bwp_env_gen_v2

Advanced version of bw_env_gen with extra delay and hold phases (DAHDSHR), controllable linear/exponential curve shapes, fixed phase duration (with variable-length attack phase option), higher/sub-sample accuracy, and loop mode.

The sustain parameter implement modulation as detailed in bwp_mod_func. Modulation is however internally limited to avoid instability.

Examples

We can privately hand you one or more example plugins if you are interested.

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API

Module type: DSP

bwp_env_gen_v2_coeffs

typedef struct bwp_env_gen_v2_coeffs bwp_env_gen_v2_coeffs;

Coefficients and related.

bwp_env_gen_v2_state

typedef struct bwp_env_gen_v2_state bwp_env_gen_v2_state;

Internal state and related.

bwp_env_gen_v2_phase

typedef enum {
	bwp_env_gen_v2_phase_off,
	bwp_env_gen_v2_phase_delay,
	bwp_env_gen_v2_phase_attack,
	bwp_env_gen_v2_phase_ad_hold,
	bwp_env_gen_v2_phase_decay,
	bwp_env_gen_v2_phase_sustain,
	bwp_env_gen_v2_phase_hold,
	bwp_env_gen_v2_phase_release
} bwp_env_gen_v2_phase;

Envelope generator phase:

  • bwp_env_gen_v2_phase_off: off phase;
  • bwp_env_gen_v2_phase_delay: delay phase;
  • bwp_env_gen_v2_phase_attack: attack phase;
  • bwp_env_gen_v2_phase_ad_hold: attack/decay hold phase;
  • bwp_env_gen_v2_phase_decay: decay phase;
  • bwp_env_gen_v2_phase_sustain: sustain phase;
  • bwp_env_gen_v2_phase_hold: hold phase;
  • bwp_env_gen_v2_phase_release: release phase.

bwp_env_gen_v2_init()

static inline void bwp_env_gen_v2_init(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs);

Initializes input parameter values in coeffs.

bwp_env_gen_v2_set_sample_rate()

static inline void bwp_env_gen_v2_set_sample_rate(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               sample_rate);

Sets the sample_rate (Hz) value in coeffs.

bwp_env_gen_v2_reset_coeffs()

static inline void bwp_env_gen_v2_reset_coeffs(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs);

Resets coefficients in coeffs to assume their target values.

bwp_env_gen_v2_reset_state()

static inline float bwp_env_gen_v2_reset_state(
	const bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	bwp_env_gen_v2_state * BW_RESTRICT        state,
	char                                      gate_0);

Resets the given state to its initial values using the given coeffs and the initial gate value (0 for off, non-0 for on) gate_0.

Returns the corresponding initial output value.

bwp_env_gen_v2_reset_state_multi()

static inline void bwp_env_gen_v2_reset_state_multi(
	const bwp_env_gen_v2_coeffs * BW_RESTRICT              coeffs,
	bwp_env_gen_v2_state * BW_RESTRICT const * BW_RESTRICT state,
	const char * BW_RESTRICT                               gate_0,
	float * BW_RESTRICT                                    y_0,
	size_t                                                 n_channels);

Resets each of the n_channels states to its initial values using the given coeffs and the corresponding initial gate values (0 for off, non-0 for on) in the gate_0 array.

The corresponding initial output values are written into the y_0 array, if not BW_NULL.

bwp_env_gen_v2_update_coeffs_ctrl()

static inline void bwp_env_gen_v2_update_coeffs_ctrl(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs);

Triggers control-rate update of coefficients in coeffs.

bwp_env_gen_v2_update_coeffs_audio()

static inline void bwp_env_gen_v2_update_coeffs_audio(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs);

Triggers audio-rate update of coefficients in coeffs.

bwp_env_gen_v2_process_ctrl()

static inline void bwp_env_gen_v2_process_ctrl(
	const bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	bwp_env_gen_v2_state * BW_RESTRICT        state,
	char                                      gate);

Triggers control-rate update of the internal state using coeffs and the given gate value (0 for off, non-0 for on).

bwp_env_gen_v2_process1*()

static inline float bwp_env_gen_v2_process1(
	const bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	bwp_env_gen_v2_state * BW_RESTRICT        state);

static inline float bwp_env_gen_v2_process1_mod_sustain(
	const bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	bwp_env_gen_v2_state * BW_RESTRICT        state,
	float                                     x_mod_sustain);

These functions generates and return one sample using coeffs, while using and updating state (audio rate only).

bwp_env_gen_v2_process1() does not apply sustain modulation, unlike bwp_env_gen_v2_process1_mod_sustain() which takes the x_mod_sustain audio-rate modulation signal.

bwp_env_gen_v2_process()

static inline void bwp_env_gen_v2_process(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	bwp_env_gen_v2_state * BW_RESTRICT  state,
	char                                gate,
	const float *                       x_mod_sustain,
	float *                             y,
	size_t                              n_samples);

Generates and fills the first n_samples of the output buffer y using the given gate value (0 for off, non-0 for on), while using and updating both coeffs and state (control and audio rate).

If x_mod_sustain is not BW_NULL, it is used as a source of sustain modulation.

y may be BW_NULL.

bwp_env_gen_v2_process_multi()

static inline void bwp_env_gen_v2_process_multi(
	bwp_env_gen_v2_coeffs * BW_RESTRICT                    coeffs,
	bwp_env_gen_v2_state * BW_RESTRICT const * BW_RESTRICT state,
	const char * BW_RESTRICT                               gate,
	const float * const *                                  x_mod_sustain,
	float * const *                                        y,
	size_t                                                 n_channels,
	size_t                                                 n_samples);

Generates and fills the first n_samples of the n_channels output buffers y using the given n_channels gate values (0 for off, non-0 for on), while using and updating both the common coeffs and each of the n_channels states (control and audio rate).

If x_mod_sustain and the channel-specific element are not BW_NULL, this is used as a source of sustain modulation for that channel.

y or any element of y may be BW_NULL.

bwp_env_gen_v2_set_delay()

static inline void bwp_env_gen_v2_set_delay(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the delay time to value (s) in coeffs.

Valid range: [0.f, 600.f].

Default value: 0.f.

bwp_env_gen_v2_set_attack()

static inline void bwp_env_gen_v2_set_attack(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the attack time to value (s) in coeffs.

Valid range: [0.f, 600.f].

Default value: 0.f.

bwp_env_gen_v2_set_ad_hold()

static inline void bwp_env_gen_v2_set_ad_hold(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the attack/decay hold time to value (s) in coeffs.

Valid range: [0.f, 600.f].

Default value: 0.f.

bwp_env_gen_v2_set_decay()

static inline void bwp_env_gen_v2_set_decay(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the decay time to value (s) in coeffs.

Valid range: [0.f, 600.f].

Default value: 0.f.

bwp_env_gen_v2_set_sustain()

static inline void bwp_env_gen_v2_set_sustain(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the sustain level to value in coeffs.

Valid range: [0.f, 1.f].

Default value: 1.f.

bwp_env_gen_v2_set_sustain_mod()

static inline void bwp_env_gen_v2_set_sustain_mod(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the non-smoothed sustain level modulation component to the given value in coeffs.

value must be finite.

Default value: 0.f.

bwp_env_gen_v2_set_mod_func_sustain()

static inline void bwp_env_gen_v2_set_mod_func_sustain(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	bwp_mod_func                        value);

Sets the sustain level modulation function.

Default value: bwp_mod_func_sum.

bwp_env_gen_v2_set_hold()

static inline void bwp_env_gen_v2_set_hold(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the hold time to value (s) in coeffs.

Valid range: [0.f, 600.f].

Default value: 0.f.

bwp_env_gen_v2_set_release()

static inline void bwp_env_gen_v2_set_release(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the release time to value (s) in coeffs.

Valid range: [0.f, 600.f].

Default value: 0.f.

bwp_env_gen_v2_set_attack_midpoint()

static inline void bwp_env_gen_v2_set_attack_midpoint(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the attack midpoint value (%) in coeffs.

Valid range: [0.001f, 99.999f].

Default value: 50.f.

bwp_env_gen_v2_set_decay_midpoint()

static inline void bwp_env_gen_v2_set_decay_midpoint(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the decay midpoint value (%) in coeffs.

Valid range: [0.001f, 99.999f].

Default value: 50.f.

bwp_env_gen_v2_set_release_midpoint()

static inline void bwp_env_gen_v2_set_release_midpoint(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	float                               value);

Sets the release midpoint value (%) in coeffs.

Valid range: [0.001f, 99.999f].

Default value: 50.f.

bwp_env_gen_v2_set_attack_fixed()

static inline void bwp_env_gen_v2_set_attack_fixed(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	char                                value);

Sets whether the attack phase has fixed duration (value non-0) or not (0) in coeffs.

Default value: non-0 (fixed duration).

bwp_env_gen_v2_set_skip_sustain()

static inline void bwp_env_gen_v2_set_skip_sustain(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	char                                value);

Sets whether the sustain phase should be skipped (value non-0) or not (0).

Default value: 0 (do not skip).

bwp_env_gen_v2_set_skip_hold()

static inline void bwp_env_gen_v2_set_skip_hold(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	char                                value);

Sets whether the hold phase should be skipped (value non-0) or not (0).

Default value: 0 (do not skip).

bwp_env_gen_v2_set_always_reach_sustain()

static inline void bwp_env_gen_v2_set_always_reach_sustain(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	char                                value);

Sets whether the sustain phase should be reached even if gate goes off before (value non-0) or not (0).

Default value: 0 (off).

bwp_env_gen_v2_set_loop()

static inline void bwp_env_gen_v2_set_loop(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	char                                value);

Sets whether loop mode is on (value non-0) or not (0).

Default value: 0 (off).

bwp_env_gen_v2_set_skip_first_delay()

static inline void bwp_env_gen_v2_set_skip_first_delay(
	bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	char                                value);

Sets whether the delay phase (onlt the first one in loop mode) should be skipped (value non-0) or not (0).

Default value: 0 (do not skip).

bwp_env_gen_v2_get_phase()

static inline bwp_env_gen_v2_phase bwp_env_gen_v2_get_phase(
	const bwp_env_gen_v2_state * BW_RESTRICT state);

Returns the current envelope generator phase as stored in state.

bwp_env_gen_v2_get_y_z1()

static inline float bwp_env_gen_v2_get_y_z1(
	const bwp_env_gen_v2_state * BW_RESTRICT state);

Returns the last output sample as stored in state.

bwp_env_gen_v2_coeffs_is_valid()

static inline char bwp_env_gen_v2_coeffs_is_valid(
	const bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs);

Tries to determine whether coeffs is valid and returns non-0 if it seems to be the case and 0 if it is certainly not. False positives are possible, false negatives are not.

coeffs must at least point to a readable memory block of size greater than or equal to that of bwp_env_gen_v2_coeffs.

bwp_env_gen_v2_state_is_valid()

static inline char bwp_env_gen_v2_state_is_valid(
	const bwp_env_gen_v2_coeffs * BW_RESTRICT coeffs,
	const bwp_env_gen_v2_state * BW_RESTRICT  state);

Tries to determine whether state is valid and returns non-0 if it seems to be the case and 0 if it is certainly not. False positives are possible, false negatives are not.

If coeffs is not BW_NULL extra cross-checks might be performed (state is supposed to be associated to coeffs).

state must at least point to a readable memory block of size greater than or equal to that of bwp_env_gen_v2_state.

C++ wrapper

BrickworksPro::EnvGenV2
template<size_t N_CHANNELS = 1>
class EnvGenV2 {
public:
	EnvGenV2();

	void setSampleRate(
		float sampleRate);

	void reset(
		char                gate0 = 0,
		float * BW_RESTRICT y0 = BW_NULL);

# ifndef BW_CXX_NO_ARRAY
	void reset(
		char                                        gate0,
		std::array<float, N_CHANNELS> * BW_RESTRICT y0);
# endif

	void reset(
		const char * BW_RESTRICT gate0,
		float * BW_RESTRICT      y0 = BW_NULL);

# ifndef BW_CXX_NO_ARRAY
	void reset(
		std::array<char, N_CHANNELS>                gate0,
		std::array<float, N_CHANNELS> * BW_RESTRICT y0 = BW_NULL);
# endif

	void process(
		const char * BW_RESTRICT gate,
		const float * const *    xModSustain,
		float * const *          y,
		size_t                   nSamples);

# ifndef BW_CXX_NO_ARRAY
	void process(
		std::array<char, N_CHANNELS>          gate,
		std::array<const float *, N_CHANNELS> xModSustian,
		std::array<float *, N_CHANNELS>       y,
		size_t                                nSamples);
# endif

	void setDelay(
		float value);

	void setAttack(
		float value);

	void setADHold(
		float value);

	void setDecay(
		float value);

	void setSustain(
		float value);

	void setSustainMod(
		float value);

	void setModFuncSustain(
		bwp_mod_func value);

	void setHold(
		float value);

	void setRelease(
		float value);

	void setAttackMidpoint(
		float value);

	void setDecayMidpoint(
		float value);

	void setReleaseMidpoint(
		float value);

	void setAttackFixed(
		bool value);

	void setSkipSustain(
		bool value);

	void setSkipHold(
		bool value);

	void setAlwaysReachSustain(
		bool value);

	void setLoop(
		bool value);

	void setSkipFirstDelay(
		bool value);

	bwp_env_gen_v2_phase getPhase(
		size_t channel);

	float getYZ1(
		size_t channel);
...
}

Changelog

  • Verison 2.0.0:
    • Added attack/decay hold phase and ad_hold, loop mode, skip hold, skip first delay, and attack fixed parameters.
    • Added advanced sustain parameter modulation.
    • Enlarged maximum phase durations to 600 s.
    • Added default value for N_CHANNELS in C++ API.
    • Fixed bug by which skip_sustain was not taken into account in bwp_env_gen_process_ctrl().
    • Fixed bug by which could have bwp_env_gen_coeffs_is_valid() return false negatives.
    • Added an explicit cast in implementation to fix a compiler warning.
    • Fixed typo in the documentation of bwp_env_gen_set_release_midpoint().
    • Updated dependencies.
  • Verison 1.0.1:
    • Now using BW_NULL in the C++ API and implementation.
    • Updated dependencies in the distribution.
  • Version 1.0.0:
    • First release.