Alexandre Lision | 7c6f4a6 | 2013-09-05 13:27:01 -0400 | [diff] [blame] | 1 | /* |
| 2 | ** Copyright (C) 2007-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| 3 | ** |
| 4 | ** This program is free software; you can redistribute it and/or modify |
| 5 | ** it under the terms of the GNU General Public License as published by |
| 6 | ** the Free Software Foundation; either version 2 of the License, or |
| 7 | ** (at your option) any later version. |
| 8 | ** |
| 9 | ** This program is distributed in the hope that it will be useful, |
| 10 | ** but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | ** GNU General Public License for more details. |
| 13 | ** |
| 14 | ** You should have received a copy of the GNU General Public License |
| 15 | ** along with this program; if not, write to the Free Software |
| 16 | ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | #include <stdio.h> |
| 20 | #include <stdlib.h> |
| 21 | #include <string.h> |
| 22 | #include <math.h> |
| 23 | |
| 24 | #include <sndfile.h> |
| 25 | |
| 26 | #include "utils.h" |
| 27 | #include "generate.h" |
| 28 | |
| 29 | #define SF_MAX(x,y) ((x) > (y) ? (x) : (y)) |
| 30 | |
| 31 | static float crappy_snare (float *output, int len, int offset, float gain, float maxabs) ; |
| 32 | |
| 33 | void |
| 34 | generate_file (const char * filename, int format, int len) |
| 35 | { float * output ; |
| 36 | float maxabs = 0.0 ; |
| 37 | |
| 38 | output = calloc (len, sizeof (float)) ; |
| 39 | |
| 40 | maxabs = crappy_snare (output, len, 0, 0.95, maxabs) ; |
| 41 | maxabs = crappy_snare (output, len, len / 4, 0.85, maxabs) ; |
| 42 | maxabs = crappy_snare (output, len, 2 * len / 4, 0.85, maxabs) ; |
| 43 | crappy_snare (output, len, 3 * len / 4, 0.85, maxabs) ; |
| 44 | |
| 45 | write_mono_file (filename, format, 44100, output, len) ; |
| 46 | |
| 47 | free (output) ; |
| 48 | } /* generate_file */ |
| 49 | |
| 50 | static inline float |
| 51 | rand_float (void) |
| 52 | { return rand () / (0.5 * RAND_MAX) - 1.0 ; |
| 53 | } /* rand_float */ |
| 54 | |
| 55 | static float |
| 56 | crappy_snare (float *output, int len, int offset, float gain, float maxabs) |
| 57 | { int k ; |
| 58 | float env = 0.0 ; |
| 59 | |
| 60 | for (k = offset ; k < len && env < gain ; k++) |
| 61 | { env += 0.03 ; |
| 62 | output [k] += env * rand_float () ; |
| 63 | maxabs = SF_MAX (maxabs, fabs (output [k])) ; |
| 64 | } ; |
| 65 | |
| 66 | for ( ; k < len && env > 1e-8 ; k++) |
| 67 | { env *= 0.995 ; |
| 68 | output [k] += env * rand_float () ; |
| 69 | maxabs = SF_MAX (maxabs, fabs (output [k])) ; |
| 70 | } ; |
| 71 | |
| 72 | return maxabs ; |
| 73 | } /* crappy_snare */ |