[PD-dev] What goes on during dsp ticks?

Hi,

I would highly appreciate some assistance in grasping how signals are processed in DSP objects.

Working on the following template, I will demonstrate variations in the <PROCESS BLOCK>. As results do not appear as the way I expect, there must be something I am not understanding correctly.

========== Template ==========

t_int *foobar_tilde_perform(t_int *w) { t_sample *in = (t_sample *)(w[1]); t_sample *out = (t_sample *)(w[2]); int n = (int)(w[3]);

<PROCESS BLOCK>

return (w+4); }

===================== == PROCESS BLOCK.1 == =====================

while (n--) { *out++ = *in++; }

Remarks: Simple THRU... works as expected.

===================== == PROCESS BLOCK.2 == =====================

while (n--) { // *out++ = *in++; }

Remarks: Action is commented out but signal goes through.. Why?

===================== == PROCESS BLOCK.3 == =====================

while (n--) { *out++ = *in++ * -1; }

Remarks: Inverse signal, as expected

===================== == PROCESS BLOCK.4 == =====================

n--; *out++ = 0; while (n--) { *out++ = *in++; }

Remarks: Expecting first sample of the block to be zero and others delayed by 1 sample. Instead, I get an constant output of zero.

I hope what I am missing is something obvious to those with insight.

Thanks.

-- David Shimamoto