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FFT.cpp
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FFT.cpp
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/*
FFT.CPP a module for Exploring Fast Fourier Transform
Written in Microsoft Visual C++ by Paul de Leeuw.
*/
#include <conio.h>
#include <string.h>
#include <stdio.h>
#include <windowsx.h>
#include "manp.h"
#include "resource.h"
#include "fractype.h"
#include "Plot.h"
#include "Dib.h"
#include "preview.h"
#define TIME_HEIGHT 240 // time domain window.
#define TIME_WIDTH 400
#define TIME_HOR_OFFSET 158
#define TIME_VERT_OFFSET 25
#define FREQ_HEIGHT 240 // time domain window.
#define FREQ_WIDTH 395
#define FREQ_HOR_OFFSET 620
#define FREQ_VERT_OFFSET 25
#define MAX_N 1024
extern int user_data(HWND);
extern int subtype; // see below
extern PAINTSTRUCT ps;
int steps;
#define LEVELS 32 // number of harmonic sliders
#define SQUARE '0'
#define TRIANGLE '1'
#define SAWTOOTH '2'
#define FULLWAVE '3'
#define HALFWAVE '4'
#define SINEWAVE '5'
#define COSINEWAVE '6'
#define IMPULSE '9'
#define USER 'U'
#define FFTREAL 0
#define FFTIMAG 1
#define REALIMAG 2
#define FFTPOWER 3
BYTE OutputType = REALIMAG;
static short level[LEVELS];
//static double real[MAX_N], imag[MAX_N];
static double real[LEVELS], imag[LEVELS];
//double *real, *imag;
extern int bits_per_pixel, xdots, ydots;
extern double ctable[];
extern double stable[];
extern double *wpixels; // an array of doubles holding slope modified iteration counts
extern CTrueCol TrueCol; // palette info
extern CPlot Plot; // image plotting routines
static CPreview TimeScreen, FreqScreen;
////////////////////////////
// Trig tables - refer TRIG.CPP
////////////////////////////
double cosgen(int i)
{
return ctable[i];
}
double singen(int i)
{
return stable[i];
}
/**************************************************************************
Fast Fourier Transform Subroutine
**************************************************************************/
void fft(int n, int m)
{
double xt, yt, c, s;
register int i, j, k;
int l, n1, n2, ie, ia, jt, trig_ptr, temp;
trig_ptr = MAX_N / n; /* point to right part of cos & sin */
n2 = n;
for (k = 0; k < m; ++k)
{
// cursor_at(16, 38);
// printf("%d", k);
n1 = n2;
n2 >>= 1;
jt = n2 >> 1;
for (i = 0; i < n; i += n1)
{
l = i + n2;
xt = real[i] - real[l];
real[i] += real[l];
real[l] = xt;
yt = imag[i] - imag[l];
imag[i] += imag[l];
imag[l] = yt;
}
if (k != m - 1)
{
ie = n / n1;
ia = 0;
for (j = 1; j < n2; ++j)
{
ia += ie;
if (j == jt)
{
for (i = j; i < n; i += n1)
{
l = i + n2;
xt = real[i] - real[l];
real[i] += real[l];
yt = imag[i] - imag[l];
imag[i] += imag[l];
real[l] = yt;
imag[l] = - xt;
}
}
else
{
temp = ia * trig_ptr;
c = cosgen(temp);
s = singen(temp);
for (i = j; i < n; i += n1)
{
l = i + n2;
xt = real[i] - real[l];
real[i] += real[l];
yt = imag[i] - imag[l];
imag[i] += imag[l];
real[l] = c * xt + s * yt;
imag[l] = c * yt - s * xt;
}
}
}
}
}
/* unscramble order of samples */
j = 1;
for (i = 1; i < n; ++i)
{
if (i < j)
{
xt = real[j - 1];
real[j - 1] = real[i - 1];
real[i - 1] = xt;
yt = imag[j - 1];
imag[j - 1] = imag[i - 1];
imag[i - 1] = yt;
}
k = n >> 1;
while (k < j)
{
j -= k;
k >>= 1;
}
j += k;
}
}
/**************************************************************************
Set up screen scaling and other inits
***************************************************************************/
void InitFFT(char WaveType)
{
int i;
switch (WaveType)
{
case IMPULSE:
for (i = 0; i < LEVELS; i++)
level[i] = -255;
level[LEVELS/2] = 255;
break;
case SAWTOOTH:
for (i = 0; i < LEVELS; i++)
level[i] = (i * 510) / LEVELS - 255;
break;
case SQUARE:
for (i = 0; i < LEVELS/2; i++)
level[i] = -255;
for (i = LEVELS/2; i < LEVELS; i++)
level[i] = 255;
break;
case TRIANGLE:
for (i = 0; i < LEVELS/2; i++)
level[i] = (i * 510) / (LEVELS/2) - 255;
for (i = LEVELS/2; i < LEVELS; i++)
level[i] = 765 - (i * 510) / (LEVELS/2);
break;
case FULLWAVE:
for (i = 0; i < LEVELS/2; i++)
level[i] = level[i+LEVELS/2] = (int)(510.0 * sin(2.0*PI*i / LEVELS)) - 255;
break;
case HALFWAVE:
for (i = 0; i < LEVELS/2; i++)
level[i] = (int)(510.0 * sin(2.0*PI*i / LEVELS)) - 255;
for (i = LEVELS/2; i < LEVELS; i++)
level[i] = -255;
break;
case SINEWAVE:
for (i = 0; i < LEVELS; i++)
level[i] = (int)(255.0 * sin(2.0*PI*i / LEVELS));
break;
case COSINEWAVE:
for (i = 0; i < LEVELS; i++)
level[i] = (int)(255.0 * sin(PI/2.0 + 2.0*PI*i / LEVELS));
break;
}
for (i = 0; i < LEVELS; i++)
{
real[i] = (double)level[i] / 255.0;
imag[i] = 0.0;
// *(real + i) = (double)level[i] / 255.0;
// *(imag + i) = 0.0;
}
return;
}
/**************************************************************************
Draw Preview Fourier Images
***************************************************************************/
int TimePreview(HWND hwnd, CPlot Plot)
{
int j, jump = TimeScreen.PreviewWidth/LEVELS;
int start = jump/2, end = 0;
memset(TimeScreen.PreviewDib.DibPixels, 0, (WIDTHBYTES((DWORD)TimeScreen.PreviewWidth * (DWORD)bits_per_pixel)) * TimeScreen.PreviewHeight); // set background to black
Plot.InitPlot(1000000L, &TrueCol, wpixels, xdots, ydots, TimeScreen.PreviewWidth, TimeScreen.PreviewHeight, TimeScreen.PreviewDib.BitsPerPixel, &TimeScreen.PreviewDib, 0);
for (j = 1; j < LEVELS; ++j)
{
end = start + jump;
Plot.genline(start, level[j - 1] * 118 / 255 + 120, end, level[j] * 118 / 255 + 120, 0x0000ff00);
start = end;
}
end = start + jump;
Plot.genline(start, level[LEVELS-1]*118/255+120, end, level[0]*118/255+120, 0x0000ff00);
ShowWindow (hwnd, SW_SHOWNORMAL);
return 0;
}
/**************************************************************************
Draw Preview Fourier Images
***************************************************************************/
int FreqPreview(HWND hwnd, CPlot Plot)
{
int j, jump = FreqScreen.PreviewWidth/LEVELS;
int start = jump/2, end = 0;
double rms;
Plot.InitPlot(1000000L, &TrueCol, wpixels, xdots, ydots, FreqScreen.PreviewWidth, FreqScreen.PreviewHeight, FreqScreen.PreviewDib.BitsPerPixel, &FreqScreen.PreviewDib, 0);
FreqScreen.PreviewDib.ClearDib(0L);
//memset(FreqScreen.PreviewDib.DibPixels, 127, (WIDTHBYTES((DWORD)PreviewWidth * (DWORD)bits_per_pixel)) * PreviewHeight); // set background to black
for (j = 0; j < LEVELS; ++j)
{
switch (OutputType)
{
case FFTREAL:
Plot.genline(start, 120, start, (int)(real[j]*30.0)+120, 0x00ffff00);
break;
case FFTIMAG:
Plot.genline(start, 120, start, (int)(imag[j]*30.0)+120, 0x00ff0000);
break;
case REALIMAG:
Plot.genline(start, 120, start, (int)(real[j]*30.0)+120, 0x00ffff00);
Plot.genline(start+2, 120, start+2, (int)(imag[j]*30.0)+120, 0x00ff0000);
break;
case FFTPOWER:
rms = sqrt(real[j]*real[j]+imag[j]*imag[j]);
Plot.genline(start, 2, start, (int)(rms*30.0), 0x00ffffff);
break;
}
start += jump;
}
ShowWindow (hwnd, SW_SHOWNORMAL);
return 0;
}
/**************************************************************************
Dialog Control for Displaying Fast Fourier Transforms
**************************************************************************/
DLGPROC FAR PASCAL FastFourierDlg (HWND hDlg, UINT message, UINT wParam, LONG lParam)
{
static HANDLE hCursor;
static char temp, temp1;
static UINT tempParam, tempParam1;
short nCtrlID, nIndex;
HWND hwndParent, hCtrl;
char s[MAXLINE];
// set the dimensions and location of the windows
TimeScreen.HorOffset = TIME_HOR_OFFSET; // dimensions of time domain window
TimeScreen.VertOffset = TIME_VERT_OFFSET;
TimeScreen.PreviewHeight = TIME_HEIGHT;
TimeScreen.PreviewWidth = TIME_WIDTH;
FreqScreen.HorOffset = FREQ_HOR_OFFSET; // dimensions of frequency domain window
FreqScreen.VertOffset = FREQ_VERT_OFFSET;
FreqScreen.PreviewHeight = FREQ_HEIGHT;
FreqScreen.PreviewWidth = FREQ_WIDTH;
switch (message)
{
case WM_INITDIALOG:
temp = subtype;
switch (subtype)
{
case SQUARE:
tempParam = IDC_SQUAREWAVE;
break;
case COSINEWAVE:
tempParam = IDC_COSWAVE;
break;
case SINEWAVE:
tempParam = IDC_SINWAVE;
break;
case TRIANGLE:
tempParam = IDC_TRIANGLE;
break;
case IMPULSE:
tempParam = IDC_IMPULSETRAIN;
break;
case SAWTOOTH:
tempParam = IDC_SAWTOOTH;
break;
case FULLWAVE:
tempParam = IDC_FULLWAVE;
break;
case HALFWAVE:
tempParam = IDC_HALFWAVE;
break;
case USER:
tempParam = IDC_USER;
break;
default: // uninitialised
tempParam = IDC_SQUAREWAVE;
temp = SQUARE;
break;
}
CheckRadioButton(hDlg, IDC_SQUAREWAVE, IDC_USER, tempParam);
// subtype = temp;
InitFFT(temp);
for (nCtrlID = IDC_SCROLLBAR1 ; nCtrlID < IDC_SCROLLBAR1 + LEVELS ; nCtrlID++)
{
nIndex = nCtrlID - IDC_SCROLLBAR1;
hCtrl = GetDlgItem (hDlg, nCtrlID) ;
SetScrollRange (hCtrl, SB_CTL, -255, 255, FALSE) ;
SetScrollPos (hCtrl, SB_CTL, -level[nIndex], FALSE) ;
SetDlgItemInt (hDlg, nIndex + IDC_LABEL1, level[nIndex], TRUE) ;
}
temp1 = OutputType;
switch (OutputType)
{
case FFTREAL:
tempParam1 = IDC_FFT_REAL;
break;
case FFTIMAG:
tempParam1 = IDC_FFT_IMAG;
break;
case REALIMAG:
tempParam1 = IDC_FFT_REALIMAG;
break;
case FFTPOWER:
tempParam1 = IDC_FFT_POWER;
break;
// default: // uninitialised
// tempParam1 = IDC_FFT_REALIMAG;
// temp1 = REALIMAG;
// break;
}
CheckRadioButton(hDlg, IDC_FFT_REAL, IDC_FFT_POWER, tempParam1);
// OutputType = temp1;
// SetFocus(GetDlgItem(hDlg, tempParam));
if (TimeScreen.InitPreview(hDlg) < 0)
{
wsprintf(s, "Error: No memory for preview");
MessageBox (hDlg, s, "ManpWIN", MB_ICONEXCLAMATION | MB_OK);
// delete [] real;
// delete [] imag;
EndDialog (hDlg, FALSE);
}
if (FreqScreen.InitPreview(hDlg) < 0)
{
wsprintf(s, "Error: No memory for FFT");
MessageBox (hDlg, s, "ManpWIN", MB_ICONEXCLAMATION | MB_OK);
TimeScreen.PreviewDib.CloseDibPtrs();
// delete [] real;
// delete [] imag;
EndDialog (hDlg, FALSE);
}
temp1 = OutputType;
InvalidateRect(hDlg,NULL,FALSE);
return (DLGPROC)TRUE ;
case WM_VSCROLL :
hCtrl = GET_WM_COMMAND_HWND (wParam, (_int64)lParam);
if ((nCtrlID = ((WORD)(GetWindowLong (hCtrl, GWL_ID)))) == 0)
{
wsprintf(s, "Error: Scrollbar fail: <%ld>", GetLastError());
MessageBox (hDlg, s, "Paul's Graphics Viewer", MB_ICONEXCLAMATION | MB_OK);
}
nIndex = nCtrlID - IDC_SCROLLBAR1;
hwndParent = GetParent (hDlg) ;
switch ((int) LOWORD(wParam))
{
case SB_PAGEDOWN :
level [nIndex] -= 15 ; // fall through
case SB_LINEDOWN :
level [nIndex] = max (-255, level [nIndex] - 1) ;
break ;
case SB_PAGEUP :
level [nIndex] += 15 ; // fall through
case SB_LINEUP :
level [nIndex] = min (255, level [nIndex] + 1) ;
break ;
case SB_TOP:
level [nIndex] = 255 ;
break ;
case SB_BOTTOM :
level [nIndex] = -255 ;
break ;
case SB_THUMBPOSITION :
case SB_THUMBTRACK :
level[nIndex] = -HIWORD (wParam) ;
break ;
default :
return FALSE ;
}
SetScrollPos (hCtrl, SB_CTL, -level [nIndex], TRUE) ;
SetDlgItemInt (hDlg, nIndex + IDC_LABEL1, level[nIndex], TRUE) ;
CheckRadioButton(hDlg, IDC_SQUAREWAVE, IDC_USER, IDC_USER);
temp = USER;
InvalidateRect(hDlg,NULL,FALSE);
return (DLGPROC)TRUE ;
case WM_PAINT:
BeginPaint(hDlg, &ps);
InitFFT(temp);
TimePreview(hDlg, Plot);
TimeScreen.Preview(hDlg);
fft(32, 5);
FreqPreview(hDlg, Plot);
FreqScreen.Preview(hDlg);
EndPaint(hDlg, &ps);
return (DLGPROC)TRUE ;
case WM_COMMAND:
switch ((int) LOWORD(wParam))
{
case IDC_TRIANGLE:
case IDC_SINWAVE:
case IDC_COSWAVE:
case IDC_SQUAREWAVE:
case IDC_SAWTOOTH:
case IDC_FULLWAVE:
case IDC_HALFWAVE:
case IDC_USER:
case IDC_IMPULSETRAIN:
switch ((int) LOWORD(wParam))
{
case IDC_TRIANGLE:
temp = TRIANGLE;
break;
case IDC_SINWAVE:
temp = SINEWAVE;
break;
case IDC_COSWAVE:
temp = COSINEWAVE;
break;
case IDC_IMPULSETRAIN:
temp = IMPULSE;
break;
case IDC_SQUAREWAVE:
temp = SQUARE;
break;
case IDC_SAWTOOTH:
temp = SAWTOOTH;
break;
case IDC_FULLWAVE:
temp = FULLWAVE;
break;
case IDC_HALFWAVE:
temp = HALFWAVE;
break;
case IDC_USER:
temp = USER;
break;
}
CheckRadioButton(hDlg, IDC_SQUAREWAVE, IDC_USER, (int) LOWORD(wParam));
subtype = temp;
InitFFT(temp);
for (nCtrlID = IDC_SCROLLBAR1 ; nCtrlID < IDC_SCROLLBAR1 + LEVELS ; nCtrlID++)
{
nIndex = nCtrlID - IDC_SCROLLBAR1;
hCtrl = GetDlgItem (hDlg, nCtrlID) ;
SetScrollRange (hCtrl, SB_CTL, -255, 255, FALSE) ;
SetScrollPos (hCtrl, SB_CTL, -level[nIndex], TRUE) ;
SetDlgItemInt (hDlg, nIndex + IDC_LABEL1, level[nIndex], TRUE) ;
}
InvalidateRect(hDlg,NULL,FALSE);
return (DLGPROC)TRUE ;
case IDC_FFT_REAL:
case IDC_FFT_IMAG:
case IDC_FFT_REALIMAG:
case IDC_FFT_POWER:
switch ((int) LOWORD(wParam))
{
case IDC_FFT_REAL:
temp1 = FFTREAL;
break;
case IDC_FFT_IMAG:
temp1 = FFTIMAG;
break;
case IDC_FFT_REALIMAG:
temp1 = REALIMAG;
break;
case IDC_FFT_POWER:
temp1 = FFTPOWER;
break;
}
CheckRadioButton(hDlg, IDC_FFT_REAL, IDC_FFT_POWER, (int) LOWORD(wParam));
OutputType = temp1;
// InitFFT(temp);
InvalidateRect(hDlg,NULL,FALSE);
return (DLGPROC)TRUE ;
case IDOK:
case IDCANCEL:
TimeScreen.PreviewDib.CloseDibPtrs();
FreqScreen.PreviewDib.CloseDibPtrs();
// delete [] real;
// delete [] imag;
EndDialog (hDlg, FALSE);
return (DLGPROC)FALSE;
}
break;
}
return (DLGPROC)FALSE ;
}