src/gtk1/region.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        gtk/region.cpp
   3 // Purpose:
   4 // Author:      Robert Roebling
   5 // Modified:    VZ at 05.10.00: use Unshare(), comparison fixed
   6 // Id:          $Id$
   7 // Copyright:   (c) 1998 Robert Roebling
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 // ============================================================================
  12 // declarations
  13 // ============================================================================
  14
  15 #ifdef __GNUG__
  16     #pragma implementation "region.h"
  17 #endif
  18
  19 // ----------------------------------------------------------------------------
  20 // headers
  21 // ----------------------------------------------------------------------------
  22
  23 #include "wx/region.h"
  24
  25 #include <gdk/gdk.h>
  26 #include <gtk/gtk.h>
  27
  28 // Unfortunately the new way of implementing the region iterator
  29 // doesn't work with GTK+ 2.0 or above (can't access a Region in
  30 // GdkPrivateRegion)
  31 #ifdef __WXGTK20__
  32 #define OLDCODE 1
  33 #else
  34 #define OLDCODE 0
  35 #endif
  36
  37 #include "wx/log.h"
  38
  39 // ----------------------------------------------------------------------------
  40 // wxRegionRefData: private class containing the information about the region
  41 // ----------------------------------------------------------------------------
  42
  43 class wxRegionRefData : public wxObjectRefData
  44 {
  45 public:
  46     wxRegionRefData();
  47     wxRegionRefData(const wxRegionRefData& refData);
  48     virtual ~wxRegionRefData();
  49
  50     GdkRegion  *m_region;
  51 #if OLDCODE
  52     wxList      m_rects;
  53 #endif
  54 };
  55
  56 // ----------------------------------------------------------------------------
  57 // macros
  58 // ----------------------------------------------------------------------------
  59
  60 #define M_REGIONDATA ((wxRegionRefData *)m_refData)
  61 #define M_REGIONDATA_OF(rgn) ((wxRegionRefData *)(rgn.m_refData))
  62
  63 IMPLEMENT_DYNAMIC_CLASS(wxRegion, wxGDIObject);
  64 IMPLEMENT_DYNAMIC_CLASS(wxRegionIterator,wxObject);
  65
  66 // ============================================================================
  67 // implementation
  68 // ============================================================================
  69
  70 // ----------------------------------------------------------------------------
  71 // wxRegionRefData
  72 // ----------------------------------------------------------------------------
  73
  74 wxRegionRefData::wxRegionRefData()
  75 {
  76     m_region = (GdkRegion *) NULL;
  77 }
  78
  79 wxRegionRefData::wxRegionRefData(const wxRegionRefData& refData)
  80 {
  81 #ifdef __WXGTK20__
  82     m_region = gdk_region_copy(refData.m_region);
  83 #else
  84     m_region = gdk_region_new();
  85     GdkRegion *regCopy = gdk_regions_union(m_region, refData.m_region);
  86     gdk_region_destroy(m_region);
  87     m_region = regCopy;
  88 #endif
  89
  90 #if OLDCODE
  91     wxNode *node = refData.m_rects.First();
  92     while (node)
  93     {
  94         wxRect *r = (wxRect*)node->Data();
  95         m_rects.Append( (wxObject*) new wxRect(*r) );
  96         node = node->Next();
  97     }
  98 #endif
  99 }
 100
 101 wxRegionRefData::~wxRegionRefData()
 102 {
 103     if (m_region) gdk_region_destroy( m_region );
 104
 105 #if OLDCODE
 106     wxNode *node = m_rects.First();
 107     while (node)
 108     {
 109         wxRect *r = (wxRect*)node->Data();
 110         delete r;
 111         node = node->Next();
 112     }
 113 #endif
 114 }
 115
 116 // ----------------------------------------------------------------------------
 117 // wxRegion construction
 118 // ----------------------------------------------------------------------------
 119
 120 #define M_REGIONDATA ((wxRegionRefData *)m_refData)
 121
 122 wxRegion::wxRegion()
 123 {
 124 }
 125
 126 wxRegion::wxRegion( wxCoord x, wxCoord y, wxCoord w, wxCoord h )
 127 {
 128     m_refData = new wxRegionRefData();
 129     GdkRegion *reg = gdk_region_new();
 130     GdkRectangle rect;
 131     rect.x = x;
 132     rect.y = y;
 133     rect.width = w;
 134     rect.height = h;
 135 #ifdef __WXGTK20__
 136     gdk_region_union_with_rect( reg, &rect );
 137     M_REGIONDATA->m_region = reg;
 138 #else
 139     M_REGIONDATA->m_region = gdk_region_union_with_rect( reg, &rect );
 140     gdk_region_destroy( reg );
 141 #endif
 142 #if OLDCODE
 143     M_REGIONDATA->m_rects.Append( (wxObject*) new wxRect(x,y,w,h) );
 144 #endif
 145 }
 146
 147 wxRegion::wxRegion( const wxPoint& topLeft, const wxPoint& bottomRight )
 148 {
 149     m_refData = new wxRegionRefData();
 150     GdkRegion *reg = gdk_region_new();
 151     GdkRectangle rect;
 152     rect.x = topLeft.x;
 153     rect.y = topLeft.y;
 154     rect.width = bottomRight.x - rect.x;
 155     rect.height = bottomRight.y - rect.y;
 156 #ifdef __WXGTK20__
 157     gdk_region_union_with_rect( reg, &rect );
 158     M_REGIONDATA->m_region = reg;
 159 #else
 160     M_REGIONDATA->m_region = gdk_region_union_with_rect( reg, &rect );
 161     gdk_region_destroy( reg );
 162 #endif
 163 #if OLDCODE
 164     M_REGIONDATA->m_rects.Append( (wxObject*) new wxRect(topLeft,bottomRight) );
 165 #endif
 166 }
 167
 168 wxRegion::wxRegion( const wxRect& rect )
 169 {
 170     m_refData = new wxRegionRefData();
 171     GdkRegion *reg = gdk_region_new();
 172     GdkRectangle g_rect;
 173     g_rect.x = rect.x;
 174     g_rect.y = rect.y;
 175     g_rect.width = rect.width;
 176     g_rect.height = rect.height;
 177 #ifdef __WXGTK20__
 178     gdk_region_union_with_rect( reg, &g_rect );
 179     M_REGIONDATA->m_region = reg;
 180 #else
 181     M_REGIONDATA->m_region = gdk_region_union_with_rect( reg, &g_rect );
 182     gdk_region_destroy( reg );
 183 #endif
 184 #if OLDCODE
 185     M_REGIONDATA->m_rects.Append( (wxObject*) new wxRect(rect.x,rect.y,rect.width,rect.height) );
 186 #endif
 187 }
 188
 189 wxRegion::~wxRegion()
 190 {
 191 }
 192
 193 bool wxRegion::operator==( const wxRegion& region )
 194 {
 195     // VZ: compare the regions themselves, not the pointers to ref data!
 196     return gdk_region_equal(M_REGIONDATA->m_region,
 197                             M_REGIONDATA_OF(region)->m_region);
 198 }
 199
 200 bool wxRegion::operator != ( const wxRegion& region )
 201 {
 202     return !(*this == region);
 203 }
 204
 205 void wxRegion::Unshare()
 206 {
 207     if ( !m_refData )
 208     {
 209         m_refData = new wxRegionRefData;
 210         M_REGIONDATA->m_region = gdk_region_new();
 211     }
 212     else if ( m_refData->GetRefCount() > 1 )
 213     {
 214         wxRegionRefData *refData = new wxRegionRefData(*M_REGIONDATA);
 215         UnRef();
 216         m_refData = refData;
 217     }
 218     //else: we're not shared
 219 }
 220
 221 // ----------------------------------------------------------------------------
 222 // wxRegion operations
 223 // ----------------------------------------------------------------------------
 224
 225 void wxRegion::Clear()
 226 {
 227     UnRef();
 228 }
 229
 230 bool wxRegion::Union( wxCoord x, wxCoord y, wxCoord width, wxCoord height )
 231 {
 232     GdkRectangle rect;
 233     rect.x = x;
 234     rect.y = y;
 235     rect.width = width;
 236     rect.height = height;
 237     if (!m_refData)
 238     {
 239         m_refData = new wxRegionRefData();
 240         GdkRegion *reg = gdk_region_new();
 241 #ifdef __WXGTK20__
 242         gdk_region_union_with_rect( reg, &rect );
 243         M_REGIONDATA->m_region = reg;
 244 #else
 245         M_REGIONDATA->m_region = gdk_region_union_with_rect( reg, &rect );
 246         gdk_region_destroy( reg );
 247 #endif
 248     }
 249     else
 250     {
 251         Unshare();
 252
 253 #ifdef __WXGTK20__
 254         gdk_region_union_with_rect( M_REGIONDATA->m_region, &rect );
 255 #else
 256         GdkRegion *reg = gdk_region_union_with_rect( M_REGIONDATA->m_region, &rect );
 257         gdk_region_destroy( M_REGIONDATA->m_region );
 258         M_REGIONDATA->m_region = reg;
 259 #endif
 260     }
 261
 262 #if OLDCODE
 263     M_REGIONDATA->m_rects.Append( (wxObject*) new wxRect(x,y,width,height) );
 264 #endif
 265
 266     return TRUE;
 267 }
 268
 269 bool wxRegion::Union( const wxRect& rect )
 270 {
 271     return Union( rect.x, rect.y, rect.width, rect.height );
 272 }
 273
 274 bool wxRegion::Union( const wxRegion& region )
 275 {
 276     if (region.IsNull())
 277         return FALSE;
 278
 279     Unshare();
 280
 281 #ifdef __WXGTK20__
 282     gdk_region_union( M_REGIONDATA->m_region, region.GetRegion() );
 283 #else
 284     GdkRegion *reg = gdk_regions_union( M_REGIONDATA->m_region, region.GetRegion() );
 285     gdk_region_destroy( M_REGIONDATA->m_region );
 286     M_REGIONDATA->m_region = reg;
 287 #endif
 288
 289 #if OLDCODE
 290     wxNode *node = region.GetRectList()->First();
 291     while (node)
 292     {
 293         wxRect *r = (wxRect*)node->Data();
 294         M_REGIONDATA->m_rects.Append( (wxObject*) new wxRect(r->x,r->y,r->width,r->height) );
 295         node = node->Next();
 296     }
 297 #endif
 298
 299     return TRUE;
 300 }
 301
 302 bool wxRegion::Intersect( wxCoord x, wxCoord y, wxCoord width, wxCoord height )
 303 {
 304     wxRegion reg( x, y, width, height );
 305
 306     return Intersect( reg );
 307 }
 308
 309 bool wxRegion::Intersect( const wxRect& rect )
 310 {
 311     wxRegion reg( rect );
 312     return Intersect( reg );
 313 }
 314
 315 // this helper function just computes the region intersection without updating
 316 // the list of rectangles each region maintaints: this allows us to call it
 317 // from Intersect() itself without going into infinite recursion as we would
 318 // if we called Intersect() itself recursively
 319 bool wxRegion::IntersectRegionOnly(const wxRegion& region)
 320 {
 321     Unshare();
 322
 323 #ifdef __WXGTK20__
 324     gdk_region_intersect( M_REGIONDATA->m_region, region.GetRegion() );
 325 #else
 326     GdkRegion *reg = gdk_regions_intersect( M_REGIONDATA->m_region, region.GetRegion() );
 327     gdk_region_destroy( M_REGIONDATA->m_region );
 328     M_REGIONDATA->m_region = reg;
 329 #endif
 330
 331     return TRUE;
 332 }
 333
 334 bool wxRegion::Intersect( const wxRegion& region )
 335 {
 336     if (region.IsNull())
 337         return FALSE;
 338
 339     if (!m_refData)
 340     {
 341         m_refData = new wxRegionRefData();
 342         M_REGIONDATA->m_region = gdk_region_new();
 343         return TRUE;
 344     }
 345
 346     if ( !IntersectRegionOnly(region) )
 347     {
 348         GetRectList()->Clear();
 349
 350         return FALSE;
 351     }
 352
 353     // we need to update the rect list as well
 354 #if OLDCODE
 355     wxList& list = *GetRectList();
 356     wxNode *node = list.First();
 357     while (node)
 358     {
 359         wxRect *r = (wxRect*)node->Data();
 360
 361         wxRegion regCopy = region;
 362         if ( regCopy.IntersectRegionOnly(*r) )
 363         {
 364             // replace the node with the intersection
 365             *r = regCopy.GetBox();
 366         }
 367         else
 368         {
 369             // TODO remove the rect from the list
 370             r->width = 0;
 371             r->height = 0;
 372         }
 373
 374         node = node->Next();
 375     }
 376 #endif
 377     return TRUE;
 378 }
 379
 380 bool wxRegion::Subtract( wxCoord x, wxCoord y, wxCoord width, wxCoord height )
 381 {
 382     wxRegion reg( x, y, width, height );
 383     return Subtract( reg );
 384 }
 385
 386 bool wxRegion::Subtract( const wxRect& rect )
 387 {
 388     wxRegion reg( rect );
 389     return Subtract( reg );
 390 }
 391
 392 bool wxRegion::Subtract( const wxRegion& region )
 393 {
 394     if (region.IsNull())
 395         return FALSE;
 396
 397     if (!m_refData)
 398     {
 399         m_refData = new wxRegionRefData();
 400         M_REGIONDATA->m_region = gdk_region_new();
 401     }
 402
 403     Unshare();
 404
 405 #ifdef __WXGTK20__
 406     gdk_region_subtract( M_REGIONDATA->m_region, region.GetRegion() );
 407 #else
 408     GdkRegion *reg = gdk_regions_subtract( M_REGIONDATA->m_region, region.GetRegion() );
 409     gdk_region_destroy( M_REGIONDATA->m_region );
 410     M_REGIONDATA->m_region = reg;
 411 #endif
 412
 413     return TRUE;
 414 }
 415
 416 bool wxRegion::Xor( wxCoord x, wxCoord y, wxCoord width, wxCoord height )
 417 {
 418     wxRegion reg( x, y, width, height );
 419     return Xor( reg );
 420 }
 421
 422 bool wxRegion::Xor( const wxRect& rect )
 423 {
 424     wxRegion reg( rect );
 425     return Xor( reg );
 426 }
 427
 428 bool wxRegion::Xor( const wxRegion& region )
 429 {
 430     if (region.IsNull())
 431         return FALSE;
 432
 433     if (!m_refData)
 434     {
 435         m_refData = new wxRegionRefData();
 436         M_REGIONDATA->m_region = gdk_region_new();
 437     }
 438     else
 439     {
 440         Unshare();
 441     }
 442
 443 #ifdef __WXGTK20__
 444     gdk_region_xor( M_REGIONDATA->m_region, region.GetRegion() );
 445 #else
 446     GdkRegion *reg = gdk_regions_xor( M_REGIONDATA->m_region, region.GetRegion() );
 447     gdk_region_destroy( M_REGIONDATA->m_region );
 448     M_REGIONDATA->m_region = reg;
 449 #endif
 450
 451 #if OLDCODE
 452     wxNode *node = region.GetRectList()->First();
 453     while (node)
 454     {
 455         wxRect *r = (wxRect*)node->Data();
 456         M_REGIONDATA->m_rects.Append( (wxObject*) new wxRect(r->x,r->y,r->width,r->height) );
 457         node = node->Next();
 458     }
 459 #endif
 460
 461     return TRUE;
 462 }
 463
 464 // ----------------------------------------------------------------------------
 465 // wxRegion tests
 466 // ----------------------------------------------------------------------------
 467
 468 void wxRegion::GetBox( wxCoord &x, wxCoord &y, wxCoord &w, wxCoord &h ) const
 469 {
 470     if ( m_refData )
 471     {
 472         GdkRectangle rect;
 473         gdk_region_get_clipbox( M_REGIONDATA->m_region, &rect );
 474         x = rect.x;
 475         y = rect.y;
 476         w = rect.width;
 477         h = rect.height;
 478     }
 479     else
 480     {
 481         x = 0;
 482         y = 0;
 483         w = -1;
 484         h = -1;
 485     }
 486 }
 487
 488 wxRect wxRegion::GetBox() const
 489 {
 490     wxCoord x, y, w, h;
 491     GetBox( x, y, w, h );
 492     return wxRect( x, y, w, h );
 493 }
 494
 495 bool wxRegion::Empty() const
 496 {
 497     if (!m_refData)
 498         return TRUE;
 499
 500     return gdk_region_empty( M_REGIONDATA->m_region );
 501 }
 502
 503 wxRegionContain wxRegion::Contains( wxCoord x, wxCoord y ) const
 504 {
 505     if (!m_refData)
 506         return wxOutRegion;
 507
 508     if (gdk_region_point_in( M_REGIONDATA->m_region, x, y ))
 509         return wxInRegion;
 510     else
 511         return wxOutRegion;
 512 }
 513
 514 wxRegionContain wxRegion::Contains( wxCoord x, wxCoord y, wxCoord w, wxCoord h ) const
 515 {
 516     if (!m_refData)
 517         return wxOutRegion;
 518
 519     GdkRectangle rect;
 520     rect.x = x;
 521     rect.y = y;
 522     rect.width = w;
 523     rect.height = h;
 524     GdkOverlapType res = gdk_region_rect_in( M_REGIONDATA->m_region, &rect );
 525     switch (res)
 526     {
 527         case GDK_OVERLAP_RECTANGLE_IN:   return wxInRegion;
 528         case GDK_OVERLAP_RECTANGLE_OUT:  return wxOutRegion;
 529         case GDK_OVERLAP_RECTANGLE_PART: return wxPartRegion;
 530     }
 531     return wxOutRegion;
 532 }
 533
 534 wxRegionContain wxRegion::Contains(const wxPoint& pt) const
 535 {
 536     return Contains( pt.x, pt.y );
 537 }
 538
 539 wxRegionContain wxRegion::Contains(const wxRect& rect) const
 540 {
 541     return Contains( rect.x, rect.y, rect.width, rect.height );
 542 }
 543
 544 GdkRegion *wxRegion::GetRegion() const
 545 {
 546     if (!m_refData)
 547         return (GdkRegion*) NULL;
 548
 549     return M_REGIONDATA->m_region;
 550 }
 551
 552 wxList *wxRegion::GetRectList() const
 553 {
 554 #if OLDCODE
 555     if (!m_refData)
 556         return (wxList*) NULL;
 557
 558     return &(M_REGIONDATA->m_rects);
 559 #else
 560     return (wxList*) NULL;
 561 #endif
 562 }
 563
 564 // ----------------------------------------------------------------------------
 565 // wxRegionIterator
 566 // ----------------------------------------------------------------------------
 567
 568 #if OLDCODE
 569
 570 wxRegionIterator::wxRegionIterator()
 571 {
 572     Reset();
 573 }
 574
 575 wxRegionIterator::wxRegionIterator( const wxRegion& region )
 576 {
 577     Reset(region);
 578 }
 579
 580 void wxRegionIterator::Reset( const wxRegion& region )
 581 {
 582     m_region = region;
 583     Reset();
 584 }
 585
 586 wxRegionIterator::operator bool () const
 587 {
 588     return m_region.GetRectList() && m_current < (size_t)m_region.GetRectList()->Number();
 589 }
 590
 591 bool wxRegionIterator::HaveRects() const
 592 {
 593     return m_region.GetRectList() && m_current < (size_t)m_region.GetRectList()->Number();
 594 }
 595
 596 void wxRegionIterator::operator ++ ()
 597 {
 598     if (HaveRects()) ++m_current;
 599 }
 600
 601 void wxRegionIterator::operator ++ (int)
 602 {
 603     if (HaveRects()) ++m_current;
 604 }
 605
 606 wxCoord wxRegionIterator::GetX() const
 607 {
 608     wxNode *node = m_region.GetRectList()->Nth( m_current );
 609     if (!node) return 0;
 610     wxRect *r = (wxRect*)node->Data();
 611     return r->x;
 612 }
 613
 614 wxCoord wxRegionIterator::GetY() const
 615 {
 616     wxNode *node = m_region.GetRectList()->Nth( m_current );
 617     if (!node) return 0;
 618     wxRect *r = (wxRect*)node->Data();
 619     return r->y;
 620 }
 621
 622 wxCoord wxRegionIterator::GetW() const
 623 {
 624     wxNode *node = m_region.GetRectList()->Nth( m_current );
 625     if (!node) return 0;
 626     wxRect *r = (wxRect*)node->Data();
 627     return r->width;
 628 }
 629
 630 wxCoord wxRegionIterator::GetH() const
 631 {
 632     wxNode *node = m_region.GetRectList()->Nth( m_current );
 633     if (!node) return 0;
 634     wxRect *r = (wxRect*)node->Data();
 635     return r->height;
 636 }
 637
 638 #else
 639
 640 // the following structures must match the private structures
 641 // in X11 region code ( xc/lib/X11/region.h )
 642
 643 // this makes the Region type transparent
 644 // and we have access to the region rectangles
 645
 646 struct _XBox {
 647     short x1, x2, y1, y2;
 648 };
 649
 650 struct _XRegion {
 651     long   size , numRects;
 652     _XBox *rects, extents;
 653 };
 654
 655 class wxRIRefData: public wxObjectRefData
 656 {
 657 public:
 658
 659     wxRIRefData() : m_rects(0), m_numRects(0){}
 660    ~wxRIRefData();
 661
 662     wxRect *m_rects;
 663     size_t  m_numRects;
 664
 665     void CreateRects( const wxRegion& r );
 666 };
 667
 668 wxRIRefData::~wxRIRefData()
 669 {
 670     delete m_rects;
 671 }
 672
 673 #include <gdk/gdkprivate.h>
 674
 675 void wxRIRefData::CreateRects( const wxRegion& region )
 676 {
 677   if( m_rects )
 678     delete m_rects;
 679   m_rects   = 0;
 680   m_numRects= 0;
 681   GdkRegion *gdkregion= region.GetRegion();
 682   if( gdkregion ){
 683     Region r= ((GdkRegionPrivate *)gdkregion)->xregion;
 684     if( r ){
 685       m_numRects= r->numRects;
 686       if( m_numRects )
 687       {
 688         m_rects= new wxRect[m_numRects];
 689         for( size_t i=0; i<m_numRects; ++i )
 690         {
 691           _XBox &xr= r->rects[i];
 692           wxRect&wr= m_rects[i];
 693           wr.x     = xr.x1;
 694           wr.y     = xr.y1;
 695           wr.width = xr.x2-xr.x1;
 696           wr.height= xr.y2-xr.y1;
 697         }
 698       }
 699     }
 700   }
 701 }
 702
 703 wxRegionIterator::wxRegionIterator()
 704 {
 705     m_refData = new wxRIRefData();
 706     Reset();
 707 }
 708
 709 wxRegionIterator::wxRegionIterator( const wxRegion& region )
 710 {
 711     m_refData = new wxRIRefData();
 712     Reset(region);
 713 }
 714
 715 void wxRegionIterator::Reset( const wxRegion& region )
 716 {
 717     m_region = region;
 718     ((wxRIRefData*)m_refData)->CreateRects(region);
 719     Reset();
 720 }
 721
 722 bool wxRegionIterator::HaveRects() const
 723 {
 724     return m_current < ((wxRIRefData*)m_refData)->m_numRects;
 725 }
 726
 727 wxRegionIterator::operator bool () const
 728 {
 729     return HaveRects();
 730 }
 731
 732 void wxRegionIterator::operator ++ ()
 733 {
 734     if (HaveRects()) ++m_current;
 735 }
 736
 737 void wxRegionIterator::operator ++ (int)
 738 {
 739     if (HaveRects()) ++m_current;
 740 }
 741
 742 wxCoord wxRegionIterator::GetX() const
 743 {
 744     if( !HaveRects() ) return 0;
 745     return ((wxRIRefData*)m_refData)->m_rects[m_current].x;
 746 }
 747
 748 wxCoord wxRegionIterator::GetY() const
 749 {
 750     if( !HaveRects() ) return 0;
 751     return ((wxRIRefData*)m_refData)->m_rects[m_current].y;
 752 }
 753
 754 wxCoord wxRegionIterator::GetW() const
 755 {
 756     if( !HaveRects() ) return -1;
 757     return ((wxRIRefData*)m_refData)->m_rects[m_current].width;
 758 }
 759
 760 wxCoord wxRegionIterator::GetH() const
 761 {
 762     if( !HaveRects() ) return -1;
 763     return ((wxRIRefData*)m_refData)->m_rects[m_current].height;
 764 }
 765
 766 wxRect wxRegionIterator::GetRect() const
 767 {
 768     wxRect r;
 769     if( HaveRects() )
 770         r = ((wxRIRefData*)m_refData)->m_rects[m_current];
 771
 772     return r;
 773 }
 774
 775 #endif
 776