headless option

1 files changed, 885 insertions, 0 deletions

diff --git a/src/headless.js b/src/headless.js
new file mode 100644
index 00000000..a528e8af
--- /dev/null
+++ b/src/headless.js
@@ -0,0 +1,885 @@
+
+//== HEADLESS ==//
+
+var window = {
+  location: {
+    toString: function() {
+      return '%s';
+    },
+    search: '?%s',
+  },
+  fakeNow: 0, // we don't use Date.now()
+  rafs: [],
+  timeouts: [],
+  uid: 0,
+  requestAnimationFrame: function(func) {
+    func.uid = window.uid++;
+    print('adding raf ' + func.uid);
+    window.rafs.push(func);
+  },
+  setTimeout: function(func, ms) {
+    func.uid = window.uid++;
+    print('adding timeout ' + func.uid);
+    window.timeouts.push({
+      func: func,
+      when: window.fakeNow + (ms || 0)
+    });
+    window.timeouts.sort(function(x, y) { return y.when - x.when });
+  },
+  onIdle: %s,
+  runEventLoop: function() {
+    // run forever until an exception stops this replay
+    var iter = 0;
+    while (1) {
+      var start = Recorder.dnow();
+      print('event loop: ' + (iter++));
+      if (window.rafs.length == 0 && window.timeouts.length == 0) {
+        if (window.onIdle) {
+          window.onIdle();
+        } else {
+          throw 'main loop is idle!';
+        }
+      }
+      // rafs
+      var currRafs = window.rafs;
+      window.rafs = [];
+      for (var i = 0; i < currRafs.length; i++) {
+        var raf = currRafs[i];
+        print('calling raf: ' + raf.uid);// + ': ' + raf.toString().substring(0, 50));
+        raf();
+      }
+      // timeouts
+      var now = window.fakeNow;
+      var timeouts = window.timeouts;
+      window.timeouts = [];
+      while (timeouts.length && timeouts[timeouts.length-1].when <= now) {
+        var timeout = timeouts.pop();
+        print('calling timeout: ' + timeout.func.uid);// + ': ' + timeout.func.toString().substring(0, 50));
+        timeout.func();
+      }
+      // increment 'time'
+      window.fakeNow += 16.666;
+      print('main event loop iteration took ' + (Recorder.dnow() - start) + ' ms');
+    }
+  },
+  URL: {
+    createObjectURL: function(x) {
+      return x; // the blob itself is returned
+    },
+    revokeObjectURL: function(x) {},
+  },
+};
+var setTimeout = window.setTimeout;
+var document = {
+  eventListeners: {},
+  addEventListener: function(id, func) {
+    var listeners = this.eventListeners[id];
+    if (!listeners) {
+      listeners = this.eventListeners[id] = [];
+    }
+    listeners.push(func);
+  },
+  callEventListeners: function(id) {
+    var listeners = this.eventListeners[id];
+    if (listeners) {
+      listeners.forEach(function(listener) { listener() });
+    }
+  },
+  getElementById: function(id) {
+    switch(id) {
+      case 'canvas': {
+        if (this.canvas) return this.canvas;
+        return this.canvas = {
+          getContext: function(which) {
+            switch(which) {
+              case 'experimental-webgl': {
+                return {
+                  /* ClearBufferMask */
+                  DEPTH_BUFFER_BIT               : 0x00000100,
+                  STENCIL_BUFFER_BIT             : 0x00000400,
+                  COLOR_BUFFER_BIT               : 0x00004000,
+                  
+                  /* BeginMode */
+                  POINTS                         : 0x0000,
+                  LINES                          : 0x0001,
+                  LINE_LOOP                      : 0x0002,
+                  LINE_STRIP                     : 0x0003,
+                  TRIANGLES                      : 0x0004,
+                  TRIANGLE_STRIP                 : 0x0005,
+                  TRIANGLE_FAN                   : 0x0006,
+                  
+                  /* AlphaFunction (not supported in ES20) */
+                  /*      NEVER */
+                  /*      LESS */
+                  /*      EQUAL */
+                  /*      LEQUAL */
+                  /*      GREATER */
+                  /*      NOTEQUAL */
+                  /*      GEQUAL */
+                  /*      ALWAYS */
+                  
+                  /* BlendingFactorDest */
+                  ZERO                           : 0,
+                  ONE                            : 1,
+                  SRC_COLOR                      : 0x0300,
+                  ONE_MINUS_SRC_COLOR            : 0x0301,
+                  SRC_ALPHA                      : 0x0302,
+                  ONE_MINUS_SRC_ALPHA            : 0x0303,
+                  DST_ALPHA                      : 0x0304,
+                  ONE_MINUS_DST_ALPHA            : 0x0305,
+                  
+                  /* BlendingFactorSrc */
+                  /*      ZERO */
+                  /*      ONE */
+                  DST_COLOR                      : 0x0306,
+                  ONE_MINUS_DST_COLOR            : 0x0307,
+                  SRC_ALPHA_SATURATE             : 0x0308,
+                  /*      SRC_ALPHA */
+                  /*      ONE_MINUS_SRC_ALPHA */
+                  /*      DST_ALPHA */
+                  /*      ONE_MINUS_DST_ALPHA */
+                  
+                  /* BlendEquationSeparate */
+                  FUNC_ADD                       : 0x8006,
+                  BLEND_EQUATION                 : 0x8009,
+                  BLEND_EQUATION_RGB             : 0x8009,   /* same as BLEND_EQUATION */
+                  BLEND_EQUATION_ALPHA           : 0x883D,
+                  
+                  /* BlendSubtract */
+                  FUNC_SUBTRACT                  : 0x800A,
+                  FUNC_REVERSE_SUBTRACT          : 0x800B,
+                  
+                  /* Separate Blend Functions */
+                  BLEND_DST_RGB                  : 0x80C8,
+                  BLEND_SRC_RGB                  : 0x80C9,
+                  BLEND_DST_ALPHA                : 0x80CA,
+                  BLEND_SRC_ALPHA                : 0x80CB,
+                  CONSTANT_COLOR                 : 0x8001,
+                  ONE_MINUS_CONSTANT_COLOR       : 0x8002,
+                  CONSTANT_ALPHA                 : 0x8003,
+                  ONE_MINUS_CONSTANT_ALPHA       : 0x8004,
+                  BLEND_COLOR                    : 0x8005,
+                  
+                  /* Buffer Objects */
+                  ARRAY_BUFFER                   : 0x8892,
+                  ELEMENT_ARRAY_BUFFER           : 0x8893,
+                  ARRAY_BUFFER_BINDING           : 0x8894,
+                  ELEMENT_ARRAY_BUFFER_BINDING   : 0x8895,
+                  
+                  STREAM_DRAW                    : 0x88E0,
+                  STATIC_DRAW                    : 0x88E4,
+                  DYNAMIC_DRAW                   : 0x88E8,
+                  
+                  BUFFER_SIZE                    : 0x8764,
+                  BUFFER_USAGE                   : 0x8765,
+                  
+                  CURRENT_VERTEX_ATTRIB          : 0x8626,
+                  
+                  /* CullFaceMode */
+                  FRONT                          : 0x0404,
+                  BACK                           : 0x0405,
+                  FRONT_AND_BACK                 : 0x0408,
+                  
+                  /* DepthFunction */
+                  /*      NEVER */
+                  /*      LESS */
+                  /*      EQUAL */
+                  /*      LEQUAL */
+                  /*      GREATER */
+                  /*      NOTEQUAL */
+                  /*      GEQUAL */
+                  /*      ALWAYS */
+                  
+                  /* EnableCap */
+                  /* TEXTURE_2D */
+                  CULL_FACE                      : 0x0B44,
+                  BLEND                          : 0x0BE2,
+                  DITHER                         : 0x0BD0,
+                  STENCIL_TEST                   : 0x0B90,
+                  DEPTH_TEST                     : 0x0B71,
+                  SCISSOR_TEST                   : 0x0C11,
+                  POLYGON_OFFSET_FILL            : 0x8037,
+                  SAMPLE_ALPHA_TO_COVERAGE       : 0x809E,
+                  SAMPLE_COVERAGE                : 0x80A0,
+                  
+                  /* ErrorCode */
+                  NO_ERROR                       : 0,
+                  INVALID_ENUM                   : 0x0500,
+                  INVALID_VALUE                  : 0x0501,
+                  INVALID_OPERATION              : 0x0502,
+                  OUT_OF_MEMORY                  : 0x0505,
+                  
+                  /* FrontFaceDirection */
+                  CW                             : 0x0900,
+                  CCW                            : 0x0901,
+                  
+                  /* GetPName */
+                  LINE_WIDTH                     : 0x0B21,
+                  ALIASED_POINT_SIZE_RANGE       : 0x846D,
+                  ALIASED_LINE_WIDTH_RANGE       : 0x846E,
+                  CULL_FACE_MODE                 : 0x0B45,
+                  FRONT_FACE                     : 0x0B46,
+                  DEPTH_RANGE                    : 0x0B70,
+                  DEPTH_WRITEMASK                : 0x0B72,
+                  DEPTH_CLEAR_VALUE              : 0x0B73,
+                  DEPTH_FUNC                     : 0x0B74,
+                  STENCIL_CLEAR_VALUE            : 0x0B91,
+                  STENCIL_FUNC                   : 0x0B92,
+                  STENCIL_FAIL                   : 0x0B94,
+                  STENCIL_PASS_DEPTH_FAIL        : 0x0B95,
+                  STENCIL_PASS_DEPTH_PASS        : 0x0B96,
+                  STENCIL_REF                    : 0x0B97,
+                  STENCIL_VALUE_MASK             : 0x0B93,
+                  STENCIL_WRITEMASK              : 0x0B98,
+                  STENCIL_BACK_FUNC              : 0x8800,
+                  STENCIL_BACK_FAIL              : 0x8801,
+                  STENCIL_BACK_PASS_DEPTH_FAIL   : 0x8802,
+                  STENCIL_BACK_PASS_DEPTH_PASS   : 0x8803,
+                  STENCIL_BACK_REF               : 0x8CA3,
+                  STENCIL_BACK_VALUE_MASK        : 0x8CA4,
+                  STENCIL_BACK_WRITEMASK         : 0x8CA5,
+                  VIEWPORT                       : 0x0BA2,
+                  SCISSOR_BOX                    : 0x0C10,
+                  /*      SCISSOR_TEST */
+                  COLOR_CLEAR_VALUE              : 0x0C22,
+                  COLOR_WRITEMASK                : 0x0C23,
+                  UNPACK_ALIGNMENT               : 0x0CF5,
+                  PACK_ALIGNMENT                 : 0x0D05,
+                  MAX_TEXTURE_SIZE               : 0x0D33,
+                  MAX_VIEWPORT_DIMS              : 0x0D3A,
+                  SUBPIXEL_BITS                  : 0x0D50,
+                  RED_BITS                       : 0x0D52,
+                  GREEN_BITS                     : 0x0D53,
+                  BLUE_BITS                      : 0x0D54,
+                  ALPHA_BITS                     : 0x0D55,
+                  DEPTH_BITS                     : 0x0D56,
+                  STENCIL_BITS                   : 0x0D57,
+                  POLYGON_OFFSET_UNITS           : 0x2A00,
+                  /*      POLYGON_OFFSET_FILL */
+                  POLYGON_OFFSET_FACTOR          : 0x8038,
+                  TEXTURE_BINDING_2D             : 0x8069,
+                  SAMPLE_BUFFERS                 : 0x80A8,
+                  SAMPLES                        : 0x80A9,
+                  SAMPLE_COVERAGE_VALUE          : 0x80AA,
+                  SAMPLE_COVERAGE_INVERT         : 0x80AB,
+                  
+                  /* GetTextureParameter */
+                  /*      TEXTURE_MAG_FILTER */
+                  /*      TEXTURE_MIN_FILTER */
+                  /*      TEXTURE_WRAP_S */
+                  /*      TEXTURE_WRAP_T */
+                  
+                  COMPRESSED_TEXTURE_FORMATS     : 0x86A3,
+                  
+                  /* HintMode */
+                  DONT_CARE                      : 0x1100,
+                  FASTEST                        : 0x1101,
+                  NICEST                         : 0x1102,
+                  
+                  /* HintTarget */
+                  GENERATE_MIPMAP_HINT            : 0x8192,
+                  
+                  /* DataType */
+                  BYTE                           : 0x1400,
+                  UNSIGNED_BYTE                  : 0x1401,
+                  SHORT                          : 0x1402,
+                  UNSIGNED_SHORT                 : 0x1403,
+                  INT                            : 0x1404,
+                  UNSIGNED_INT                   : 0x1405,
+                  FLOAT                          : 0x1406,
+                  
+                  /* PixelFormat */
+                  DEPTH_COMPONENT                : 0x1902,
+                  ALPHA                          : 0x1906,
+                  RGB                            : 0x1907,
+                  RGBA                           : 0x1908,
+                  LUMINANCE                      : 0x1909,
+                  LUMINANCE_ALPHA                : 0x190A,
+                  
+                  /* PixelType */
+                  /*      UNSIGNED_BYTE */
+                  UNSIGNED_SHORT_4_4_4_4         : 0x8033,
+                  UNSIGNED_SHORT_5_5_5_1         : 0x8034,
+                  UNSIGNED_SHORT_5_6_5           : 0x8363,
+                  
+                  /* Shaders */
+                  FRAGMENT_SHADER                  : 0x8B30,
+                  VERTEX_SHADER                    : 0x8B31,
+                  MAX_VERTEX_ATTRIBS               : 0x8869,
+                  MAX_VERTEX_UNIFORM_VECTORS       : 0x8DFB,
+                  MAX_VARYING_VECTORS              : 0x8DFC,
+                  MAX_COMBINED_TEXTURE_IMAGE_UNITS : 0x8B4D,
+                  MAX_VERTEX_TEXTURE_IMAGE_UNITS   : 0x8B4C,
+                  MAX_TEXTURE_IMAGE_UNITS          : 0x8872,
+                  MAX_FRAGMENT_UNIFORM_VECTORS     : 0x8DFD,
+                  SHADER_TYPE                      : 0x8B4F,
+                  DELETE_STATUS                    : 0x8B80,
+                  LINK_STATUS                      : 0x8B82,
+                  VALIDATE_STATUS                  : 0x8B83,
+                  ATTACHED_SHADERS                 : 0x8B85,
+                  ACTIVE_UNIFORMS                  : 0x8B86,
+                  ACTIVE_ATTRIBUTES                : 0x8B89,
+                  SHADING_LANGUAGE_VERSION         : 0x8B8C,
+                  CURRENT_PROGRAM                  : 0x8B8D,
+                  
+                  /* StencilFunction */
+                  NEVER                          : 0x0200,
+                  LESS                           : 0x0201,
+                  EQUAL                          : 0x0202,
+                  LEQUAL                         : 0x0203,
+                  GREATER                        : 0x0204,
+                  NOTEQUAL                       : 0x0205,
+                  GEQUAL                         : 0x0206,
+                  ALWAYS                         : 0x0207,
+                  
+                  /* StencilOp */
+                  /*      ZERO */
+                  KEEP                           : 0x1E00,
+                  REPLACE                        : 0x1E01,
+                  INCR                           : 0x1E02,
+                  DECR                           : 0x1E03,
+                  INVERT                         : 0x150A,
+                  INCR_WRAP                      : 0x8507,
+                  DECR_WRAP                      : 0x8508,
+                  
+                  /* StringName */
+                  VENDOR                         : 0x1F00,
+                  RENDERER                       : 0x1F01,
+                  VERSION                        : 0x1F02,
+                  
+                  /* TextureMagFilter */
+                  NEAREST                        : 0x2600,
+                  LINEAR                         : 0x2601,
+                  
+                  /* TextureMinFilter */
+                  /*      NEAREST */
+                  /*      LINEAR */
+                  NEAREST_MIPMAP_NEAREST         : 0x2700,
+                  LINEAR_MIPMAP_NEAREST          : 0x2701,
+                  NEAREST_MIPMAP_LINEAR          : 0x2702,
+                  LINEAR_MIPMAP_LINEAR           : 0x2703,
+                  
+                  /* TextureParameterName */
+                  TEXTURE_MAG_FILTER             : 0x2800,
+                  TEXTURE_MIN_FILTER             : 0x2801,
+                  TEXTURE_WRAP_S                 : 0x2802,
+                  TEXTURE_WRAP_T                 : 0x2803,
+                  
+                  /* TextureTarget */
+                  TEXTURE_2D                     : 0x0DE1,
+                  TEXTURE                        : 0x1702,
+                  
+                  TEXTURE_CUBE_MAP               : 0x8513,
+                  TEXTURE_BINDING_CUBE_MAP       : 0x8514,
+                  TEXTURE_CUBE_MAP_POSITIVE_X    : 0x8515,
+                  TEXTURE_CUBE_MAP_NEGATIVE_X    : 0x8516,
+                  TEXTURE_CUBE_MAP_POSITIVE_Y    : 0x8517,
+                  TEXTURE_CUBE_MAP_NEGATIVE_Y    : 0x8518,
+                  TEXTURE_CUBE_MAP_POSITIVE_Z    : 0x8519,
+                  TEXTURE_CUBE_MAP_NEGATIVE_Z    : 0x851A,
+                  MAX_CUBE_MAP_TEXTURE_SIZE      : 0x851C,
+                  
+                  /* TextureUnit */
+                  TEXTURE0                       : 0x84C0,
+                  TEXTURE1                       : 0x84C1,
+                  TEXTURE2                       : 0x84C2,
+                  TEXTURE3                       : 0x84C3,
+                  TEXTURE4                       : 0x84C4,
+                  TEXTURE5                       : 0x84C5,
+                  TEXTURE6                       : 0x84C6,
+                  TEXTURE7                       : 0x84C7,
+                  TEXTURE8                       : 0x84C8,
+                  TEXTURE9                       : 0x84C9,
+                  TEXTURE10                      : 0x84CA,
+                  TEXTURE11                      : 0x84CB,
+                  TEXTURE12                      : 0x84CC,
+                  TEXTURE13                      : 0x84CD,
+                  TEXTURE14                      : 0x84CE,
+                  TEXTURE15                      : 0x84CF,
+                  TEXTURE16                      : 0x84D0,
+                  TEXTURE17                      : 0x84D1,
+                  TEXTURE18                      : 0x84D2,
+                  TEXTURE19                      : 0x84D3,
+                  TEXTURE20                      : 0x84D4,
+                  TEXTURE21                      : 0x84D5,
+                  TEXTURE22                      : 0x84D6,
+                  TEXTURE23                      : 0x84D7,
+                  TEXTURE24                      : 0x84D8,
+                  TEXTURE25                      : 0x84D9,
+                  TEXTURE26                      : 0x84DA,
+                  TEXTURE27                      : 0x84DB,
+                  TEXTURE28                      : 0x84DC,
+                  TEXTURE29                      : 0x84DD,
+                  TEXTURE30                      : 0x84DE,
+                  TEXTURE31                      : 0x84DF,
+                  ACTIVE_TEXTURE                 : 0x84E0,
+                  
+                  /* TextureWrapMode */
+                  REPEAT                         : 0x2901,
+                  CLAMP_TO_EDGE                  : 0x812F,
+                  MIRRORED_REPEAT                : 0x8370,
+                  
+                  /* Uniform Types */
+                  FLOAT_VEC2                     : 0x8B50,
+                  FLOAT_VEC3                     : 0x8B51,
+                  FLOAT_VEC4                     : 0x8B52,
+                  INT_VEC2                       : 0x8B53,
+                  INT_VEC3                       : 0x8B54,
+                  INT_VEC4                       : 0x8B55,
+                  BOOL                           : 0x8B56,
+                  BOOL_VEC2                      : 0x8B57,
+                  BOOL_VEC3                      : 0x8B58,
+                  BOOL_VEC4                      : 0x8B59,
+                  FLOAT_MAT2                     : 0x8B5A,
+                  FLOAT_MAT3                     : 0x8B5B,
+                  FLOAT_MAT4                     : 0x8B5C,
+                  SAMPLER_2D                     : 0x8B5E,
+                  SAMPLER_CUBE                   : 0x8B60,
+                  
+                  /* Vertex Arrays */
+                  VERTEX_ATTRIB_ARRAY_ENABLED        : 0x8622,
+                  VERTEX_ATTRIB_ARRAY_SIZE           : 0x8623,
+                  VERTEX_ATTRIB_ARRAY_STRIDE         : 0x8624,
+                  VERTEX_ATTRIB_ARRAY_TYPE           : 0x8625,
+                  VERTEX_ATTRIB_ARRAY_NORMALIZED     : 0x886A,
+                  VERTEX_ATTRIB_ARRAY_POINTER        : 0x8645,
+                  VERTEX_ATTRIB_ARRAY_BUFFER_BINDING : 0x889F,
+                  
+                  /* Shader Source */
+                  COMPILE_STATUS                 : 0x8B81,
+                  
+                  /* Shader Precision-Specified Types */
+                  LOW_FLOAT                      : 0x8DF0,
+                  MEDIUM_FLOAT                   : 0x8DF1,
+                  HIGH_FLOAT                     : 0x8DF2,
+                  LOW_INT                        : 0x8DF3,
+                  MEDIUM_INT                     : 0x8DF4,
+                  HIGH_INT                       : 0x8DF5,
+                  
+                  /* Framebuffer Object. */
+                  FRAMEBUFFER                    : 0x8D40,
+                  RENDERBUFFER                   : 0x8D41,
+                  
+                  RGBA4                          : 0x8056,
+                  RGB5_A1                        : 0x8057,
+                  RGB565                         : 0x8D62,
+                  DEPTH_COMPONENT16              : 0x81A5,
+                  STENCIL_INDEX                  : 0x1901,
+                  STENCIL_INDEX8                 : 0x8D48,
+                  DEPTH_STENCIL                  : 0x84F9,
+                  
+                  RENDERBUFFER_WIDTH             : 0x8D42,
+                  RENDERBUFFER_HEIGHT            : 0x8D43,
+                  RENDERBUFFER_INTERNAL_FORMAT   : 0x8D44,
+                  RENDERBUFFER_RED_SIZE          : 0x8D50,
+                  RENDERBUFFER_GREEN_SIZE        : 0x8D51,
+                  RENDERBUFFER_BLUE_SIZE         : 0x8D52,
+                  RENDERBUFFER_ALPHA_SIZE        : 0x8D53,
+                  RENDERBUFFER_DEPTH_SIZE        : 0x8D54,
+                  RENDERBUFFER_STENCIL_SIZE      : 0x8D55,
+                  
+                  FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE           : 0x8CD0,
+                  FRAMEBUFFER_ATTACHMENT_OBJECT_NAME           : 0x8CD1,
+                  FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL         : 0x8CD2,
+                  FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE : 0x8CD3,
+                  
+                  COLOR_ATTACHMENT0              : 0x8CE0,
+                  DEPTH_ATTACHMENT               : 0x8D00,
+                  STENCIL_ATTACHMENT             : 0x8D20,
+                  DEPTH_STENCIL_ATTACHMENT       : 0x821A,
+                  
+                  NONE                           : 0,
+                  
+                  FRAMEBUFFER_COMPLETE                      : 0x8CD5,
+                  FRAMEBUFFER_INCOMPLETE_ATTACHMENT         : 0x8CD6,
+                  FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT : 0x8CD7,
+                  FRAMEBUFFER_INCOMPLETE_DIMENSIONS         : 0x8CD9,
+                  FRAMEBUFFER_UNSUPPORTED                   : 0x8CDD,
+                  
+                  FRAMEBUFFER_BINDING            : 0x8CA6,
+                  RENDERBUFFER_BINDING           : 0x8CA7,
+                  MAX_RENDERBUFFER_SIZE          : 0x84E8,
+                  
+                  INVALID_FRAMEBUFFER_OPERATION  : 0x0506,
+                  
+                  /* WebGL-specific enums */
+                  UNPACK_FLIP_Y_WEBGL            : 0x9240,
+                  UNPACK_PREMULTIPLY_ALPHA_WEBGL : 0x9241,
+                  CONTEXT_LOST_WEBGL             : 0x9242,
+                  UNPACK_COLORSPACE_CONVERSION_WEBGL : 0x9243,
+                  BROWSER_DEFAULT_WEBGL          : 0x9244,
+
+                  items: {},
+                  id: 0,
+                  getExtension: function() { return 1 },
+                  createBuffer: function() {
+                    var id = this.id++;
+                    this.items[id] = {
+                      which: 'buffer',
+                    };
+                    return id;
+                  },
+                  deleteBuffer: function(){},
+                  bindBuffer: function(){},
+                  bufferData: function(){},
+                  getParameter: function(pname) {
+                    switch(pname) {
+                      case /* GL_VENDOR                           */ 0x1F00: return 'FakeShellGLVendor';
+                      case /* GL_RENDERER                         */ 0x1F01: return 'FakeShellGLRenderer';
+                      case /* GL_VERSION                          */ 0x1F02: return '0.0.1';
+                      case /* GL_MAX_TEXTURE_SIZE                 */ 0x0D33: return 16384;
+                      case /* GL_MAX_CUBE_MAP_TEXTURE_SIZE        */ 0x851C: return 16384;
+                      case /* GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT   */ 0x84FF: return 16;
+                      case /* GL_MAX_TEXTURE_IMAGE_UNITS_NV       */ 0x8872: return 16;
+                      case /* GL_MAX_VERTEX_UNIFORM_VECTORS       */ 0x8DFB: return 4096;
+                      case /* GL_MAX_FRAGMENT_UNIFORM_VECTORS     */ 0x8DFD: return 4096;
+                      case /* GL_MAX_VARYING_VECTORS              */ 0x8DFC: return 32;
+                      case /* GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS */ 0x8B4D: return 32;
+                      default: throw 'getParameter ' + pname;
+                    }
+                  },
+                  getSupportedExtensions: function() {
+                    return ["OES_texture_float", "OES_standard_derivatives", "EXT_texture_filter_anisotropic", "MOZ_EXT_texture_filter_anisotropic", "MOZ_WEBGL_lose_context", "MOZ_WEBGL_compressed_texture_s3tc", "MOZ_WEBGL_depth_texture"];
+                  },
+                  createShader: function(type) {
+                    var id = this.id++;
+                    this.items[id] = {
+                      which: 'shader',
+                      type: type,
+                    };
+                    return id;
+                  },
+                  getShaderParameter: function(shader, pname) {
+                    switch(pname) {
+                      case /* GL_SHADER_TYPE    */ 0x8B4F: return this.items[shader].type;
+                      case /* GL_COMPILE_STATUS */ 0x8B81: return true;
+                      default: throw 'getShaderParameter ' + pname;
+                    }
+                  },
+                  shaderSource: function(){},
+                  compileShader: function(){},
+                  createProgram: function() {
+                    var id = this.id++;
+                    this.items[id] = {
+                      which: 'program',
+                      shaders: [],
+                    };
+                    return id;
+                  },
+                  attachShader: function(program, shader) {
+                    this.items[program].shaders.push(shader);
+                  },
+                  bindAttribLocation: function(){},
+                  linkProgram: function(){},
+                  getProgramParameter: function(program, pname) {
+                    switch(pname) {
+                      case /* LINK_STATUS     */ 0x8B82: return true;
+                      case /* ACTIVE_UNIFORMS */ 0x8B86: return 4;
+                      default: throw 'getProgramParameter ' + pname;
+                    }
+                  },
+                  deleteShader: function(){},
+                  deleteProgram: function(){},
+                  viewport: function(){},
+                  clearColor: function(){},
+                  clearDepth: function(){},
+                  depthFunc: function(){},
+                  enable: function(){},
+                  disable: function(){},
+                  frontFace: function(){},
+                  cullFace: function(){},
+                  activeTexture: function(){},
+                  createTexture: function() {
+                    var id = this.id++;
+                    this.items[id] = {
+                      which: 'texture',
+                    };
+                    return id;
+                  },
+                  deleteTexture: function(){},
+                  boundTextures: {},
+                  bindTexture: function(target, texture) {
+                    this.boundTextures[target] = texture;
+                  },
+                  texParameteri: function(){},
+                  pixelStorei: function(){},
+                  texImage2D: function(){},
+                  compressedTexImage2D: function(){},
+                  useProgram: function(){},
+                  getUniformLocation: function() {
+                    return null;
+                  },
+                  getActiveUniform: function(program, index) {
+                    return {
+                      size: 1,
+                      type: /* INT_VEC3 */ 0x8B54,
+                      name: 'activeUniform' + index,
+                    };
+                  },
+                  clear: function(){},
+                  uniform4fv: function(){},
+                  uniform1i: function(){},
+                  getAttribLocation: function() { return 1 },
+                  vertexAttribPointer: function(){},
+                  enableVertexAttribArray: function(){},
+                  disableVertexAttribArray: function(){},
+                  drawElements: function(){},
+                  drawArrays: function(){},
+                  depthMask: function(){},
+                  depthRange: function(){},
+                  bufferSubData: function(){},
+                  blendFunc: function(){},
+                  createFramebuffer: function() {
+                    var id = this.id++;
+                    this.items[id] = {
+                      which: 'framebuffer',
+                      shaders: [],
+                    };
+                    return id;
+                  },
+                  bindFramebuffer: function(){},
+                  framebufferTexture2D: function(){},
+                  checkFramebufferStatus: function() {
+                    return /* FRAMEBUFFER_COMPLETE */ 0x8CD5;
+                  },
+                  createRenderbuffer: function() {
+                    var id = this.id++;
+                    this.items[id] = {
+                      which: 'renderbuffer',
+                      shaders: [],
+                    };
+                    return id;
+                  },
+                  bindRenderbuffer: function(){},
+                  renderbufferStorage: function(){},
+                  framebufferRenderbuffer: function(){},
+                  scissor: function(){},
+                  colorMask: function(){},
+                  lineWidth: function(){},
+                };
+              }
+              case '2d': {
+                return {
+                  drawImage: function(){},
+                  getImageData: function(x, y, w, h) {
+                    return {
+                      width: w,
+                      height: h,
+                      data: new Uint8ClampedArray(w*h),
+                    };
+                  },
+                  save: function(){},
+                  restore: function(){},
+                  fillRect: function(){},
+                  measureText: function() { return 10 },
+                  fillText: function(){},
+                };
+              }
+              default: throw 'canvas.getContext: ' + which;
+            }
+          },
+          requestPointerLock: function() {
+            document.pointerLockElement = document.getElementById('canvas');
+            window.setTimeout(function() {
+              document.callEventListeners('pointerlockchange');
+            });
+          },
+          style: {},
+          eventListeners: {},
+          addEventListener: document.addEventListener,
+          callEventListeners: document.callEventListeners,
+          requestFullScreen: function() {
+            document.fullscreenElement = document.getElementById('canvas');
+            window.setTimeout(function() {
+              document.callEventListeners('fullscreenchange');
+            });
+          },
+          offsetTop: 0,
+          offsetLeft: 0,
+        };
+      }
+      case 'status-text': case 'progress': {
+        return {};
+      }
+      default: throw 'getElementById: ' + id;
+    }
+  },
+  createElement: function(what) {
+    switch (what) {
+      case 'canvas': return document.getElementById(what);
+      case 'script': {
+        var ret = {};
+        window.setTimeout(function() {
+          print('loading script: ' + ret.src);
+          load(ret.src);
+          print('   script loaded.');
+          if (ret.onload) {
+            window.setTimeout(function() {
+              ret.onload(); // yeah yeah this might vanish
+            });
+          }
+        });
+        return ret;
+      }
+      default: throw 'createElement ' + what;
+    }
+  },
+  elements: {},
+  querySelector: function(id) {
+    if (!document.elements[id]) {
+      document.elements[id] = {
+        classList: {
+          add: function(){},
+          remove: function(){},
+        },
+        eventListeners: {},
+        addEventListener: document.addEventListener,
+        callEventListeners: document.callEventListeners,
+      };
+    };
+    return document.elements[id];
+  },
+  styleSheets: [{
+    cssRules: [],
+    insertRule: function(){},
+  }],
+  body: {
+    appendChild: function(){},
+  },
+};
+var alert = function(x) {
+  print(x);
+};
+var originalDateNow = Date.now;
+var performance = {
+  now: function() {
+    return originalDateNow.call(Date);
+  },
+};
+function fixPath(path) {
+  if (path[0] == '/') path = path.substring(1);
+  var dirsToDrop = %d; // go back to root dir if first_js is in a subdir
+  for (var i = 0; i < dirsToDrop; i++) {
+    path = '../' + path;
+  }
+  return path
+}
+var XMLHttpRequest = function() {
+  return {
+    open: function(mode, path, async) {
+      path = fixPath(path);
+      this.mode = mode;
+      this.path = path;
+      this.async = async;
+    },
+    send: function() {
+      if (!this.async) {
+        this.doSend();
+      } else {
+        var that = this;
+        window.setTimeout(function() {
+          that.doSend();
+          if (that.onload) that.onload();
+        }, 0);
+      }
+    },
+    doSend: function() {
+      if (this.responseType == 'arraybuffer') {
+        this.response = read(this.path, 'binary');
+      } else {
+        this.responseText = read(this.path);
+      }
+    },
+  };
+};
+var Audio = function() {
+  return {
+    play: function(){},
+    pause: function(){},
+    cloneNode: function() {
+      return this;
+    },
+  };
+};
+var Image = function() {
+  var that = this;
+  window.setTimeout(function() {
+    that.complete = true;
+    that.width = 64;
+    that.height = 64;
+    if (that.onload) that.onload();
+  });
+};
+var Worker = function(workerPath) {
+  workerPath = fixPath(workerPath);
+  var workerCode = read(workerPath);
+  workerCode = workerCode.replace(/Module/g, 'zzModuleyy' + (Worker.id++)). // prevent collision with the global Module object. Note that this becomes global, so we need unique ids
+                          replace(/Date.now/g, 'Recorder.dnow'). // recorded values are just for the "main thread" - workers were not recorded, and should not consume
+                          replace(/performance.now/g, 'Recorder.pnow').
+                          replace(/Math.random/g, 'Recorder.random').
+                          replace(/\nonmessage = /, '\nvar onmessage = '); // workers commonly do "onmessage = ", we need to varify that to sandbox
+  print('loading worker ' + workerPath + ' : ' + workerCode.substring(0, 50));
+  eval(workerCode); // will implement onmessage()
+
+  function duplicateJSON(json) {
+    function handleTypedArrays(key, value) {
+      if (value && value.toString && value.toString().substring(0, 8) == '[object ' && value.length && value.byteLength) {
+        return Array.prototype.slice.call(value);
+      }
+      return value;
+    }
+    return JSON.parse(JSON.stringify(json, handleTypedArrays))
+  }
+  this.terminate = function(){};
+  this.postMessage = function(msg) {
+    msg.messageId = Worker.messageId++;
+    print('main thread sending message ' + msg.messageId + ' to worker ' + workerPath);
+    window.setTimeout(function() {
+      print('worker ' + workerPath + ' receiving message ' + msg.messageId);
+      onmessage({ data: duplicateJSON(msg) });
+    });
+  };
+  var thisWorker = this;
+  var postMessage = function(msg) {
+    msg.messageId = Worker.messageId++;
+    print('worker ' + workerPath + ' sending message ' + msg.messageId);
+    window.setTimeout(function() {
+      print('main thread receiving message ' + msg.messageId + ' from ' + workerPath);
+      thisWorker.onmessage({ data: duplicateJSON(msg) });
+    });
+  };
+};
+Worker.id = 0;
+Worker.messageId = 0;
+var screen = { // XXX these values may need to be adjusted
+  width: 2100,
+  height: 1313,
+  availWidth: 2100,
+  availHeight: 1283,
+};
+var console = {
+  log: function(x) {
+    print(x);
+  },
+};
+var MozBlobBuilder = function() {
+  this.data = new Uint8Array(0);
+  this.append = function(buffer) {
+    var data = new Uint8Array(buffer);
+    var combined = new Uint8Array(this.data.length + data.length);
+    combined.set(this.data);
+    combined.set(data, this.data.length);
+    this.data = combined;
+  };
+  this.getBlob = function() {
+    return this.data.buffer; // return the buffer as a "blob". XXX We might need to change this if it is not opaque
+  };
+};
+
+// additional setup
+if (!Module['canvas']) {
+  Module['canvas'] = document.getElementById('canvas');
+}
+
+//== HEADLESS ==//
+