From 6c655321e6b04b8648802e296bb5ca11d290ae68 Mon Sep 17 00:00:00 2001 From: swurl Date: Sat, 31 May 2025 02:33:02 -0400 Subject: Move dead submodules in-tree Signed-off-by: swurl --- .../main/cpp/analyzer/RoundedManchesterEncoder.h | 88 ++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 externals/oboe/apps/OboeTester/app/src/main/cpp/analyzer/RoundedManchesterEncoder.h (limited to 'externals/oboe/apps/OboeTester/app/src/main/cpp/analyzer/RoundedManchesterEncoder.h') diff --git a/externals/oboe/apps/OboeTester/app/src/main/cpp/analyzer/RoundedManchesterEncoder.h b/externals/oboe/apps/OboeTester/app/src/main/cpp/analyzer/RoundedManchesterEncoder.h new file mode 100644 index 0000000000..51461526ce --- /dev/null +++ b/externals/oboe/apps/OboeTester/app/src/main/cpp/analyzer/RoundedManchesterEncoder.h @@ -0,0 +1,88 @@ +/* + * Copyright 2019 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef ANALYZER_ROUNDED_MANCHESTER_ENCODER_H +#define ANALYZER_ROUNDED_MANCHESTER_ENCODER_H + +#include +#include +#include +#include "ManchesterEncoder.h" + +/** + * Encode bytes using Manchester Code. + * Round the edges using a half cosine to reduce ringing caused by a hard edge. + */ + +class RoundedManchesterEncoder : public ManchesterEncoder { +public: + RoundedManchesterEncoder(int samplesPerPulse) + : ManchesterEncoder(samplesPerPulse) { + int rampSize = samplesPerPulse / 4; + mZeroAfterZero = std::make_unique(samplesPerPulse); + mZeroAfterOne = std::make_unique(samplesPerPulse); + + int sampleIndex = 0; + for (int rampIndex = 0; rampIndex < rampSize; rampIndex++) { + float phase = (rampIndex + 1) * M_PI / rampSize; + float sample = -cosf(phase); + mZeroAfterZero[sampleIndex] = sample; + mZeroAfterOne[sampleIndex] = 1.0f; + sampleIndex++; + } + for (int rampIndex = 0; rampIndex < rampSize; rampIndex++) { + mZeroAfterZero[sampleIndex] = 1.0f; + mZeroAfterOne[sampleIndex] = 1.0f; + sampleIndex++; + } + for (int rampIndex = 0; rampIndex < rampSize; rampIndex++) { + float phase = (rampIndex + 1) * M_PI / rampSize; + float sample = cosf(phase); + mZeroAfterZero[sampleIndex] = sample; + mZeroAfterOne[sampleIndex] = sample; + sampleIndex++; + } + for (int rampIndex = 0; rampIndex < rampSize; rampIndex++) { + mZeroAfterZero[sampleIndex] = -1.0f; + mZeroAfterOne[sampleIndex] = -1.0f; + sampleIndex++; + } + } + + void onNextBit(bool current) override { + // Do we need to use the rounded edge? + mCurrentSamples = (current ^ mPreviousBit) + ? mZeroAfterOne.get() + : mZeroAfterZero.get(); + mPreviousBit = current; + } + + float nextFloat() override { + advanceSample(); + float output = mCurrentSamples[mCursor]; + if (getCurrentBit()) output = -output; + return output; + } + +private: + + bool mPreviousBit = false; + float *mCurrentSamples = nullptr; + std::unique_ptr mZeroAfterZero; + std::unique_ptr mZeroAfterOne; +}; + +#endif //ANALYZER_ROUNDED_MANCHESTER_ENCODER_H -- cgit v1.2.3