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/*
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Copyright 2013 Google Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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#ifndef __PITCHENV_H
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#define __PITCHENV_H
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// Computation of the DX7 pitch envelope
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class PitchEnv {
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public:
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static void init(FRAC_NUM sample_rate);
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// The rates and levels arrays are calibrated to match the Dx7 parameters
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// (ie, value 0..99).
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void set(const int rates[4], const int levels[4]);
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// Result is in Q24/octave
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int32_t getsample();
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void keydown(bool down);
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void getPosition(char *step);
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private:
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static int unit_;
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int rates_[4];
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int levels_[4];
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int32_t level_;
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int targetlevel_;
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bool rising_;
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int ix_;
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int inc_;
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bool down_;
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void advance(int newix);
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};
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extern const uint8_t pitchenv_rate[];
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extern const int8_t pitchenv_tab[];
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#endif // __PITCHENV_H
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