dlls/gdi/bitmap.c

   1 /*
   2  * GDI bitmap objects
   3  *
   4  * Copyright 1993 Alexandre Julliard
   5  *           1998 Huw D M Davies
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include "wine/winbase16.h"
  26 #include "wine/wingdi16.h"
  27 #include "gdi.h"
  28 #include "gdi_private.h"
  29 #include "wine/debug.h"
  30
  31 WINE_DEFAULT_DEBUG_CHANNEL(bitmap);
  32
  33
  34 static HGDIOBJ BITMAP_SelectObject( HGDIOBJ handle, void *obj, HDC hdc );
  35 static INT BITMAP_GetObject16( HGDIOBJ handle, void *obj, INT count, LPVOID buffer );
  36 static INT BITMAP_GetObject( HGDIOBJ handle, void *obj, INT count, LPVOID buffer );
  37 static BOOL BITMAP_DeleteObject( HGDIOBJ handle, void *obj );
  38
  39 static const struct gdi_obj_funcs bitmap_funcs =
  40 {
  41     BITMAP_SelectObject,  /* pSelectObject */
  42     BITMAP_GetObject16,   /* pGetObject16 */
  43     BITMAP_GetObject,     /* pGetObjectA */
  44     BITMAP_GetObject,     /* pGetObjectW */
  45     NULL,                 /* pUnrealizeObject */
  46     BITMAP_DeleteObject   /* pDeleteObject */
  47 };
  48
  49 /***********************************************************************
  50  *           BITMAP_GetWidthBytes
  51  *
  52  * Return number of bytes taken by a scanline of 16-bit aligned Windows DDB
  53  * data.
  54  */
  55 INT BITMAP_GetWidthBytes( INT bmWidth, INT bpp )
  56 {
  57     switch(bpp)
  58     {
  59     case 1:
  60         return 2 * ((bmWidth+15) >> 4);
  61
  62     case 24:
  63         bmWidth *= 3; /* fall through */
  64     case 8:
  65         return bmWidth + (bmWidth & 1);
  66
  67     case 32:
  68         return bmWidth * 4;
  69
  70     case 16:
  71     case 15:
  72         return bmWidth * 2;
  73
  74     case 4:
  75         return 2 * ((bmWidth+3) >> 2);
  76
  77     default:
  78         WARN("Unknown depth %d, please report.\n", bpp );
  79     }
  80     return -1;
  81 }
  82
  83
  84 /******************************************************************************
  85  * CreateBitmap [GDI32.@]
  86  *
  87  * Creates a bitmap with the specified info.
  88  *
  89  * PARAMS
  90  *    width  [I] bitmap width
  91  *    height [I] bitmap height
  92  *    planes [I] Number of color planes
  93  *    bpp    [I] Number of bits to identify a color
  94  *    bits   [I] Pointer to array containing color data
  95  *
  96  * RETURNS
  97  *    Success: Handle to bitmap
  98  *    Failure: 0
  99  */
 100 HBITMAP WINAPI CreateBitmap( INT width, INT height, UINT planes,
 101                              UINT bpp, LPCVOID bits )
 102 {
 103     BITMAP bm;
 104
 105     bm.bmType = 0;
 106     bm.bmWidth = width;
 107     bm.bmHeight = height;
 108     bm.bmWidthBytes = BITMAP_GetWidthBytes( width, bpp );
 109     bm.bmPlanes = planes;
 110     bm.bmBitsPixel = bpp;
 111     bm.bmBits = (LPVOID)bits;
 112
 113     return CreateBitmapIndirect( &bm );
 114 }
 115
 116 /******************************************************************************
 117  * CreateCompatibleBitmap [GDI32.@]
 118  *
 119  * Creates a bitmap compatible with the DC.
 120  *
 121  * PARAMS
 122  *    hdc    [I] Handle to device context
 123  *    width  [I] Width of bitmap
 124  *    height [I] Height of bitmap
 125  *
 126  * RETURNS
 127  *    Success: Handle to bitmap
 128  *    Failure: 0
 129  */
 130 HBITMAP WINAPI CreateCompatibleBitmap( HDC hdc, INT width, INT height)
 131 {
 132     HBITMAP hbmpRet = 0;
 133     DC *dc;
 134
 135     TRACE("(%p,%d,%d) =\n", hdc, width, height);
 136
 137     if ((width >= 0x10000) || (height >= 0x10000))
 138     {
 139         FIXME("got bad width %d or height %d, please look for reason\n",
 140               width, height);
 141     }
 142     else
 143     {
 144         if (!(dc = DC_GetDCPtr(hdc))) return 0;
 145
 146         if (GDIMAGIC( dc->header.wMagic ) != MEMORY_DC_MAGIC)
 147         {
 148             hbmpRet = CreateBitmap(width, height,
 149                                    GetDeviceCaps(hdc, PLANES),
 150                                    GetDeviceCaps(hdc, BITSPIXEL),
 151                                    NULL);
 152         }
 153         else  /* Memory DC */
 154         {
 155             BITMAPOBJ *bmp = GDI_GetObjPtr( dc->hBitmap, BITMAP_MAGIC );
 156
 157             if (!bmp->dib)
 158             {
 159                 /* A device-dependent bitmap is selected in the DC */
 160                 hbmpRet = CreateBitmap(width, height,
 161                                        bmp->bitmap.bmPlanes,
 162                                        bmp->bitmap.bmBitsPixel,
 163                                        NULL);
 164             }
 165             else
 166             {
 167                 /* A DIB section is selected in the DC */
 168                 BITMAPINFO *bi;
 169                 void *bits;
 170
 171                 /* Allocate memory for a BITMAPINFOHEADER structure and a
 172                    color table. The maximum number of colors in a color table
 173                    is 256 which corresponds to a bitmap with depth 8.
 174                    Bitmaps with higher depths don't have color tables. */
 175                 bi = HeapAlloc(GetProcessHeap(), 0, sizeof(BITMAPINFOHEADER) + 256 * sizeof(RGBQUAD));
 176
 177                 if (bi)
 178                 {
 179                     bi->bmiHeader.biSize          = sizeof(bi->bmiHeader);
 180                     bi->bmiHeader.biWidth         = width;
 181                     bi->bmiHeader.biHeight        = height;
 182                     bi->bmiHeader.biPlanes        = bmp->dib->dsBmih.biPlanes;
 183                     bi->bmiHeader.biBitCount      = bmp->dib->dsBmih.biBitCount;
 184                     bi->bmiHeader.biCompression   = bmp->dib->dsBmih.biCompression;
 185                     bi->bmiHeader.biSizeImage     = 0;
 186                     bi->bmiHeader.biXPelsPerMeter = bmp->dib->dsBmih.biXPelsPerMeter;
 187                     bi->bmiHeader.biYPelsPerMeter = bmp->dib->dsBmih.biYPelsPerMeter;
 188                     bi->bmiHeader.biClrUsed       = bmp->dib->dsBmih.biClrUsed;
 189                     bi->bmiHeader.biClrImportant  = bmp->dib->dsBmih.biClrImportant;
 190
 191                     if (bi->bmiHeader.biCompression == BI_BITFIELDS)
 192                     {
 193                         /* Copy the color masks */
 194                         CopyMemory(bi->bmiColors, bmp->dib->dsBitfields, 3 * sizeof(DWORD));
 195                     }
 196                     else if (bi->bmiHeader.biBitCount <= 8)
 197                     {
 198                         /* Copy the color table */
 199                         GetDIBColorTable(hdc, 0, 256, bi->bmiColors);
 200                     }
 201
 202                     hbmpRet = CreateDIBSection(hdc, bi, DIB_RGB_COLORS, &bits, NULL, 0);
 203                     HeapFree(GetProcessHeap(), 0, bi);
 204                 }
 205             }
 206             GDI_ReleaseObj(dc->hBitmap);
 207         }
 208         GDI_ReleaseObj(hdc);
 209     }
 210
 211     TRACE("\t\t%p\n", hbmpRet);
 212     return hbmpRet;
 213 }
 214
 215
 216 /******************************************************************************
 217  * CreateBitmapIndirect [GDI32.@]
 218  *
 219  * Creates a bitmap with the specified info.
 220  *
 221  * PARAMS
 222  *  bmp [I] Pointer to the bitmap info describing the bitmap
 223  *
 224  * RETURNS
 225  *    Success: Handle to bitmap
 226  *    Failure: NULL. Use GetLastError() to determine the cause.
 227  *
 228  * NOTES
 229  *  If a width or height of 0 are given, a 1x1 monochrome bitmap is returned.
 230  */
 231 HBITMAP WINAPI CreateBitmapIndirect( const BITMAP *bmp )
 232 {
 233     BITMAP bm;
 234     BITMAPOBJ *bmpobj;
 235     HBITMAP hbitmap;
 236
 237     if (!bmp || bmp->bmType || bmp->bmPlanes != 1)
 238     {
 239         if (bmp && bmp->bmPlanes != 1)
 240             FIXME("planes = %d\n", bmp->bmPlanes);
 241         SetLastError( ERROR_INVALID_PARAMETER );
 242         return NULL;
 243     }
 244
 245     bm = *bmp;
 246
 247     if (!bm.bmWidth || !bm.bmHeight)
 248     {
 249         bm.bmWidth = bm.bmHeight = 1;
 250         bm.bmPlanes = bm.bmBitsPixel = 1;
 251         bm.bmWidthBytes = 2;
 252         bm.bmBits = NULL;
 253     }
 254     else
 255     {
 256         if (bm.bmHeight < 0)
 257             bm.bmHeight = -bm.bmHeight;
 258         if (bm.bmWidth < 0)
 259             bm.bmWidth = -bm.bmWidth;
 260     }
 261
 262       /* Create the BITMAPOBJ */
 263     bmpobj = GDI_AllocObject( sizeof(BITMAPOBJ), BITMAP_MAGIC,
 264                               (HGDIOBJ *)&hbitmap, &bitmap_funcs );
 265
 266     if (!bmpobj)
 267     {
 268         SetLastError( ERROR_NOT_ENOUGH_MEMORY );
 269         return NULL;
 270     }
 271
 272     TRACE("%dx%d, %d colors returning %p\n", bm.bmWidth, bm.bmHeight,
 273           1 << (bm.bmPlanes * bm.bmBitsPixel), hbitmap);
 274
 275     bmpobj->size.cx = 0;
 276     bmpobj->size.cy = 0;
 277     bmpobj->bitmap = bm;
 278     bmpobj->bitmap.bmBits = NULL;
 279     bmpobj->funcs = NULL;
 280     bmpobj->dib = NULL;
 281     bmpobj->segptr_bits = 0;
 282
 283     if (bm.bmBits)
 284         SetBitmapBits( hbitmap, bm.bmHeight * bm.bmWidthBytes, bm.bmBits );
 285
 286     GDI_ReleaseObj( hbitmap );
 287     return hbitmap;
 288 }
 289
 290
 291 /***********************************************************************
 292  * GetBitmapBits [GDI32.@]
 293  *
 294  * Copies bitmap bits of bitmap to buffer.
 295  *
 296  * RETURNS
 297  *    Success: Number of bytes copied
 298  *    Failure: 0
 299  */
 300 LONG WINAPI GetBitmapBits(
 301     HBITMAP hbitmap, /* [in]  Handle to bitmap */
 302     LONG count,        /* [in]  Number of bytes to copy */
 303     LPVOID bits)       /* [out] Pointer to buffer to receive bits */
 304 {
 305     BITMAPOBJ *bmp = (BITMAPOBJ *) GDI_GetObjPtr( hbitmap, BITMAP_MAGIC );
 306     LONG height, ret;
 307
 308     if (!bmp) return 0;
 309
 310     /* If the bits vector is null, the function should return the read size */
 311     if(bits == NULL)
 312     {
 313         ret = bmp->bitmap.bmWidthBytes * bmp->bitmap.bmHeight;
 314         goto done;
 315     }
 316
 317     if (count < 0) {
 318         WARN("(%ld): Negative number of bytes passed???\n", count );
 319         count = -count;
 320     }
 321
 322     /* Only get entire lines */
 323     height = count / bmp->bitmap.bmWidthBytes;
 324     if (height > bmp->bitmap.bmHeight) height = bmp->bitmap.bmHeight;
 325     count = height * bmp->bitmap.bmWidthBytes;
 326     if (count == 0)
 327       {
 328         WARN("Less than one entire line requested\n");
 329         ret = 0;
 330         goto done;
 331       }
 332
 333
 334     TRACE("(%p, %ld, %p) %dx%d %d colors fetched height: %ld\n",
 335           hbitmap, count, bits, bmp->bitmap.bmWidth, bmp->bitmap.bmHeight,
 336           1 << bmp->bitmap.bmBitsPixel, height );
 337
 338     if(bmp->funcs && bmp->funcs->pGetBitmapBits)
 339     {
 340         TRACE("Calling device specific BitmapBits\n");
 341         ret = bmp->funcs->pGetBitmapBits(hbitmap, bits, count);
 342     } else {
 343
 344         if(!bmp->bitmap.bmBits) {
 345             WARN("Bitmap is empty\n");
 346             ret = 0;
 347         } else {
 348             memcpy(bits, bmp->bitmap.bmBits, count);
 349             ret = count;
 350         }
 351
 352     }
 353  done:
 354     GDI_ReleaseObj( hbitmap );
 355     return ret;
 356 }
 357
 358
 359 /******************************************************************************
 360  * SetBitmapBits [GDI32.@]
 361  *
 362  * Sets bits of color data for a bitmap.
 363  *
 364  * RETURNS
 365  *    Success: Number of bytes used in setting the bitmap bits
 366  *    Failure: 0
 367  */
 368 LONG WINAPI SetBitmapBits(
 369     HBITMAP hbitmap, /* [in] Handle to bitmap */
 370     LONG count,        /* [in] Number of bytes in bitmap array */
 371     LPCVOID bits)      /* [in] Address of array with bitmap bits */
 372 {
 373     BITMAPOBJ *bmp = (BITMAPOBJ *) GDI_GetObjPtr( hbitmap, BITMAP_MAGIC );
 374     LONG height, ret;
 375
 376     if ((!bmp) || (!bits))
 377         return 0;
 378
 379     if (count < 0) {
 380         WARN("(%ld): Negative number of bytes passed???\n", count );
 381         count = -count;
 382     }
 383
 384     if (bmp->dib)  /* simply copy the bits into the DIB */
 385     {
 386         DIBSECTION *dib = bmp->dib;
 387         char *dest = dib->dsBm.bmBits;
 388         DWORD max = dib->dsBm.bmWidthBytes * dib->dsBm.bmHeight;
 389         if (count > max) count = max;
 390         ret = count;
 391
 392         if (bmp->dib->dsBmih.biHeight >= 0)  /* not top-down, need to flip contents vertically */
 393         {
 394             dest += dib->dsBm.bmWidthBytes * dib->dsBm.bmHeight;
 395             while (count > 0)
 396             {
 397                 dest -= dib->dsBm.bmWidthBytes;
 398                 memcpy( dest, bits, min( count, dib->dsBm.bmWidthBytes ) );
 399                 bits = (char *)bits + dib->dsBm.bmWidthBytes;
 400                 count -= dib->dsBm.bmWidthBytes;
 401             }
 402         }
 403         else memcpy( dest, bits, count );
 404
 405         GDI_ReleaseObj( hbitmap );
 406         return ret;
 407     }
 408
 409     /* Only get entire lines */
 410     height = count / bmp->bitmap.bmWidthBytes;
 411     if (height > bmp->bitmap.bmHeight) height = bmp->bitmap.bmHeight;
 412     count = height * bmp->bitmap.bmWidthBytes;
 413
 414     TRACE("(%p, %ld, %p) %dx%d %d colors fetched height: %ld\n",
 415           hbitmap, count, bits, bmp->bitmap.bmWidth, bmp->bitmap.bmHeight,
 416           1 << bmp->bitmap.bmBitsPixel, height );
 417
 418     if(bmp->funcs && bmp->funcs->pSetBitmapBits) {
 419
 420         TRACE("Calling device specific BitmapBits\n");
 421         ret = bmp->funcs->pSetBitmapBits(hbitmap, bits, count);
 422     } else {
 423
 424         if(!bmp->bitmap.bmBits) /* Alloc enough for entire bitmap */
 425             bmp->bitmap.bmBits = HeapAlloc( GetProcessHeap(), 0, count );
 426         if(!bmp->bitmap.bmBits) {
 427             WARN("Unable to allocate bit buffer\n");
 428             ret = 0;
 429         } else {
 430             memcpy(bmp->bitmap.bmBits, bits, count);
 431             ret = count;
 432         }
 433     }
 434
 435     GDI_ReleaseObj( hbitmap );
 436     return ret;
 437 }
 438
 439 /**********************************************************************
 440  *              BITMAP_CopyBitmap
 441  *
 442  */
 443 HBITMAP BITMAP_CopyBitmap(HBITMAP hbitmap)
 444 {
 445     BITMAPOBJ *bmp = (BITMAPOBJ *) GDI_GetObjPtr( hbitmap, BITMAP_MAGIC );
 446     HBITMAP res = 0;
 447     BITMAP bm;
 448
 449     if(!bmp) return 0;
 450
 451     bm = bmp->bitmap;
 452     bm.bmBits = NULL;
 453     res = CreateBitmapIndirect(&bm);
 454
 455     if(res) {
 456         char *buf = HeapAlloc( GetProcessHeap(), 0, bm.bmWidthBytes *
 457                                bm.bmHeight );
 458         GetBitmapBits (hbitmap, bm.bmWidthBytes * bm.bmHeight, buf);
 459         SetBitmapBits (res, bm.bmWidthBytes * bm.bmHeight, buf);
 460         HeapFree( GetProcessHeap(), 0, buf );
 461     }
 462
 463     GDI_ReleaseObj( hbitmap );
 464     return res;
 465 }
 466
 467
 468 /***********************************************************************
 469  *           BITMAP_SetOwnerDC
 470  *
 471  * Set the type of DC that owns the bitmap. This is used when the
 472  * bitmap is selected into a device to initialize the bitmap function
 473  * table.
 474  */
 475 BOOL BITMAP_SetOwnerDC( HBITMAP hbitmap, DC *dc )
 476 {
 477     BITMAPOBJ *bitmap;
 478     BOOL ret;
 479
 480     /* never set the owner of the stock bitmap since it can be selected in multiple DCs */
 481     if (hbitmap == GetStockObject(DEFAULT_BITMAP)) return TRUE;
 482
 483     if (!(bitmap = GDI_GetObjPtr( hbitmap, BITMAP_MAGIC ))) return FALSE;
 484
 485     ret = TRUE;
 486     if (!bitmap->funcs)  /* not owned by a DC yet */
 487     {
 488         if (dc->funcs->pCreateBitmap) ret = dc->funcs->pCreateBitmap( dc->physDev, hbitmap );
 489         if (ret) bitmap->funcs = dc->funcs;
 490     }
 491     else if (bitmap->funcs != dc->funcs)
 492     {
 493         FIXME( "Trying to select bitmap %p in different DC type\n", hbitmap );
 494         ret = FALSE;
 495     }
 496     GDI_ReleaseObj( hbitmap );
 497     return ret;
 498 }
 499
 500
 501 /***********************************************************************
 502  *           BITMAP_SelectObject
 503  */
 504 static HGDIOBJ BITMAP_SelectObject( HGDIOBJ handle, void *obj, HDC hdc )
 505 {
 506     HGDIOBJ ret;
 507     BITMAPOBJ *bitmap = obj;
 508     DC *dc = DC_GetDCPtr( hdc );
 509
 510     if (!dc) return 0;
 511     if (GetObjectType( hdc ) != OBJ_MEMDC)
 512     {
 513         GDI_ReleaseObj( hdc );
 514         return 0;
 515     }
 516     ret = dc->hBitmap;
 517     if (handle == dc->hBitmap) goto done;  /* nothing to do */
 518
 519     if (bitmap->header.dwCount && (handle != GetStockObject(DEFAULT_BITMAP)))
 520     {
 521         WARN( "Bitmap already selected in another DC\n" );
 522         GDI_ReleaseObj( hdc );
 523         return 0;
 524     }
 525
 526     if (!bitmap->funcs && !BITMAP_SetOwnerDC( handle, dc ))
 527     {
 528         GDI_ReleaseObj( hdc );
 529         return 0;
 530     }
 531
 532     if (dc->funcs->pSelectBitmap) handle = dc->funcs->pSelectBitmap( dc->physDev, handle );
 533
 534     if (handle)
 535     {
 536         dc->hBitmap = handle;
 537         dc->flags &= ~DC_DIRTY;
 538         SetRectRgn( dc->hVisRgn, 0, 0, bitmap->bitmap.bmWidth, bitmap->bitmap.bmHeight);
 539         DC_InitDC( dc );
 540     }
 541     else ret = 0;
 542
 543  done:
 544     GDI_ReleaseObj( hdc );
 545     return ret;
 546 }
 547
 548
 549 /***********************************************************************
 550  *           BITMAP_DeleteObject
 551  */
 552 static BOOL BITMAP_DeleteObject( HGDIOBJ handle, void *obj )
 553 {
 554     BITMAPOBJ * bmp = obj;
 555
 556     if (bmp->funcs && bmp->funcs->pDeleteBitmap)
 557         bmp->funcs->pDeleteBitmap( handle );
 558
 559     HeapFree( GetProcessHeap(), 0, bmp->bitmap.bmBits );
 560
 561     if (bmp->dib)
 562     {
 563         DIBSECTION *dib = bmp->dib;
 564
 565         if (dib->dsBm.bmBits)
 566         {
 567             if (dib->dshSection)
 568             {
 569                 SYSTEM_INFO SystemInfo;
 570                 GetSystemInfo( &SystemInfo );
 571                 UnmapViewOfFile( (char *)dib->dsBm.bmBits -
 572                                  (dib->dsOffset % SystemInfo.dwAllocationGranularity) );
 573             }
 574             else if (!dib->dsOffset)
 575                 VirtualFree(dib->dsBm.bmBits, 0L, MEM_RELEASE );
 576         }
 577         HeapFree(GetProcessHeap(), 0, dib);
 578         bmp->dib = NULL;
 579         if (bmp->segptr_bits)
 580         { /* free its selector array */
 581             WORD sel = SELECTOROF(bmp->segptr_bits);
 582             WORD count = (GetSelectorLimit16(sel) / 0x10000) + 1;
 583             int i;
 584
 585             for (i = 0; i < count; i++) FreeSelector16(sel + (i << __AHSHIFT));
 586         }
 587     }
 588     return GDI_FreeObject( handle, obj );
 589 }
 590
 591
 592 /***********************************************************************
 593  *           BITMAP_GetObject16
 594  */
 595 static INT BITMAP_GetObject16( HGDIOBJ handle, void *obj, INT count, LPVOID buffer )
 596 {
 597     BITMAPOBJ *bmp = obj;
 598
 599     if (bmp->dib)
 600     {
 601         if ( count <= sizeof(BITMAP16) )
 602         {
 603             BITMAP *bmp32 = &bmp->dib->dsBm;
 604             BITMAP16 bmp16;
 605             bmp16.bmType       = bmp32->bmType;
 606             bmp16.bmWidth      = bmp32->bmWidth;
 607             bmp16.bmHeight     = bmp32->bmHeight;
 608             bmp16.bmWidthBytes = bmp32->bmWidthBytes;
 609             bmp16.bmPlanes     = bmp32->bmPlanes;
 610             bmp16.bmBitsPixel  = bmp32->bmBitsPixel;
 611             bmp16.bmBits       = (SEGPTR)0;
 612             memcpy( buffer, &bmp16, count );
 613             return count;
 614         }
 615         else
 616         {
 617             FIXME("not implemented for DIBs: count %d\n", count);
 618             return 0;
 619         }
 620     }
 621     else
 622     {
 623         BITMAP16 bmp16;
 624         bmp16.bmType       = bmp->bitmap.bmType;
 625         bmp16.bmWidth      = bmp->bitmap.bmWidth;
 626         bmp16.bmHeight     = bmp->bitmap.bmHeight;
 627         bmp16.bmWidthBytes = bmp->bitmap.bmWidthBytes;
 628         bmp16.bmPlanes     = bmp->bitmap.bmPlanes;
 629         bmp16.bmBitsPixel  = bmp->bitmap.bmBitsPixel;
 630         bmp16.bmBits       = (SEGPTR)0;
 631         if (count > sizeof(bmp16)) count = sizeof(bmp16);
 632         memcpy( buffer, &bmp16, count );
 633         return count;
 634     }
 635 }
 636
 637
 638 /***********************************************************************
 639  *           BITMAP_GetObject
 640  */
 641 static INT BITMAP_GetObject( HGDIOBJ handle, void *obj, INT count, LPVOID buffer )
 642 {
 643     BITMAPOBJ *bmp = obj;
 644
 645     if (bmp->dib)
 646     {
 647         if( !buffer )
 648             return sizeof(DIBSECTION);
 649         if (count < sizeof(DIBSECTION))
 650         {
 651             if (count > sizeof(BITMAP)) count = sizeof(BITMAP);
 652         }
 653         else
 654         {
 655             if (count > sizeof(DIBSECTION)) count = sizeof(DIBSECTION);
 656         }
 657
 658         memcpy( buffer, bmp->dib, count );
 659         return count;
 660     }
 661     else
 662     {
 663         if( !buffer )
 664             return sizeof(BITMAP);
 665         if (count > sizeof(BITMAP)) count = sizeof(BITMAP);
 666         memcpy( buffer, &bmp->bitmap, count );
 667         return count;
 668     }
 669 }
 670
 671
 672 /******************************************************************************
 673  * CreateDiscardableBitmap [GDI32.@]
 674  *
 675  * Creates a discardable bitmap.
 676  *
 677  * RETURNS
 678  *    Success: Handle to bitmap
 679  *    Failure: NULL
 680  */
 681 HBITMAP WINAPI CreateDiscardableBitmap(
 682     HDC hdc,    /* [in] Handle to device context */
 683     INT width,  /* [in] Bitmap width */
 684     INT height) /* [in] Bitmap height */
 685 {
 686     return CreateCompatibleBitmap( hdc, width, height );
 687 }
 688
 689
 690 /******************************************************************************
 691  * GetBitmapDimensionEx [GDI32.@]
 692  *
 693  * Retrieves dimensions of a bitmap.
 694  *
 695  * RETURNS
 696  *    Success: TRUE
 697  *    Failure: FALSE
 698  */
 699 BOOL WINAPI GetBitmapDimensionEx(
 700     HBITMAP hbitmap, /* [in]  Handle to bitmap */
 701     LPSIZE size)     /* [out] Address of struct receiving dimensions */
 702 {
 703     BITMAPOBJ * bmp = (BITMAPOBJ *) GDI_GetObjPtr( hbitmap, BITMAP_MAGIC );
 704     if (!bmp) return FALSE;
 705     *size = bmp->size;
 706     GDI_ReleaseObj( hbitmap );
 707     return TRUE;
 708 }
 709
 710
 711 /******************************************************************************
 712  * SetBitmapDimensionEx [GDI32.@]
 713  *
 714  * Assigns dimensions to a bitmap.
 715  * MSDN says that this function will fail if hbitmap is a handle created by
 716  * CreateDIBSection, but that's not true on Windows 2000.
 717  *
 718  * RETURNS
 719  *    Success: TRUE
 720  *    Failure: FALSE
 721  */
 722 BOOL WINAPI SetBitmapDimensionEx(
 723     HBITMAP hbitmap, /* [in]  Handle to bitmap */
 724     INT x,           /* [in]  Bitmap width */
 725     INT y,           /* [in]  Bitmap height */
 726     LPSIZE prevSize) /* [out] Address of structure for orig dims */
 727 {
 728     BITMAPOBJ * bmp = (BITMAPOBJ *) GDI_GetObjPtr( hbitmap, BITMAP_MAGIC );
 729     if (!bmp) return FALSE;
 730     if (prevSize) *prevSize = bmp->size;
 731     bmp->size.cx = x;
 732     bmp->size.cy = y;
 733     GDI_ReleaseObj( hbitmap );
 734     return TRUE;
 735 }