src/wasm-gc-teavm/java/com/jcraft/jorbis/Drft.java

/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
/* JOrbis
 * Copyright (C) 2000 ymnk, JCraft,Inc.
 *  
 * Written by: 2000 ymnk<ymnk@jcraft.com>
 *   
 * Many thanks to 
 *   Monty <monty@xiph.org> and 
 *   The XIPHOPHORUS Company http://www.xiph.org/ .
 * JOrbis has been based on their awesome works, Vorbis codec.
 *   
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License
 * as published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
   
 * This program 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 Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

package com.jcraft.jorbis;

class Drft {
	int n;
	float[] trigcache;
	int[] splitcache;

	void backward(float[] data) {
		if (n == 1)
			return;
		drftb1(n, data, trigcache, trigcache, n, splitcache);
	}

	void init(int n) {
		this.n = n;
		trigcache = new float[3 * n];
		splitcache = new int[32];
		fdrffti(n, trigcache, splitcache);
	}

	void clear() {
		if (trigcache != null)
			trigcache = null;
		if (splitcache != null)
			splitcache = null;
	}

	static int[] ntryh = { 4, 2, 3, 5 };
	static float tpi = 6.28318530717958647692528676655900577f;
	static float hsqt2 = .70710678118654752440084436210485f;
	static float taui = .86602540378443864676372317075293618f;
	static float taur = -.5f;
	static float sqrt2 = 1.4142135623730950488016887242097f;

	static void drfti1(int n, float[] wa, int index, int[] ifac) {
		float arg, argh, argld, fi;
		int ntry = 0, i, j = -1;
		int k1, l1, l2, ib;
		int ld, ii, ip, is, nq, nr;
		int ido, ipm, nfm1;
		int nl = n;
		int nf = 0;

		int state = 101;

		loop: while (true) {
			switch (state) {
			case 101:
				j++;
				if (j < 4)
					ntry = ntryh[j];
				else
					ntry += 2;
			case 104:
				nq = nl / ntry;
				nr = nl - ntry * nq;
				if (nr != 0) {
					state = 101;
					break;
				}
				nf++;
				ifac[nf + 1] = ntry;
				nl = nq;
				if (ntry != 2) {
					state = 107;
					break;
				}
				if (nf == 1) {
					state = 107;
					break;
				}

				for (i = 1; i < nf; i++) {
					ib = nf - i + 1;
					ifac[ib + 1] = ifac[ib];
				}
				ifac[2] = 2;
			case 107:
				if (nl != 1) {
					state = 104;
					break;
				}
				ifac[0] = n;
				ifac[1] = nf;
				argh = tpi / n;
				is = 0;
				nfm1 = nf - 1;
				l1 = 1;

				if (nfm1 == 0)
					return;

				for (k1 = 0; k1 < nfm1; k1++) {
					ip = ifac[k1 + 2];
					ld = 0;
					l2 = l1 * ip;
					ido = n / l2;
					ipm = ip - 1;

					for (j = 0; j < ipm; j++) {
						ld += l1;
						i = is;
						argld = (float) ld * argh;
						fi = 0.f;
						for (ii = 2; ii < ido; ii += 2) {
							fi += 1.f;
							arg = fi * argld;
							wa[index + i++] = (float) Math.cos(arg);
							wa[index + i++] = (float) Math.sin(arg);
						}
						is += ido;
					}
					l1 = l2;
				}
				break loop;
			}
		}
	}

	static void fdrffti(int n, float[] wsave, int[] ifac) {
		if (n == 1)
			return;
		drfti1(n, wsave, n, ifac);
	}

	static void dradf2(int ido, int l1, float[] cc, float[] ch, float[] wa1, int index) {
		int i, k;
		float ti2, tr2;
		int t0, t1, t2, t3, t4, t5, t6;

		t1 = 0;
		t0 = (t2 = l1 * ido);
		t3 = ido << 1;
		for (k = 0; k < l1; k++) {
			ch[t1 << 1] = cc[t1] + cc[t2];
			ch[(t1 << 1) + t3 - 1] = cc[t1] - cc[t2];
			t1 += ido;
			t2 += ido;
		}

		if (ido < 2)
			return;

		if (ido != 2) {
			t1 = 0;
			t2 = t0;
			for (k = 0; k < l1; k++) {
				t3 = t2;
				t4 = (t1 << 1) + (ido << 1);
				t5 = t1;
				t6 = t1 + t1;
				for (i = 2; i < ido; i += 2) {
					t3 += 2;
					t4 -= 2;
					t5 += 2;
					t6 += 2;
					tr2 = wa1[index + i - 2] * cc[t3 - 1] + wa1[index + i - 1] * cc[t3];
					ti2 = wa1[index + i - 2] * cc[t3] - wa1[index + i - 1] * cc[t3 - 1];
					ch[t6] = cc[t5] + ti2;
					ch[t4] = ti2 - cc[t5];
					ch[t6 - 1] = cc[t5 - 1] + tr2;
					ch[t4 - 1] = cc[t5 - 1] - tr2;
				}
				t1 += ido;
				t2 += ido;
			}
			if (ido % 2 == 1)
				return;
		}

		t3 = (t2 = (t1 = ido) - 1);
		t2 += t0;
		for (k = 0; k < l1; k++) {
			ch[t1] = -cc[t2];
			ch[t1 - 1] = cc[t3];
			t1 += ido << 1;
			t2 += ido;
			t3 += ido;
		}
	}

	static void dradf4(int ido, int l1, float[] cc, float[] ch, float[] wa1, int index1, float[] wa2, int index2,
			float[] wa3, int index3) {
		int i, k, t0, t1, t2, t3, t4, t5, t6;
		float ci2, ci3, ci4, cr2, cr3, cr4, ti1, ti2, ti3, ti4, tr1, tr2, tr3, tr4;
		t0 = l1 * ido;

		t1 = t0;
		t4 = t1 << 1;
		t2 = t1 + (t1 << 1);
		t3 = 0;

		for (k = 0; k < l1; k++) {
			tr1 = cc[t1] + cc[t2];
			tr2 = cc[t3] + cc[t4];

			ch[t5 = t3 << 2] = tr1 + tr2;
			ch[(ido << 2) + t5 - 1] = tr2 - tr1;
			ch[(t5 += (ido << 1)) - 1] = cc[t3] - cc[t4];
			ch[t5] = cc[t2] - cc[t1];

			t1 += ido;
			t2 += ido;
			t3 += ido;
			t4 += ido;
		}
		if (ido < 2)
			return;

		if (ido != 2) {
			t1 = 0;
			for (k = 0; k < l1; k++) {
				t2 = t1;
				t4 = t1 << 2;
				t5 = (t6 = ido << 1) + t4;
				for (i = 2; i < ido; i += 2) {
					t3 = (t2 += 2);
					t4 += 2;
					t5 -= 2;

					t3 += t0;
					cr2 = wa1[index1 + i - 2] * cc[t3 - 1] + wa1[index1 + i - 1] * cc[t3];
					ci2 = wa1[index1 + i - 2] * cc[t3] - wa1[index1 + i - 1] * cc[t3 - 1];
					t3 += t0;
					cr3 = wa2[index2 + i - 2] * cc[t3 - 1] + wa2[index2 + i - 1] * cc[t3];
					ci3 = wa2[index2 + i - 2] * cc[t3] - wa2[index2 + i - 1] * cc[t3 - 1];
					t3 += t0;
					cr4 = wa3[index3 + i - 2] * cc[t3 - 1] + wa3[index3 + i - 1] * cc[t3];
					ci4 = wa3[index3 + i - 2] * cc[t3] - wa3[index3 + i - 1] * cc[t3 - 1];

					tr1 = cr2 + cr4;
					tr4 = cr4 - cr2;
					ti1 = ci2 + ci4;
					ti4 = ci2 - ci4;

					ti2 = cc[t2] + ci3;
					ti3 = cc[t2] - ci3;
					tr2 = cc[t2 - 1] + cr3;
					tr3 = cc[t2 - 1] - cr3;

					ch[t4 - 1] = tr1 + tr2;
					ch[t4] = ti1 + ti2;

					ch[t5 - 1] = tr3 - ti4;
					ch[t5] = tr4 - ti3;

					ch[t4 + t6 - 1] = ti4 + tr3;
					ch[t4 + t6] = tr4 + ti3;

					ch[t5 + t6 - 1] = tr2 - tr1;
					ch[t5 + t6] = ti1 - ti2;
				}
				t1 += ido;
			}
			if ((ido & 1) != 0)
				return;
		}

		t2 = (t1 = t0 + ido - 1) + (t0 << 1);
		t3 = ido << 2;
		t4 = ido;
		t5 = ido << 1;
		t6 = ido;

		for (k = 0; k < l1; k++) {
			ti1 = -hsqt2 * (cc[t1] + cc[t2]);
			tr1 = hsqt2 * (cc[t1] - cc[t2]);

			ch[t4 - 1] = tr1 + cc[t6 - 1];
			ch[t4 + t5 - 1] = cc[t6 - 1] - tr1;

			ch[t4] = ti1 - cc[t1 + t0];
			ch[t4 + t5] = ti1 + cc[t1 + t0];

			t1 += ido;
			t2 += ido;
			t4 += t3;
			t6 += ido;
		}
	}

	static void dradfg(int ido, int ip, int l1, int idl1, float[] cc, float[] c1, float[] c2, float[] ch, float[] ch2,
			float[] wa, int index) {
		int idij, ipph, i, j, k, l, ic, ik, is;
		int t0, t1, t2 = 0, t3, t4, t5, t6, t7, t8, t9, t10;
		float dc2, ai1, ai2, ar1, ar2, ds2;
		int nbd;
		float dcp = 0, arg, dsp = 0, ar1h, ar2h;
		int idp2, ipp2;

		arg = tpi / (float) ip;
		dcp = (float) Math.cos(arg);
		dsp = (float) Math.sin(arg);
		ipph = (ip + 1) >> 1;
		ipp2 = ip;
		idp2 = ido;
		nbd = (ido - 1) >> 1;
		t0 = l1 * ido;
		t10 = ip * ido;

		int state = 100;
		loop: while (true) {
			switch (state) {
			case 101:
				if (ido == 1) {
					state = 119;
					break;
				}
				for (ik = 0; ik < idl1; ik++)
					ch2[ik] = c2[ik];

				t1 = 0;
				for (j = 1; j < ip; j++) {
					t1 += t0;
					t2 = t1;
					for (k = 0; k < l1; k++) {
						ch[t2] = c1[t2];
						t2 += ido;
					}
				}

				is = -ido;
				t1 = 0;
				if (nbd > l1) {
					for (j = 1; j < ip; j++) {
						t1 += t0;
						is += ido;
						t2 = -ido + t1;
						for (k = 0; k < l1; k++) {
							idij = is - 1;
							t2 += ido;
							t3 = t2;
							for (i = 2; i < ido; i += 2) {
								idij += 2;
								t3 += 2;
								ch[t3 - 1] = wa[index + idij - 1] * c1[t3 - 1] + wa[index + idij] * c1[t3];
								ch[t3] = wa[index + idij - 1] * c1[t3] - wa[index + idij] * c1[t3 - 1];
							}
						}
					}
				} else {

					for (j = 1; j < ip; j++) {
						is += ido;
						idij = is - 1;
						t1 += t0;
						t2 = t1;
						for (i = 2; i < ido; i += 2) {
							idij += 2;
							t2 += 2;
							t3 = t2;
							for (k = 0; k < l1; k++) {
								ch[t3 - 1] = wa[index + idij - 1] * c1[t3 - 1] + wa[index + idij] * c1[t3];
								ch[t3] = wa[index + idij - 1] * c1[t3] - wa[index + idij] * c1[t3 - 1];
								t3 += ido;
							}
						}
					}
				}

				t1 = 0;
				t2 = ipp2 * t0;
				if (nbd < l1) {
					for (j = 1; j < ipph; j++) {
						t1 += t0;
						t2 -= t0;
						t3 = t1;
						t4 = t2;
						for (i = 2; i < ido; i += 2) {
							t3 += 2;
							t4 += 2;
							t5 = t3 - ido;
							t6 = t4 - ido;
							for (k = 0; k < l1; k++) {
								t5 += ido;
								t6 += ido;
								c1[t5 - 1] = ch[t5 - 1] + ch[t6 - 1];
								c1[t6 - 1] = ch[t5] - ch[t6];
								c1[t5] = ch[t5] + ch[t6];
								c1[t6] = ch[t6 - 1] - ch[t5 - 1];
							}
						}
					}
				} else {
					for (j = 1; j < ipph; j++) {
						t1 += t0;
						t2 -= t0;
						t3 = t1;
						t4 = t2;
						for (k = 0; k < l1; k++) {
							t5 = t3;
							t6 = t4;
							for (i = 2; i < ido; i += 2) {
								t5 += 2;
								t6 += 2;
								c1[t5 - 1] = ch[t5 - 1] + ch[t6 - 1];
								c1[t6 - 1] = ch[t5] - ch[t6];
								c1[t5] = ch[t5] + ch[t6];
								c1[t6] = ch[t6 - 1] - ch[t5 - 1];
							}
							t3 += ido;
							t4 += ido;
						}
					}
				}
			case 119:
				for (ik = 0; ik < idl1; ik++)
					c2[ik] = ch2[ik];

				t1 = 0;
				t2 = ipp2 * idl1;
				for (j = 1; j < ipph; j++) {
					t1 += t0;
					t2 -= t0;
					t3 = t1 - ido;
					t4 = t2 - ido;
					for (k = 0; k < l1; k++) {
						t3 += ido;
						t4 += ido;
						c1[t3] = ch[t3] + ch[t4];
						c1[t4] = ch[t4] - ch[t3];
					}
				}

				ar1 = 1.f;
				ai1 = 0.f;
				t1 = 0;
				t2 = ipp2 * idl1;
				t3 = (ip - 1) * idl1;
				for (l = 1; l < ipph; l++) {
					t1 += idl1;
					t2 -= idl1;
					ar1h = dcp * ar1 - dsp * ai1;
					ai1 = dcp * ai1 + dsp * ar1;
					ar1 = ar1h;
					t4 = t1;
					t5 = t2;
					t6 = t3;
					t7 = idl1;

					for (ik = 0; ik < idl1; ik++) {
						ch2[t4++] = c2[ik] + ar1 * c2[t7++];
						ch2[t5++] = ai1 * c2[t6++];
					}

					dc2 = ar1;
					ds2 = ai1;
					ar2 = ar1;
					ai2 = ai1;

					t4 = idl1;
					t5 = (ipp2 - 1) * idl1;
					for (j = 2; j < ipph; j++) {
						t4 += idl1;
						t5 -= idl1;

						ar2h = dc2 * ar2 - ds2 * ai2;
						ai2 = dc2 * ai2 + ds2 * ar2;
						ar2 = ar2h;

						t6 = t1;
						t7 = t2;
						t8 = t4;
						t9 = t5;
						for (ik = 0; ik < idl1; ik++) {
							ch2[t6++] += ar2 * c2[t8++];
							ch2[t7++] += ai2 * c2[t9++];
						}
					}
				}
				t1 = 0;
				for (j = 1; j < ipph; j++) {
					t1 += idl1;
					t2 = t1;
					for (ik = 0; ik < idl1; ik++)
						ch2[ik] += c2[t2++];
				}

				if (ido < l1) {
					state = 132;
					break;
				}

				t1 = 0;
				t2 = 0;
				for (k = 0; k < l1; k++) {
					t3 = t1;
					t4 = t2;
					for (i = 0; i < ido; i++)
						cc[t4++] = ch[t3++];
					t1 += ido;
					t2 += t10;
				}
				state = 135;
				break;

			case 132:
				for (i = 0; i < ido; i++) {
					t1 = i;
					t2 = i;
					for (k = 0; k < l1; k++) {
						cc[t2] = ch[t1];
						t1 += ido;
						t2 += t10;
					}
				}
			case 135:
				t1 = 0;
				t2 = ido << 1;
				t3 = 0;
				t4 = ipp2 * t0;
				for (j = 1; j < ipph; j++) {
					t1 += t2;
					t3 += t0;
					t4 -= t0;

					t5 = t1;
					t6 = t3;
					t7 = t4;

					for (k = 0; k < l1; k++) {
						cc[t5 - 1] = ch[t6];
						cc[t5] = ch[t7];
						t5 += t10;
						t6 += ido;
						t7 += ido;
					}
				}

				if (ido == 1)
					return;
				if (nbd < l1) {
					state = 141;
					break;
				}

				t1 = -ido;
				t3 = 0;
				t4 = 0;
				t5 = ipp2 * t0;
				for (j = 1; j < ipph; j++) {
					t1 += t2;
					t3 += t2;
					t4 += t0;
					t5 -= t0;
					t6 = t1;
					t7 = t3;
					t8 = t4;
					t9 = t5;
					for (k = 0; k < l1; k++) {
						for (i = 2; i < ido; i += 2) {
							ic = idp2 - i;
							cc[i + t7 - 1] = ch[i + t8 - 1] + ch[i + t9 - 1];
							cc[ic + t6 - 1] = ch[i + t8 - 1] - ch[i + t9 - 1];
							cc[i + t7] = ch[i + t8] + ch[i + t9];
							cc[ic + t6] = ch[i + t9] - ch[i + t8];
						}
						t6 += t10;
						t7 += t10;
						t8 += ido;
						t9 += ido;
					}
				}
				return;
			case 141:
				t1 = -ido;
				t3 = 0;
				t4 = 0;
				t5 = ipp2 * t0;
				for (j = 1; j < ipph; j++) {
					t1 += t2;
					t3 += t2;
					t4 += t0;
					t5 -= t0;
					for (i = 2; i < ido; i += 2) {
						t6 = idp2 + t1 - i;
						t7 = i + t3;
						t8 = i + t4;
						t9 = i + t5;
						for (k = 0; k < l1; k++) {
							cc[t7 - 1] = ch[t8 - 1] + ch[t9 - 1];
							cc[t6 - 1] = ch[t8 - 1] - ch[t9 - 1];
							cc[t7] = ch[t8] + ch[t9];
							cc[t6] = ch[t9] - ch[t8];
							t6 += t10;
							t7 += t10;
							t8 += ido;
							t9 += ido;
						}
					}
				}
				break loop;
			}
		}
	}

	static void drftf1(int n, float[] c, float[] ch, float[] wa, int[] ifac) {
		int i, k1, l1, l2;
		int na, kh, nf;
		int ip, iw, ido, idl1, ix2, ix3;

		nf = ifac[1];
		na = 1;
		l2 = n;
		iw = n;

		for (k1 = 0; k1 < nf; k1++) {
			kh = nf - k1;
			ip = ifac[kh + 1];
			l1 = l2 / ip;
			ido = n / l2;
			idl1 = ido * l1;
			iw -= (ip - 1) * ido;
			na = 1 - na;

			int state = 100;
			loop: while (true) {
				switch (state) {
				case 100:
					if (ip != 4) {
						state = 102;
						break;
					}

					ix2 = iw + ido;
					ix3 = ix2 + ido;
					if (na != 0)
						dradf4(ido, l1, ch, c, wa, iw - 1, wa, ix2 - 1, wa, ix3 - 1);
					else
						dradf4(ido, l1, c, ch, wa, iw - 1, wa, ix2 - 1, wa, ix3 - 1);
					state = 110;
					break;
				case 102:
					if (ip != 2) {
						state = 104;
						break;
					}
					if (na != 0) {
						state = 103;
						break;
					}
					dradf2(ido, l1, c, ch, wa, iw - 1);
					state = 110;
					break;
				case 103:
					dradf2(ido, l1, ch, c, wa, iw - 1);
				case 104:
					if (ido == 1)
						na = 1 - na;
					if (na != 0) {
						state = 109;
						break;
					}
					dradfg(ido, ip, l1, idl1, c, c, c, ch, ch, wa, iw - 1);
					na = 1;
					state = 110;
					break;
				case 109:
					dradfg(ido, ip, l1, idl1, ch, ch, ch, c, c, wa, iw - 1);
					na = 0;
				case 110:
					l2 = l1;
					break loop;
				}
			}
		}
		if (na == 1)
			return;
		for (i = 0; i < n; i++)
			c[i] = ch[i];
	}

	static void dradb2(int ido, int l1, float[] cc, float[] ch, float[] wa1, int index) {
		int i, k, t0, t1, t2, t3, t4, t5, t6;
		float ti2, tr2;

		t0 = l1 * ido;

		t1 = 0;
		t2 = 0;
		t3 = (ido << 1) - 1;
		for (k = 0; k < l1; k++) {
			ch[t1] = cc[t2] + cc[t3 + t2];
			ch[t1 + t0] = cc[t2] - cc[t3 + t2];
			t2 = (t1 += ido) << 1;
		}

		if (ido < 2)
			return;
		if (ido != 2) {
			t1 = 0;
			t2 = 0;
			for (k = 0; k < l1; k++) {
				t3 = t1;
				t5 = (t4 = t2) + (ido << 1);
				t6 = t0 + t1;
				for (i = 2; i < ido; i += 2) {
					t3 += 2;
					t4 += 2;
					t5 -= 2;
					t6 += 2;
					ch[t3 - 1] = cc[t4 - 1] + cc[t5 - 1];
					tr2 = cc[t4 - 1] - cc[t5 - 1];
					ch[t3] = cc[t4] - cc[t5];
					ti2 = cc[t4] + cc[t5];
					ch[t6 - 1] = wa1[index + i - 2] * tr2 - wa1[index + i - 1] * ti2;
					ch[t6] = wa1[index + i - 2] * ti2 + wa1[index + i - 1] * tr2;
				}
				t2 = (t1 += ido) << 1;
			}
			if ((ido % 2) == 1)
				return;
		}

		t1 = ido - 1;
		t2 = ido - 1;
		for (k = 0; k < l1; k++) {
			ch[t1] = cc[t2] + cc[t2];
			ch[t1 + t0] = -(cc[t2 + 1] + cc[t2 + 1]);
			t1 += ido;
			t2 += ido << 1;
		}
	}

	static void dradb3(int ido, int l1, float[] cc, float[] ch, float[] wa1, int index1, float[] wa2, int index2) {
		int i, k, t0, t1, t2, t3, t4, t5, t6, t7, t8, t9, t10;
		float ci2, ci3, di2, di3, cr2, cr3, dr2, dr3, ti2, tr2;
		t0 = l1 * ido;

		t1 = 0;
		t2 = t0 << 1;
		t3 = ido << 1;
		t4 = ido + (ido << 1);
		t5 = 0;
		for (k = 0; k < l1; k++) {
			tr2 = cc[t3 - 1] + cc[t3 - 1];
			cr2 = cc[t5] + (taur * tr2);
			ch[t1] = cc[t5] + tr2;
			ci3 = taui * (cc[t3] + cc[t3]);
			ch[t1 + t0] = cr2 - ci3;
			ch[t1 + t2] = cr2 + ci3;
			t1 += ido;
			t3 += t4;
			t5 += t4;
		}

		if (ido == 1)
			return;

		t1 = 0;
		t3 = ido << 1;
		for (k = 0; k < l1; k++) {
			t7 = t1 + (t1 << 1);
			t6 = (t5 = t7 + t3);
			t8 = t1;
			t10 = (t9 = t1 + t0) + t0;

			for (i = 2; i < ido; i += 2) {
				t5 += 2;
				t6 -= 2;
				t7 += 2;
				t8 += 2;
				t9 += 2;
				t10 += 2;
				tr2 = cc[t5 - 1] + cc[t6 - 1];
				cr2 = cc[t7 - 1] + (taur * tr2);
				ch[t8 - 1] = cc[t7 - 1] + tr2;
				ti2 = cc[t5] - cc[t6];
				ci2 = cc[t7] + (taur * ti2);
				ch[t8] = cc[t7] + ti2;
				cr3 = taui * (cc[t5 - 1] - cc[t6 - 1]);
				ci3 = taui * (cc[t5] + cc[t6]);
				dr2 = cr2 - ci3;
				dr3 = cr2 + ci3;
				di2 = ci2 + cr3;
				di3 = ci2 - cr3;
				ch[t9 - 1] = wa1[index1 + i - 2] * dr2 - wa1[index1 + i - 1] * di2;
				ch[t9] = wa1[index1 + i - 2] * di2 + wa1[index1 + i - 1] * dr2;
				ch[t10 - 1] = wa2[index2 + i - 2] * dr3 - wa2[index2 + i - 1] * di3;
				ch[t10] = wa2[index2 + i - 2] * di3 + wa2[index2 + i - 1] * dr3;
			}
			t1 += ido;
		}
	}

	static void dradb4(int ido, int l1, float[] cc, float[] ch, float[] wa1, int index1, float[] wa2, int index2,
			float[] wa3, int index3) {
		int i, k, t0, t1, t2, t3, t4, t5, t6, t7, t8;
		float ci2, ci3, ci4, cr2, cr3, cr4, ti1, ti2, ti3, ti4, tr1, tr2, tr3, tr4;
		t0 = l1 * ido;

		t1 = 0;
		t2 = ido << 2;
		t3 = 0;
		t6 = ido << 1;
		for (k = 0; k < l1; k++) {
			t4 = t3 + t6;
			t5 = t1;
			tr3 = cc[t4 - 1] + cc[t4 - 1];
			tr4 = cc[t4] + cc[t4];
			tr1 = cc[t3] - cc[(t4 += t6) - 1];
			tr2 = cc[t3] + cc[t4 - 1];
			ch[t5] = tr2 + tr3;
			ch[t5 += t0] = tr1 - tr4;
			ch[t5 += t0] = tr2 - tr3;
			ch[t5 += t0] = tr1 + tr4;
			t1 += ido;
			t3 += t2;
		}

		if (ido < 2)
			return;
		if (ido != 2) {
			t1 = 0;
			for (k = 0; k < l1; k++) {
				t5 = (t4 = (t3 = (t2 = t1 << 2) + t6)) + t6;
				t7 = t1;
				for (i = 2; i < ido; i += 2) {
					t2 += 2;
					t3 += 2;
					t4 -= 2;
					t5 -= 2;
					t7 += 2;
					ti1 = cc[t2] + cc[t5];
					ti2 = cc[t2] - cc[t5];
					ti3 = cc[t3] - cc[t4];
					tr4 = cc[t3] + cc[t4];
					tr1 = cc[t2 - 1] - cc[t5 - 1];
					tr2 = cc[t2 - 1] + cc[t5 - 1];
					ti4 = cc[t3 - 1] - cc[t4 - 1];
					tr3 = cc[t3 - 1] + cc[t4 - 1];
					ch[t7 - 1] = tr2 + tr3;
					cr3 = tr2 - tr3;
					ch[t7] = ti2 + ti3;
					ci3 = ti2 - ti3;
					cr2 = tr1 - tr4;
					cr4 = tr1 + tr4;
					ci2 = ti1 + ti4;
					ci4 = ti1 - ti4;

					ch[(t8 = t7 + t0) - 1] = wa1[index1 + i - 2] * cr2 - wa1[index1 + i - 1] * ci2;
					ch[t8] = wa1[index1 + i - 2] * ci2 + wa1[index1 + i - 1] * cr2;
					ch[(t8 += t0) - 1] = wa2[index2 + i - 2] * cr3 - wa2[index2 + i - 1] * ci3;
					ch[t8] = wa2[index2 + i - 2] * ci3 + wa2[index2 + i - 1] * cr3;
					ch[(t8 += t0) - 1] = wa3[index3 + i - 2] * cr4 - wa3[index3 + i - 1] * ci4;
					ch[t8] = wa3[index3 + i - 2] * ci4 + wa3[index3 + i - 1] * cr4;
				}
				t1 += ido;
			}
			if (ido % 2 == 1)
				return;
		}

		t1 = ido;
		t2 = ido << 2;
		t3 = ido - 1;
		t4 = ido + (ido << 1);
		for (k = 0; k < l1; k++) {
			t5 = t3;
			ti1 = cc[t1] + cc[t4];
			ti2 = cc[t4] - cc[t1];
			tr1 = cc[t1 - 1] - cc[t4 - 1];
			tr2 = cc[t1 - 1] + cc[t4 - 1];
			ch[t5] = tr2 + tr2;
			ch[t5 += t0] = sqrt2 * (tr1 - ti1);
			ch[t5 += t0] = ti2 + ti2;
			ch[t5 += t0] = -sqrt2 * (tr1 + ti1);

			t3 += ido;
			t1 += t2;
			t4 += t2;
		}
	}

	static void dradbg(int ido, int ip, int l1, int idl1, float[] cc, float[] c1, float[] c2, float[] ch, float[] ch2,
			float[] wa, int index) {

		int idij, ipph = 0, i, j, k, l, ik, is, t0 = 0, t1, t2, t3, t4, t5, t6, t7, t8, t9, t10 = 0, t11, t12;
		float dc2, ai1, ai2, ar1, ar2, ds2;
		int nbd = 0;
		float dcp = 0, arg, dsp = 0, ar1h, ar2h;
		int ipp2 = 0;

		int state = 100;

		loop: while (true) {
			switch (state) {
			case 100:
				t10 = ip * ido;
				t0 = l1 * ido;
				arg = tpi / (float) ip;
				dcp = (float) Math.cos(arg);
				dsp = (float) Math.sin(arg);
				nbd = (ido - 1) >>> 1;
				ipp2 = ip;
				ipph = (ip + 1) >>> 1;
				if (ido < l1) {
					state = 103;
					break;
				}
				t1 = 0;
				t2 = 0;
				for (k = 0; k < l1; k++) {
					t3 = t1;
					t4 = t2;
					for (i = 0; i < ido; i++) {
						ch[t3] = cc[t4];
						t3++;
						t4++;
					}
					t1 += ido;
					t2 += t10;
				}
				state = 106;
				break;
			case 103:
				t1 = 0;
				for (i = 0; i < ido; i++) {
					t2 = t1;
					t3 = t1;
					for (k = 0; k < l1; k++) {
						ch[t2] = cc[t3];
						t2 += ido;
						t3 += t10;
					}
					t1++;
				}
			case 106:
				t1 = 0;
				t2 = ipp2 * t0;
				t7 = (t5 = ido << 1);
				for (j = 1; j < ipph; j++) {
					t1 += t0;
					t2 -= t0;
					t3 = t1;
					t4 = t2;
					t6 = t5;
					for (k = 0; k < l1; k++) {
						ch[t3] = cc[t6 - 1] + cc[t6 - 1];
						ch[t4] = cc[t6] + cc[t6];
						t3 += ido;
						t4 += ido;
						t6 += t10;
					}
					t5 += t7;
				}
				if (ido == 1) {
					state = 116;
					break;
				}
				if (nbd < l1) {
					state = 112;
					break;
				}

				t1 = 0;
				t2 = ipp2 * t0;
				t7 = 0;
				for (j = 1; j < ipph; j++) {
					t1 += t0;
					t2 -= t0;
					t3 = t1;
					t4 = t2;

					t7 += (ido << 1);
					t8 = t7;
					for (k = 0; k < l1; k++) {
						t5 = t3;
						t6 = t4;
						t9 = t8;
						t11 = t8;
						for (i = 2; i < ido; i += 2) {
							t5 += 2;
							t6 += 2;
							t9 += 2;
							t11 -= 2;
							ch[t5 - 1] = cc[t9 - 1] + cc[t11 - 1];
							ch[t6 - 1] = cc[t9 - 1] - cc[t11 - 1];
							ch[t5] = cc[t9] - cc[t11];
							ch[t6] = cc[t9] + cc[t11];
						}
						t3 += ido;
						t4 += ido;
						t8 += t10;
					}
				}
				state = 116;
				break;
			case 112:
				t1 = 0;
				t2 = ipp2 * t0;
				t7 = 0;
				for (j = 1; j < ipph; j++) {
					t1 += t0;
					t2 -= t0;
					t3 = t1;
					t4 = t2;
					t7 += (ido << 1);
					t8 = t7;
					t9 = t7;
					for (i = 2; i < ido; i += 2) {
						t3 += 2;
						t4 += 2;
						t8 += 2;
						t9 -= 2;
						t5 = t3;
						t6 = t4;
						t11 = t8;
						t12 = t9;
						for (k = 0; k < l1; k++) {
							ch[t5 - 1] = cc[t11 - 1] + cc[t12 - 1];
							ch[t6 - 1] = cc[t11 - 1] - cc[t12 - 1];
							ch[t5] = cc[t11] - cc[t12];
							ch[t6] = cc[t11] + cc[t12];
							t5 += ido;
							t6 += ido;
							t11 += t10;
							t12 += t10;
						}
					}
				}
			case 116:
				ar1 = 1.f;
				ai1 = 0.f;
				t1 = 0;
				t9 = (t2 = ipp2 * idl1);
				t3 = (ip - 1) * idl1;
				for (l = 1; l < ipph; l++) {
					t1 += idl1;
					t2 -= idl1;

					ar1h = dcp * ar1 - dsp * ai1;
					ai1 = dcp * ai1 + dsp * ar1;
					ar1 = ar1h;
					t4 = t1;
					t5 = t2;
					t6 = 0;
					t7 = idl1;
					t8 = t3;
					for (ik = 0; ik < idl1; ik++) {
						c2[t4++] = ch2[t6++] + ar1 * ch2[t7++];
						c2[t5++] = ai1 * ch2[t8++];
					}
					dc2 = ar1;
					ds2 = ai1;
					ar2 = ar1;
					ai2 = ai1;

					t6 = idl1;
					t7 = t9 - idl1;
					for (j = 2; j < ipph; j++) {
						t6 += idl1;
						t7 -= idl1;
						ar2h = dc2 * ar2 - ds2 * ai2;
						ai2 = dc2 * ai2 + ds2 * ar2;
						ar2 = ar2h;
						t4 = t1;
						t5 = t2;
						t11 = t6;
						t12 = t7;
						for (ik = 0; ik < idl1; ik++) {
							c2[t4++] += ar2 * ch2[t11++];
							c2[t5++] += ai2 * ch2[t12++];
						}
					}
				}

				t1 = 0;
				for (j = 1; j < ipph; j++) {
					t1 += idl1;
					t2 = t1;
					for (ik = 0; ik < idl1; ik++)
						ch2[ik] += ch2[t2++];
				}

				t1 = 0;
				t2 = ipp2 * t0;
				for (j = 1; j < ipph; j++) {
					t1 += t0;
					t2 -= t0;
					t3 = t1;
					t4 = t2;
					for (k = 0; k < l1; k++) {
						ch[t3] = c1[t3] - c1[t4];
						ch[t4] = c1[t3] + c1[t4];
						t3 += ido;
						t4 += ido;
					}
				}

				if (ido == 1) {
					state = 132;
					break;
				}
				if (nbd < l1) {
					state = 128;
					break;
				}

				t1 = 0;
				t2 = ipp2 * t0;
				for (j = 1; j < ipph; j++) {
					t1 += t0;
					t2 -= t0;
					t3 = t1;
					t4 = t2;
					for (k = 0; k < l1; k++) {
						t5 = t3;
						t6 = t4;
						for (i = 2; i < ido; i += 2) {
							t5 += 2;
							t6 += 2;
							ch[t5 - 1] = c1[t5 - 1] - c1[t6];
							ch[t6 - 1] = c1[t5 - 1] + c1[t6];
							ch[t5] = c1[t5] + c1[t6 - 1];
							ch[t6] = c1[t5] - c1[t6 - 1];
						}
						t3 += ido;
						t4 += ido;
					}
				}
				state = 132;
				break;
			case 128:
				t1 = 0;
				t2 = ipp2 * t0;
				for (j = 1; j < ipph; j++) {
					t1 += t0;
					t2 -= t0;
					t3 = t1;
					t4 = t2;
					for (i = 2; i < ido; i += 2) {
						t3 += 2;
						t4 += 2;
						t5 = t3;
						t6 = t4;
						for (k = 0; k < l1; k++) {
							ch[t5 - 1] = c1[t5 - 1] - c1[t6];
							ch[t6 - 1] = c1[t5 - 1] + c1[t6];
							ch[t5] = c1[t5] + c1[t6 - 1];
							ch[t6] = c1[t5] - c1[t6 - 1];
							t5 += ido;
							t6 += ido;
						}
					}
				}
			case 132:
				if (ido == 1)
					return;

				for (ik = 0; ik < idl1; ik++)
					c2[ik] = ch2[ik];

				t1 = 0;
				for (j = 1; j < ip; j++) {
					t2 = (t1 += t0);
					for (k = 0; k < l1; k++) {
						c1[t2] = ch[t2];
						t2 += ido;
					}
				}

				if (nbd > l1) {
					state = 139;
					break;
				}

				is = -ido - 1;
				t1 = 0;
				for (j = 1; j < ip; j++) {
					is += ido;
					t1 += t0;
					idij = is;
					t2 = t1;
					for (i = 2; i < ido; i += 2) {
						t2 += 2;
						idij += 2;
						t3 = t2;
						for (k = 0; k < l1; k++) {
							c1[t3 - 1] = wa[index + idij - 1] * ch[t3 - 1] - wa[index + idij] * ch[t3];
							c1[t3] = wa[index + idij - 1] * ch[t3] + wa[index + idij] * ch[t3 - 1];
							t3 += ido;
						}
					}
				}
				return;

			case 139:
				is = -ido - 1;
				t1 = 0;
				for (j = 1; j < ip; j++) {
					is += ido;
					t1 += t0;
					t2 = t1;
					for (k = 0; k < l1; k++) {
						idij = is;
						t3 = t2;
						for (i = 2; i < ido; i += 2) {
							idij += 2;
							t3 += 2;
							c1[t3 - 1] = wa[index + idij - 1] * ch[t3 - 1] - wa[index + idij] * ch[t3];
							c1[t3] = wa[index + idij - 1] * ch[t3] + wa[index + idij] * ch[t3 - 1];
						}
						t2 += ido;
					}
				}
				break loop;
			}
		}
	}

	static void drftb1(int n, float[] c, float[] ch, float[] wa, int index, int[] ifac) {
		int i, k1, l1, l2 = 0;
		int na;
		int nf, ip = 0, iw, ix2, ix3, ido = 0, idl1 = 0;

		nf = ifac[1];
		na = 0;
		l1 = 1;
		iw = 1;

		for (k1 = 0; k1 < nf; k1++) {
			int state = 100;
			loop: while (true) {
				switch (state) {
				case 100:
					ip = ifac[k1 + 2];
					l2 = ip * l1;
					ido = n / l2;
					idl1 = ido * l1;
					if (ip != 4) {
						state = 103;
						break;
					}
					ix2 = iw + ido;
					ix3 = ix2 + ido;

					if (na != 0)
						dradb4(ido, l1, ch, c, wa, index + iw - 1, wa, index + ix2 - 1, wa, index + ix3 - 1);
					else
						dradb4(ido, l1, c, ch, wa, index + iw - 1, wa, index + ix2 - 1, wa, index + ix3 - 1);
					na = 1 - na;
					state = 115;
					break;
				case 103:
					if (ip != 2) {
						state = 106;
						break;
					}

					if (na != 0)
						dradb2(ido, l1, ch, c, wa, index + iw - 1);
					else
						dradb2(ido, l1, c, ch, wa, index + iw - 1);
					na = 1 - na;
					state = 115;
					break;

				case 106:
					if (ip != 3) {
						state = 109;
						break;
					}

					ix2 = iw + ido;
					if (na != 0)
						dradb3(ido, l1, ch, c, wa, index + iw - 1, wa, index + ix2 - 1);
					else
						dradb3(ido, l1, c, ch, wa, index + iw - 1, wa, index + ix2 - 1);
					na = 1 - na;
					state = 115;
					break;
				case 109:
					if (na != 0)
						dradbg(ido, ip, l1, idl1, ch, ch, ch, c, c, wa, index + iw - 1);
					else
						dradbg(ido, ip, l1, idl1, c, c, c, ch, ch, wa, index + iw - 1);
					if (ido == 1)
						na = 1 - na;

				case 115:
					l1 = l2;
					iw += (ip - 1) * ido;
					break loop;
				}
			}
		}
		if (na == 0)
			return;
		for (i = 0; i < n; i++)
			c[i] = ch[i];
	}
}