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Simplified code for modulation waveforms (#321)

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extract calculations that never changed during the loop
This commit is contained in:
carlo-bramini 2018-01-07 10:23:18 +01:00 committed by Tom M
parent 292b7e028f
commit 1a201a2d4d
1 changed files with 32 additions and 14 deletions
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46
src/rvoice/fluid_chorus.c
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@ -479,13 +479,22 @@ static void
fluid_chorus_sine(int *buf, int len, int depth)
{
int i;
double val;
double angle, incr, mult;
/* Pre-calculate increment between angles. */
incr = (2. * M_PI) / (double)len;
/* Pre-calculate 'depth' multiplier. */
mult = (double) depth / 2.0 * (double) INTERPOLATION_SUBSAMPLES;
/* Initialize to zero degrees. */
angle = 0.;
/* Build sine modulation waveform */
for (i = 0; i < len; i++) {
val = sin((double) i / (double)len * 2.0 * M_PI);
buf[i] = (int) ((1.0 + val) * (double) depth / 2.0 * (double) INTERPOLATION_SUBSAMPLES);
buf[i] -= 3* MAX_SAMPLES * INTERPOLATION_SUBSAMPLES;
// printf("%i %i\n",i,buf[i]);
buf[i] = (int) ((1. + sin(angle)) * mult) - 3 * MAX_SAMPLES * INTERPOLATION_SUBSAMPLES;
angle += incr;
}
}
@ -496,15 +505,24 @@ fluid_chorus_sine(int *buf, int len, int depth)
static void
fluid_chorus_triangle(int *buf, int len, int depth)
{
int i=0;
int ii=len-1;
double val;
double val2;
int *il = buf;
int *ir = buf + len-1;
int ival;
double val, incr;
while (i <= ii){
val = i * 2.0 / len * (double)depth * (double) INTERPOLATION_SUBSAMPLES;
val2= (int) (val + 0.5) - 3 * MAX_SAMPLES * INTERPOLATION_SUBSAMPLES;
buf[i++] = (int) val2;
buf[ii--] = (int) val2;
/* Pre-calculate increment for the ramp. */
incr = 2.0 / len * (double)depth * (double) INTERPOLATION_SUBSAMPLES;
/* Initialize first value */
val = 0.;
/* Build triangular modulation waveform */
while (il <= ir) {
ival= (int)(val + 0.5) - 3 * MAX_SAMPLES * INTERPOLATION_SUBSAMPLES;
*il++ = ival;
*ir-- = ival;
val += incr;
}
}