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  1. // Copyright 2014 Olivier Gillet.
  2. //
  3. // Author: Olivier Gillet (ol.gillet@gmail.com)
  4. //
  5. // Permission is hereby granted, free of charge, to any person obtaining a copy
  6. // of this software and associated documentation files (the "Software"), to deal
  7. // in the Software without restriction, including without limitation the rights
  8. // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  9. // copies of the Software, and to permit persons to whom the Software is
  10. // furnished to do so, subject to the following conditions:
  11. //
  12. // The above copyright notice and this permission notice shall be included in
  13. // all copies or substantial portions of the Software.
  14. //
  15. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16. // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17. // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18. // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19. // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20. // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21. // THE SOFTWARE.
  22. //
  23. // See http://creativecommons.org/licenses/MIT/ for more information.
  24. //
  25. // -----------------------------------------------------------------------------
  26. //
  27. // Control of several parameters from one single knob.
  28. #ifndef STREAMS_META_PARAMETERS_H_
  29. #define STREAMS_META_PARAMETERS_H_
  30. #include "stmlib/stmlib.h"
  31. namespace streams {
  32. inline void ComputeAmountOffset(
  33. int32_t value,
  34. int32_t* amount,
  35. int32_t* offset) {
  36. if (value < 32768) {
  37. value = 32767 - value;
  38. value = value * value >> 15;
  39. *amount = (32767 - value) << 1;
  40. *offset = 0;
  41. } else {
  42. *amount = 65535 - ((value - 32768) << 1);
  43. *offset = (value - 32768) << 1;
  44. }
  45. }
  46. inline void ComputeAttackDecay(int32_t shape, uint16_t* a, uint16_t* d) {
  47. if (shape < 32768) {
  48. *a = 0;
  49. *d = 13 * (shape >> 3) + 12288;
  50. } else if (shape < 49152) {
  51. *a = (shape - 32768) << 1;
  52. *d = 65535 - ((shape - 32768) >> 1) * 3;
  53. } else {
  54. *a = 32768 - ((shape - 49152) >> 2) * 5;
  55. *d = 65535 - ((shape - 32768) >> 1) * 3;
  56. }
  57. }
  58. } // namespace streams
  59. #endif // STREAMS_META_PARAMETERS_H_