michael@0: // Helpers for Web Audio tests
michael@0: 
michael@0: function expectException(func, exceptionCode) {
michael@0:   var threw = false;
michael@0:   try {
michael@0:     func();
michael@0:   } catch (ex) {
michael@0:     threw = true;
michael@0:     ok(ex instanceof DOMException, "Expect a DOM exception");
michael@0:     is(ex.code, exceptionCode, "Expect the correct exception code");
michael@0:   }
michael@0:   ok(threw, "The exception was thrown");
michael@0: }
michael@0: 
michael@0: function expectNoException(func) {
michael@0:   var threw = false;
michael@0:   try {
michael@0:     func();
michael@0:   } catch (ex) {
michael@0:     threw = true;
michael@0:   }
michael@0:   ok(!threw, "An exception was not thrown");
michael@0: }
michael@0: 
michael@0: function expectTypeError(func) {
michael@0:   var threw = false;
michael@0:   try {
michael@0:     func();
michael@0:   } catch (ex) {
michael@0:     threw = true;
michael@0:     ok(ex instanceof TypeError, "Expect a TypeError");
michael@0:   }
michael@0:   ok(threw, "The exception was thrown");
michael@0: }
michael@0: 
michael@0: function fuzzyCompare(a, b) {
michael@0:   return Math.abs(a - b) < 9e-3;
michael@0: }
michael@0: 
michael@0: function compareChannels(buf1, buf2,
michael@0:                         /*optional*/ length,
michael@0:                         /*optional*/ sourceOffset,
michael@0:                         /*optional*/ destOffset,
michael@0:                         /*optional*/ skipLengthCheck) {
michael@0:   if (!skipLengthCheck) {
michael@0:     is(buf1.length, buf2.length, "Channels must have the same length");
michael@0:   }
michael@0:   sourceOffset = sourceOffset || 0;
michael@0:   destOffset = destOffset || 0;
michael@0:   if (length == undefined) {
michael@0:     length = buf1.length - sourceOffset;
michael@0:   }
michael@0:   var difference = 0;
michael@0:   var maxDifference = 0;
michael@0:   var firstBadIndex = -1;
michael@0:   for (var i = 0; i < length; ++i) {
michael@0:     if (!fuzzyCompare(buf1[i + sourceOffset], buf2[i + destOffset])) {
michael@0:       difference++;
michael@0:       maxDifference = Math.max(maxDifference, Math.abs(buf1[i + sourceOffset] - buf2[i + destOffset]));
michael@0:       if (firstBadIndex == -1) {
michael@0:         firstBadIndex = i;
michael@0:       }
michael@0:     }
michael@0:   };
michael@0: 
michael@0:   is(difference, 0, "maxDifference: " + maxDifference +
michael@0:      ", first bad index: " + firstBadIndex +
michael@0:      " with test-data offset " + sourceOffset + " and expected-data offset " +
michael@0:      destOffset + "; corresponding values " + buf1[firstBadIndex + sourceOffset] +
michael@0:      " and " + buf2[firstBadIndex + destOffset] + " --- differences");
michael@0: }
michael@0: 
michael@0: function compareBuffers(got, expected) {
michael@0:   if (got.numberOfChannels != expected.numberOfChannels) {
michael@0:     is(got.numberOfChannels, expected.numberOfChannels,
michael@0:        "Correct number of buffer channels");
michael@0:     return;
michael@0:   }
michael@0:   if (got.length != expected.length) {
michael@0:     is(got.length, expected.length,
michael@0:        "Correct buffer length");
michael@0:     return;
michael@0:   }
michael@0:   if (got.sampleRate != expected.sampleRate) {
michael@0:     is(got.sampleRate, expected.sampleRate,
michael@0:        "Correct sample rate");
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   for (var i = 0; i < got.numberOfChannels; ++i) {
michael@0:     compareChannels(got.getChannelData(i), expected.getChannelData(i),
michael@0:                     got.length, 0, 0, true);
michael@0:   }
michael@0: }
michael@0: 
michael@0: function getEmptyBuffer(context, length) {
michael@0:   return context.createBuffer(gTest.numberOfChannels, length, context.sampleRate);
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * This function assumes that the test file defines a single gTest variable with
michael@0:  * the following properties and methods:
michael@0:  *
michael@0:  * + numberOfChannels: optional property which specifies the number of channels
michael@0:  *                     in the output.  The default value is 2.
michael@0:  * + createGraph: mandatory method which takes a context object and does
michael@0:  *                everything needed in order to set up the Web Audio graph.
michael@0:  *                This function returns the node to be inspected.
michael@0:  * + createGraphAsync: async version of createGraph.  This function takes
michael@0:  *                     a callback which should be called with an argument
michael@0:  *                     set to the node to be inspected when the callee is
michael@0:  *                     ready to proceed with the test.  Either this function
michael@0:  *                     or createGraph must be provided.
michael@0:  * + createExpectedBuffers: optional method which takes a context object and
michael@0:  *                          returns either one expected buffer or an array of
michael@0:  *                          them, designating what is expected to be observed
michael@0:  *                          in the output.  If omitted, the output is expected
michael@0:  *                          to be silence.  All buffers must have the same
michael@0:  *                          length, which must be a bufferSize supported by
michael@0:  *                          ScriptProcessorNode.  This function is guaranteed
michael@0:  *                          to be called before createGraph.
michael@0:  * + length: property equal to the total number of frames which we are waiting
michael@0:  *           to see in the output, mandatory if createExpectedBuffers is not
michael@0:  *           provided, in which case it must be a bufferSize supported by
michael@0:  *           ScriptProcessorNode (256, 512, 1024, 2048, 4096, 8192, or 16384).
michael@0:  *           If createExpectedBuffers is provided then this must be equal to
michael@0:  *           the number of expected buffers * the expected buffer length.
michael@0:  *
michael@0:  * + skipOfflineContextTests: optional. when true, skips running tests on an offline
michael@0:  *                            context by circumventing testOnOfflineContext.
michael@0:  */
michael@0: function runTest()
michael@0: {
michael@0:   function done() {
michael@0:     SimpleTest.finish();
michael@0:   }
michael@0: 
michael@0:   SimpleTest.waitForExplicitFinish();
michael@0:   function runTestFunction () {
michael@0:     if (!gTest.numberOfChannels) {
michael@0:       gTest.numberOfChannels = 2; // default
michael@0:     }
michael@0: 
michael@0:     var testLength;
michael@0: 
michael@0:     function runTestOnContext(context, callback, testOutput) {
michael@0:       if (!gTest.createExpectedBuffers) {
michael@0:         // Assume that the output is silence
michael@0:         var expectedBuffers = getEmptyBuffer(context, gTest.length);
michael@0:       } else {
michael@0:         var expectedBuffers = gTest.createExpectedBuffers(context);
michael@0:       }
michael@0:       if (!(expectedBuffers instanceof Array)) {
michael@0:         expectedBuffers = [expectedBuffers];
michael@0:       }
michael@0:       var expectedFrames = 0;
michael@0:       for (var i = 0; i < expectedBuffers.length; ++i) {
michael@0:         is(expectedBuffers[i].numberOfChannels, gTest.numberOfChannels,
michael@0:            "Correct number of channels for expected buffer " + i);
michael@0:         expectedFrames += expectedBuffers[i].length;
michael@0:       }
michael@0:       if (gTest.length && gTest.createExpectedBuffers) {
michael@0:         is(expectedFrames, gTest.length, "Correct number of expected frames");
michael@0:       }
michael@0: 
michael@0:       if (gTest.createGraphAsync) {
michael@0:         gTest.createGraphAsync(context, function(nodeToInspect) {
michael@0:           testOutput(nodeToInspect, expectedBuffers, callback);
michael@0:         });
michael@0:       } else {
michael@0:         testOutput(gTest.createGraph(context), expectedBuffers, callback);
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     function testOnNormalContext(callback) {
michael@0:       function testOutput(nodeToInspect, expectedBuffers, callback) {
michael@0:         testLength = 0;
michael@0:         var sp = context.createScriptProcessor(expectedBuffers[0].length, gTest.numberOfChannels);
michael@0:         nodeToInspect.connect(sp);
michael@0:         sp.connect(context.destination);
michael@0:         sp.onaudioprocess = function(e) {
michael@0:           var expectedBuffer = expectedBuffers.shift();
michael@0:           testLength += expectedBuffer.length;
michael@0:           compareBuffers(e.inputBuffer, expectedBuffer);
michael@0:           if (expectedBuffers.length == 0) {
michael@0:             sp.onaudioprocess = null;
michael@0:             callback();
michael@0:           }
michael@0:         };
michael@0:       }
michael@0:       var context = new AudioContext();
michael@0:       runTestOnContext(context, callback, testOutput);
michael@0:     }
michael@0: 
michael@0:     function testOnOfflineContext(callback, sampleRate) {
michael@0:       function testOutput(nodeToInspect, expectedBuffers, callback) {
michael@0:         nodeToInspect.connect(context.destination);
michael@0:         context.oncomplete = function(e) {
michael@0:           var samplesSeen = 0;
michael@0:           while (expectedBuffers.length) {
michael@0:             var expectedBuffer = expectedBuffers.shift();
michael@0:             is(e.renderedBuffer.numberOfChannels, expectedBuffer.numberOfChannels,
michael@0:                "Correct number of input buffer channels");
michael@0:             for (var i = 0; i < e.renderedBuffer.numberOfChannels; ++i) {
michael@0:               compareChannels(e.renderedBuffer.getChannelData(i),
michael@0:                              expectedBuffer.getChannelData(i),
michael@0:                              expectedBuffer.length,
michael@0:                              samplesSeen,
michael@0:                              undefined,
michael@0:                              true);
michael@0:             }
michael@0:             samplesSeen += expectedBuffer.length;
michael@0:           }
michael@0:           callback();
michael@0:         };
michael@0:         context.startRendering();
michael@0:       }
michael@0: 
michael@0:       var context = new OfflineAudioContext(gTest.numberOfChannels, testLength, sampleRate);
michael@0:       runTestOnContext(context, callback, testOutput);
michael@0:     }
michael@0: 
michael@0:     testOnNormalContext(function() {
michael@0:       if (!gTest.skipOfflineContextTests) {
michael@0:         testOnOfflineContext(function() {
michael@0:           testOnOfflineContext(done, 44100);
michael@0:         }, 48000);
michael@0:       } else {
michael@0:         done();
michael@0:       }
michael@0:     });
michael@0:   };
michael@0: 
michael@0:   if (document.readyState !== 'complete') {
michael@0:     addLoadEvent(runTestFunction);
michael@0:   } else {
michael@0:     runTestFunction();
michael@0:   }
michael@0: }