path: root/src/apu.rs

#![allow(dead_code)]
use mos6502;

pub trait Speaker {
    fn queue(&mut self, sample: u16);
    fn push(&mut self);
}

const CPU_SAMPLE_FREQ: u32 = 240;
pub const AUDIO_SAMPLE_FREQ: u32 = 44100;

const TRI_SEQ_TABLE: [u8; 32] = [
    15, 14, 13, 12, 11, 10,  9,  8,  7,  6,  5,  4,  3,  2,  1,  0,
     0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15
];

const LEN_TABLE: [u8; 32] = [
    10, 254, 20,  2, 40,  4, 80,  6, 160,  8, 60, 10, 14, 12, 26, 14,
    12,  16, 24, 18, 48, 20, 96, 22, 192, 24, 72, 26, 16, 28, 32, 30,
];

const DUTY_TABLE: [u8; 4] = [
    0b00000010,
    0b00000110,
    0b00011110,
    0b11111001,
];

const PULSE_TABLE: [u16; 31] = [
    0x0000, 0x02f8, 0x05df, 0x08b4, 0x0b78, 0x0e2b,
    0x10cf, 0x1363, 0x15e9, 0x1860, 0x1ac9, 0x1d25,
    0x1f75, 0x21b7, 0x23ee, 0x2618, 0x2837, 0x2a4c,
    0x2c55, 0x2e54, 0x3049, 0x3234, 0x3416, 0x35ee,
    0x37be, 0x3985, 0x3b43, 0x3cf9, 0x3ea7, 0x404d,
    0x41ec
];

const TND_TABLE: [u16; 203] = [
    0x0000, 0x01b7, 0x036a, 0x051a, 0x06c6, 0x086f,
    0x0a15, 0x0bb7, 0x0d56, 0x0ef2, 0x108a, 0x121f,
    0x13b1, 0x1540, 0x16cc, 0x1855, 0x19da, 0x1b5d,
    0x1cdd, 0x1e59, 0x1fd3, 0x214a, 0x22be, 0x2430,
    0x259e, 0x270a, 0x2874, 0x29da, 0x2b3e, 0x2c9f,
    0x2dfe, 0x2f5a, 0x30b4, 0x320b, 0x335f, 0x34b2,
    0x3601, 0x374f, 0x389a, 0x39e2, 0x3b29, 0x3c6d,
    0x3dae, 0x3eee, 0x402b, 0x4166, 0x429f, 0x43d6,
    0x450a, 0x463d, 0x476d, 0x489c, 0x49c8, 0x4af2,
    0x4c1b, 0x4d41, 0x4e65, 0x4f87, 0x50a8, 0x51c6,
    0x52e3, 0x53fe, 0x5517, 0x562e, 0x5743, 0x5856,
    0x5968, 0x5a78, 0x5b86, 0x5c93, 0x5d9d, 0x5ea6,
    0x5fae, 0x60b3, 0x61b7, 0x62ba, 0x63bb, 0x64ba,
    0x65b7, 0x66b3, 0x67ae, 0x68a7, 0x699e, 0x6a94,
    0x6b88, 0x6c7b, 0x6d6d, 0x6e5d, 0x6f4b, 0x7038,
    0x7124, 0x720e, 0x72f7, 0x73de, 0x74c4, 0x75a9,
    0x768c, 0x776e, 0x784f, 0x792e, 0x7a0d, 0x7ae9,
    0x7bc5, 0x7c9f, 0x7d78, 0x7e50, 0x7f26, 0x7ffc,
    0x80d0, 0x81a3, 0x8274, 0x8345, 0x8414, 0x84e2,
    0x85af, 0x867b, 0x8746, 0x880f, 0x88d8, 0x899f,
    0x8a65, 0x8b2b, 0x8bef, 0x8cb2, 0x8d74, 0x8e35,
    0x8ef4, 0x8fb3, 0x9071, 0x912e, 0x91ea, 0x92a4,
    0x935e, 0x9417, 0x94cf, 0x9586, 0x963c, 0x96f0,
    0x97a4, 0x9857, 0x990a, 0x99bb, 0x9a6b, 0x9b1a,
    0x9bc9, 0x9c76, 0x9d23, 0x9dcf, 0x9e7a, 0x9f24,
    0x9fcd, 0xa075, 0xa11c, 0xa1c3, 0xa269, 0xa30e,
    0xa3b2, 0xa455, 0xa4f7, 0xa599, 0xa63a, 0xa6da,
    0xa779, 0xa818, 0xa8b5, 0xa952, 0xa9ef, 0xaa8a,
    0xab25, 0xabbe, 0xac58, 0xacf0, 0xad88, 0xae1f,
    0xaeb5, 0xaf4a, 0xafdf, 0xb073