drum.c

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/*-------------------------------------
   DRUM.C -- MIDI Drum Machine
             (c) Charles Petzold, 1998
  -------------------------------------*/

#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "drumtime.h"
#include "drumfile.h"
#include "resource.h"

LRESULT CALLBACK WndProc   (HWND, UINT, WPARAM, LPARAM) ;
BOOL    CALLBACK AboutProc (HWND, UINT, WPARAM, LPARAM) ;
                            
void  DrawRectangle (HDC, int, int, DWORD *, DWORD *) ;
void  ErrorMessage  (HWND, TCHAR *, TCHAR *) ;
void  DoCaption     (HWND, TCHAR *) ;
int   AskAboutSave  (HWND, TCHAR *) ;

TCHAR * szPerc [NUM_PERC] =
{
     TEXT ("Acoustic Bass Drum"), TEXT ("Bass Drum 1"),     
     TEXT ("Side Stick"),         TEXT ("Acoustic Snare"),     
     TEXT ("Hand Clap"),          TEXT ("Electric Snare"),
     TEXT ("Low Floor Tom"),      TEXT ("Closed High Hat"), 
     TEXT ("High Floor Tom"),     TEXT ("Pedal High Hat"),     
     TEXT ("Low Tom"),            TEXT ("Open High Hat"),
     TEXT ("Low-Mid Tom"),        TEXT ("High-Mid Tom"),    
     TEXT ("Crash Cymbal 1"),     TEXT ("High Tom"),           
     TEXT ("Ride Cymbal 1"),      TEXT ("Chinese Cymbal"),
     TEXT ("Ride Bell"),          TEXT ("Tambourine"),      
     TEXT ("Splash Cymbal"),      TEXT ("Cowbell"),            
     TEXT ("Crash Cymbal 2"),     TEXT ("Vibraslap"),
     TEXT ("Ride Cymbal 2"),      TEXT ("High Bongo"),      
     TEXT ("Low Bongo"),          TEXT ("Mute High Conga"),    
     TEXT ("Open High Conga"),    TEXT ("Low Conga"),
     TEXT ("High Timbale"),       TEXT ("Low Timbale"),     
     TEXT ("High Agogo"),         TEXT ("Low Agogo"),          
     TEXT ("Cabasa"),             TEXT ("Maracas"),
     TEXT ("Short Whistle"),      TEXT ("Long Whistle"),    
     TEXT ("Short Guiro"),        TEXT ("Long Guiro"),         
     TEXT ("Claves"),             TEXT ("High Wood Block"),
     TEXT ("Low Wood Block"),     TEXT ("Mute Cuica"),      
     TEXT ("Open Cuica"),         TEXT ("Mute Triangle"),      
     TEXT ("Open Triangle")
} ;

TCHAR   szAppName  [] = TEXT ("Drum") ;
TCHAR   szUntitled [] = TEXT ("(Untitled)") ;
TCHAR   szBuffer [80 + MAX_PATH] ;
HANDLE  hInst ;
int     cxChar, cyChar ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     HWND        hwnd ;
     MSG         msg ;
     WNDCLASS    wndclass ;
     
     hInst = hInstance ;
     
     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (hInstance, szAppName) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = szAppName ;
     wndclass.lpszClassName = szAppName ;
          
     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"),
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }

     hwnd = CreateWindow (szAppName, NULL,
                          WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU |
                                   WS_MINIMIZEBOX | WS_HSCROLL | WS_VSCROLL,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          NULL, NULL, hInstance, szCmdLine) ;
     
     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;
     
     while (GetMessage (&msg, NULL, 0, 0))
     {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
     }
     return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
     static BOOL  bNeedSave ;
     static DRUM  drum ;
     static HMENU hMenu ;
     static int   iTempo = 50, iIndexLast ;
     static TCHAR szFileName  [MAX_PATH], szTitleName [MAX_PATH] ;
     HDC          hdc ;
     int          i, x, y ;
     PAINTSTRUCT  ps ;
     POINT        point ;
     RECT         rect ;
     TCHAR      * szError ;
     
     switch (message)
     {
     case WM_CREATE:
               // Initialize DRUM structure
          
          drum.iMsecPerBeat = 100 ;
          drum.iVelocity    =  64 ;
          drum.iNumBeats    =  32 ;
          
          DrumSetParams (&drum) ;
          
               // Other initialization
          
          cxChar = LOWORD (GetDialogBaseUnits ()) ;
          cyChar = HIWORD (GetDialogBaseUnits ()) ;

          GetWindowRect (hwnd, &rect) ;
          MoveWindow (hwnd, rect.left, rect.top, 
                            77 * cxChar, 29 * cyChar, FALSE) ;
          
          hMenu = GetMenu (hwnd) ;
          
               // Initialize "Volume" scroll bar
          
          SetScrollRange (hwnd, SB_HORZ, 1, 127, FALSE) ;
          SetScrollPos   (hwnd, SB_HORZ, drum.iVelocity, TRUE) ;
          
               // Initialize "Tempo" scroll bar
          
          SetScrollRange (hwnd, SB_VERT, 0, 100, FALSE) ;
          SetScrollPos   (hwnd, SB_VERT, iTempo, TRUE) ;
          
          DoCaption (hwnd, szTitleName) ;
          return 0 ;
          
     case WM_COMMAND:
          switch (LOWORD (wParam))
          {
          case IDM_FILE_NEW:
               if (bNeedSave && IDCANCEL == AskAboutSave (hwnd, szTitleName))
                    return 0 ;
               
                    // Clear drum pattern
               
               for (i = 0 ; i < NUM_PERC ; i++)
               {
                    drum.dwSeqPerc [i] = 0 ;
                    drum.dwSeqPian [i] = 0 ;
               }
               
               InvalidateRect (hwnd, NULL, FALSE) ;
               DrumSetParams (&drum) ;
               bNeedSave = FALSE ;
               return 0 ;
               
          case IDM_FILE_OPEN:
                    // Save previous file
               
               if (bNeedSave && IDCANCEL ==
                    AskAboutSave (hwnd, szTitleName))
                    return 0 ;
               
                    // Open the selected file
               
               if (DrumFileOpenDlg (hwnd, szFileName, szTitleName))
               {
                    szError = DrumFileRead (&drum, szFileName) ;
                    
                    if (szError != NULL)
                    {
                         ErrorMessage (hwnd, szError, szTitleName) ;
                         szTitleName [0] = '\0' ;
                    }
                    else
                    {
                              // Set new parameters
                         
                         iTempo = (int) (50 *
                              (log10 (drum.iMsecPerBeat) - 1)) ;
                         
                         SetScrollPos (hwnd, SB_VERT, iTempo, TRUE) ;
                         SetScrollPos (hwnd, SB_HORZ, drum.iVelocity, TRUE) ;
                         
                         DrumSetParams (&drum) ;
                         InvalidateRect (hwnd, NULL, FALSE) ;
                         bNeedSave = FALSE ;
                    }
                    
                    DoCaption (hwnd, szTitleName) ;
               }
               return 0 ;
               
          case IDM_FILE_SAVE:
          case IDM_FILE_SAVE_AS:
                    // Save the selected file
               
               if ((LOWORD (wParam) == IDM_FILE_SAVE && szTitleName [0]) ||
                         DrumFileSaveDlg (hwnd, szFileName, szTitleName))
               {
                    szError = DrumFileWrite (&drum, szFileName) ;
                    
                    if (szError != NULL)
                    {
                         ErrorMessage (hwnd, szError, szTitleName) ;
                         szTitleName [0] = '\0' ;
                    }
                    else
                         bNeedSave = FALSE ;
                    
                    DoCaption (hwnd, szTitleName) ;
               }
               return 0 ;
               
          case IDM_APP_EXIT:
               SendMessage (hwnd, WM_SYSCOMMAND, SC_CLOSE, 0L) ;
               return 0 ;
               
          case IDM_SEQUENCE_RUNNING:
                    // Begin sequence
               
               if (!DrumBeginSequence (hwnd))
               {
                    ErrorMessage (hwnd,
                         TEXT ("Could not start MIDI sequence -- ")
                         TEXT ("MIDI Mapper device is unavailable!"),
                         szTitleName) ;
               }
               else
               {
                    CheckMenuItem (hMenu, IDM_SEQUENCE_RUNNING,   MF_CHECKED) ;
                    CheckMenuItem (hMenu, IDM_SEQUENCE_STOPPED, MF_UNCHECKED) ;
               }
               return 0 ;
               
          case IDM_SEQUENCE_STOPPED:
                    // Finish at end of sequence
               
               DrumEndSequence (FALSE) ;
               return 0 ;
               
          case IDM_APP_ABOUT:
               DialogBox (hInst, TEXT ("AboutBox"), hwnd, AboutProc) ;
               return 0 ;
          }
          return 0 ;
                    
     case WM_LBUTTONDOWN:
     case WM_RBUTTONDOWN:
          hdc = GetDC (hwnd) ;