/*----------------------------------------------------------------
   THREADS1.C -- Demonstrates off-screen drawing in second thread
                 (c) 1990, Ziff Communications Co.
                 PC Magazine * Charles Petzold, 1/89
  ----------------------------------------------------------------*/

#define INCL_GPI
#define INCL_DOSPROCESS
#include <os2.h>
#include <mt\process.h>
#include <mt\stdlib.h>
#include <mt\string.h>

#define FONTNAME              "Tms Rmn Bold"
#define XFONTSIZE             500            // in points
#define YFONTSIZE             500
#define TEXT                  "PC"
#define TEXTLEN               (LONG) strlen (TEXT)
#define BKGNDCOLOR            CLR_BLUE
#define DIVISIONS             64             // number of spline areas

#define LCID_FONT             1L
#define ID_PATH               1L
#define STACKSIZE             (4096 * sizeof (int))
#define RGB(r,g,b)            (((LONG) (r) << 16) | ((g) << 8) | (b))
#define WM_BITMAP_CREATED     (WM_USER + 0)

typedef struct
     {
     int       aiThreadStack[STACKSIZE / sizeof (int)] ;
     HBITMAP   hbm ;
     HWND      hwndNotify ;
     }
     THREADPARAMS ;

MPARAM EXPENTRY ClientWndProc    (HWND, USHORT, MPARAM, MPARAM) ;
VOID   FAR      SecondThread     (THREADPARAMS *) ;
HBITMAP         CreateBitmap     (HAB) ;
VOID            DrawImage        (HPS, SIZEL *) ;
LONG            CreateVectorFont (HPS, LONG, CHAR *) ;
VOID            Message          (HWND, SHORT, CHAR *) ;

int main (void)
     {
     static CHAR  szClientClass[] = "Threads1" ;
     static ULONG flFrameFlags = FCF_TITLEBAR      | FCF_SYSMENU |
                                 FCF_SIZEBORDER    | FCF_MINMAX  |
                                 FCF_SHELLPOSITION | FCF_TASKLIST ;
     HAB          hab ;
     HMQ          hmq ;
     HWND         hwndFrame, hwndClient ;
     QMSG         qmsg ;

     hab = WinInitialize (0) ;
     hmq = WinCreateMsgQueue (hab, 0) ;
     WinRegisterClass (hab, szClientClass, ClientWndProc, CS_SIZEREDRAW, 0) ;

     hwndFrame = WinCreateStdWindow (HWND_DESKTOP, WS_VISIBLE,
                                     &flFrameFlags, szClientClass, NULL,
                                     0L, NULL, 0, &hwndClient) ;

     while (WinGetMsg (hab, &qmsg, NULL, 0, 0))
          WinDispatchMsg (hab, &qmsg) ;

     WinDestroyWindow (hwndFrame) ;
     WinDestroyMsgQueue (hmq) ;
     WinTerminate (hab) ;
     return 0 ;
     }

MPARAM EXPENTRY ClientWndProc (HWND hwnd, USHORT msg, MPARAM mp1, MPARAM mp2)
     {
     static BOOL      fError = FALSE ;
     static HBITMAP   hbm ;
     BITMAPINFOHEADER bmp ;
     HPS              hps ;
     POINTL           ptl ;
     RECTL            rclClient ;
     THREADPARAMS     *ptp ;

     switch (msg)
          {
          case WM_CREATE:
                              // allocate memory for thread structure

               if ((ptp = malloc (sizeof (THREADPARAMS))) == NULL)
                    {
                    Message (hwnd, MB_ICONEXCLAMATION,
                             "Cannot allocate memory for thread!") ;
                    return 0 ;
                    }

               ptp->hwndNotify = hwnd ;

                              // start the thread

               if (_beginthread (SecondThread, ptp->aiThreadStack,
                                 STACKSIZE, ptp) == -1)
                    {
                    free (ptp) ;
                    Message (hwnd, MB_ICONEXCLAMATION,
                             "Cannot create print thread!") ;
                    return 0 ;
                    }
               return 0 ;

          case WM_BITMAP_CREATED:
               ptp = PVOIDFROMMP (mp1) ;
               hbm = ptp->hbm ;
               free (ptp) ;

               if (hbm == NULL)
                    fError = TRUE ;

               WinInvalidateRect (hwnd, NULL, FALSE) ;
               return 0 ;

          case WM_PAINT:
               hps = WinBeginPaint (hwnd, NULL, NULL) ;
               WinQueryWindowRect (hwnd, &rclClient) ;

               if (fError == TRUE)
                    WinDrawText (hps, -1,
                                 "Error occurred during bitmap creation.",
                                 &rclClient, 0L, 0L, DT_CENTER | DT_VCENTER |
                                 DT_TEXTATTRS | DT_ERASERECT) ;

               else if (hbm == NULL)
                    WinDrawText (hps, -1,
                                 "Bitmap being created....",
                                 &rclClient, 0L, 0L, DT_CENTER | DT_VCENTER |
                                 DT_TEXTATTRS | DT_ERASERECT) ;
               else
                    {
                    WinFillRect (hps, &rclClient, BKGNDCOLOR) ;
                    GpiQueryBitmapParameters (hbm, &bmp) ;
                    ptl.x = (rclClient.xRight - bmp.cx) / 2 ;
                    ptl.y = (rclClient.yTop   - bmp.cy) / 2 ;
                    WinDrawBitmap (hps, hbm, NULL, &ptl, 0L, 0L, DBM_NORMAL) ;
                    }

               WinEndPaint (hps) ;
               return 0 ;

          case WM_DESTROY:
               if (hbm != NULL)
                    GpiDeleteBitmap (hbm) ;

               return 0 ;
          }
     return WinDefWindowProc (hwnd, msg, mp1, mp2) ;
     }

VOID FAR SecondThread (THREADPARAMS *ptp)
     {
     HAB   hab ;

     hab = WinInitialize (0) ;
     ptp->hbm = CreateBitmap (hab) ;                        // create bitmap

     DosEnterCritSec () ;
     WinPostMsg (ptp->hwndNotify, WM_BITMAP_CREATED,        // post message
                                  MPFROMP (ptp), NULL) ;
     WinTerminate (hab) ;
     _endthread () ;
     }

HBITMAP CreateBitmap (HAB hab)
     {
     BITMAPINFOHEADER bmp ;
     HBITMAP          hbm ;
     HDC              hdcMemory ;
     HPS              hpsMemory ;
     LONG             alBitmapFormat[2] ;
     POINTL           aptlTextBox[TXTBOX_COUNT] ;
     SIZEF            sizfx ;
     SIZEL            sizl ;

                              // create memory presentation space

     hdcMemory = DevOpenDC (hab, OD_MEMORY, "*", 0L, NULL, NULL) ;
     sizl.cx = 0 ;
     sizl.cy = 0 ;
     hpsMemory = GpiCreatePS (hab, hdcMemory, &sizl,
                              PU_TWIPS   | GPIF_DEFAULT |
                              GPIT_MICRO | GPIA_ASSOC) ;

                              // create font, select it in PS, and size it

     CreateVectorFont (hpsMemory, LCID_FONT, FONTNAME) ;
     GpiSetCharSet (hpsMemory, LCID_FONT) ;

     sizfx.cx = MAKEFIXED (XFONTSIZE * 20, 0) ;
     sizfx.cy = MAKEFIXED (YFONTSIZE * 20, 0) ;
     GpiSetCharBox (hpsMemory, &sizfx) ;

                              // obtain text dimensions and delete font

     GpiQueryTextBox (hpsMemory, TEXTLEN, TEXT, TXTBOX_COUNT, aptlTextBox) ;
     GpiSetCharSet (hpsMemory, LCID_DEFAULT) ;
     GpiDeleteSetId (hpsMemory, LCID_FONT) ;

                              // convert text dimensions to device coordinates

     sizl.cx = aptlTextBox[TXTBOX_CONCAT].x ;
     sizl.cy = aptlTextBox[TXTBOX_TOPLEFT].y -
               aptlTextBox[TXTBOX_BOTTOMLEFT].y ;

     GpiConvert (hpsMemory, CVTC_PAGE, CVTC_DEVICE, 1L, (PPOINTL) &sizl) ;

                              // create bitmap and set it in the PS

     GpiQueryDeviceBitmapFormats (hpsMemory, 2L, alBitmapFormat) ;

     bmp.cbFix     = 12 ;
     bmp.cx        = (SHORT) sizl.cx ;
     bmp.cy        = (SHORT) sizl.cy ;
     bmp.cPlanes   = (SHORT) alBitmapFormat[0] ;
     bmp.cBitCount = (SHORT) alBitmapFormat[1] ;

     hbm = GpiCreateBitmap (hpsMemory, &bmp, 0L, NULL, NULL) ;

                              // convert bitmap size back to page coordinates

     GpiConvert (hpsMemory, CVTC_DEVICE, CVTC_PAGE, 1L, (PPOINTL) &sizl) ;

                              // draw the text on the bitmap
     if (hbm != NULL)
          {
          GpiSetBitmap (hpsMemory, hbm) ;
          DrawImage (hpsMemory, &sizl) ;
          GpiSetBitmap (hpsMemory, NULL) ;
          }
                              // clean up

     GpiDestroyPS (hpsMemory) ;
     DevCloseDC (hdcMemory) ;

     return hbm ;
     }

VOID DrawImage (HPS hps, SIZEL *psizl)
     {
     INT         i ;
     LONG        lColor ;
     POINTL      ptl, aptl[8], aptlTextBox[TXTBOX_COUNT] ;
     SIZEF       sizfx ;
                              // color the background

     GpiSetColor (hps, BKGNDCOLOR) ;

     ptl.x = 0 ;
     ptl.y = 0 ;
     GpiMove (hps, &ptl) ;

     ptl.x = psizl->cx ;
     ptl.y = psizl->cy ;
     GpiBox (hps, DRO_FILL, &ptl, 0L, 0L) ;

                              // create font, select it in PS, and size it

     CreateVectorFont (hps, LCID_FONT, FONTNAME) ;
     GpiSetCharSet (hps, LCID_FONT) ;

     sizfx.cx = MAKEFIXED (XFONTSIZE * 20, 0) ;
     sizfx.cy = MAKEFIXED (YFONTSIZE * 20, 0) ;
     GpiSetCharBox (hps, &sizfx) ;

                              // create clipping path based on text outline

     GpiBeginPath (hps, ID_PATH) ;

     GpiQueryTextBox (hps, TEXTLEN, TEXT, TXTBOX_COUNT, aptlTextBox) ;
     ptl.x = 0 ;
     ptl.y = -aptlTextBox[TXTBOX_BOTTOMLEFT].y ;
     GpiCharStringAt (hps, &ptl, TEXTLEN, TEXT) ;

     GpiEndPath (hps) ;
     GpiSetClipPath (hps, ID_PATH, SCP_AND | SCP_ALTERNATE) ;

                              // switch to RGB colors

     GpiCreateLogColorTable (hps, 0L, LCOLF_RGB, 0L, 0L, NULL) ;

     for (i = 0 ; i < DIVISIONS ; i++)
          {
                              // set the color

          if (i < DIVISIONS / 2)
               lColor = RGB (i * 512 / DIVISIONS, 0, 0) ;
          else
               lColor = RGB (255, i * 512 / DIVISIONS - 256,
                                  i * 512 / DIVISIONS - 256) ;

          GpiSetColor (hps, lColor) ;

                              // define coordinates for spline curves

          aptl[0].x = 0 ;
          aptl[0].y = i * psizl->cy / DIVISIONS ;

          aptl[1].x = psizl->cx / 4 ;
          aptl[1].y = aptl[0].y + psizl->cy / 2 ;

          aptl[2].x = 3 * psizl->cx / 4 ;
          aptl[2].y = aptl[0].y - psizl->cy / 2 ;

          aptl[3].x = psizl->cx ;
          aptl[3].y = aptl[0].y ;

          aptl[4].x = psizl->cx ;
          aptl[4].y = (i + 1) * psizl->cy / DIVISIONS ;

          aptl[5].x = 3 * psizl->cx / 4 ;
          aptl[5].y = aptl[4].y - psizl->cy / 2 ;

          aptl[6].x = psizl->cx / 4 ;
          aptl[6].y = aptl[4].y + psizl->cy / 2 ;

          aptl[7].x = 0 ;
          aptl[7].y = aptl[4].y ;

                              // draw the curves in an area bracket

          GpiBeginArea (hps, BA_NOBOUNDARY | BA_ALTERNATE) ;

          GpiMove (hps, aptl) ;                   // set current position
          GpiPolySpline (hps, 3L, aptl + 1) ;     // draw one spline
          GpiLine (hps, aptl + 4) ;               // draw line
          GpiPolySpline (hps, 3L, aptl + 5) ;     // draw second spline
          GpiLine (hps, aptl) ;                   // line to beginning

          GpiEndArea (hps) ;
          }
                              // Clean up

     GpiCreateLogColorTable (hps, LCOL_RESET, LCOLF_INDRGB, 0L, 0L, NULL) ;
     GpiSetCharSet (hps, LCID_DEFAULT) ;
     GpiDeleteSetId (hps, LCID_FONT) ;
     }

LONG CreateVectorFont (HPS hps, LONG lcid, CHAR *szFacename)
     {
     FATTRS fat ;
                              // set up FATTRS structure

     fat.usRecordLength  = sizeof fat ;
     fat.fsSelection     = 0 ;
     fat.lMatch          = 0 ;
     fat.idRegistry      = 0 ;
     fat.usCodePage      = GpiQueryCp (hps) ;
     fat.lMaxBaselineExt = 0 ;
     fat.lAveCharWidth   = 0 ;
     fat.fsType          = 0 ;
     fat.fsFontUse       = FATTR_FONTUSE_OUTLINE |
                           FATTR_FONTUSE_TRANSFORMABLE ;

     strcpy (fat.szFacename, szFacename) ;

                              // create the font

     return GpiCreateLogFont (hps, NULL, lcid, &fat) ;
     }

VOID Message (HWND hwnd, SHORT sIcon, CHAR *pszMessage)
     {
     WinMessageBox (HWND_DESKTOP, hwnd, pszMessage, "Thread1",
                    0, sIcon | MB_OK | MB_MOVEABLE) ;
     }