-// 40.24 fixpoint math
-#define FIXPOINT_ONE 0x1000000
-
-class FixedPointLinearInterpolation : public Interpolation {
- protected:
- /// speed in fixed point math
- uint64_t phi;
-
- /// target speed in fixed point math
- uint64_t target_phi;
-
- std::vector<uint64_t> last_phase;
-
- // Fixed point is just an integer with an implied scaling factor.
- // In 40.24 the scaling factor is 2^24 = 16777216,
- // so a value of 10*2^24 (in integer space) is equivalent to 10.0.
- //
- // The advantage is that addition and modulus [like x = (x + y) % 2^40]
- // have no rounding errors and no drift, and just require a single integer add.
- // (swh)
-
- static const int64_t fractional_part_mask = 0xFFFFFF;
- static const Sample binary_scaling_factor = 16777216.0f;
-
- public:
-
- FixedPointLinearInterpolation () : phi (FIXPOINT_ONE), target_phi (FIXPOINT_ONE) {}
-
- void set_speed (double new_speed) {
- target_phi = (uint64_t) (FIXPOINT_ONE * fabs(new_speed));
- phi = target_phi;
- }
-
- uint64_t get_phi() { return phi; }
- uint64_t get_target_phi() { return target_phi; }
- uint64_t get_last_phase() { assert(last_phase.size()); return last_phase[0]; }
- void set_last_phase(uint64_t phase) { assert(last_phase.size()); last_phase[0] = phase; }
-
- void add_channel_to (int input_buffer_size, int output_buffer_size);
- void remove_channel_from ();
-
- nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output);
- void reset ();