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Diffstat (limited to 'src/random.c')
-rw-r--r-- | src/random.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/src/random.c b/src/random.c new file mode 100644 index 0000000..9aab30a --- /dev/null +++ b/src/random.c @@ -0,0 +1,348 @@ +/* + An LV2 plugin to generate a random wave of varying frequency and smoothness. + Copyright 2011 David Robillard + Copyright 2002 Mike Rawes + + This is free software: you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This software is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this software. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdlib.h> +#include "lv2/lv2plug.in/ns/lv2core/lv2.h" +#include <time.h> +#include "math_func.h" +#include "common.h" + +#define RANDOM_FREQUENCY 0 +#define RANDOM_SMOOTH 1 +#define RANDOM_OUTPUT 2 + +typedef struct { + float* frequency; + float* smooth; + float* output; + float nyquist; + float inv_nyquist; + float phase; + float value1; + float value2; +} Random; + +float inv_rand_max; + +static void +cleanup(LV2_Handle instance) +{ + free(instance); +} + +static void +connect_port(LV2_Handle instance, + uint32_t port, + void* data) +{ + Random* plugin = (Random*)instance; + + switch (port) { + case RANDOM_FREQUENCY: + plugin->frequency = data; + break; + case RANDOM_SMOOTH: + plugin->smooth = data; + break; + case RANDOM_OUTPUT: + plugin->output = data; + break; + } +} + +static LV2_Handle +instantiate(const LV2_Descriptor* descriptor, + double sample_rate, + const char* bundle_path, + const LV2_Feature* const* features) +{ + Random* plugin = (Random*)malloc(sizeof(Random)); + + srand((int)time((time_t*)0)); + + inv_rand_max = 2.0f / (float)RAND_MAX; + + plugin->nyquist = (float)sample_rate / 2.0f; + plugin->inv_nyquist = 1.0f / plugin->nyquist; + + plugin->value1 = rand() * inv_rand_max - 1.0f; + plugin->value2 = rand() * inv_rand_max - 1.0f; + + return (LV2_Handle)plugin; +} + +static void +activate(LV2_Handle instance) +{ + Random* plugin = (Random*)instance; + + plugin->phase = 0.0f; +} + +static void +runRandom_fasa_oa(LV2_Handle instance, + uint32_t sample_count) +{ + Random* plugin = (Random*)instance; + + /* Frequency (Hz) (array of floats of length sample_count) */ + float* frequency = plugin->frequency; + + /* Wave smoothness (array of floats of length sample_count) */ + float* smooth = plugin->smooth; + + /* Output (array of floats of length sample_count) */ + float* output = plugin->output; + + /* Instance data */ + float nyquist = plugin->nyquist; + float inv_nyquist = plugin->inv_nyquist; + float phase = plugin->phase; + float value1 = plugin->value1; + float value2 = plugin->value2; + + float freq; + float smth; + float interval; + float result; + + for (uint32_t s = 0; s < sample_count; ++s) { + freq = f_clip(frequency[s], 0.0f, nyquist); + + smth = f_clip(smooth[s], 0.0f, 1.0f); + interval = (1.0f - smth) * 0.5f; + + if (phase < interval) { + result = 1.0f; + } else if (phase > (1.0f - interval)) { + result = -1.0f; + } else if (interval > 0.0f) { + result = COSF((phase - interval) / smth * M_PI); + } else { + result = COSF(phase * M_PI); + } + + result *= (value2 - value1) * 0.5f; + result -= (value2 + value1) * 0.5f; + + output[s] = result; + + phase += freq * inv_nyquist; + if (phase > 1.0f) { + phase -= 1.0f; + value1 = value2; + value2 = (float)rand() * inv_rand_max - 1.0f; + } + } + + plugin->phase = phase; + plugin->value1 = value1; + plugin->value2 = value2; +} + +static void +runRandom_fasc_oa(LV2_Handle instance, + uint32_t sample_count) +{ + Random* plugin = (Random*)instance; + + /* Frequency (Hz) (array of floats of length sample_count) */ + float* frequency = plugin->frequency; + + /* Wave smoothness (float value) */ + float smooth = f_clip(*(plugin->smooth), 0.0f, 1.0f); + + /* Output (array of floats of length sample_count) */ + float* output = plugin->output; + + /* Instance data */ + float nyquist = plugin->nyquist; + float inv_nyquist = plugin->inv_nyquist; + float phase = plugin->phase; + float value1 = plugin->value1; + float value2 = plugin->value2; + + float freq; + float interval = (1.0f - smooth) * 0.5f; + float result; + + for (uint32_t s = 0; s < sample_count; ++s) { + freq = f_clip(frequency[s], 0.0f, nyquist); + + if (phase < interval) { + result = 1.0f; + } else if (phase > (1.0f - interval)) { + result = -1.0f; + } else if (interval > 0.0f) { + result = COSF((phase - interval) / smooth * M_PI); + } else { + result = COSF(phase * M_PI); + } + + result *= (value2 - value1) * 0.5f; + result -= (value2 + value1) * 0.5f; + + output[s] = result; + + phase += freq * inv_nyquist; + if (phase > 1.0f) { + phase -= 1.0f; + value1 = value2; + value2 = (float)rand() * inv_rand_max - 1.0f; + } + } + + plugin->phase = phase; + plugin->value1 = value1; + plugin->value2 = value2; +} + +static void +runRandom_fcsa_oa(LV2_Handle instance, + uint32_t sample_count) +{ + Random* plugin = (Random*)instance; + + /* Frequency (Hz) (float value) */ + float frequency = *(plugin->frequency); + + /* Wave smoothness (array of floats of length sample_count) */ + float* smooth = plugin->smooth; + + /* Output (pointer to float value) */ + float* output = plugin->output; + + /* Instance data */ + float nyquist = plugin->nyquist; + float inv_nyquist = plugin->inv_nyquist; + float phase = plugin->phase; + float value1 = plugin->value1; + float value2 = plugin->value2; + + float phase_scale = f_clip(frequency, 0.0f, nyquist) * inv_nyquist; + float smth; + float interval; + float result; + + for (uint32_t s = 0; s < sample_count; ++s) { + smth = f_clip(smooth[s], 0.0f, 1.0f); + interval = (1.0f - smth) * 0.5f; + + if (phase < interval) { + result = 1.0f; + } else if (phase > (1.0f - interval)) { + result = -1.0f; + } else if (interval > 0.0f) { + result = COSF((phase - interval) / smth * M_PI); + } else { + result = COSF(phase * M_PI); + } + + result *= (value2 - value1) * 0.5f; + result -= (value2 + value1) * 0.5f; + + output[s] = result; + + phase += phase_scale; + if (phase > 1.0f) { + phase -= 1.0f; + value1 = value2; + value2 = (float)rand() * inv_rand_max - 1.0f; + } + } + + plugin->phase = phase; + plugin->value1 = value1; + plugin->value2 = value2; +} + +static void +runRandom_fcsc_oa(LV2_Handle instance, + uint32_t sample_count) +{ + Random* plugin = (Random*)instance; + + /* Frequency (Hz) (float value) */ + float frequency = *(plugin->frequency); + + /* Wave smoothness (float value) */ + float smooth = f_clip(*(plugin->smooth), 0.0f, 1.0f); + + /* Output (array of floats of length sample_count) */ + float* output = plugin->output; + + /* Instance data */ + float nyquist = plugin->nyquist; + float inv_nyquist = plugin->inv_nyquist; + float phase = plugin->phase; + float value1 = plugin->value1; + float value2 = plugin->value2; + + float phase_scale = f_clip(frequency, 0.0f, nyquist) * inv_nyquist; + float interval = (1.0f - smooth) * 0.5f; + float result; + + for (uint32_t s = 0; s < sample_count; ++s) { + if (phase < interval) { + result = 1.0f; + } else if (phase > (1.0f - interval)) { + result = -1.0f; + } else if (interval > 0.0f) { + result = COSF((phase - interval) / smooth * M_PI); + } else { + result = COSF(phase * M_PI); + } + + result *= (value2 - value1) * 0.5f; + result -= (value2 + value1) * 0.5f; + + output[s] = result; + + phase += phase_scale; + if (phase > 1.0f) { + phase -= 1.0f; + value1 = value2; + value2 = (float)rand() * inv_rand_max - 1.0f; + } + } + + plugin->phase = phase; + plugin->value1 = value1; + plugin->value2 = value2; +} + +static const LV2_Descriptor descriptor = { + "http://drobilla.net/plugins/blip/random", + instantiate, + connect_port, + activate, + runRandom_fcsc_oa, + NULL, + cleanup, + NULL, +}; + +LV2_SYMBOL_EXPORT const LV2_Descriptor* +lv2_descriptor(uint32_t index) +{ + switch (index) { + case 0: return &descriptor; + default: return NULL; + } +} |