet*a21;
+    n[2] = idet*a31;
+    n[3] = idet*a12;
+    n[4] = idet*a22;
+    n[5] = idet*a32;
+    n[6] = idet*a13;
+    n[7] = idet*a23;
+    n[8] = idet*a33;
+    return n;
+  },
+
+  inverse3x3 : function(m) {
+    return this.inverse3x3InPlace(m, this.newIdentity3x3());
+  },
+
+  inverse3x3InPlace : function(m,n) {
+    var a11 = m[8]*m[4]-m[5]*m[7],
+        a21 = -m[8]*m[1]+m[2]*m[7],
+        a31 = m[5]*m[1]-m[2]*m[4],
+        a12 = -m[8]*m[3]+m[5]*m[6],
+        a22 = m[8]*m[0]-m[2]*m[6],
+        a32 = -m[5]*m[0]+m[2]*m[3],
+        a13 = m[7]*m[4]-m[4]*m[8],
+        a23 = -m[7]*m[0]+m[1]*m[6],
+        a33 = m[4]*m[0]-m[1]*m[3];
+    var det = m[0]*(a11) + m[1]*(a12) + m[2]*(a13);
+    if (det == 0) // no inverse
+      return [1,0,0,0,1,0,0,0,1];
+    var idet = 1 / det;
+    n[0] = idet*a11;
+    n[1] = idet*a21;
+    n[2] = idet*a31;
+    n[3] = idet*a12;
+    n[4] = idet*a22;
+    n[5] = idet*a32;
+    n[6] = idet*a13;
+    n[7] = idet*a23;
+    n[8] = idet*a33;
+    return n;
+  },
+
+  frustum : function (left, right, bottom, top, znear, zfar) {
+    var X = 2*znear/(right-left);
+    var Y = 2*znear/(top-bottom);
+    var A = (right+left)/(right-left);
+    var B = (top+bottom)/(top-bottom);
+    var C = -(zfar+znear)/(zfar-znear);
+    var D = -2*zfar*znear/(zfar-znear);
+
+    return [
+      X, 0, 0, 0,
+      0, Y, 0, 0,
+      A, B, C, -1,
+      0, 0, D, 0
+    ];
+ },
+
+  perspective : function (fovy, aspect, znear, zfar) {
+    var ymax = znear * Math.tan(fovy * Math.PI / 360.0);
+    var ymin = -ymax;
+    var xmin = ymin * aspect;
+    var xmax = ymax * aspect;
+
+    return this.frustum(xmin, xmax, ymin, ymax, znear, zfar);
+  },
+
+  mul4x4 : function (a,b) {
+    return this.mul4x4InPlace(a,b,this.newIdentity());
+  },
+
+  mul4x4InPlace : function (a, b, c) {
+        c[0] =   b[0] * a[0] +
+                 b[0+1] * a[4] +
+                 b[0+2] * a[8] +
+                 b[0+3] * a[12];
+        c[0+1] = b[0] * a[1] +
+                 b[0+1] * a[5] +
+                 b[0+2] * a[9] +
+                 b[0+3] * a[13];
+        c[0+2] = b[0] * a[2] +
+                 b[0+1] * a[6] +
+                 b[0+2] * a[10] +
+                 b[0+3] * a[14];
+        c[0+3] = b[0] * a[3] +
+                 b[0+1] * a[7] +
+                 b[0+2] * a[11] +
+                 b[0+3] * a[15];
+        c[4] =   b[4] * a[0] +
+                 b[4+1] * a[4] +
+                 b[4+2] * a[8] +
+                 b[4+3] * a[12];
+        c[4+1] = b[4] * a[1] +
+                 b[4+1] * a[5] +
+                 b[4+2] * a[9] +
+                 b[4+3] * a[13];
+        c[4+2] = b[4] * a[2] +
+                 b[4+1] * a[6] +
+                 b[4+2] * a[10] +
+                 b[4+3] * a[14];
+        c[4+3] = b[4] * a[3] +
+                 b[4+1] * a[7] +
+                 b[4+2] * a[11] +
+                 b[4+3] * a[15];
+        c[8] =   b[8] * a[0] +
+                 b[8+1] * a[4] +
+                 b[8+2] * a[8] +
+                 b[8+3] * a[12];
+        c[8+1] = b[8] * a[1] +
+                 b[8+1] * a[5] +
+                 b[8+2] * a[9] +
+                 b[8+3] * a[13];
+        c[8+2] = b[8] * a[2] +
+                 b[8+1] * a[6] +
+                 b[8+2] * a[10] +
+                 b[8+3] * a[14];
+        c[8+3] = b[8] * a[3] +
+                 b[8+1] * a[7] +
+                 b[8+2] * a[11] +
+                 b[8+3] * a[15];
+        c[12] =   b[12] * a[0] +
+                 b[12+1] * a[4] +
+                 b[12+2] * a[8] +
+                 b[12+3] * a[12];
+        c[12+1] = b[12] * a[1] +
+                 b[12+1] * a[5] +
+                 b[12+2] * a[9] +
+                 b[12+3] * a[13];
+        c[12+2] = b[12] * a[2] +
+                 b[12+1] * a[6] +
+                 b[12+2] * a[10] +
+                 b[12+3] * a[14];
+        c[12+3] = b[12] * a[3] +
+                 b[12+1] * a[7] +
+                 b[12+2] * a[11] +
+                 b[12+3] * a[15];
+    return c;
+  },
+
+  mulv4 : function (a, v) {
+    c = new Array(4);
+    for (var i=0; i<4; ++i) {
+      var x = 0;
+      for (var k=0; k<4; ++k)
+        x += v[k] * a[k*4+i];
+      c[i] = x;
+    }
+    return c;
+  },
+
+  rotate : function (angle, axis) {
+    axis = Vec3.normalize(axis);
+    var x=axis[0], y=axis[1], z=axis[2];
+    var c = Math.cos(angle);
+    var c1 = 1-c;
+    var s = Math.sin(angle);
+    return [
+      x*x*c1+c, y*x*c1+z*s, z*x*c1-y*s, 0,
+      x*y*c1-z*s, y*y*c1+c, y*z*c1+x*s, 0,
+      x*z*c1+y*s, y*z*c1-x*s, z*z*c1+c, 0,
+      0,0,0,1
+    ];
+  },
+  rotateInPlace : function(angle, axis, m) {
+    axis = Vec3.normalize(axis);
+    var x=axis[0], y=axis[1], z=axis[2];
+    var c = Math.cos(angle);
+    var c1 = 1-c;
+    var s = Math.sin(angle);
+    var tmpMatrix = this.tmpMatrix;
+    var tmpMatrix2 = this.tmpMatrix2;
+    tmpMatrix[0] = x*x*c1+c; tmpMatrix[1] = y*x*c1+z*s; tmpMatrix[2] = z*x*c1-y*s; tmpMatrix[3] = 0;
+    tmpMatrix[4] = x*y*c1-z*s; tmpMatrix[5] = y*y*c1+c; tmpMatrix[6] = y*z*c1+x*s; tmpMatrix[7] = 0;
+    tmpMatrix[8] = x*z*c1+y*s; tmpMatrix[9] = y*z*c1-x*s; tmpMatrix[10] = z*z*c1+c; tmpMatrix[11] = 0;
+    tmpMatrix[12] = 0; tmpMatrix[13] = 0; tmpMatrix[14] = 0; tmpMatrix[15] = 1;
+    this.copyMatrix(m, tmpMatrix2);
+    return this.mul4x4InPlace(tmpMatrix2, tmpMatrix, m);
+  },
+
+  scale : function(v) {
+    return [
+      v[0], 0, 0, 0,
+      0, v[1], 0, 0,
+      0, 0, v[2], 0,
+      0, 0, 0, 1
+    ];
+  },
+  scale3 : function(x,y,z) {
+    return [
+      x, 0, 0, 0,
+      0, y, 0, 0,
+      0, 0, z, 0,
+      0, 0, 0, 1
+    ];
+  },
+  scale1 : function(s) {
+    return [
+      s, 0, 0, 0,
+      0, s, 0, 0,
+      0, 0, s, 0,
+      0, 0, 0, 1
+    ];
+  },
+  scale3InPlace : function(x, y, z, m) {
+    var tmpMatrix = this.tmpMatrix;
+    var tmpMatrix2 = this.tmpMatrix2;
+    tmpMatrix[0] = x; tmpMatrix[1] = 0; tmpMatrix[2] = 0; tmpMatrix[3] = 0;
+    tmpMatrix[4] = 0; tmpMatrix[5] = y; tmpMatrix[6] = 0; tmpMatrix[7] = 0;
+    tmpMatrix[8] = 0; tmpMatrix[9] = 0; tmpMatrix[10] = z; tmpMatrix[11] = 0;
+    tmpMatrix[12] = 0; tmpMatrix[13] = 0; tmpMatrix[14] = 0; tmpMatrix[15] = 1;
+    this.copyMatrix(m, tmpMatrix2);
+    return this.mul4x4InPlace(tmpMatrix2, tmpMatrix, m);
+  },
+  scale1InPlace : function(s, m) { return this.scale3InPlace(s, s, s, m); },
+  scaleInPlace : function(s, m) { return this.scale3InPlace(s[0],s[1],s[2],m); },
+
+  translate3 : function(x,y,z) {
+    return [
+      1, 0, 0, 0,
+      0, 1, 0, 0,
+      0, 0, 1, 0,
+      x, y, z, 1
+    ];
+  },
+
+  translate : function(v) {
+    return this.translate3(v[0], v[1], v[2]);
+  },
+  tmpMatrix : [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0],
+  tmpMatrix2 : [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0],
+  translate3InPlace : function(x,y,z,m) {
+    var tmpMatrix = this.tmpMatrix;
+    var tmpMatrix2 = this.tmpMatrix2;
+    tmpMatrix[0] = 1; tmpMatrix[1] = 0; tmpMatrix[2] = 0; tmpMatrix[3] = 0;
+    tmpMatrix[4] = 0; tmpMatrix[5] = 1; tmpMatrix[6] = 0; tmpMatrix[7] = 0;
+    tmpMatrix[8] = 0; tmpMatrix[9] = 0; tmpMatrix[10] = 1; tmpMatrix[11] = 0;
+    tmpMatrix[12] = x; tmpMatrix[13] = y; tmpMatrix[14] = z; tmpMatrix[15] = 1;
+    this.copyMatrix(m, tmpMatrix2);
+    return this.mul4x4InPlace(tmpMatrix2, tmpMatrix, m);
+  },
+  translateInPlace : function(v,m){ return this.translate3InPlace(v[0], v[1], v[2], m); },
+
+  lookAt : function (eye, center, up) {
+    var z = Vec3.direction(eye, center);
+    var x = Vec3.normalizeInPlace(Vec3.cross(up, z));
+    var y = Vec3.normalizeInPlace(Vec3.cross(z, x));
+
+    var m = [
+      x[0], y[0], z[0], 0,
+      x[1], y[1], z[1], 0,
+      x[2], y[2], z[2], 0,
+      0, 0, 0, 1
+    ];
+
+    var t = [
+      1, 0, 0, 0,
+      0, 1, 0, 0,
+      0, 0, 1, 0,
+      -eye[0], -eye[1], -eye[2], 1
+    ];
+
+    return this.mul4x4(m,t);
+  },
+
+  transpose4x4 : function(m) {
+    return [
+      m[0], m[4], m[8], m[12],
+      m[1], m[5], m[9], m[13],
+      m[2], m[6], m[10], m[14],
+      m[3], m[7], m[11], m[15]
+    ];
+  },
+
+  transpose4x4InPlace : function(m) {
+    var tmp = 0.0;
+    tmp = m[1]; m[1] = m[4]; m[4] = tmp;
+    tmp = m[2]; m[2] = m[8]; m[8] = tmp;
+    tmp = m[3]; m[3] = m[12]; m[12] = tmp;
+    tmp = m[6]; m[6] = m[9]; m[9] = tmp;
+    tmp = m[7]; m[7] = m[13]; m[13] = tmp;
+    tmp = m[11]; m[11] = m[14]; m[14] = tmp;
+    return m;
+  },
+
+  transpose3x3 : function(m) {
+    return [
+      m[0], m[3], m[6],
+      m[1], m[4], m[7],
+      m[2], m[5], m[8]
+    ];
+  },
+
+  transpose3x3InPlace : function(m) {
+    var tmp = 0.0;
+    tmp = m[1]; m[1] = m[3]; m[3] = tmp;
+    tmp = m[2]; m[2] = m[6]; m[6] = tmp;
+    tmp = m[5]; m[5] = m[7]; m[7] = tmp;
+    return m;
+  },
+}
+
+Vec3 = {
+  make : function() { return [0,0,0]; },
+  copy : function(v) { return [v[0],v[1],v[2]]; },
+
+  add : function (u,v) {
+    return [u[0]+v[0], u[1]+v[1], u[2]+v[2]];
+  },
+
+  sub : function (u,v) {
+    return [u[0]-v[0], u[1]-v[1], u[2]-v[2]];
+  },
+
+  negate : function (u) {
+    return [-u[0], -u[1], -u[2]];
+  },
+
+  direction : function (u,v) {
+    return this.normalizeInPlace(this.sub(u,v));
+  },
+
+  normalizeInPlace : function(v) {
+    var imag = 1.0 / Math.sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]);
+    v[0] *= imag; v[1] *= imag; v[2] *= imag;
+    return v;
+  },
+
+  normalize : function(v) {
+    return this.normalizeInPlace(this.copy(v));
+  },
+
+  scale : function(f, v) {
+    return [f*v[0], f*v[1], f*v[2]];
+  },
+
+  dot : function(u,v) {
+    return u[0]*v[0] + u[1]*v[1] + u[2]*v[2];
+  },
+
+  inner : function(u,v) {
+    return [u[0]*v[0], u[1]*v[1], u[2]*v[2]];
+  },
+
+  cross : function(u,v) {
+    return [
+      u[1]*v[2] - u[2]*v[1],
+      u[2]*v[0] - u[0]*v[2],
+      u[0]*v[1] - u[1]*v[0]
+    ];
+  }
+}
+
+Shader = function(gl){
+  this.gl = gl;
+  this.shaders = [];
+  this.uniformLocations = {};
+  this.attribLocations = {};
+  for (var i=1; i<arguments.length; i++) {
+    this.shaders.push(arguments[i]);
+  }
+}
+Shader.prototype = {
+  id : null,
+  gl : null,
+  compiled : false,
+  shader : null,
+  shaders : [],
+
+  destroy : function() {
+    if (this.shader != null) deleteShader(this.gl, this.shader);
+  },
+
+  compile : function() {
+    this.shader = loadShaderArray(this.gl, this.shaders);
+  },
+
+  use : function() {
+    if (this.shader == null)
+      this.compile();
+    this.gl.useProgram(this.shader.program);
+  },
+
+  uniform1fv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform1fv(loc, value);
+  },
+
+  uniform2fv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform2fv(loc, value);
+  },
+
+  uniform3fv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform3fv(loc, value);
+  },
+
+  uniform4fv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform4fv(loc, value);
+  },
+
+  uniform1f : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform1f(loc, value);
+  },
+
+  uniform2f : function(name, v1,v2) {
+    var loc = this.uniform(name);
+    this.gl.uniform2f(loc, v1,v2);
+  },
+
+  uniform3f : function(name, v1,v2,v3) {
+    var loc = this.uniform(name);
+    this.gl.uniform3f(loc, v1,v2,v3);
+  },
+
+  uniform4f : function(name, v1,v2,v3,v4) {
+    var loc = this.uniform(name);
+    this.gl.uniform4f(loc, v1, v2, v3, v4);
+  },
+
+  uniform1iv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform1iv(loc, value);
+  },
+
+  uniform2iv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform2iv(loc, value);
+  },
+
+  uniform3iv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform3iv(loc, value);
+  },
+
+  uniform4iv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform4iv(loc, value);
+  },
+
+  uniform1i : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniform1i(loc, value);
+  },
+
+  uniform2i : function(name, v1,v2) {
+    var loc = this.uniform(name);
+    this.gl.uniform2i(loc, v1,v2);
+  },
+
+  uniform3i : function(name, v1,v2,v3) {
+    var loc = this.uniform(name);
+    this.gl.uniform3i(loc, v1,v2,v3);
+  },
+
+  uniform4i : function(name, v1,v2,v3,v4) {
+    var loc = this.uniform(name);
+    this.gl.uniform4i(loc, v1, v2, v3, v4);
+  },
+
+  uniformMatrix4fv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniformMatrix4fv(loc, false, value);
+  },
+
+  uniformMatrix3fv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniformMatrix3fv(loc, false, value);
+  },
+
+  uniformMatrix2fv : function(name, value) {
+    var loc = this.uniform(name);
+    this.gl.uniformMatrix2fv(loc, false, value);
+  },
+
+  attrib : function(name) {
+    if (this.attribLocations[name] == null) {
+      var loc = this.gl.getAttribLocation(this.shader.program, name);
+      this.attribLocations[name] = loc;
+    }
+    return this.attribLocations[name];
+  },
+
+  uniform : function(name) {
+    if (this.uniformLocations[name] == null) {
+      var loc = this.gl.getUniformLocation(this.shader.program, name);
+      this.uniformLocations[name] = loc;
+    }
+    return this.uniformLocations[name];
+  }
+}
+Filter = function(gl, shader) {
+  Shader.apply(this, arguments);
+}
+Filter.prototype = new Shader();
+Filter.prototype.apply = function(init) {
+  this.use();
+  var va = this.attrib("Vertex");
+  var ta = this.attrib("Tex");
+  var vbo = Quad.getCachedVBO(this.gl);
+  if (init) init(this);
+  vbo.draw(va, null, ta);
+}
+
+
+VBO = function(gl) {
+  this.gl = gl;
+  this.data = [];
+  this.elementsVBO = null;
+  for (var i=1; i<arguments.length; i++) {
+    if (arguments[i].elements)
+      this.elements = arguments[i];
+    else
+      this.data.push(arguments[i]);
+  }
+}
+
+VBO.prototype = {
+  initialized : false,
+  length : 0,
+  vbos : null,
+  type : 'TRIANGLES',
+  elementsVBO : null,
+  elements : null,
+
+  setData : function() {
+    this.destroy();
+    this.data = [];
+    for (var i=0; i<arguments.length; i++) {
+      if (arguments[i].elements)
+        this.elements = arguments[i];
+      else
+        this.data.push(arguments[i]);
+    }
+  },
+
+  destroy : function() {
+    if (this.vbos != null)
+      for (var i=0; i<this.vbos.length; i++)
+        this.gl.deleteBuffer(this.vbos[i]);
+    if (this.elementsVBO != null)
+      this.gl.deleteBuffer(this.elementsVBO);
+    this.length = this.elementsLength = 0;
+    this.vbos = this.elementsVBO = null;
+    this.initialized = false;
+  },
+
+  init : function() {
+    this.destroy();
+    var gl = this.gl;
+
+    gl.getError();
+    var vbos = [];
+    var length = 0;
+    for (var i=0; i<this.data.length; i++)
+      vbos.push(gl.createBuffer());
+    if (this.elements != null)
+      this.elementsVBO = gl.createBuffer();
+    try {
+      throwError(gl, "genBuffers");
+      for (var i = 0; i<this.data.length; i++) {
+        var d = this.data[i];
+        var dlen = Math.floor(d.data.length / d.size);
+        if (i == 0 || dlen < length)
+            length = dlen;
+        if (!d.floatArray)
+          d.floatArray = new Float32Array(d.data);
+        gl.bindBuffer(gl.ARRAY_BUFFER, vbos[i]);
+        throwError(gl, "bindBuffer");
+        gl.bufferData(gl.ARRAY_BUFFER, d.floatArray, gl.STATIC_DRAW);
+        throwError(gl, "bufferData");
+      }
+      if (this.elementsVBO != null) {
+        var d = this.elements;
+        this.elementsLength = d.data.length;
+        this.elementsType = d.type == gl.UNSIGNED_BYTE ? d.type : gl.UNSIGNED_SHORT;
+        gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, this.elementsVBO);
+        throwError(gl, "bindBuffer ELEMENT_ARRAY_BUFFER");
+        if (this.elementsType == gl.UNSIGNED_SHORT && !d.ushortArray) {
+          d.ushortArray = new Uint16Array(d.data);
+          gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, d.ushortArray, gl.STATIC_DRAW);
+        } else if (this.elementsType == gl.UNSIGNED_BYTE && !d.ubyteArray) {
+          d.ubyteArray = new Uint8Array(d.data);
+          gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, d.ubyteArray, gl.STATIC_DRAW);
+        }
+        throwError(gl, "bufferData ELEMENT_ARRAY_BUFFER");
+      }
+    } catch(e) {
+      for (var i=0; i<vbos.length; i++)
+        gl.deleteBuffer(vbos[i]);
+      throw(e);
+    }
+
+    gl.bindBuffer(gl.ARRAY_BUFFER, null);
+    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, null);
+
+    this.length = length;
+    this.vbos = vbos;
+
+    this.initialized = true;
+  },
+
+  use : function() {
+    if (!this.initialized) this.init();
+    var gl = this.gl;
+    for (var i=0; i<arguments.length; i++) {
+      if (arguments[i] == null) continue;
+      gl.bindBuffer(gl.ARRAY_BUFFER, this.vbos[i]);
+      gl.vertexAttribPointer(arguments[i], this.data[i].size, gl.FLOAT, false, 0, 0);
+      gl.enableVertexAttribArray(arguments[i]);
+    }
+    if (this.elementsVBO != null) {
+      gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, this.elementsVBO);
+    }
+  },
+
+  draw : function() {
+    var args = [];
+    this.use.apply(this, arguments);
+    var gl = this.gl;
+    if (this.elementsVBO != null) {
+      gl.drawElements(gl[this.type], this.elementsLength, this.elementsType, 0);
+    } else {
+      gl.drawArrays(gl[this.type], 0, this.length);
+    }
+  }
+}
+
+FBO = function(gl, width, height, use_depth) {
+  this.gl = gl;
+  this.width = width;
+  this.height = height;
+  if (use_depth != null)
+    this.useDepth = use_depth;
+}
+FBO.prototype = {
+  initialized : false,
+  useDepth : true,
+  fbo : null,
+  rbo : null,
+  texture : null,
+
+  destroy : function() {
+    if (this.fbo) this.gl.deleteFramebuffer(this.fbo);
+    if (this.rbo) this.gl.deleteRenderbuffer(this.rbo);
+    if (this.texture) this.gl.deleteTexture(this.texture);
+  },
+
+  init : function() {
+    var gl = this.gl;
+    var w = this.width, h = this.height;
+    var fbo = this.fbo != null ? this.fbo : gl.createFramebuffer();
+    var rb;
+
+    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
+    checkError(gl, "FBO.init bindFramebuffer");
+    if (this.useDepth) {
+      rb = this.rbo != null ? this.rbo : gl.createRenderbuffer();
+      gl.bindRenderbuffer(gl.RENDERBUFFER, rb);
+      checkError(gl, "FBO.init bindRenderbuffer");
+      gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, w, h);
+      checkError(gl, "FBO.init renderbufferStorage");
+    }
+
+    var tex = this.texture != null ? this.texture : gl.createTexture();
+    gl.bindTexture(gl.TEXTURE_2D, tex);
+    try {
+      gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, w, h, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
+    } catch (e) { // argh, no null texture support
+      var tmp = this.getTempCanvas(w,h);
+      gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, tmp);
+    }
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
+    checkError(gl, "FBO.init tex");
+
+    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, tex, 0);
+    checkError(gl, "FBO.init bind tex");
+
+    if (this.useDepth) {
+      gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, rb);
+      checkError(gl, "FBO.init bind depth buffer");
+    }
+
+    var fbstat = gl.checkFramebufferStatus(gl.FRAMEBUFFER);
+    if (fbstat != gl.FRAMEBUFFER_COMPLETE) {
+      var glv;
+      for (var v in gl) {
+        try { glv = gl[v]; } catch (e) { glv = null; }
+        if (glv == fbstat) { fbstat = v; break; }}
+        log("Framebuffer status: " + fbstat);
+    }
+    checkError(gl, "FBO.init check fbo");
+
+    this.fbo = fbo;
+    this.rbo = rb;
+    this.texture = tex;
+    this.initialized = true;
+  },
+
+  getTempCanvas : function(w, h) {
+    if (!FBO.tempCanvas) {
+      FBO.tempCanvas = document.createElement('canvas');
+    }
+    FBO.tempCanvas.width = w;
+    FBO.tempCanvas.height = h;
+    return FBO.tempCanvas;
+  },
+
+  use : function() {
+    if (!this.initialized) this.init();
+    this.gl.bindFramebuffer(this.gl.FRAMEBUFFER, this.fbo);
+  }
+}
+
+function GLError(err, msg, fileName, lineNumber) {
+  this.message = msg;
+  this.glError = err;
+}
+
+GLError.prototype = new Error();
+
+function makeGLErrorWrapper(gl, fname) {
+  return (function() {
+    try {
+      var rv = gl[fname].apply(gl, arguments);
+      var err = gl.getError();
+      if (err != gl.NO_ERROR) {
+        throw(new GLError(
+            err, "GL error "+getGLErrorAsString(gl, err)+" in "+fname));
+      }
+      return rv;
+    } catch (e) {
+      if (e.glError !== undefined) {
+        throw e;
+      }
+      throw(new Error("Threw " + e.name +
+                      " in " + fname + "\n" +
+                      e.message + "\n" +
+                      arguments.callee.caller));
+    }
+  });
+}
+
+function wrapGLContext(gl) {
+  var wrap = {};
+  for (var i in gl) {
+    try {
+      if (typeof gl[i] == 'function') {
+          wrap[i] = makeGLErrorWrapper(gl, i);
+      } else {
+          wrap[i] = gl[i];
+      }
+    } catch (e) {
+      // log("wrapGLContext: Error accessing " + i);
+    }
+  }
+  wrap.getError = function(){ return gl.getError(); };
+  return wrap;
+}
+
+function getGLContext(canvas) {
+  return canvas.getContext(GL_CONTEXT_ID, {antialias: false});
+}
+
+// Assert that f generates a specific GL error.
+function assertGLError(gl, err, name, f) {
+  if (f == null) { f = name; name = null; }
+  var r = false;
+  var glErr = 0;
+  try { f(); } catch(e) { r=true; glErr = e.glError; }
+  if (glErr !== err) {
+    if (glErr === undefined) {
+      testFailed("assertGLError: UNEXPECTED EXCEPTION", name, f);
+    } else {
+      testFailed("assertGLError: expected: " + getGLErrorAsString(gl, err) +
+                 " actual: " + getGLErrorAsString(gl, glErr), name, f);
+    }
+    return false;
+  }
+  return true;
+}
+
+// Assert that f generates some GL error. Used in situations where it's
+// ambigious which of multiple possible errors will be generated.
+function assertSomeGLError(gl, name, f) {
+  if (f == null) { f = name; name = null; }
+  var r = false;
+  var glErr = 0;
+  var err = 0;
+  try { f(); } catch(e) { r=true; glErr = e.glError; }
+  if (glErr === 0) {
+    if (glErr === undefined) {
+      testFailed("assertGLError: UNEXPECTED EXCEPTION", name, f);
+    } else {
+      testFailed("assertGLError: expected: " + getGLErrorAsString(gl, err) +
+                 " actual: " + getGLErrorAsString(gl, glErr), name, f);
+    }
+    return false;
+  }
+  return true;
+}
+
+// Assert that f throws an exception but does not generate a GL error.
+function assertThrowNoGLError(gl, name, f) {
+  if (f == null) { f = name; name = null; }
+  var r = false;
+  var glErr = undefined;
+  var exp;
+  try { f(); } catch(e) { r=true; glErr = e.glError; exp = e;}
+  if (!r) {
+    testFailed(
+      "assertThrowNoGLError: should have thrown exception", name, f);
+    return false;
+  } else {
+    if (glErr !== undefined) {
+      testFailed(
+        "assertThrowNoGLError: should be no GL error but generated: " +
+        getGLErrorAsString(gl, glErr), name, f);
+      return false;
+    }
+  }
+  testPassed("assertThrowNoGLError", name, f);
+  return true;
+}
+
+Quad = {
+  vertices : [
+    -1,-1,0,
+    1,-1,0,
+    -1,1,0,
+    1,-1,0,
+    1,1,0,
+    -1,1,0
+  ],
+  normals : [
+    0,0,-1,
+    0,0,-1,
+    0,0,-1,
+    0,0,-1,
+    0,0,-1,
+    0,0,-1
+  ],
+  texcoords : [
+    0,0,
+    1,0,
+    0,1,
+    1,0,
+    1,1,
+    0,1
+  ],
+  indices : [0,1,2,1,5,2],
+  makeVBO : function(gl) {
+    return new VBO(gl,
+        {size:3, data: Quad.vertices},
+        {size:3, data: Quad.normals},
+        {size:2, data: Quad.texcoords}
+    )
+  },
+  cache: {},
+  getCachedVBO : function(gl) {
+    if (!this.cache[gl])
+      this.cache[gl] = this.makeVBO(gl);
+    return this.cache[gl];
+  }
+}
+Cube = {
+  vertices : [  0.5, -0.5,  0.5, // +X
+                0.5, -0.5, -0.5,
+                0.5,  0.5, -0.5,
+                0.5,  0.5,  0.5,
+
+                0.5,  0.5,  0.5, // +Y
+                0.5,  0.5, -0.5,
+                -0.5,  0.5, -0.5,
+                -0.5,  0.5,  0.5,
+
+                0.5,  0.5,  0.5, // +Z
+                -0.5,  0.5,  0.5,
+                -0.5, -0.5,  0.5,
+                0.5, -0.5,  0.5,
+
+                -0.5, -0.5,  0.5, // -X
+                -0.5,  0.5,  0.5,
+                -0.5,  0.5, -0.5,
+                -0.5, -0.5, -0.5,
+
+                -0.5, -0.5,  0.5, // -Y
+                -0.5, -0.5, -0.5,
+                0.5, -0.5, -0.5,
+                0.5, -0.5,  0.5,
+
+                -0.5, -0.5, -0.5, // -Z
+                -0.5,  0.5, -0.5,
+                0.5,  0.5, -0.5,
+                0.5, -0.5, -0.5,
+      ],
+
+  normals : [ 1, 0, 0,
+              1, 0, 0,
+              1, 0, 0,
+              1, 0, 0,
+
+              0, 1, 0,
+              0, 1, 0,
+              0, 1, 0,
+              0, 1, 0,
+
+              0, 0, 1,
+              0, 0, 1,
+              0, 0, 1,
+              0, 0, 1,
+
+              -1, 0, 0,
+              -1, 0, 0,
+              -1, 0, 0,
+              -1, 0, 0,
+
+              0,-1, 0,
+              0,-1, 0,
+              0,-1, 0,
+              0,-1, 0,
+
+              0, 0,-1,
+              0, 0,-1,
+              0, 0,-1,
+              0, 0,-1
+      ],
+
+  indices : [],
+  create : function(){
+    for (var i = 0; i < 6; i++) {
+      Cube.indices.push(i*4 + 0);
+      Cube.indices.push(i*4 + 1);
+      Cube.indices.push(i*4 + 3);
+      Cube.indices.push(i*4 + 1);
+      Cube.indices.push(i*4 + 2);
+      Cube.indices.push(i*4 + 3);
+    }
+  },
+
+  makeVBO : function(gl) {
+    return new VBO(gl,
+        {size:3, data: Cube.vertices},
+        {size:3, data: Cube.normals},
+        {elements: true, data: Cube.indices}
+    )
+  },
+  cache : {},
+  getCachedVBO : function(gl) {
+    if (!this.cache[gl])
+      this.cache[gl] = this.makeVBO(gl);
+    return this.cache[gl];
+  }
+}
+Cube.create();
+
+Sphere = {
+  vertices : [],
+  normals : [],
+  indices : [],
+  create : function(){
+    var r = 0.75;
+    function vert(theta, phi)
+    {
+      var r = 0.75;
+      var x, y, z, nx, ny, nz;
+
+      nx = Math.sin(theta) * Math.cos(phi);
+      ny = Math.sin(phi);
+      nz = Math.cos(theta) * Math.cos(phi);
+      Sphere.normals.push(nx);
+      Sphere.normals.push(ny);
+      Sphere.normals.push(nz);
+
+      x = r * Math.sin(theta) * Math.cos(phi);
+      y = r * Math.sin(phi);
+      z = r * Math.cos(theta) * Math.cos(phi);
+      Sphere.vertices.push(x);
+      Sphere.vertices.push(y);
+      Sphere.vertices.push(z);
+    }
+    for (var phi = -Math.PI/2; phi < Math.PI/2; phi += Math.PI/20) {
+      var phi2 = phi + Math.PI/20;
+      for (var theta = -Math.PI/2; theta <= Math.PI/2; theta += Math.PI/20) {
+        vert(theta, phi);
+        vert(theta, phi2);
+      }
+    }
+  }
+}
+
+Sphere.create();
+
+initGL_CONTEXT_ID = function(){
+  var c = document.createElement('canvas');
+  var contextNames = ['webgl', 'experimental-webgl'];
+  GL_CONTEXT_ID = null;
+  for (var i=0; i<contextNames.length; i++) {
+    try {
+      if (c.getContext(contextNames[i])) {
+        GL_CONTEXT_ID = contextNames[i];
+        break;
+      }
+    } catch (e) {
+    }
+  }
+  if (!GL_CONTEXT_ID) {
+    log("No WebGL context found. Unable to run tests.");
+  }
+}
+
+initGL_CONTEXT_ID();