/*------------------------------------------
   NTXFORM.C -- Windows NT Matrix Tranforms
                (c) Charles Petzold, 1993
  ------------------------------------------*/

#include <windows.h>
#include <stdio.h>
#include <math.h>
#include "ntxform.h"

#define TWO_PI (2 * 3.14159)

long APIENTRY WndProc   (HWND, UINT, WPARAM, LPARAM) ;
BOOL APIENTRY MatrixBox (HWND, UINT, WPARAM, LPARAM) ;
BOOL APIENTRY AngleBox  (HWND, UINT, WPARAM, LPARAM) ;

HANDLE hInst ;

int PASCAL WinMain (HANDLE hInstance, HANDLE hPrevInstance,
                    LPSTR lpszCmdLine, int nCmdShow)
     {
     static   char szAppName[] = "NtXform" ;
     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 (NULL, IDI_APPLICATION) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = szAppName ;
     wndclass.lpszClassName = szAppName ;

     RegisterClass (&wndclass) ;

     hwnd = CreateWindow (szAppName, "Matrix Transforms",
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          NULL, NULL, hInstance, NULL) ;

     ShowWindow (hwnd, nCmdShow) ;
     UpdateWindow (hwnd) ;

     while (GetMessage (&msg, NULL, 0, 0))
          {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
          }
     return msg.wParam ;
     }

long APIENTRY WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
     {
     static int        cxClient, cyClient ;
     static LOGFONT    logfont ;
     static XFORM      xform = { (FLOAT) 1.0, (FLOAT) 0.0,
                                 (FLOAT) 0.0, (FLOAT) 1.0,
                                 (FLOAT) 0.0, (FLOAT) 0.0 } ;
     HDC               hdc ;
     PAINTSTRUCT       ps ;

     switch (message)
          {
          case WM_CREATE:

                         // initialize LOGFONT structure

               logfont.lfHeight = -1440 ;
               strcpy (logfont.lfFaceName, "Times New Roman") ;

               return 0 ;

          case WM_SIZE:
               cxClient = LOWORD (lParam) ;
               cyClient = HIWORD (lParam) ;

               return 0 ;

          case WM_COMMAND:
               switch (wParam)
                    {
                    case IDM_SELECT:
                         if (DialogBoxParam (hInst, "MatrixBox", hwnd,
                                             MatrixBox, (LPARAM) &xform))
                              InvalidateRect (hwnd, NULL, TRUE) ;

                         break ;
                    }
               return 0 ;

          case WM_PAINT:
               hdc = BeginPaint (hwnd, &ps) ;

                         // Draw horizontal and vertical lines

               MoveToEx (hdc,        0, cyClient / 2, NULL) ;
               LineTo   (hdc, cxClient, cyClient / 2) ;

               MoveToEx (hdc, cxClient / 2,        0, NULL) ;
               LineTo   (hdc, cxClient / 2, cyClient) ;

                         // Set window/viewport transform

               SetMapMode (hdc, MM_TWIPS) ;
               SetViewportOrgEx (hdc, cxClient / 2, cyClient / 2, NULL) ;

                         // Set font and alignment

               SelectObject (hdc, CreateFontIndirect (&logfont)) ;
               SetTextAlign (hdc, TA_BASELINE | TA_LEFT) ;
               SetBkMode (hdc, TRANSPARENT) ;

                         // Set world transform

               SetGraphicsMode (hdc, GM_ADVANCED) ;
               SetWorldTransform (hdc, &xform) ;

                         // Display text

               TextOut (hdc, 0, 0, "Hello!", 6) ;

                         // Clean up

               DeleteObject (SelectObject (hdc, GetStockObject (SYSTEM_FONT)));

               EndPaint (hwnd, &ps) ;
               return 0 ;

          case WM_DESTROY:
               PostQuitMessage (0) ;
               return 0 ;
          }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
     }

BOOL SetDlgItemFloat (HWND hwnd, int idControl, FLOAT eValue)
     {
     char szBuffer [32] ;

     sprintf (szBuffer, "%f", eValue) ;

     return SetDlgItemText (hwnd, idControl, szBuffer) ;
     }

FLOAT GetDlgItemFloat (HWND hwnd, int idControl)
     {
     char szBuffer [32] ;

     GetDlgItemText (hwnd, idControl, szBuffer, 32) ;

     return (FLOAT) atof (szBuffer) ;
     }

BOOL APIENTRY MatrixBox (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
     {
     static PXFORM pxform ;

     switch (message)
          {
          case WM_INITDIALOG:
               pxform = (PXFORM) lParam ;

               SetDlgItemFloat (hwnd, IDD_EM11, pxform->eM11) ;
               SetDlgItemFloat (hwnd, IDD_EM12, pxform->eM12) ;
               SetDlgItemFloat (hwnd, IDD_EM21, pxform->eM21) ;
               SetDlgItemFloat (hwnd, IDD_EM22, pxform->eM22) ;
               SetDlgItemFloat (hwnd, IDD_EDX , pxform->eDx ) ;
               SetDlgItemFloat (hwnd, IDD_EDY , pxform->eDy ) ;

               return TRUE ;

          case WM_COMMAND:
               switch (wParam)
                    {
                    case IDD_ANGLE:
                         if (DialogBoxParam (hInst, "AngleBox", hwnd,
                                             AngleBox, (LPARAM) pxform))
                              {
                              SetDlgItemFloat (hwnd, IDD_EM11, pxform->eM11) ;
                              SetDlgItemFloat (hwnd, IDD_EM12, pxform->eM12) ;
                              SetDlgItemFloat (hwnd, IDD_EM21, pxform->eM21) ;
                              SetDlgItemFloat (hwnd, IDD_EM22, pxform->eM22) ;
                              }

                         return TRUE ;

                    case IDOK:
                         pxform->eM11 = GetDlgItemFloat (hwnd, IDD_EM11) ;
                         pxform->eM12 = GetDlgItemFloat (hwnd, IDD_EM12) ;
                         pxform->eM21 = GetDlgItemFloat (hwnd, IDD_EM21) ;
                         pxform->eM22 = GetDlgItemFloat (hwnd, IDD_EM22) ;
                         pxform->eDx  = GetDlgItemFloat (hwnd, IDD_EDX ) ;
                         pxform->eDy  = GetDlgItemFloat (hwnd, IDD_EDY ) ;

                         EndDialog (hwnd, TRUE) ;
                         return TRUE ;

                    case IDCANCEL:
                         EndDialog (hwnd, FALSE) ;
                         return TRUE ;
                    }
               break ;

          }
     return FALSE ;
     }

BOOL APIENTRY AngleBox (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
     {
     static FLOAT  eAngle = (FLOAT) 0.0, eScale = (FLOAT) 1.0 ;
     static PXFORM pxform ;

     switch (message)
          {
          case WM_INITDIALOG:
               pxform = (PXFORM) lParam ;

               SetDlgItemFloat (hwnd, IDD_ANGLE, eAngle) ;
               SetDlgItemFloat (hwnd, IDD_SCALE, eScale) ;

               return TRUE ;

          case WM_COMMAND:
               switch (wParam)
                    {
                    case IDOK:
                         eAngle = GetDlgItemFloat (hwnd, IDD_ANGLE) ;
                         eScale = GetDlgItemFloat (hwnd, IDD_SCALE) ;

                         pxform->eM11 = (FLOAT) (eScale *
                                             cos (TWO_PI * eAngle / 360)) ;

                         pxform->eM12 = (FLOAT) (eScale *
                                             sin (TWO_PI * eAngle / 360)) ;

                         pxform->eM21 = -pxform->eM12 ;
                         pxform->eM22 =  pxform->eM11 ;

                         EndDialog (hwnd, TRUE) ;
                         return TRUE ;

                    case IDCANCEL:
                         EndDialog (hwnd, FALSE) ;
                         return TRUE ;
                    }
               break ;

          }
     return FALSE ;
     }