cute_dsp
cute_dsp is a C API for various DSP effects suitable for video games and meant to interface directly with the cute_sound library created by Randy Gaul. The scope of cute_dsp will eventually include:
- Lowpass filter
- Highpass filter
- White noise injection
- Lowpass filtering with resonances
- Wind noise presets for resonant filters
- Realtime reverb
- Echo filter
- Randomization settings
- Filter presets
Implemented Features
Lowpass Filtering
Uses a second order Butterworth filter with a 6dB per octave rolloff, with added resonance.
Highpass Filtering
Uses a second order Butterworth filter with a 6dB per octave rolloff, converted from the lowpass filter equation, without resonance.
Echo Filtering
Uses two ring buffers for delay of input and output samples. There are three designable parameters:
- Delay time
- Mix factor (echo loudness)
- Feedback factor (amount that echoes feedback into themselves)
Noise Generator
Generates white noise and adds to a signal. The signal path of cute_dsp allows this white noise to be fed into other filters in the signal chain. The white noise is generated using a xorshift128 PRNG.
Usage
cute_dsp must be used concurrently with cute_sound.
To set up cute_dsp, #include "cute_dsp.h" somewhere below your include for cute_sound.h. Above the include to cute_dsp, there must be one place where you #define CUTE_DSP_IMPLEMENTATION.
cd_context_t
After creating your cs_context_t cute sound context, you will need to create a cute_dsp context.
cs_context_t* sound_context = cs_make_context(...);
cd_context_def_t dsp_context_definition; // statically create dsp context
// set the max number of mixers
dsp_context_definition.playing_pool_count = num_elements_in_playing_pool;
// set dsp sampling rate
dsp_context_definition.sampling_rate = (float)frequency;
// set which filters you would like to use and some optional parameters
dsp_context_definition.use_highpass = 1;
dsp_context_definition.use_lowpass = 1;
dsp_context_definition.use_echo = 0;
dsp_context_definition.use_noise = 1;
dsp_context_definition.echo_max_delay_s = 0.f;
dsp_context_definition.rand_seed = 2;
// allocate the context
cd_context_t* dsp_context = cd_make_context(dsp_context_definition);
//...
// at the end of the application, after shutting down the sound context, release the dsp context
cs_shutdown_context(sound_context);
cd_release_context(&dsp_context);
For each sound played using cute_sound, there will be a copy of each filter you've enabled added as a cute_sound plugin. However, the filter will by default set its internal values such that the effect of the filter is not audible. I.e. if you've enabled lowpass filters in cd_context_def_t, then each sound played using cute_sound will have an instance of a lowpass filter. That lowpass filter will have its cutoff frequency at 20kHz, therefore negating its effect.
cd_lowpass_t/cd_highpass_t
To modify the cutoff frequencies of the lowpass/highpass filters:
void cd_set_lowpass_cutoff(cs_playing_sound_t* playing_sound, float cutoff_in_hz);
void cd_set_lowpass_resonance(cs_playing_sound_t* playing_sound, float resonance);
void cd_set_highpass_cutoff(cs_playing_sound_t* playing_sound, float cutoff_in_hz);
float cd_get_lowpass_cutoff(const cs_playing_sound_t* playing_sound);
float cd_get_lowpass_resonance(const cs_playing_sound_t* playing_sound);
float cd_get_highpass_cutoff(const cs_playing_sound_t* playing_sound);
Cutoff frequency is limited to the range of frequencies able to be heard by humans, [20, 20,000] Hz. Resonance is limited to the range of [0, 1].
cd_echo_t
To modify the parameters of the echo filter:
void cd_set_echo_delay(cs_playing_sound_t* playing_sound, float t);
void cd_set_echo_mix(cs_playing_sound_t* playing_sound, float a);
void cd_set_echo_feedback(cs_playing_sound_t* playing_sound, float b);
float cd_get_echo_delay(const cs_playing_sound_t* playing_sound);
float cd_get_echo_mix(const cs_playing_sound_t* playing_sound);
float cd_get_echo_feedback(const cs_playing_sound_t* playing_sound);
float cd_get_echo_max_delay(const cs_playing_sound_t* playing_sound);
cd_noise_t
To modify the parameters of the noise generator:
void cd_set_noise_amplitude_db(cs_playing_sound_t* playing_sound, float db);
void cd_set_noise_amplitude_gain(cs_playing_sound_t* playing_sound, float gain);
float cd_get_noise_amplitude_db(const cs_playing_sound_t* playing_sound);
float cd_get_noise_amplitude_gain(const cs_playing_sound_t* playing_sound);
14 Nov 5, 2022
9 Sep 27, 2022
605 Dec 27, 2022
29 Sep 29, 2022
1.3k Jan 3, 2023
2 Nov 29, 2021
173 Jan 2, 2023
7 Nov 23, 2022
2.5k Dec 31, 2022
10.1k Jan 7, 2023
34 Dec 15, 2022
457 Dec 21, 2022
11 Apr 22, 2022
9 Jan 5, 2022
56 Dec 21, 2022
3 Dec 19, 2021
8 Dec 27, 2022
25 Dec 3, 2022
102 Dec 14, 2021
101 Dec 26, 2022
35 Jun 19, 2022
229 Jan 5, 2023
5 Jul 29, 2022
43 Dec 15, 2022
519 Jan 1, 2023
198 Dec 26, 2022
1.4k Jan 8, 2023