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Annotation of mstools/samples/plgblt/track.c, revision 1.1

1.1     ! root        1: /**************************************************************************\
        !             2: *  track.c -- support for direct manipulation of parallelogram object.
        !             3: *
        !             4: \**************************************************************************/
        !             5: 
        !             6: #include <windows.h>
        !             7: #include <math.h>
        !             8: #include "track.h"
        !             9: 
        !            10: #define EPSILON  (float) 0.0001
        !            11: #define RECTSIZE  60
        !            12: 
        !            13: 
        !            14: 
        !            15: /**************************************************************************\
        !            16: *
        !            17: *  function:  doTrackObject()
        !            18: *
        !            19: *  input parameters:
        !            20: *   pto -  pointer to a track object.
        !            21: *   msg -  message selecting what action to take.  Values may include WM_*'s
        !            22: *           (see case statements below for more information.)
        !            23: *   hwnd - Window handle for the window the track object exists within.
        !            24: *   lParam - Usually fourth param to window proc. varies based on msg.
        !            25: *
        !            26: *  global variables:  none.
        !            27: *
        !            28: *  coordinate spaces:  There are three coordinate spaces of interest here,
        !            29: *   and this routine is frequently switching between them...
        !            30: *
        !            31: *           WORLD                   DEVICE                  SCREEN
        !            32: *
        !            33: *      object coordinates       input mouse pos       used w/ SetCursorPos()
        !            34: *         (pto->rect)          (lParam for WM_*)
        !            35: *
        !            36: *             ----->  LPtoDP() ---->    ----> ClientToScreen() -->
        !            37: *             <-----  DPtoLP() <----    <---- ScreenToClient() <--
        !            38: *
        !            39: *   in addition, the HDC has an offset origin.  Device coordinates for the
        !            40: *   mouse (lParam) never take this into account, but it is necessary to
        !            41: *   translate them in order to get direct manipulation right.
        !            42: *
        !            43: \**************************************************************************/
        !            44: PTrackObject doTrackObject(PTrackObject pto, int msg, HWND hwnd, LONG lParam)
        !            45: {
        !            46:   if ((pto == NULL) && (msg != TROB_NEW))  return NULL;
        !            47: 
        !            48:   switch (msg) {
        !            49: 
        !            50: 
        !            51:     /**********************************************************************\
        !            52:     *  TROB_NEW
        !            53:     *
        !            54:     * Allocate new PTrackObject structure.  Fill in default values
        !            55:     *  for the fields of the structure.  Set up the HDC correctly.
        !            56:     * return - pointer to the new object.
        !            57:     \**********************************************************************/
        !            58:     case  TROB_NEW: {
        !            59:         PTrackObject  pto;
        !            60: 
        !            61:         /* with LPTR returned value is a pointer. */
        !            62:         pto = (PTrackObject) LocalAlloc (LPTR, sizeof (TrackObject));
        !            63: 
        !            64:         /* initialize the HDC and other fields. */
        !            65:         pto->hdc = GetDC (hwnd);
        !            66:         SetROP2(pto->hdc, R2_NOT);
        !            67:         SelectObject (pto->hdc, GetStockObject (NULL_BRUSH));
        !            68:         pto->Mode = TMNONE;
        !            69:         pto->allowedModes = TMMOVE | TMSIZEXY;
        !            70: 
        !            71:         GetWorldTransform (pto->hdc, &(pto->xfmChange));
        !            72: 
        !            73:         /* initialize the size. */
        !            74:         pto->rect.top = pto->rect.left = 0;
        !            75:         pto->rect.bottom = pto->rect.right = RECTSIZE;
        !            76: 
        !            77:         return (pto);
        !            78:     }
        !            79: 
        !            80: 
        !            81: 
        !            82:     /**********************************************************************\
        !            83:     *  TROB_DELETE
        !            84:     *
        !            85:     * Complement of TROB_NEW.  Free up the memory allocated for the object.
        !            86:     \**********************************************************************/
        !            87:     case  TROB_DELETE:
        !            88:         doTrackObject (pto, TROB_PAINT, hwnd, lParam);
        !            89:         ReleaseDC (hwnd, pto->hdc);
        !            90:         LocalFree (LocalHandle ((LPSTR)pto));
        !            91:     return NULL;
        !            92: 
        !            93: 
        !            94: 
        !            95:     /**********************************************************************\
        !            96:     *  TROB_PAINT
        !            97:     *
        !            98:     * Paint the object into its hdc.  Called half the time to erase
        !            99:     *  the object, and half the time to redraw it.
        !           100:     \**********************************************************************/
        !           101:     case TROB_PAINT: {
        !           102:         MoveToEx (pto->hdc, pto->rect.right, pto->rect.top, NULL);
        !           103:         LineTo (pto->hdc,  pto->rect.left, pto->rect.top);
        !           104:         LineTo (pto->hdc,  pto->rect.left, pto->rect.bottom);
        !           105: 
        !           106:         if (pto->allowedModes & TMSIZEXY) {
        !           107:           LineTo (pto->hdc,  pto->rect.right, pto->rect.bottom);
        !           108:           LineTo (pto->hdc,  pto->rect.right, pto->rect.top);
        !           109:         }
        !           110: 
        !           111:         if (pto->allowedModes & TMROTATE) {
        !           112:           MoveToEx (pto->hdc, pto->rect.left, pto->rect.bottom/ 4, NULL);
        !           113:           AngleArc (pto->hdc, pto->rect.left, pto->rect.top,
        !           114:                  (DWORD) pto->rect.bottom/ 4, (float) 270.0, (float) 90.0);
        !           115:         }
        !           116: 
        !           117:     } return NULL;
        !           118: 
        !           119: 
        !           120: 
        !           121:     /**********************************************************************\
        !           122:     *  TROB_HITTEST
        !           123:     *
        !           124:     * Check the point sent in in the lParam to see if it lays within
        !           125:     *  the bounds of the objects defining rectangle.
        !           126:     * return - pointer to the object iff the point is in rectangle,
        !           127:     *  otherwise return NULL.
        !           128:     \**********************************************************************/
        !           129:     case TROB_HITTEST:{
        !           130:         POINT  mouWorld;
        !           131:         mouWorld.x = LOWORD(lParam);
        !           132:         mouWorld.y = HIWORD(lParam);
        !           133: 
        !           134:         DPtoLP (pto->hdc, &mouWorld, 1);
        !           135: 
        !           136:         if (PtInRect (&pto->rect, mouWorld))  return pto;
        !           137:         else  return NULL;
        !           138:     }
        !           139: 
        !           140: 
        !           141: 
        !           142:     /**********************************************************************\
        !           143:     *  WM_LBUTTONDOWN &  WM_RBUTTONDOWN
        !           144:     *
        !           145:     * Capture the mouse, set the tracking mode depending on the mouse
        !           146:     *  location in world coordinates, reset the mouse position.
        !           147:     *
        !           148:     \**********************************************************************/
        !           149:     case WM_LBUTTONDOWN:
        !           150:     case WM_RBUTTONDOWN: {
        !           151:       POINT  newmouScreen;
        !           152:       POINT  mouWorld;
        !           153: 
        !           154:       mouWorld.x = LOWORD(lParam);
        !           155:       mouWorld.y = HIWORD(lParam);
        !           156:       DPtoLP (pto->hdc, &mouWorld, 1);
        !           157: 
        !           158:       /* upper left hand corner. right button is no-op. */
        !           159:       if ((mouWorld.x <= (pto->rect.right  / 2)) &&
        !           160:           (mouWorld.y <= (pto->rect.bottom / 2))) {
        !           161:           if (msg == WM_RBUTTONDOWN) return NULL;
        !           162:           pto->Mode = TMMOVE;
        !           163:           newmouScreen.x = pto->rect.left;
        !           164:           newmouScreen.y = pto->rect.top;
        !           165: 
        !           166:       /* lower left hand corner */
        !           167:       } else if ((mouWorld.x <= (pto->rect.right  / 2)) &&
        !           168:           (mouWorld.y > (pto->rect.bottom / 2))) {
        !           169: 
        !           170:           pto->Mode = (msg == WM_RBUTTONDOWN) ? TMSHEARY : TMSIZEY;
        !           171:           newmouScreen.x = pto->rect.left;
        !           172:           newmouScreen.y = pto->rect.bottom;
        !           173: 
        !           174:       /* upper right hand corner */
        !           175:       } else if ((mouWorld.x > (pto->rect.right  / 2)) &&
        !           176:           (mouWorld.y <= (pto->rect.bottom / 2))) {
        !           177: 
        !           178:           pto->Mode = (msg == WM_RBUTTONDOWN) ? TMSHEARX : TMSIZEX;
        !           179:           newmouScreen.x = pto->rect.right;
        !           180:           newmouScreen.y = pto->rect.top;
        !           181: 
        !           182:       /* lower right hand corner */
        !           183:       } else if ((mouWorld.x > (pto->rect.right  / 2)) &&
        !           184:           (mouWorld.y > (pto->rect.bottom / 2))) {
        !           185: 
        !           186:           pto->Mode = (msg == WM_RBUTTONDOWN) ? TMROTATE : TMSIZEXY;
        !           187:           newmouScreen.x = pto->rect.right;
        !           188:           newmouScreen.y = pto->rect.bottom;
        !           189:       }
        !           190: 
        !           191:       if (! (pto->Mode & pto->allowedModes)) {
        !           192:         pto->Mode = TMNONE;
        !           193:         return NULL;
        !           194:       }
        !           195: 
        !           196:       SetCapture(hwnd);
        !           197:       LPtoDP (pto->hdc, &newmouScreen, 1);
        !           198:       ClientToScreen (hwnd, &newmouScreen);
        !           199:       SetCursorPos (newmouScreen.x,newmouScreen.y);
        !           200: 
        !           201:       GetWorldTransform (pto->hdc, &pto->xfmDown);
        !           202:     } return NULL;
        !           203: 
        !           204: 
        !           205: 
        !           206:     /**********************************************************************\
        !           207:     *  WM_MOUSEMOVE
        !           208:     *
        !           209:     * this is where almost all of the interesting calculation is done.
        !           210:     *  First clip the mouse location to be in rectClip, then
        !           211:     *  call MouseMove() to handle the different tracking modes.
        !           212:     \**********************************************************************/
        !           213:     case WM_MOUSEMOVE: {
        !           214:       if ((short) LOWORD(lParam) < (short)pto->rectClip.left)
        !           215:         lParam = MAKELONG ((WORD)pto->rectClip.left, HIWORD(lParam));
        !           216: 
        !           217:       if (LOWORD(lParam) > (WORD)pto->rectClip.right)
        !           218:         lParam = MAKELONG ((WORD)pto->rectClip.right, HIWORD(lParam));
        !           219: 
        !           220:       if ((short) HIWORD(lParam) < (short)pto->rectClip.top)
        !           221:         lParam = MAKELONG (LOWORD(lParam), (WORD)pto->rectClip.top);
        !           222: 
        !           223:       if (HIWORD(lParam) > (WORD)pto->rectClip.bottom)
        !           224:         lParam = MAKELONG (LOWORD(lParam),(WORD)pto->rectClip.bottom);
        !           225: 
        !           226:       MouseMove (pto, msg, hwnd, lParam);
        !           227: 
        !           228:     } return NULL;
        !           229: 
        !           230: 
        !           231: 
        !           232:     /**********************************************************************\
        !           233:     *  WM_RBUTTONUP & WM_LBUTTONUP
        !           234:     *
        !           235:     * simply release the mouse capture, and set the mode to TMNONE.
        !           236:     \**********************************************************************/
        !           237:     case WM_RBUTTONUP:
        !           238:     case WM_LBUTTONUP: {
        !           239:       if (pto->Mode) {
        !           240:          ReleaseCapture();
        !           241:          pto->Mode = TMNONE;
        !           242:       }
        !           243:     } return NULL;
        !           244: 
        !           245:   }  /* end switch(msg) */
        !           246: }
        !           247: 
        !           248: 
        !           249: 
        !           250: 
        !           251: 
        !           252: 
        !           253: /**************************************************************************\
        !           254: *  function:  MouseMove()
        !           255: *
        !           256: *  input parameters:
        !           257: *   pto -  pointer to a track object.
        !           258: *   msg -  not used.
        !           259: *   hwnd - Window handle for the window the track object exists within.
        !           260: *   lParam - Usually fourth param to window proc. varies based on msg.
        !           261: *
        !           262: *  The tracking behavior which the user observers when moving the mouse
        !           263: *   is based on the current tracking mode of the object.  This is usually
        !           264: *   determined on the mouse down event (c.f. TM*).  First erase the old
        !           265: *   object, then figure out the change to the transform matrix, finally
        !           266: *   change the world transform matrix and redraw the object.
        !           267: *
        !           268: *  Tranform:
        !           269: *    (    eM11        eM12        0   )
        !           270: *    (    eM21        eM22        0   )
        !           271: *    (    eDx         eDy         1   )
        !           272: *
        !           273: *   xDevice = (xWorld * eM11) + (yWorld * eM21) + eDx
        !           274: *   yDevice = (xWorld * eM12) + (yWorld * eM22) + eDy
        !           275: *
        !           276: *   In this routine the Device (mouse location) and World (rectangle corner)
        !           277: *   points are known.  Therefore, the two equations above are solved for
        !           278: *   the desired matrix entry value (e.g. eM11, 1M12, ... eDy).  The tracking
        !           279: *   mode determines which one of these entries may be changed.  E.g. scaling
        !           280: *   in X modifies eM11 while shearing in X modifies eM12.  So rather than
        !           281: *   using the world transform to map from world to device points, we are
        !           282: *   back-computing the proper contents of the world transform.
        !           283: *
        !           284: \**************************************************************************/
        !           285: VOID MouseMove(PTrackObject pto, int msg, HWND hwnd, LONG lParam)
        !           286: {
        !           287: POINT  mouWorld, mouDevice, orgDevice;
        !           288: 
        !           289:     UNREFERENCED_PARAMETER(msg);
        !           290: 
        !           291:     doTrackObject(pto, TROB_PAINT, hwnd, lParam);
        !           292:     mouDevice.x = mouWorld.x = LOWORD(lParam);
        !           293:     mouDevice.y = mouWorld.y = HIWORD(lParam);
        !           294: 
        !           295:     SetWorldTransform(pto->hdc, &pto->xfmDown);
        !           296:     DPtoLP (pto->hdc, &mouWorld, 1);
        !           297: 
        !           298:     /* offset the mouse device point for the viewport's origin. */
        !           299:     GetViewportOrgEx (pto->hdc, &orgDevice);
        !           300:     mouDevice.x -= orgDevice.x;
        !           301:     mouDevice.y -= orgDevice.y;
        !           302: 
        !           303:     GetWorldTransform(pto->hdc, &pto->xfmChange);
        !           304: 
        !           305:     switch (pto->Mode) {
        !           306:       /*******************************************************\
        !           307:       *    (     1         xShear       0   )
        !           308:       *    (     0           1          0   )
        !           309:       *    (     0           0          1   )
        !           310:       *
        !           311:       * xWorld = rect.left == 0;
        !           312:       \*******************************************************/
        !           313:       case TMSHEARX: {
        !           314:         pto->xfmChange.eM12 = (float) mouDevice.y;
        !           315:         pto->xfmChange.eM12 -=pto->xfmChange.eDy;
        !           316:         pto->xfmChange.eM12 /=(float) pto->rect.right ;
        !           317:         SetWorldTransform (pto->hdc, &pto->xfmChange);
        !           318:       } break;
        !           319: 
        !           320: 
        !           321:       /*******************************************************\
        !           322:       *    (     1           0          0   )
        !           323:       *    (   yShear        1          0   )
        !           324:       *    (     0           0          1   )
        !           325:       *
        !           326:       * yWorld = rect.top == 0;
        !           327:       \*******************************************************/
        !           328:       case TMSHEARY: {
        !           329:         pto->xfmChange.eM21 = (float) mouDevice.x;
        !           330:         pto->xfmChange.eM21 -=pto->xfmChange.eDx;
        !           331:         pto->xfmChange.eM21 /=(float) pto->rect.bottom ;
        !           332:         SetWorldTransform (pto->hdc, &pto->xfmChange);
        !           333: 
        !           334:       } break;
        !           335: 
        !           336: 
        !           337:       /*******************************************************\
        !           338:       *    (   cos(a)      -sin(a)      0   )
        !           339:       *    (   sin(a)       cos(a)      0   )
        !           340:       *    (     0           0          1   )
        !           341:       *
        !           342:       * a == rotation angle.  Since mouse in in lower right,
        !           343:       *  we need to shift this back 45 degrees (assuming that
        !           344:       *  straight down is 0 degrees).  Thus we actually compute
        !           345:       *  cos(a) = cos(b - 45) = cos(b)sin(45) + cos(45)sin(45)
        !           346:       *  where b is angle from the origin to the mouse (x,y)
        !           347:       *  cos(45) = sin(45) ~= 0.707107
        !           348:       *  cos(b) = y/r    sin(b) = x/r
        !           349:       *
        !           350:       \*******************************************************/
        !           351:       case TMROTATE: {
        !           352:         float r;
        !           353: 
        !           354:         /* translate back to the origin. */
        !           355:         pto->xfmChange.eDx = pto->xfmChange.eDy = (float)0.0;
        !           356:         SetWorldTransform (pto->hdc, &pto->xfmChange);
        !           357: 
        !           358:         /* rotate about the origin. */
        !           359:         r = (float) sqrt( (double)(mouWorld.x * mouWorld.x) +
        !           360:                           (double)(mouWorld.y * mouWorld.y));
        !           361: 
        !           362:         pto->xfmChange.eM11 = (float) mouWorld.y / r;
        !           363:         pto->xfmChange.eM11 += (float) mouWorld.x / r;
        !           364:         pto->xfmChange.eM11 *= (float) 0.707107;
        !           365:         pto->xfmChange.eM22 = pto->xfmChange.eM11;
        !           366: 
        !           367:         pto->xfmChange.eM12 = (float) mouWorld.y / r;
        !           368:         pto->xfmChange.eM12 -= (float) mouWorld.x / r;
        !           369:         pto->xfmChange.eM12 *= (float) 0.707107;
        !           370:         pto->xfmChange.eM21 = -pto->xfmChange.eM12;
        !           371: 
        !           372:         pto->xfmChange.eDx = pto->xfmChange.eDy = (float)0.0;
        !           373: 
        !           374:         ModifyWorldTransform (pto->hdc, &pto->xfmChange, MWT_RIGHTMULTIPLY);
        !           375: 
        !           376:         /* translate back to the original offset. */
        !           377:         pto->xfmChange.eM11 =
        !           378:         pto->xfmChange.eM22 = (float) 1.0;
        !           379:         pto->xfmChange.eM12 =
        !           380:         pto->xfmChange.eM21 = (float) 0.0;
        !           381: 
        !           382:         pto->xfmChange.eDx = pto->xfmDown.eDx;
        !           383:         pto->xfmChange.eDy = pto->xfmDown.eDy;
        !           384:         ModifyWorldTransform (pto->hdc, &pto->xfmChange, MWT_RIGHTMULTIPLY);
        !           385:         GetWorldTransform (pto->hdc, &pto->xfmChange);
        !           386:       } break;
        !           387: 
        !           388: 
        !           389:       /*******************************************************\
        !           390:       *    (  Size X         0          0   )
        !           391:       *    (     0        Size Y        0   )
        !           392:       *    (     0           0          1   )
        !           393:       *
        !           394:       \*******************************************************/
        !           395:       case TMSIZEXY: {
        !           396:         pto->xfmChange.eM11 = (float) mouDevice.x;
        !           397:         pto->xfmChange.eM11 -=pto->xfmChange.eDx;
        !           398:         pto->xfmChange.eM11 -=((float) pto->rect.bottom*pto->xfmChange.eM21);
        !           399:         pto->xfmChange.eM11 /=(float) pto->rect.right ;
        !           400:         if (fabs(pto->xfmChange.eM11) < EPSILON)  // HACK.  system bug ?
        !           401:            pto->xfmChange.eM11 = EPSILON;
        !           402: 
        !           403:         pto->xfmChange.eM22 = (float) mouDevice.y;
        !           404:         pto->xfmChange.eM22 -=pto->xfmChange.eDy;
        !           405:         pto->xfmChange.eM22 -=((float) pto->rect.right*pto->xfmChange.eM12);
        !           406:         pto->xfmChange.eM22 /=(float) pto->rect.bottom ;
        !           407:         if (fabs(pto->xfmChange.eM22) < EPSILON)  // HACK.  system bug ?
        !           408:            pto->xfmChange.eM22 = EPSILON;
        !           409:         SetWorldTransform (pto->hdc, &pto->xfmChange);
        !           410:       } break;
        !           411: 
        !           412: 
        !           413:       /*******************************************************\
        !           414:       *    (  Size X         0          0   )
        !           415:       *    (     0           1          0   )
        !           416:       *    (     0           0          1   )
        !           417:       *
        !           418:       * yWorld = rect.top == 0;
        !           419:       \*******************************************************/
        !           420:       case TMSIZEX: {
        !           421:         pto->xfmChange.eM11 = (float) mouDevice.x;
        !           422:         pto->xfmChange.eM11 -=pto->xfmChange.eDx;
        !           423:         pto->xfmChange.eM11 /=(float) pto->rect.right ;
        !           424:         if (fabs(pto->xfmChange.eM11) < EPSILON)  // HACK.  system bug ?
        !           425:            pto->xfmChange.eM11 = EPSILON;
        !           426: 
        !           427:         SetWorldTransform (pto->hdc, &pto->xfmChange);
        !           428:       } break;
        !           429: 
        !           430: 
        !           431:       /*******************************************************\
        !           432:       *    (     1           0          0   )
        !           433:       *    (     0        Size Y        0   )
        !           434:       *    (     0           0          1   )
        !           435:       *
        !           436:       * xWorld = rect.left == 0;
        !           437:       \*******************************************************/
        !           438:       case TMSIZEY: {
        !           439:         pto->xfmChange.eM22 = (float) mouDevice.y;
        !           440:         pto->xfmChange.eM22 -=pto->xfmChange.eDy;
        !           441:         pto->xfmChange.eM22 /=(float) pto->rect.bottom ;
        !           442:         if (fabs(pto->xfmChange.eM22) < EPSILON)  // HACK.  system bug ?
        !           443:            pto->xfmChange.eM22 = EPSILON;
        !           444:         SetWorldTransform (pto->hdc, &pto->xfmChange);
        !           445:       } break;
        !           446: 
        !           447: 
        !           448:       /*******************************************************\
        !           449:       *    (     1           0          0   )
        !           450:       *    (     0           1          0   )
        !           451:       *    (   Move x      Move y       1   )
        !           452:       *
        !           453:       * xWorld = rect.left == 0;
        !           454:       * yWorld = rect.top == 0;
        !           455:       \*******************************************************/
        !           456:       case TMMOVE: {
        !           457:         pto->xfmChange.eDx = (float) mouDevice.x ;
        !           458:         pto->xfmChange.eDy = (float) mouDevice.y ;
        !           459:         SetWorldTransform (pto->hdc, &pto->xfmChange);
        !           460:       } break;
        !           461:     } /* end switch */
        !           462: 
        !           463:     doTrackObject(pto, TROB_PAINT, hwnd, lParam);
        !           464: 
        !           465:     return;
        !           466:  }
        !           467: 

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