mirror of
https://git.code.sf.net/p/quake/quakeforge
synced 2024-11-30 08:00:51 +00:00
12ab283c22
And fix an error in floatview. The z-transform program is so I can test out my math and eventually develop some hopefully interesting sound generators.
50 lines
842 B
R
50 lines
842 B
R
#include <math.h>
|
|
|
|
void printf (string fnt, ...) = #0;
|
|
|
|
#define SAMPLES 4
|
|
float output[SAMPLES];
|
|
float input[SAMPLES];
|
|
|
|
float T=0.1;
|
|
float w=2;
|
|
float a=0.5;
|
|
|
|
float A[3], B[3];
|
|
|
|
void
|
|
z_transform (float *y, float *x, float *A, float *B, int n, int zind)
|
|
{
|
|
zind %= SAMPLES;
|
|
float c = x[zind] * A[0];
|
|
for (int i = 1; i < n; i++) {
|
|
int z = (SAMPLES + zind - i) % SAMPLES;
|
|
c += x[z] * A[i] - y[z] * B[i];
|
|
}
|
|
y[zind] = c / B[0];
|
|
}
|
|
|
|
int
|
|
main ()
|
|
{
|
|
float e = exp (-a*T);
|
|
float c = cos (w*T);
|
|
float s = sin (w*T);
|
|
|
|
B[0] = 1;
|
|
B[1] = -2 * e * c;
|
|
B[2] = e * e;
|
|
|
|
A[0] = 0;
|
|
A[1] = 1 - e*(c + (a/w)*s);
|
|
A[2] = e*e + e*((a/w)*s - c);
|
|
|
|
for (int i = 0; i < 200; i++) {
|
|
int ind = i % SAMPLES;
|
|
input[ind] = 1;//i ? 0 : 1;
|
|
z_transform (output, input, A, B, 3, i);
|
|
printf ("%2d %7.4f %7.4f\n", i, input[ind], output[ind]);
|
|
}
|
|
|
|
return 0;
|
|
}
|