mirror of
https://github.com/sehugg/8bitworkshop.git
synced 2024-11-04 20:05:57 +00:00
113 lines
2.7 KiB
C
113 lines
2.7 KiB
C
|
|
#include <string.h>
|
|
|
|
typedef unsigned char byte;
|
|
typedef unsigned short word;
|
|
typedef signed char sbyte;
|
|
|
|
const __sfr __at (0x0) command;
|
|
__sfr __at (0x0) dac;
|
|
|
|
#define HALT __asm halt __endasm;
|
|
|
|
// press "2" or higher to activate...
|
|
|
|
typedef struct {
|
|
word duration;
|
|
word offset;
|
|
word delta;
|
|
int deltainc;
|
|
byte* wavetable;
|
|
byte wavemask;
|
|
signed char lfo;
|
|
} SoundEffect;
|
|
|
|
const char SQUARE_LOFREQ[32] = {
|
|
-64,-64,-64,-64,-64,-64,-64,
|
|
-64,-64,-64,-64,-64,-64,-64,
|
|
64,64,64,64,64,64,64,64,
|
|
64,64,64,64,64,64,64,64
|
|
};
|
|
const char SQUARE_HIFREQ[32] = {
|
|
-64,64,-64,64,-64,64,-64,64,
|
|
-64,64,-64,64,-64,64,-64,64,
|
|
-64,64,-64,64,-64,64,-64,64,
|
|
-64,64,-64,64,-64,64,-64,64,
|
|
};
|
|
const char SINTBL[128] = {
|
|
0, 3, 6, 9, 12, 16, 19, 22, 25, 28, 31, 34, 37, 40, 43, 46,
|
|
49, 51, 54, 57, 60, 63, 65, 68, 71, 73, 76, 78, 81, 83, 85, 88,
|
|
90, 92, 94, 96, 98, 100, 102, 104, 106, 107, 109, 111, 112, 113, 115, 116,
|
|
117, 118, 120, 121, 122, 122, 123, 124, 125, 125, 126, 126, 126, 127, 127, 127,
|
|
127, 127, 127, 127, 126, 126, 126, 125, 125, 124, 123, 122, 122, 121, 120, 118,
|
|
117, 116, 115, 113, 112, 111, 109, 107, 106, 104, 102, 100, 98, 96, 94, 92,
|
|
90, 88, 85, 83, 81, 78, 76, 73, 71, 68, 65, 63, 60, 57, 54, 51,
|
|
49, 46, 43, 40, 37, 34, 31, 28, 25, 22, 19, 16, 12, 9, 6, 3,
|
|
};
|
|
const char TRIANGLE[32] = {
|
|
-0x80,-0x78,-0x70,-0x68, -0x60,-0x58,-0x50,-0x48,
|
|
-0x40,-0x38,-0x30,-0x28, -0x20,-0x18,-0x10,-0x08,
|
|
0x00,0x08,0x10,0x18, 0x20,0x28,0x30,0x38,
|
|
0x40,0x48,0x50,0x58, 0x60,0x68,0x70,0x78,
|
|
};
|
|
const char NOISE[32] = {
|
|
0x60,0x37,0x3f,0x5c,0x16,0xca,0xc2,0xa5,0xfe,0xba,0x77,0x89,0xaa,0x77,0x13,0xd8,
|
|
0xae,0x82,0xfd,0x22,0x9c,0x46,0xde,0x14,0x50,0xb4,0x97,0x46,0x54,0x9d,0x60,0x2b,
|
|
};
|
|
|
|
SoundEffect e;
|
|
byte volume;
|
|
|
|
const SoundEffect SOUNDS[] = {
|
|
{ 1200, 0, 0, 1, NOISE, 0xff, 0 },
|
|
{ 250, 0, 1000, -4, SINTBL, 0x7f, 0 },
|
|
{ 500, 0, 1000, 2, TRIANGLE, 0x1f, 0 },
|
|
{ 600, 0, 3000, -1, SQUARE_LOFREQ, 0x1f, 0 },
|
|
{ 600, 0, 3000, -1, SQUARE_HIFREQ, 0x1f, 0 },
|
|
{ 600, 0, 3000, 1, SQUARE_LOFREQ, 0x3f, 0 },
|
|
{ 1200, 0, 0, 1, SINTBL, 0x7f, 1 },
|
|
};
|
|
|
|
void play();
|
|
|
|
void main() {
|
|
// halt on command = 0
|
|
if (command == 0) HALT;
|
|
// load stack pointer
|
|
__asm
|
|
ld sp,#0x8000
|
|
di
|
|
__endasm;
|
|
// copy sound to RAM
|
|
memcpy(&e, &SOUNDS[command-1], sizeof(e));
|
|
// play sound
|
|
play();
|
|
// turn off speaker and halt
|
|
dac = 0;
|
|
HALT;
|
|
}
|
|
|
|
void sample() {
|
|
byte val = e.wavetable[(byte)(e.offset >> 8) & e.wavemask];
|
|
if (val <= volume) dac = val;
|
|
e.offset += e.delta;
|
|
}
|
|
|
|
void play() {
|
|
volume = 0xff;
|
|
while (e.duration--) {
|
|
sample();
|
|
sample();
|
|
sample();
|
|
sample();
|
|
sample();
|
|
sample();
|
|
sample();
|
|
sample();
|
|
e.delta += e.deltainc;
|
|
e.deltainc += e.lfo;
|
|
// taper off volume
|
|
if (e.duration <= 0xff) volume = e.duration;
|
|
}
|
|
}
|