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Diffstat (limited to 'src/lp4pole.c')
| -rw-r--r-- | src/lp4pole.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/src/lp4pole.c b/src/lp4pole.c new file mode 100644 index 0000000..7d2eb6b --- /dev/null +++ b/src/lp4pole.c @@ -0,0 +1,206 @@ +/* + An LV2 plugin simulating a 4 pole low pass resonant filter. + Copyright 2011 David Robillard + Copyright 2003 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 "lp4pole_filter.h" +#include "common.h" +#include "uris.h" + +#define LP4POLE_CUTOFF 0 +#define LP4POLE_RESONANCE 1 +#define LP4POLE_INPUT 2 +#define LP4POLE_OUTPUT 3 + +typedef struct { + const float* cutoff; + const float* resonance; + const float* input; + float* output; + LP4PoleFilter* lpf; + uint32_t cutoff_is_cv; + uint32_t resonance_is_cv; + URIs uris; +} Lp4pole; + +static void +cleanup(LV2_Handle instance) +{ + Lp4pole* plugin = (Lp4pole*)instance; + + lp4pole_cleanup(plugin->lpf); + + free(instance); +} + +static void +connect_port(LV2_Handle instance, + uint32_t port, + void* data) +{ + Lp4pole* plugin = (Lp4pole*)instance; + + switch (port) { + case LP4POLE_CUTOFF: + plugin->cutoff = (const float*)data; + break; + case LP4POLE_RESONANCE: + plugin->resonance = (const float*)data; + break; + case LP4POLE_INPUT: + plugin->input = (const float*)data; + break; + case LP4POLE_OUTPUT: + plugin->output = (float*)data; + break; + } +} + +static uint32_t +options_set(LV2_Handle instance, + const LV2_Options_Option* options) +{ + Lp4pole* plugin = (Lp4pole*)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 LP4POLE_CUTOFF: + plugin->cutoff_is_cv = (port_type == plugin->uris.lv2_CVPort); + break; + case LP4POLE_RESONANCE: + plugin->resonance_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) +{ + Lp4pole* plugin = (Lp4pole*)malloc(sizeof(Lp4pole)); + + if (plugin) { + plugin->lpf = lp4pole_new(sample_rate); + if (!plugin->lpf) { + free(plugin); + return NULL; + } + plugin->cutoff_is_cv = 0; + plugin->resonance_is_cv = 0; + map_uris(&plugin->uris, features); + } + + return (LV2_Handle)plugin; +} + +static void +activate(LV2_Handle instance) +{ + Lp4pole* plugin = (Lp4pole*)instance; + + lp4pole_init(plugin->lpf); +} + +static void +run(LV2_Handle instance, + uint32_t sample_count) +{ + Lp4pole* plugin = (Lp4pole*)instance; + + /* Cutoff Frequency (array of floats of length 1 or sample_count) */ + const float* cutoff = plugin->cutoff; + + /* Resonance (array of floats of length 1 or sample_count) */ + const float* resonance = plugin->resonance; + + /* Input (array of floats of length sample_count) */ + const float* input = plugin->input; + + /* Output (pointer to float value) */ + float* output = plugin->output; + + /* Instance data */ + LP4PoleFilter* lpf = plugin->lpf; + + for (uint32_t s = 0; s < sample_count; ++s) { + const float co = cutoff[s * plugin->cutoff_is_cv]; + const float res = resonance[s * plugin->resonance_is_cv]; + const float in = input[s]; + + /* TODO: There is no branching in this function. + Would it actually be faster to check if co or res has changed? + */ + lp4pole_set_params(lpf, co, res); + + output[s] = lp4pole_run(lpf, in); + } +} + +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/lp4pole", + 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; + } +} |