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Diffstat (limited to 'src/waveguide_mesh.c')
| -rw-r--r-- | src/waveguide_mesh.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/src/waveguide_mesh.c b/src/waveguide_mesh.c new file mode 100644 index 0000000..5232ff5 --- /dev/null +++ b/src/waveguide_mesh.c @@ -0,0 +1,274 @@ +/* This file is an audio plugin. + * Copyright 2005 Loki Davison. + * + * Based on code by Brook Eaton and a couple of papers... + * + * Implements a Waveguide Mesh drum. FIXME to be extended, to have rimguides, power normalisation and all + * manner of other goodies. + * + * Tension is well, drum tension + * power is how hard you hit it. + * + * + * This plugin 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 2 of the License, or (at your option) + * any later version. + * + * This plugin 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 + * details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA + */ + +#define _XOPEN_SOURCE 600 /* strdup */ +#include <stdlib.h> +#include <string.h> +#include <math.h> + +#include <lv2/lv2plug.in/ns/lv2core/lv2.h> + +#define MESH_BASE_ID 2670 + +#define MESH_NUM_PORTS 6 + +/* Port Numbers */ +#define MESH_INPUT1 0 +#define MESH_OUTPUT 1 +#define MESH_TENSION 2 +#define MESH_POWER 3 +#define MESH_EX_X 4 +#define MESH_EX_Y 5 + +#define LENGTH 8 // must be divisible by 4!! +#define WIDTH 8 +#define SIZE LENGTH*WIDTH // Size of mesh +#define INITIAL 0 // initial values stored at junctions +#define LOSS 0.2 // loss in wave propagation +#define INIT_DELTA 6 // initial values +#define INIT_T 0.1 // for the impedances +#define INIT_GAMMA 8 // +#define PORTS 8 //for the initialization of junction velocities from excitation + +// 2D array of junctions. +// The important function of the junction is to store +// the velocities of travelling waves so that adjacent junction's +// velocities can be calculated. +typedef struct _junction +{ + float v_junction; // junction velocity + float n_junction; // velocity heading north into junction + float s_junction; // velocity heading south into junction + float e_junction; // velocity heading east into junction + float w_junction; // velocity heading west into junction + float c_junction; // velocity heading back into the junction (delayed) + float s_temp; // these two 'temp' values are used because calculation + float e_temp; // of the mesh updates s/e values before they are used +} _junction; // to calculate north and south velocities! + +/* All state information for plugin */ + +typedef struct +{ + /* Ports */ + float* input1; + float* output; + float* tension; + float* power; + float* ex_x; + float* ex_y; + + /* vars */ + _junction mesh[LENGTH][WIDTH]; + float last_trigger; + +} WgMesh; + +/* Construct a new plugin instance */ +static LV2_Handle +instantiate(const LV2_Descriptor* descriptor, + double sample_rate, + const char* bundle_path, + const LV2_Feature* const* features) +{ + WgMesh * plugin = (WgMesh *) malloc (sizeof (WgMesh)); + + return (LV2_Handle)plugin; +} + +static void +activate(LV2_Handle instance) +{ + WgMesh * plugin = (WgMesh *) instance; + for (int i=0; i<LENGTH; i++) { + for (int j=0; j<WIDTH; j++) { + plugin->mesh[i][j].v_junction = INITIAL; + plugin->mesh[i][j].n_junction = INITIAL; + plugin->mesh[i][j].s_junction = INITIAL; + plugin->mesh[i][j].e_junction = INITIAL; + plugin->mesh[i][j].w_junction = INITIAL; + plugin->mesh[i][j].c_junction = INITIAL; + plugin->mesh[i][j].s_temp = INITIAL; + plugin->mesh[i][j].e_temp = INITIAL; + } + } + plugin->last_trigger = 0.0; +} + +/* Connect a port to a data location */ +static void +connect_port(LV2_Handle instance, + uint32_t port, + void* data) +{ + WgMesh* plugin; + + plugin = (WgMesh*)instance; + switch (port) { + case MESH_INPUT1: + plugin->input1 = (float*)data; + break; + case MESH_OUTPUT: + plugin->output = (float*)data; + break; + case MESH_TENSION: + plugin->tension = (float*)data; + break; + case MESH_POWER: + plugin->power = (float*)data; + break; + case MESH_EX_X: + plugin->ex_x = (float*)data; + break; + case MESH_EX_Y: + plugin->ex_y = (float*)data; + break; + } +} + +inline static void excite_mesh(WgMesh* plugin, float power, float ex_x, float ex_y) +{ + int i=ex_x,j=ex_y; + float temp; + float Yj; + + Yj = 2*(INIT_DELTA*INIT_DELTA/((INIT_T*INIT_T)*(INIT_GAMMA*INIT_GAMMA))); // junction admittance + temp = power*2/(LENGTH+WIDTH); + plugin->mesh[i][j].v_junction = plugin->mesh[i][j].v_junction + temp; + plugin->mesh[i][j].n_junction = plugin->mesh[i][j].n_junction + Yj*temp/PORTS; + // All velocities leaving the junction are equal to + plugin->mesh[i][j].s_junction = plugin->mesh[i][j].s_junction + Yj*temp/PORTS; + // the total velocity in the junction * the admittance + plugin->mesh[i][j].e_junction = plugin->mesh[i][j].e_junction + Yj*temp/PORTS; + // divided by the number of outgoing ports. + plugin->mesh[i][j].w_junction = plugin->mesh[i][j].w_junction + Yj*temp/PORTS; + //mesh[i][j].c_junction = 0; +} + +static void +run(LV2_Handle instance, uint32_t nframes) +{ + WgMesh* plugin = (WgMesh*)instance; + float tension = *(plugin->tension); + float ex_x = *(plugin->ex_x); + float ex_y = *(plugin->ex_y); + float* input = plugin->input1; + float* out = plugin->output; + float* power = plugin->power; + float last_trigger = plugin->last_trigger; + size_t i,j,k; + float filt, trg, oldfilt; + float Yc,Yj,tempN,tempS,tempE,tempW; + + // Set input variables // + oldfilt = plugin->mesh[LENGTH-LENGTH/4][WIDTH-WIDTH/4].v_junction; + + for (k=0; k<nframes; k++) { + if (tension==0) + tension=0.0001; + trg = input[k]; + + if (trg > 0.0f && !(last_trigger > 0.0f)) + { + //printf("got trigger, exciting mesh, %f \n", tension); + excite_mesh(plugin, power[k], ex_x, ex_y); + } + + //junction admitance + Yj = 2*INIT_DELTA*INIT_DELTA/(( (tension)*((tension) )*(INIT_GAMMA*INIT_GAMMA))); + Yc = Yj-4; // junction admittance (left shift is for multiply by 2!) + //plugin->v_power = power[k]; + + for (i=1; i<LENGTH-1; i++) { + // INNER MESH // + for (j=1; j<WIDTH-1; j++) { // to multiply by 2 - simply shift to the left by 1! + plugin->mesh[i][j].v_junction = 2.0*(plugin->mesh[i][j].n_junction + plugin->mesh[i][j].s_junction + + plugin->mesh[i][j].e_junction + plugin->mesh[i][j].w_junction + Yc*plugin->mesh[i][j].c_junction)/Yj; + + plugin->mesh[i][j+1].s_junction = plugin->mesh[i][j].v_junction - plugin->mesh[i][j].n_junction; + plugin->mesh[i][j-1].n_junction = plugin->mesh[i][j].v_junction - plugin->mesh[i][j].s_temp; + + plugin->mesh[i+1][j].e_junction = plugin->mesh[i][j].v_junction - plugin->mesh[i][j].w_junction; + plugin->mesh[i-1][j].w_junction = plugin->mesh[i][j].v_junction - plugin->mesh[i][j].e_temp; + + plugin->mesh[i][j].c_junction = plugin->mesh[i][j].v_junction - plugin->mesh[i][j].c_junction; + + plugin->mesh[i][j].s_temp = plugin->mesh[i][j].s_junction; // + plugin->mesh[i][j].e_temp = plugin->mesh[i][j].e_junction; // update current values in the temp slots! + } + // BOUNDARY // + tempS = plugin->mesh[i][0].s_junction; + plugin->mesh[i][0].s_junction = -plugin->mesh[i][0].n_junction; + plugin->mesh[i][1].s_junction = plugin->mesh[i][1].s_temp = tempS; + tempN = plugin->mesh[i][WIDTH-1].n_junction; + plugin->mesh[i][WIDTH-1].n_junction = -plugin->mesh[i][WIDTH-1].s_junction; + plugin->mesh[i][WIDTH-2].n_junction = tempN; + // 'i's in the neplugint few lines are really 'j's! + tempE = plugin->mesh[0][i].e_junction; + plugin->mesh[0][i].e_junction = -plugin->mesh[0][i].w_junction; + plugin->mesh[1][i].e_junction = plugin->mesh[1][i].e_temp = tempE; + tempW = plugin->mesh[WIDTH-1][i].w_junction; + plugin->mesh[WIDTH-1][i].w_junction = -plugin->mesh[WIDTH-1][i].e_junction; + plugin->mesh[WIDTH-2][i].w_junction = tempW; + } + + filt = LOSS*(plugin->mesh[LENGTH-LENGTH/4][WIDTH-WIDTH/4].v_junction + oldfilt); + oldfilt = plugin->mesh[LENGTH-LENGTH/4][WIDTH-WIDTH/4].v_junction; + plugin->mesh[LENGTH-LENGTH/4][WIDTH-WIDTH/4].v_junction = filt; + + out[k] = plugin->mesh[WIDTH/4][WIDTH/4-1].v_junction; + last_trigger = trg; + } + plugin->last_trigger = last_trigger; + +} + +static void +cleanup(LV2_Handle instance) +{ + free(instance); +} + +static const LV2_Descriptor descriptor = { + "http://drobilla.net/plugins/omins/waveguide_mesh", + instantiate, + connect_port, + activate, + run, + NULL, + cleanup, + NULL, +}; + +LV2_SYMBOL_EXPORT const LV2_Descriptor* +lv2_descriptor(uint32_t index) +{ + switch (index) { + case 0: return &descriptor; + default: return NULL; + } +} |