musiclight2/lua_wrappers.c

/*
 * vim: sw=2 ts=2 expandtab
 *
 * "THE PIZZA-WARE LICENSE" (derived from "THE BEER-WARE LICENCE"):
 * Thomas Kolb <cfr34k@tkolb.de> wrote this file. As long as you retain this
 * notice you can do whatever you want with this stuff. If we meet some day,
 * and you think this stuff is worth it, you can buy me a pizza in return.
 * - Thomas Kolb
 */

#include <semaphore.h>

#include <lua5.3/lua.h>
#include <lua5.3/lualib.h>
#include <lua5.3/lauxlib.h>

#include "fft.h"
#include "utils.h"

#include "config.h"

#include "lua_utils.h"
#include "lua_wrappers.h"

extern sem_t  fftSemaphore;
extern double fft[BLOCK_LEN];
extern sample signal[BLOCK_LEN];
extern double rms;

static int l_get_energy_in_band(lua_State *L) {
  int lowerFreq, higherFreq;

  luaL_checktype(L, 1, LUA_TNUMBER);
  lowerFreq = lua_tointeger(L, 1);

  luaL_checktype(L, 2, LUA_TNUMBER);
  higherFreq = lua_tointeger(L, 2);

  sem_wait(&fftSemaphore);
  lua_pushnumber(L, get_energy_in_band(fft, lowerFreq, higherFreq));
  sem_post(&fftSemaphore);

  return 1; // number of arguments
}

static int l_get_fft(lua_State *L) {
  sem_wait(&fftSemaphore);
  lua_pushdoublearray(L, fft, BLOCK_LEN);
  sem_post(&fftSemaphore);

  return 1; // number of return values
}

static int l_get_signal(lua_State *L) {
  sem_wait(&fftSemaphore);
  lua_pushsamplearray(L, signal, BLOCK_LEN);
  sem_post(&fftSemaphore);

  return 1; // number of return values
}

static int l_get_rms(lua_State *L) {
  sem_wait(&fftSemaphore);
  lua_pushnumber(L, rms);
  sem_post(&fftSemaphore);

  return 1; // number of return values
}

// calculate the position in the output arrays from strip and module index
static int l_idx(lua_State *L) {
  luaL_checktype(L, 1, LUA_TNUMBER);
  int strip = lua_tointeger(L, 1) - 1; // -1 because Lua counts from 1

  luaL_checktype(L, 2, LUA_TNUMBER);
  int module = lua_tointeger(L, 2) - 1; // -1 because Lua counts from 1

  lua_pushnumber(L, idx(strip, module) + 1); // +1 because Lua counts from 1

  return 1; // number of return values
}

void lua_register_funcs(lua_State *L) {
  lua_register(L, "get_energy_in_band", l_get_energy_in_band);
  lua_register(L, "get_fft", l_get_fft);
  lua_register(L, "get_signal", l_get_signal);
  lua_register(L, "get_rms", l_get_rms);

  lua_register(L, "idx", l_idx);
}