fixed.hpp

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// sbl/dsp/fixed.hpp — Fixed-point constants and audio sample types
//
// Phase convention: uint32_t full range [0, 2^32) = one cycle
 
#ifndef SBL_DSP_TYPES_FIXED_HPP_
#define SBL_DSP_TYPES_FIXED_HPP_
 
#include <cstdint>
 
namespace sbl::dsp::types {
 
// Master sample rate. All DSP coefficient math reads this directly — no per-
// component sample_rate_ members. Set once at audio init, never changes at
// runtime. Tests can modify between batch runs (tear down DSP graph, set new
// rate, rebuild, run all tests again).
inline uint32_t SAMPLE_RATE = 48000;
inline float SAMPLE_RATE_F = 48000.0f;
 
// 24-bit audio sample range (matches SAI/I2S int32 format)
inline constexpr int32_t SAMPLE_MAX_24 =  8388607;   // 2^23 - 1
inline constexpr int32_t SAMPLE_MIN_24 = -8388607;   // -(2^23 - 1), symmetric
 
/// Clamp value to 24-bit audio range
inline constexpr int32_t saturate_24(int32_t x) {
    return (x > SAMPLE_MAX_24) ? SAMPLE_MAX_24
         : (x < SAMPLE_MIN_24) ? SAMPLE_MIN_24
         : x;
}
 
} // namespace sbl::dsp::types
 
#endif // SBL_DSP_TYPES_FIXED_HPP_