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Diffstat (limited to 'src/random.c')
| -rw-r--r-- | src/random.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/src/random.c b/src/random.c new file mode 100644 index 0000000..45d8de8 --- /dev/null +++ b/src/random.c @@ -0,0 +1,237 @@ +/* + 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/ext/morph/morph.h" +#include "lv2/lv2plug.in/ns/ext/options/options.h" +#include "lv2/lv2plug.in/ns/lv2core/lv2.h" +#include <time.h> +#include "math_func.h" +#include "common.h" +#include "uris.h" + +#define RANDOM_FREQUENCY 0 +#define RANDOM_SMOOTH 1 +#define RANDOM_OUTPUT 2 + +typedef struct { + const float* frequency; + const float* smooth; + float* output; + float nyquist; + float inv_nyquist; + float phase; + float value1; + float value2; + uint32_t frequency_is_cv; + uint32_t smooth_is_cv; + URIs uris; +} 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 = (const float*)data; + break; + case RANDOM_SMOOTH: + plugin->smooth = (const float*)data; + break; + case RANDOM_OUTPUT: + plugin->output = (float*)data; + break; + } +} + +static uint32_t +options_set(LV2_Handle instance, + const LV2_Options_Option* options) +{ + Random* plugin = (Random*)instance; + uint32_t ret = 0; + for (const LV2_Options_Option* o = options; o->key; ++o) { + if (o->context != LV2_OPTIONS_PORT) { + ret |= LV2_OPTIONS_ERR_BAD_SUBJECT; + } else if (o->key != plugin->uris.morph_currentType) { + ret |= LV2_OPTIONS_ERR_BAD_KEY; + } else if (o->type != plugin->uris.atom_URID) { + ret |= LV2_OPTIONS_ERR_BAD_VALUE; + } else { + LV2_URID port_type = *(const LV2_URID*)(o->value); + if (port_type != plugin->uris.lv2_ControlPort && + port_type != plugin->uris.lv2_CVPort) { + ret |= LV2_OPTIONS_ERR_BAD_VALUE; + continue; + } + + switch (o->subject) { + case RANDOM_FREQUENCY: + plugin->frequency_is_cv = (port_type == plugin->uris.lv2_CVPort); + break; + case RANDOM_SMOOTH: + plugin->smooth_is_cv = (port_type == plugin->uris.lv2_CVPort); + break; + default: + ret |= LV2_OPTIONS_ERR_BAD_SUBJECT; + } + } + } + return ret; +} + +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)); + if (!plugin) { + return NULL; + } + + 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; + + plugin->frequency_is_cv = 0; + plugin->smooth_is_cv = 0; + + map_uris(&plugin->uris, features); + + return (LV2_Handle)plugin; +} + +static void +activate(LV2_Handle instance) +{ + Random* plugin = (Random*)instance; + + plugin->phase = 0.0f; +} + +static void +run(LV2_Handle instance, + uint32_t sample_count) +{ + Random* plugin = (Random*)instance; + + /* Frequency (Hz) (array of floats of length 1 or sample_count) */ + const float* frequency = plugin->frequency; + + /* Wave smoothness (array of floats of length 1 or sample_count) */ + const 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 result; + + for (uint32_t s = 0; s < sample_count; ++s) { + const float freq = f_clip(frequency[s * plugin->frequency_is_cv], + 0.0f, nyquist); + + const float smth = f_clip(smooth[s * plugin->smooth_is_cv], + 0.0f, 1.0f); + + const float 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 const void* +extension_data(const char* uri) +{ + static const LV2_Options_Interface options = { NULL, options_set }; + if (!strcmp(uri, LV2_OPTIONS__interface)) { + return &options; + } + return NULL; +} + +static const LV2_Descriptor descriptor = { + "http://drobilla.net/plugins/blop/random", + instantiate, + connect_port, + activate, + run, + NULL, + cleanup, + extension_data, +}; + +LV2_SYMBOL_EXPORT const LV2_Descriptor* +lv2_descriptor(uint32_t index) +{ + switch (index) { + case 0: return &descriptor; + default: return NULL; + } +} |