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/**********************************************************************
Audacity: A Digital Audio Editor
Echo.cpp
Dominic Mazzoni
**********************************************************************/
#include <wx/generic/textdlgg.h>
#include "Echo.h"
#include "../WaveTrack.h"
EffectEcho::EffectEcho()
{
delay = 1.0;
decay = 0.5;
}
bool EffectEcho::PromptUser()
{
wxString temp;
wxString title = "Echo";
wxString caption = "Delay time (seconds): ";
wxString default_value = wxString::Format("%f", delay);
temp = wxGetTextFromUser(caption, title,
default_value, mParent, -1, -1, TRUE);
if (temp == "")
return false;
while (sscanf((const char *) temp, "%f", &delay) < 0) {
caption = "Please enter a positive number for the delay time: ";
temp = wxGetTextFromUser(caption, title,
default_value, mParent, -1, -1, TRUE);
if (temp == "")
return false;
}
caption = "Enter the decay factor: ";
default_value = wxString::Format("%f", decay);
temp = wxGetTextFromUser(caption, title,
default_value, mParent, -1, -1, TRUE);
if (temp == "")
return false;
while (sscanf((const char *) temp, "%f", &decay) < 0) {
caption = "Please enter a positive number for the decay factor: ";
temp = wxGetTextFromUser(caption, title,
default_value, mParent, -1, -1, TRUE);
if (temp == "")
return false;
}
return true;
}
bool EffectEcho::Process()
{
TrackListIterator iter(mWaveTracks);
VTrack *t = iter.First();
int count = 0;
while(t) {
sampleCount start, len;
GetSamples((WaveTrack *)t, &start, &len);
bool success = ProcessOne(count, (WaveTrack *)t, start, len);
if (!success)
return false;
t = iter.Next();
count++;
}
return true;
}
bool EffectEcho::ProcessOne(int count, WaveTrack * t,
sampleCount start, sampleCount len)
{
sampleCount s = start;
sampleCount blockSize = (sampleCount) (t->rate * delay);
sampleCount originalLen = len;
if (blockSize < 1 || blockSize > len)
return true;
sampleType *buffer0 = new sampleType[blockSize];
sampleType *buffer1 = new sampleType[blockSize];
sampleType *ptr0 = buffer0;
sampleType *ptr1 = buffer1;
bool first = true;
while (len) {
sampleCount block = blockSize;
if (block > len)
block = len;
t->Get(ptr0, s, block);
if (!first) {
for (sampleCount i = 0; i < block; i++)
ptr0[i] += (sampleType) (ptr1[i] * decay);
t->Set(ptr0, s, block);
}
sampleType *ptrtemp = ptr0;
ptr0 = ptr1;
ptr1 = ptrtemp;
first = false;
len -= block;
s += block;
if (TrackProgress(count, (s-start)/(double)originalLen))
break;
}
delete[]buffer0;
delete[]buffer1;
return true;
}
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