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Diffstat (limited to 'src/amp.c')
-rw-r--r-- | src/amp.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/src/amp.c b/src/amp.c new file mode 100644 index 0000000..4c528f9 --- /dev/null +++ b/src/amp.c @@ -0,0 +1,142 @@ +/* + An LV2 plugin representing a simple mono amplifier. + 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 "math_func.h" + +#define AMP_GAIN 0 +#define AMP_INPUT 1 +#define AMP_OUTPUT 2 + +typedef struct { + const float* gain; + const float* input; + float* output; +} Amp; + +static void +cleanup(LV2_Handle instance) +{ + free(instance); +} + +static void +connect_port(LV2_Handle instance, + uint32_t port, + void* data) +{ + Amp* plugin = (Amp*)instance; + + switch (port) { + case AMP_GAIN: + plugin->gain = data; + break; + case AMP_INPUT: + plugin->input = data; + break; + case AMP_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) +{ + Amp* plugin = (Amp*)malloc(sizeof(Amp)); + + return (LV2_Handle)plugin; +} + +static void +runAmp_gaia_oa(LV2_Handle instance, + uint32_t sample_count) +{ + Amp* plugin = (Amp*)instance; + + /* Gain (dB) */ + const float* gain = plugin->gain; + + /* Input */ + const float* input = plugin->input; + + /* Output */ + float* output = plugin->output; + + float gn; + float in; + float scale; + + for (uint32_t s = 0; s < sample_count; ++s) { + gn = gain[s]; + in = input[s]; + + scale = (float)EXPF(M_LN10 * gn * 0.05f); + + output[s] = scale * in; + } +} + +static void +runAmp_gcia_oa(LV2_Handle instance, + uint32_t sample_count) +{ + Amp* plugin = (Amp*)instance; + + /* Gain (dB) */ + const float gain = *(plugin->gain); + + /* Input */ + const float* input = plugin->input; + + /* Output */ + float* output = plugin->output; + + float in; + float scale = (float)EXPF(M_LN10 * gain * 0.05f); + for (uint32_t s = 0; s < sample_count; s++) { + in = input[s]; + + output[s] = scale * in; + } +} + +static const LV2_Descriptor descriptor = { + "http://drobilla.net/plugins/blip/amp", + instantiate, + connect_port, + NULL, + runAmp_gcia_oa, + NULL, + cleanup, + NULL, +}; + +LV2_SYMBOL_EXPORT const LV2_Descriptor* +lv2_descriptor(uint32_t index) +{ + switch (index) { + case 0: return &descriptor; + default: return NULL; + } +} |