text: // ArgGenerators contains argument generators for WebGL functions.
  // The argument generators are used for running random tests against the WebGL
  // functions.
  //
  // ArgGenerators is an object consisting of functionName : argGen -properties.
  //
  // functionName is a WebGL context function name and the argGen is an argument
  // generator object that encapsulates the requirements to run
  // randomly generated tests on the WebGL function.
  //
  // An argGen object has the following methods:
  //   - setup    -- set up state for testing the GL function, returns values
  //                 that need cleanup in teardown. Run once before entering a
  //                 test loop.
  //   - teardown -- do cleanup on setup's return values after testing is complete
  //   - generate -- generate a valid set of random arguments for the GL function
  //   - returnValueCleanup -- do cleanup on value returned by the tested GL function
  //   - cleanup  -- do cleanup on generated arguments from generate
  //   - checkArgValidity -- check if passed args are valid. Has a call signature
  //                         that matches generate's return value. Returns true
  //                         if args are valid, false if not.
  //
  //   Example test loop that demonstrates how the function args and return
  //   values flow together:
  //
  //   var setupArgs = argGen.setup();
  //   for (var i=0; i<numberOfTests; i++) {
  //     var generatedArgs = argGen.generate.apply(argGen, setupArgs);
  //     var validArgs = argGen.checkArgValidity.apply(argGen, generatedArgs);
  //     var rv = call the GL function with generatedArgs;
  //     argGen.returnValueCleanup(rv);
  //     argGen.cleanup.apply(argGen, generatedArgs);
  //   }
  //   argGen.teardown.apply(argGen, setupArgs);
  //
  ArgGenerators = {
  
  // GL functions in alphabetical order
  
  // L
  
    lineWidth : {
      generate : function() { return [randomLineWidth()]; },
      teardown : function() { GL.lineWidth(1); }
    },
    linkProgram : {}, // FIXME
  
  // P
    pixelStorei : {
      generate : function() {
        return [pixelStoreiPname.random(), pixelStoreiParam.random()];
      },
      checkArgValidity : function(pname, param) {
        return pixelStoreiPname.has(pname) && pixelStoreiParam.has(param);
      },
      teardown : function() {
        GL.pixelStorei(GL.PACK_ALIGNMENT, 4);
        GL.pixelStorei(GL.UNPACK_ALIGNMENT, 4);
      }
    },
    polygonOffset : {
      generate : function() { return [randomFloat(), randomFloat()]; },
      teardown : function() { GL.polygonOffset(0,0); }
    },
  
  // R
  
    readPixels : {}, // FIXME
    renderbufferStorage : {}, // FIXME
  
  // S-1
  
    sampleCoverage : {
      generate : function() { return [randomFloatFromRange(0,1), randomBool()] },
      teardown : function() { GL.sampleCoverage(1, false); }
    },
    scissor : {
      generate : function() {
        return [randomInt(3000)-1500, randomInt(3000)-1500, randomIntFromRange(0,3000), randomIntFromRange(0,3000)];
      },
      checkArgValidity : function(x,y,w,h) {
        return castToInt(w) >= 0 && castToInt(h) >= 0;
      },
      teardown : function() {
        GL.scissor(0,0,GL.canvas.width, GL.canvas.height);
      }
    },
    shaderSource : {}, // FIXME
    stencilFunc : {
      generate : function(){
        return [stencilFuncFunc.random(), randomInt(MaxStencilValue), randomInt(0xffffffff)];
      },
      checkArgValidity : function(func, ref, mask) {
        return stencilFuncFunc.has(func) && castToInt(ref) >= 0 && castToInt(ref) < MaxStencilValue;
      },
      teardown : function() {
        GL.stencilFunc(GL.ALWAYS, 0, 0xffffffff);
      }
    },
    stencilFuncSeparate : {
      generate : function(){
        return [cullFace.random(), stencilFuncFunc.random(), randomInt(MaxStencilValue), randomInt(0xffffffff)];
      },
      checkArgValidity : function(face, func, ref, mask) {
        return cullFace.has(face) && stencilFuncFunc.has(func) && castToInt(ref) >= 0 && castToInt(ref) < MaxStencilValue;
      },
      teardown : function() {
        GL.stencilFunc(GL.ALWAYS, 0, 0xffffffff);
      }
    },
    stencilMask : {
      generate : function() { return [randomInt(0xffffffff)]; },
      teardown : function() { GL.stencilMask(0xffffffff); }
    }
  
  };
  