wavpcm.c (1101B)
1 #include <stdio.h> 2 #include <math.h> 3 4 /* 5 Copyright (c) 2020 Devine Lu Linvega 6 7 Permission to use, copy, modify, and distribute this software for any 8 purpose with or without fee is hereby granted, provided that the above 9 copyright notice and this permission notice appear in all copies. 10 11 THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 WITH REGARD TO THIS SOFTWARE. 13 */ 14 15 #define PI 3.14159265358979323846 16 #define SAMPLES 256 17 #define RATE 1 18 19 typedef unsigned char Uint8; 20 21 int 22 clamp(int val, int min, int max) 23 { 24 return (val >= min) ? (val <= max) ? val : max : min; 25 } 26 27 Uint8 28 sinw(int i) 29 { 30 return 0x7f * sin(i * RATE * 2 * PI / SAMPLES); 31 } 32 33 Uint8 34 triw(int i) 35 { 36 if(i < 0x40) 37 return i * 2; 38 if(i >= 0xc0) 39 return (i - 0xc0) * 2 - 0x7f; 40 return 0x7f - (i - 0x40) * 2; 41 } 42 43 Uint8 44 sqrw(int i) 45 { 46 return ((i * RATE) % 0xff) < 0x80 ? 0x7f : 0x80; 47 } 48 49 int 50 main() 51 { 52 int i; 53 printf("%d:\n\n", SAMPLES); 54 for(i = 0; i < SAMPLES; ++i) { 55 if(i % 0x10 == 0) 56 printf("\n"); 57 else if(i % 2 == 0) 58 printf(" "); 59 printf("%02x", (triw(i) + sinw(i)) / 2); 60 } 61 printf("\n\n"); 62 return 0; 63 }