src/common/image.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        image.cpp
   3 // Purpose:     wxImage
   4 // Author:      Robert Roebling
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) Robert Roebling
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 #ifdef __GNUG__
  11 #pragma implementation "image.h"
  12 #endif
  13
  14 // For compilers that support precompilation, includes "wx.h".
  15 #include "wx/wxprec.h"
  16
  17 #ifdef __BORLANDC__
  18     #pragma hdrstop
  19 #endif
  20
  21 #include "wx/defs.h"
  22
  23 #if wxUSE_IMAGE
  24
  25 #include "wx/image.h"
  26 #include "wx/bitmap.h"
  27 #include "wx/debug.h"
  28 #include "wx/log.h"
  29 #include "wx/app.h"
  30 #include "wx/filefn.h"
  31 #include "wx/wfstream.h"
  32 #include "wx/intl.h"
  33 #include "wx/module.h"
  34
  35 // For memcpy
  36 #include <string.h>
  37 #include <math.h>
  38
  39 #ifdef __SALFORDC__
  40     #undef FAR
  41 #endif
  42
  43
  44 //-----------------------------------------------------------------------------
  45 // wxImage
  46 //-----------------------------------------------------------------------------
  47
  48 class wxImageRefData: public wxObjectRefData
  49 {
  50 public:
  51     wxImageRefData();
  52     ~wxImageRefData();
  53
  54     int             m_width;
  55     int             m_height;
  56     unsigned char  *m_data;
  57     bool            m_hasMask;
  58     unsigned char   m_maskRed,m_maskGreen,m_maskBlue;
  59     bool            m_ok;
  60     bool            m_static;
  61 #if wxUSE_PALETTE
  62     wxPalette       m_palette;
  63 #endif // wxUSE_PALETTE
  64     wxArrayString   m_optionNames;
  65     wxArrayString   m_optionValues;
  66 };
  67
  68 wxImageRefData::wxImageRefData()
  69 {
  70     m_width = 0;
  71     m_height = 0;
  72     m_data = (unsigned char*) NULL;
  73     m_ok = FALSE;
  74     m_maskRed = 0;
  75     m_maskGreen = 0;
  76     m_maskBlue = 0;
  77     m_hasMask = FALSE;
  78     m_static = FALSE;
  79 }
  80
  81 wxImageRefData::~wxImageRefData()
  82 {
  83     if (m_data && !m_static)
  84         free( m_data );
  85 }
  86
  87 wxList wxImage::sm_handlers;
  88
  89 wxImage wxNullImage;
  90
  91 //-----------------------------------------------------------------------------
  92
  93 #define M_IMGDATA ((wxImageRefData *)m_refData)
  94
  95 IMPLEMENT_DYNAMIC_CLASS(wxImage, wxObject)
  96
  97 wxImage::wxImage()
  98 {
  99 }
 100
 101 wxImage::wxImage( int width, int height )
 102 {
 103     Create( width, height );
 104 }
 105
 106 wxImage::wxImage( int width, int height, unsigned char* data, bool static_data )
 107 {
 108     Create( width, height, data, static_data );
 109 }
 110
 111 wxImage::wxImage( const wxString& name, long type, int index )
 112 {
 113     LoadFile( name, type, index );
 114 }
 115
 116 wxImage::wxImage( const wxString& name, const wxString& mimetype, int index )
 117 {
 118     LoadFile( name, mimetype, index );
 119 }
 120
 121 #if wxUSE_STREAMS
 122 wxImage::wxImage( wxInputStream& stream, long type, int index )
 123 {
 124     LoadFile( stream, type, index );
 125 }
 126
 127 wxImage::wxImage( wxInputStream& stream, const wxString& mimetype, int index )
 128 {
 129     LoadFile( stream, mimetype, index );
 130 }
 131 #endif // wxUSE_STREAMS
 132
 133 wxImage::wxImage( const wxImage& image )
 134 {
 135     Ref(image);
 136 }
 137
 138 wxImage::wxImage( const wxImage* image )
 139 {
 140     if (image) Ref(*image);
 141 }
 142
 143 void wxImage::Create( int width, int height )
 144 {
 145     UnRef();
 146
 147     m_refData = new wxImageRefData();
 148
 149     M_IMGDATA->m_data = (unsigned char *) malloc( width*height*3 );
 150     if (M_IMGDATA->m_data)
 151     {
 152         for (int l = 0; l < width*height*3; l++) M_IMGDATA->m_data[l] = 0;
 153
 154         M_IMGDATA->m_width = width;
 155         M_IMGDATA->m_height = height;
 156         M_IMGDATA->m_ok = TRUE;
 157     }
 158     else
 159     {
 160         UnRef();
 161     }
 162 }
 163
 164 void wxImage::Create( int width, int height, unsigned char* data, bool static_data )
 165 {
 166     UnRef();
 167
 168     m_refData = new wxImageRefData();
 169
 170     M_IMGDATA->m_data = data;
 171     if (M_IMGDATA->m_data)
 172     {
 173         M_IMGDATA->m_width = width;
 174         M_IMGDATA->m_height = height;
 175         M_IMGDATA->m_ok = TRUE;
 176         M_IMGDATA->m_static = static_data;
 177     }
 178     else
 179     {
 180         UnRef();
 181     }
 182 }
 183
 184 void wxImage::Destroy()
 185 {
 186     UnRef();
 187 }
 188
 189 wxImage wxImage::Copy() const
 190 {
 191     wxImage image;
 192
 193     wxCHECK_MSG( Ok(), image, wxT("invalid image") );
 194
 195     image.Create( M_IMGDATA->m_width, M_IMGDATA->m_height );
 196
 197     char unsigned *data = image.GetData();
 198
 199     wxCHECK_MSG( data, image, wxT("unable to create image") );
 200
 201     if (M_IMGDATA->m_hasMask)
 202         image.SetMaskColour( M_IMGDATA->m_maskRed, M_IMGDATA->m_maskGreen, M_IMGDATA->m_maskBlue );
 203
 204     memcpy( data, GetData(), M_IMGDATA->m_width*M_IMGDATA->m_height*3 );
 205
 206     return image;
 207 }
 208
 209 wxImage wxImage::Scale( int width, int height ) const
 210 {
 211     wxImage image;
 212
 213     wxCHECK_MSG( Ok(), image, wxT("invalid image") );
 214
 215     // can't scale to/from 0 size
 216     wxCHECK_MSG( (width > 0) && (height > 0), image,
 217                  wxT("invalid new image size") );
 218
 219     long old_height = M_IMGDATA->m_height,
 220          old_width  = M_IMGDATA->m_width;
 221     wxCHECK_MSG( (old_height > 0) && (old_width > 0), image,
 222                  wxT("invalid old image size") );
 223
 224     image.Create( width, height );
 225
 226     char unsigned *data = image.GetData();
 227
 228     wxCHECK_MSG( data, image, wxT("unable to create image") );
 229
 230     if (M_IMGDATA->m_hasMask)
 231     {
 232         image.SetMaskColour( M_IMGDATA->m_maskRed,
 233                              M_IMGDATA->m_maskGreen,
 234                              M_IMGDATA->m_maskBlue );
 235     }
 236
 237     char unsigned *source_data = M_IMGDATA->m_data;
 238     char unsigned *target_data = data;
 239
 240 #if 0
 241     // This is nonsense, RR.
 242
 243     // We do (x, y) -> (x, y)*oldSize/newSize but the valid values of x and y
 244     // are from 0 to size-1, hence all decrement the sizes
 245     long old_old_width = old_width;
 246     old_height--;
 247     old_width--;
 248     height--;
 249     width--;
 250     for ( long j = 0; j <= height; j++ )
 251     {
 252         // don't crash for images with height == 1
 253         long y_offset = height ? (j * old_height / height)* old_old_width : 0;
 254
 255         for ( long i = 0; i <= width; i++ )
 256         {
 257             long x_offset = width ? (i * old_width) / width : 0;
 258
 259             memcpy( target_data, source_data + 3*(y_offset + x_offset), 3 );
 260             target_data += 3;
 261         }
 262     }
 263 #else
 264     for (long j = 0; j < height; j++)
 265     {
 266         long y_offset = (j * old_height / height) * old_width;
 267
 268         for (long i = 0; i < width; i++)
 269         {
 270             memcpy( target_data,
 271                 source_data + 3*(y_offset + ((i * old_width )/ width)),
 272                 3 );
 273             target_data += 3;
 274         }
 275     }
 276 #endif
 277
 278     return image;
 279 }
 280
 281 wxImage wxImage::Rotate90( bool clockwise ) const
 282 {
 283     wxImage image;
 284
 285     wxCHECK_MSG( Ok(), image, wxT("invalid image") );
 286
 287     image.Create( M_IMGDATA->m_height, M_IMGDATA->m_width );
 288
 289     char unsigned *data = image.GetData();
 290
 291     wxCHECK_MSG( data, image, wxT("unable to create image") );
 292
 293     if (M_IMGDATA->m_hasMask)
 294         image.SetMaskColour( M_IMGDATA->m_maskRed, M_IMGDATA->m_maskGreen, M_IMGDATA->m_maskBlue );
 295
 296     long height = M_IMGDATA->m_height;
 297     long width  = M_IMGDATA->m_width;
 298
 299     char unsigned *source_data = M_IMGDATA->m_data;
 300     char unsigned *target_data;
 301
 302     for (long j = 0; j < height; j++)
 303     {
 304         for (long i = 0; i < width; i++)
 305         {
 306             if (clockwise)
 307                 target_data = data + (((i+1)*height) - j - 1)*3;
 308             else
 309                 target_data = data + ((height*(width-1)) + j - (i*height))*3;
 310             memcpy( target_data, source_data, 3 );
 311             source_data += 3;
 312         }
 313     }
 314
 315     return image;
 316 }
 317
 318 wxImage wxImage::Mirror( bool horizontally ) const
 319 {
 320     wxImage image;
 321
 322     wxCHECK_MSG( Ok(), image, wxT("invalid image") );
 323
 324     image.Create( M_IMGDATA->m_width, M_IMGDATA->m_height );
 325
 326     char unsigned *data = image.GetData();
 327
 328     wxCHECK_MSG( data, image, wxT("unable to create image") );
 329
 330     if (M_IMGDATA->m_hasMask)
 331         image.SetMaskColour( M_IMGDATA->m_maskRed, M_IMGDATA->m_maskGreen, M_IMGDATA->m_maskBlue );
 332
 333     long height = M_IMGDATA->m_height;
 334     long width  = M_IMGDATA->m_width;
 335
 336     char unsigned *source_data = M_IMGDATA->m_data;
 337     char unsigned *target_data;
 338
 339     if (horizontally)
 340     {
 341         for (long j = 0; j < height; j++)
 342         {
 343             data += width*3;
 344             target_data = data-3;
 345             for (long i = 0; i < width; i++)
 346             {
 347                 memcpy( target_data, source_data, 3 );
 348                 source_data += 3;
 349                 target_data -= 3;
 350             }
 351         }
 352     }
 353     else
 354     {
 355         for (long i = 0; i < height; i++)
 356         {
 357             target_data = data + 3*width*(height-1-i);
 358             memcpy( target_data, source_data, (size_t)3*width );
 359             source_data += 3*width;
 360         }
 361     }
 362
 363     return image;
 364 }
 365
 366 wxImage wxImage::GetSubImage( const wxRect &rect ) const
 367 {
 368     wxImage image;
 369
 370     wxCHECK_MSG( Ok(), image, wxT("invalid image") );
 371
 372     wxCHECK_MSG( (rect.GetLeft()>=0) && (rect.GetTop()>=0) && (rect.GetRight()<=GetWidth()) && (rect.GetBottom()<=GetHeight()),
 373                  image, wxT("invalid subimage size") );
 374
 375     int subwidth=rect.GetWidth();
 376     const int subheight=rect.GetHeight();
 377
 378     image.Create( subwidth, subheight );
 379
 380     char unsigned *subdata = image.GetData(), *data=GetData();
 381
 382     wxCHECK_MSG( subdata, image, wxT("unable to create image") );
 383
 384     if (M_IMGDATA->m_hasMask)
 385         image.SetMaskColour( M_IMGDATA->m_maskRed, M_IMGDATA->m_maskGreen, M_IMGDATA->m_maskBlue );
 386
 387     const int subleft=3*rect.GetLeft();
 388     const int width=3*GetWidth();
 389     subwidth*=3;
 390
 391     data+=rect.GetTop()*width+subleft;
 392
 393     for (long j = 0; j < subheight; ++j)
 394     {
 395         memcpy( subdata, data, subwidth);
 396         subdata+=subwidth;
 397         data+=width;
 398     }
 399
 400     return image;
 401 }
 402
 403 void wxImage::Paste( const wxImage &image, int x, int y )
 404 {
 405     wxCHECK_RET( Ok(), wxT("invalid image") );
 406     wxCHECK_RET( image.Ok(), wxT("invalid image") );
 407
 408     int xx = 0;
 409     int yy = 0;
 410     int width = image.GetWidth();
 411     int height = image.GetHeight();
 412
 413     if (x < 0)
 414     {
 415         xx = -x;
 416         width += x;
 417     }
 418     if (y < 0)
 419     {
 420         yy = -y;
 421         height += y;
 422     }
 423
 424     if ((x+xx)+width > M_IMGDATA->m_width)
 425         width = M_IMGDATA->m_width - (x+xx);
 426     if ((y+yy)+height > M_IMGDATA->m_height)
 427         height = M_IMGDATA->m_height - (y+yy);
 428
 429     if (width < 1) return;
 430     if (height < 1) return;
 431
 432     if ((!HasMask() && !image.HasMask()) ||
 433        ((HasMask() && image.HasMask() &&
 434          (GetMaskRed()==image.GetMaskRed()) &&
 435          (GetMaskGreen()==image.GetMaskGreen()) &&
 436          (GetMaskBlue()==image.GetMaskBlue()))))
 437     {
 438         width *= 3;
 439         unsigned char* source_data = image.GetData() + xx*3 + yy*3*image.GetWidth();
 440         int source_step = image.GetWidth()*3;
 441
 442         unsigned char* target_data = GetData() + (x+xx)*3 + (y+yy)*3*M_IMGDATA->m_width;
 443         int target_step = M_IMGDATA->m_width*3;
 444         for (int j = 0; j < height; j++)
 445         {
 446             memcpy( target_data, source_data, width );
 447             source_data += source_step;
 448             target_data += target_step;
 449         }
 450         return;
 451     }
 452
 453     if (!HasMask() && image.HasMask())
 454     {
 455         unsigned char r = image.GetMaskRed();
 456         unsigned char g = image.GetMaskGreen();
 457         unsigned char b = image.GetMaskBlue();
 458
 459         width *= 3;
 460         unsigned char* source_data = image.GetData() + xx*3 + yy*3*image.GetWidth();
 461         int source_step = image.GetWidth()*3;
 462
 463         unsigned char* target_data = GetData() + (x+xx)*3 + (y+yy)*3*M_IMGDATA->m_width;
 464         int target_step = M_IMGDATA->m_width*3;
 465
 466         for (int j = 0; j < height; j++)
 467         {
 468             for (int i = 0; i < width; i+=3)
 469             {
 470                 if ((source_data[i]   != r) &&
 471                     (source_data[i+1] != g) &&
 472                     (source_data[i+2] != b))
 473                 {
 474                     memcpy( target_data+i, source_data+i, 3 );
 475                 }
 476             }
 477             source_data += source_step;
 478             target_data += target_step;
 479         }
 480     }
 481 }
 482
 483 void wxImage::Replace( unsigned char r1, unsigned char g1, unsigned char b1,
 484                        unsigned char r2, unsigned char g2, unsigned char b2 )
 485 {
 486     wxCHECK_RET( Ok(), wxT("invalid image") );
 487
 488     char unsigned *data = GetData();
 489
 490     const int w = GetWidth();
 491     const int h = GetHeight();
 492
 493     for (int j = 0; j < h; j++)
 494         for (int i = 0; i < w; i++)
 495         {
 496             if ((data[0] == r1) && (data[1] == g1) && (data[2] == b1))
 497             {
 498                 data[0] = r2;
 499                 data[1] = g2;
 500                 data[2] = b2;
 501             }
 502             data += 3;
 503         }
 504 }
 505
 506 wxImage wxImage::ConvertToMono( unsigned char r, unsigned char g, unsigned char b ) const
 507 {
 508     wxImage image;
 509
 510     wxCHECK_MSG( Ok(), image, wxT("invalid image") );
 511
 512     image.Create( M_IMGDATA->m_width, M_IMGDATA->m_height );
 513
 514     char unsigned *data = image.GetData();
 515
 516     wxCHECK_MSG( data, image, wxT("unable to create image") );
 517
 518     if (M_IMGDATA->m_hasMask)
 519     {
 520         if (M_IMGDATA->m_maskRed == r && M_IMGDATA->m_maskGreen == g &&
 521                                          M_IMGDATA->m_maskBlue == b)
 522             image.SetMaskColour( 255, 255, 255 );
 523         else
 524             image.SetMaskColour( 0, 0, 0 );
 525     }
 526
 527     long size = M_IMGDATA->m_height * M_IMGDATA->m_width;
 528
 529     char unsigned *srcd = M_IMGDATA->m_data;
 530     char unsigned *tard = image.GetData();
 531
 532     for ( long i = 0; i < size; i++, srcd += 3, tard += 3 )
 533     {
 534         if (srcd[0] == r && srcd[1] == g && srcd[2] == b)
 535             tard[0] = tard[1] = tard[2] = 255;
 536         else
 537             tard[0] = tard[1] = tard[2] = 0;
 538     }
 539
 540     return image;
 541 }
 542
 543 void wxImage::SetRGB( int x, int y, unsigned char r, unsigned char g, unsigned char b )
 544 {
 545     wxCHECK_RET( Ok(), wxT("invalid image") );
 546
 547     int w = M_IMGDATA->m_width;
 548     int h = M_IMGDATA->m_height;
 549
 550     wxCHECK_RET( (x>=0) && (y>=0) && (x<w) && (y<h), wxT("invalid image index") );
 551
 552     long pos = (y * w + x) * 3;
 553
 554     M_IMGDATA->m_data[ pos   ] = r;
 555     M_IMGDATA->m_data[ pos+1 ] = g;
 556     M_IMGDATA->m_data[ pos+2 ] = b;
 557 }
 558
 559 unsigned char wxImage::GetRed( int x, int y ) const
 560 {
 561     wxCHECK_MSG( Ok(), 0, wxT("invalid image") );
 562
 563     int w = M_IMGDATA->m_width;
 564     int h = M_IMGDATA->m_height;
 565
 566     wxCHECK_MSG( (x>=0) && (y>=0) && (x<w) && (y<h), 0, wxT("invalid image index") );
 567
 568     long pos = (y * w + x) * 3;
 569
 570     return M_IMGDATA->m_data[pos];
 571 }
 572
 573 unsigned char wxImage::GetGreen( int x, int y ) const
 574 {
 575     wxCHECK_MSG( Ok(), 0, wxT("invalid image") );
 576
 577     int w = M_IMGDATA->m_width;
 578     int h = M_IMGDATA->m_height;
 579
 580     wxCHECK_MSG( (x>=0) && (y>=0) && (x<w) && (y<h), 0, wxT("invalid image index") );
 581
 582     long pos = (y * w + x) * 3;
 583
 584     return M_IMGDATA->m_data[pos+1];
 585 }
 586
 587 unsigned char wxImage::GetBlue( int x, int y ) const
 588 {
 589     wxCHECK_MSG( Ok(), 0, wxT("invalid image") );
 590
 591     int w = M_IMGDATA->m_width;
 592     int h = M_IMGDATA->m_height;
 593
 594     wxCHECK_MSG( (x>=0) && (y>=0) && (x<w) && (y<h), 0, wxT("invalid image index") );
 595
 596     long pos = (y * w + x) * 3;
 597
 598     return M_IMGDATA->m_data[pos+2];
 599 }
 600
 601 bool wxImage::Ok() const
 602 {
 603     // image of 0 width or height can't be considered ok - at least because it
 604     // causes crashes in ConvertToBitmap() if we don't catch it in time
 605     wxImageRefData *data = M_IMGDATA;
 606     return data && data->m_ok && data->m_width && data->m_height;
 607 }
 608
 609 char unsigned *wxImage::GetData() const
 610 {
 611     wxCHECK_MSG( Ok(), (char unsigned *)NULL, wxT("invalid image") );
 612
 613     return M_IMGDATA->m_data;
 614 }
 615
 616 void wxImage::SetData( char unsigned *data )
 617 {
 618     wxCHECK_RET( Ok(), wxT("invalid image") );
 619
 620     wxImageRefData *newRefData = new wxImageRefData();
 621
 622     newRefData->m_width = M_IMGDATA->m_width;
 623     newRefData->m_height = M_IMGDATA->m_height;
 624     newRefData->m_data = data;
 625     newRefData->m_ok = TRUE;
 626     newRefData->m_maskRed = M_IMGDATA->m_maskRed;
 627     newRefData->m_maskGreen = M_IMGDATA->m_maskGreen;
 628     newRefData->m_maskBlue = M_IMGDATA->m_maskBlue;
 629     newRefData->m_hasMask = M_IMGDATA->m_hasMask;
 630
 631     UnRef();
 632
 633     m_refData = newRefData;
 634 }
 635
 636 void wxImage::SetData( char unsigned *data, int new_width, int new_height )
 637 {
 638     wxImageRefData *newRefData = new wxImageRefData();
 639
 640     if (m_refData)
 641     {
 642         newRefData->m_width = new_width;
 643         newRefData->m_height = new_height;
 644         newRefData->m_data = data;
 645         newRefData->m_ok = TRUE;
 646         newRefData->m_maskRed = M_IMGDATA->m_maskRed;
 647         newRefData->m_maskGreen = M_IMGDATA->m_maskGreen;
 648         newRefData->m_maskBlue = M_IMGDATA->m_maskBlue;
 649         newRefData->m_hasMask = M_IMGDATA->m_hasMask;
 650     }
 651     else
 652     {
 653         newRefData->m_width = new_width;
 654         newRefData->m_height = new_height;
 655         newRefData->m_data = data;
 656         newRefData->m_ok = TRUE;
 657     }
 658
 659     UnRef();
 660
 661     m_refData = newRefData;
 662 }
 663
 664 void wxImage::SetMaskColour( unsigned char r, unsigned char g, unsigned char b )
 665 {
 666     wxCHECK_RET( Ok(), wxT("invalid image") );
 667
 668     M_IMGDATA->m_maskRed = r;
 669     M_IMGDATA->m_maskGreen = g;
 670     M_IMGDATA->m_maskBlue = b;
 671     M_IMGDATA->m_hasMask = TRUE;
 672 }
 673
 674 unsigned char wxImage::GetMaskRed() const
 675 {
 676     wxCHECK_MSG( Ok(), 0, wxT("invalid image") );
 677
 678     return M_IMGDATA->m_maskRed;
 679 }
 680
 681 unsigned char wxImage::GetMaskGreen() const
 682 {
 683     wxCHECK_MSG( Ok(), 0, wxT("invalid image") );
 684
 685     return M_IMGDATA->m_maskGreen;
 686 }
 687
 688 unsigned char wxImage::GetMaskBlue() const
 689 {
 690     wxCHECK_MSG( Ok(), 0, wxT("invalid image") );
 691
 692     return M_IMGDATA->m_maskBlue;
 693 }
 694
 695 void wxImage::SetMask( bool mask )
 696 {
 697     wxCHECK_RET( Ok(), wxT("invalid image") );
 698
 699     M_IMGDATA->m_hasMask = mask;
 700 }
 701
 702 bool wxImage::HasMask() const
 703 {
 704     wxCHECK_MSG( Ok(), FALSE, wxT("invalid image") );
 705
 706     return M_IMGDATA->m_hasMask;
 707 }
 708
 709 int wxImage::GetWidth() const
 710 {
 711     wxCHECK_MSG( Ok(), 0, wxT("invalid image") );
 712
 713     return M_IMGDATA->m_width;
 714 }
 715
 716 int wxImage::GetHeight() const
 717 {
 718     wxCHECK_MSG( Ok(), 0, wxT("invalid image") );
 719
 720     return M_IMGDATA->m_height;
 721 }
 722
 723
 724 bool wxImage::FindFirstUnusedColour(
 725             unsigned char *r, unsigned char *g, unsigned char *b,
 726             unsigned char startR, unsigned char startG, unsigned char startB)
 727 {
 728     wxHashTable hTable;
 729     unsigned long key;
 730
 731     ComputeHistogram( hTable );
 732
 733     unsigned char r2 = startR;
 734     unsigned char g2 = startG;
 735     unsigned char b2 = startB;
 736
 737     key = (r2 << 16) | (g2 << 8) | b2;
 738
 739     while ( (wxHNode *) hTable.Get(key) )
 740     {
 741         // color already used
 742         r2++;
 743         if ( r2 >= 255 )
 744         {
 745             r2 = 0;
 746             g2++;
 747             if ( g2 >= 255 )
 748             {
 749                 g2 = 0;
 750                 b2++;
 751                 if ( b2 >= 255 )
 752                 {
 753                     wxLogError( _("GetUnusedColour:: No Unused Color in image ") );
 754                     return FALSE;
 755                 }
 756             }
 757         }
 758
 759         key = (r2 << 16) | (g2 << 8) | b2;
 760     }
 761
 762     if (r) *r = r2;
 763     if (g) *g = g2;
 764     if (b) *b = b2;
 765
 766     return TRUE;
 767 }
 768
 769
 770 bool wxImage::SetMaskFromImage(const wxImage& mask,
 771                                unsigned char mr, unsigned char mg, unsigned char mb)
 772 {
 773     // check that the images are the same size
 774     if ( (M_IMGDATA->m_height != mask.GetHeight() ) || (M_IMGDATA->m_width != mask.GetWidth () ) )
 775     {
 776         wxLogError( _("Image and Mask have different sizes") );
 777         return FALSE;
 778     }
 779
 780     // find unused colour
 781     unsigned char r,g,b ;
 782     if (!FindFirstUnusedColour(&r, &g, &b))
 783     {
 784         wxLogError( _("No Unused Color in image being masked") );
 785         return FALSE ;
 786     }
 787
 788     char unsigned *imgdata = GetData();
 789     char unsigned *maskdata = mask.GetData();
 790
 791     const int w = GetWidth();
 792     const int h = GetHeight();
 793
 794     for (int j = 0; j < h; j++)
 795     {
 796         for (int i = 0; i < w; i++)
 797         {
 798             if ((maskdata[0] == mr) && (maskdata[1]  == mg) && (maskdata[2] == mb))
 799             {
 800                 imgdata[0] = r;
 801                 imgdata[1] = g;
 802                 imgdata[2] = b;
 803             }
 804             imgdata  += 3;
 805             maskdata += 3;
 806         }
 807     }
 808
 809     SetMaskColour(r, g, b);
 810     SetMask(TRUE);
 811
 812     return TRUE;
 813 }
 814
 815 #if wxUSE_PALETTE
 816
 817 // Palette functions
 818
 819 bool wxImage::HasPalette() const
 820 {
 821     if (!Ok())
 822         return FALSE;
 823
 824     return M_IMGDATA->m_palette.Ok();
 825 }
 826
 827 const wxPalette& wxImage::GetPalette() const
 828 {
 829     wxCHECK_MSG( Ok(), wxNullPalette, wxT("invalid image") );
 830
 831     return M_IMGDATA->m_palette;
 832 }
 833
 834 void wxImage::SetPalette(const wxPalette& palette)
 835 {
 836     wxCHECK_RET( Ok(), wxT("invalid image") );
 837
 838     M_IMGDATA->m_palette = palette;
 839 }
 840
 841 #endif // wxUSE_PALETTE
 842
 843 // Option functions (arbitrary name/value mapping)
 844 void wxImage::SetOption(const wxString& name, const wxString& value)
 845 {
 846     wxCHECK_RET( Ok(), wxT("invalid image") );
 847
 848     int idx = M_IMGDATA->m_optionNames.Index(name, FALSE);
 849     if (idx == wxNOT_FOUND)
 850     {
 851         M_IMGDATA->m_optionNames.Add(name);
 852         M_IMGDATA->m_optionValues.Add(value);
 853     }
 854     else
 855     {
 856         M_IMGDATA->m_optionNames[idx] = name;
 857         M_IMGDATA->m_optionValues[idx] = value;
 858     }
 859 }
 860
 861 void wxImage::SetOption(const wxString& name, int value)
 862 {
 863     wxString valStr;
 864     valStr.Printf(wxT("%d"), value);
 865     SetOption(name, valStr);
 866 }
 867
 868 wxString wxImage::GetOption(const wxString& name) const
 869 {
 870     wxCHECK_MSG( Ok(), wxEmptyString, wxT("invalid image") );
 871
 872     int idx = M_IMGDATA->m_optionNames.Index(name, FALSE);
 873     if (idx == wxNOT_FOUND)
 874         return wxEmptyString;
 875     else
 876         return M_IMGDATA->m_optionValues[idx];
 877 }
 878
 879 int wxImage::GetOptionInt(const wxString& name) const
 880 {
 881     wxCHECK_MSG( Ok(), 0, wxT("invalid image") );
 882
 883     return wxAtoi(GetOption(name));
 884 }
 885
 886 bool wxImage::HasOption(const wxString& name) const
 887 {
 888     wxCHECK_MSG( Ok(), FALSE, wxT("invalid image") );
 889
 890     return (M_IMGDATA->m_optionNames.Index(name, FALSE) != wxNOT_FOUND);
 891 }
 892
 893 bool wxImage::LoadFile( const wxString& filename, long type, int index )
 894 {
 895 #if wxUSE_STREAMS
 896     if (wxFileExists(filename))
 897     {
 898         wxFileInputStream stream(filename);
 899         wxBufferedInputStream bstream( stream );
 900         return LoadFile(bstream, type, index);
 901     }
 902     else
 903     {
 904         wxLogError( _("Can't load image from file '%s': file does not exist."), filename.c_str() );
 905
 906         return FALSE;
 907     }
 908 #else // !wxUSE_STREAMS
 909     return FALSE;
 910 #endif // wxUSE_STREAMS
 911 }
 912
 913 bool wxImage::LoadFile( const wxString& filename, const wxString& mimetype, int index )
 914 {
 915 #if wxUSE_STREAMS
 916     if (wxFileExists(filename))
 917     {
 918         wxFileInputStream stream(filename);
 919         wxBufferedInputStream bstream( stream );
 920         return LoadFile(bstream, mimetype, index);
 921     }
 922     else
 923     {
 924         wxLogError( _("Can't load image from file '%s': file does not exist."), filename.c_str() );
 925
 926         return FALSE;
 927     }
 928 #else // !wxUSE_STREAMS
 929     return FALSE;
 930 #endif // wxUSE_STREAMS
 931 }
 932
 933 bool wxImage::SaveFile( const wxString& filename, int type )
 934 {
 935 #if wxUSE_STREAMS
 936     wxFileOutputStream stream(filename);
 937
 938     if ( stream.LastError() == wxStream_NOERROR )
 939     {
 940         wxBufferedOutputStream bstream( stream );
 941         return SaveFile(bstream, type);
 942     }
 943 #endif // wxUSE_STREAMS
 944
 945     return FALSE;
 946 }
 947
 948 bool wxImage::SaveFile( const wxString& filename, const wxString& mimetype )
 949 {
 950 #if wxUSE_STREAMS
 951     wxFileOutputStream stream(filename);
 952
 953     if ( stream.LastError() == wxStream_NOERROR )
 954     {
 955         wxBufferedOutputStream bstream( stream );
 956         return SaveFile(bstream, mimetype);
 957     }
 958 #endif // wxUSE_STREAMS
 959
 960     return FALSE;
 961 }
 962
 963 bool wxImage::CanRead( const wxString &name )
 964 {
 965 #if wxUSE_STREAMS
 966   wxFileInputStream stream(name);
 967   return CanRead(stream);
 968 #else
 969   return FALSE;
 970 #endif
 971 }
 972
 973 int wxImage::GetImagesCount( const wxString &name, long type )
 974 {
 975 #if wxUSE_STREAMS
 976   wxFileInputStream stream(name);
 977   return GetImagesCount(stream, type);
 978 #else
 979   return 0;
 980 #endif
 981 }
 982
 983 #if wxUSE_STREAMS
 984
 985 bool wxImage::CanRead( wxInputStream &stream )
 986 {
 987     wxList &list=GetHandlers();
 988
 989     for ( wxList::Node *node = list.GetFirst(); node; node = node->GetNext() )
 990     {
 991         wxImageHandler *handler=(wxImageHandler*)node->GetData();
 992         if (handler->CanRead( stream ))
 993             return TRUE;
 994     }
 995
 996     return FALSE;
 997 }
 998
 999 int wxImage::GetImagesCount( wxInputStream &stream, long type )
1000 {
1001     wxImageHandler *handler;
1002
1003     if ( type == wxBITMAP_TYPE_ANY )
1004     {
1005         wxList &list=GetHandlers();
1006
1007         for (wxList::Node *node = list.GetFirst(); node; node = node->GetNext())
1008         {
1009              handler=(wxImageHandler*)node->GetData();
1010              if ( handler->CanRead(stream) )
1011                  return handler->GetImagesCount(stream);
1012
1013         }
1014
1015         wxLogWarning(_("No handler found for image type."));
1016         return 0;
1017     }
1018
1019     handler = FindHandler(type);
1020
1021     if ( !handler )
1022     {
1023         wxLogWarning(_("No image handler for type %d defined."), type);
1024         return FALSE;
1025     }
1026
1027     if ( handler->CanRead(stream) )
1028     {
1029         return handler->GetImagesCount(stream);
1030     }
1031     else
1032     {
1033         wxLogError(_("Image file is not of type %d."), type);
1034         return 0;
1035     }
1036 }
1037
1038 bool wxImage::LoadFile( wxInputStream& stream, long type, int index )
1039 {
1040     UnRef();
1041
1042     m_refData = new wxImageRefData;
1043
1044     wxImageHandler *handler;
1045
1046     if ( type == wxBITMAP_TYPE_ANY )
1047     {
1048         wxList &list=GetHandlers();
1049
1050         for ( wxList::Node *node = list.GetFirst(); node; node = node->GetNext() )
1051         {
1052              handler=(wxImageHandler*)node->GetData();
1053              if ( handler->CanRead(stream) )
1054                  return handler->LoadFile(this, stream, TRUE/*verbose*/, index);
1055
1056         }
1057
1058         wxLogWarning( _("No handler found for image type.") );
1059         return FALSE;
1060     }
1061
1062     handler = FindHandler(type);
1063
1064     if (handler == NULL)
1065     {
1066         wxLogWarning( _("No image handler for type %d defined."), type );
1067
1068         return FALSE;
1069     }
1070
1071     return handler->LoadFile(this, stream, TRUE/*verbose*/, index);
1072 }
1073
1074 bool wxImage::LoadFile( wxInputStream& stream, const wxString& mimetype, int index )
1075 {
1076     UnRef();
1077
1078     m_refData = new wxImageRefData;
1079
1080     wxImageHandler *handler = FindHandlerMime(mimetype);
1081
1082     if (handler == NULL)
1083     {
1084         wxLogWarning( _("No image handler for type %s defined."), mimetype.GetData() );
1085
1086         return FALSE;
1087     }
1088
1089     return handler->LoadFile( this, stream, index );
1090 }
1091
1092 bool wxImage::SaveFile( wxOutputStream& stream, int type )
1093 {
1094     wxCHECK_MSG( Ok(), FALSE, wxT("invalid image") );
1095
1096     wxImageHandler *handler = FindHandler(type);
1097
1098     if (handler == NULL)
1099     {
1100         wxLogWarning( _("No image handler for type %d defined."), type );
1101
1102         return FALSE;
1103     }
1104
1105     return handler->SaveFile( this, stream );
1106 }
1107
1108 bool wxImage::SaveFile( wxOutputStream& stream, const wxString& mimetype )
1109 {
1110     wxCHECK_MSG( Ok(), FALSE, wxT("invalid image") );
1111
1112     wxImageHandler *handler = FindHandlerMime(mimetype);
1113
1114     if (handler == NULL)
1115     {
1116         wxLogWarning( _("No image handler for type %s defined."), mimetype.GetData() );
1117
1118         return FALSE;
1119     }
1120
1121     return handler->SaveFile( this, stream );
1122 }
1123 #endif // wxUSE_STREAMS
1124
1125 void wxImage::AddHandler( wxImageHandler *handler )
1126 {
1127     // make sure that the memory will be freed at the program end
1128     sm_handlers.DeleteContents(TRUE);
1129
1130     sm_handlers.Append( handler );
1131 }
1132
1133 void wxImage::InsertHandler( wxImageHandler *handler )
1134 {
1135     // make sure that the memory will be freed at the program end
1136     sm_handlers.DeleteContents(TRUE);
1137
1138     sm_handlers.Insert( handler );
1139 }
1140
1141 bool wxImage::RemoveHandler( const wxString& name )
1142 {
1143     wxImageHandler *handler = FindHandler(name);
1144     if (handler)
1145     {
1146         sm_handlers.DeleteObject(handler);
1147         return TRUE;
1148     }
1149     else
1150         return FALSE;
1151 }
1152
1153 wxImageHandler *wxImage::FindHandler( const wxString& name )
1154 {
1155     wxNode *node = sm_handlers.First();
1156     while (node)
1157     {
1158         wxImageHandler *handler = (wxImageHandler*)node->Data();
1159         if (handler->GetName().Cmp(name) == 0) return handler;
1160
1161         node = node->Next();
1162     }
1163     return (wxImageHandler *)NULL;
1164 }
1165
1166 wxImageHandler *wxImage::FindHandler( const wxString& extension, long bitmapType )
1167 {
1168     wxNode *node = sm_handlers.First();
1169     while (node)
1170     {
1171         wxImageHandler *handler = (wxImageHandler*)node->Data();
1172         if ( (handler->GetExtension().Cmp(extension) == 0) &&
1173             (bitmapType == -1 || handler->GetType() == bitmapType) )
1174             return handler;
1175         node = node->Next();
1176     }
1177     return (wxImageHandler*)NULL;
1178 }
1179
1180 wxImageHandler *wxImage::FindHandler( long bitmapType )
1181 {
1182     wxNode *node = sm_handlers.First();
1183     while (node)
1184     {
1185         wxImageHandler *handler = (wxImageHandler *)node->Data();
1186         if (handler->GetType() == bitmapType) return handler;
1187         node = node->Next();
1188     }
1189     return NULL;
1190 }
1191
1192 wxImageHandler *wxImage::FindHandlerMime( const wxString& mimetype )
1193 {
1194     wxNode *node = sm_handlers.First();
1195     while (node)
1196     {
1197         wxImageHandler *handler = (wxImageHandler *)node->Data();
1198         if (handler->GetMimeType().IsSameAs(mimetype, FALSE)) return handler;
1199         node = node->Next();
1200     }
1201     return NULL;
1202 }
1203
1204 void wxImage::InitStandardHandlers()
1205 {
1206     AddHandler(new wxBMPHandler);
1207 #if wxUSE_XPM && !defined(__WXGTK__) && !defined(__WXMOTIF__)
1208     AddHandler(new wxXPMHandler);
1209 #endif
1210 }
1211
1212 void wxImage::CleanUpHandlers()
1213 {
1214     wxNode *node = sm_handlers.First();
1215     while (node)
1216     {
1217         wxImageHandler *handler = (wxImageHandler *)node->Data();
1218         wxNode *next = node->Next();
1219         delete handler;
1220         delete node;
1221         node = next;
1222     }
1223 }
1224
1225 //-----------------------------------------------------------------------------
1226 // wxImageHandler
1227 //-----------------------------------------------------------------------------
1228
1229 IMPLEMENT_ABSTRACT_CLASS(wxImageHandler,wxObject)
1230
1231 #if wxUSE_STREAMS
1232 bool wxImageHandler::LoadFile( wxImage *WXUNUSED(image), wxInputStream& WXUNUSED(stream), bool WXUNUSED(verbose), int WXUNUSED(index) )
1233 {
1234     return FALSE;
1235 }
1236
1237 bool wxImageHandler::SaveFile( wxImage *WXUNUSED(image), wxOutputStream& WXUNUSED(stream), bool WXUNUSED(verbose) )
1238 {
1239     return FALSE;
1240 }
1241
1242 int wxImageHandler::GetImagesCount( wxInputStream& WXUNUSED(stream) )
1243 {
1244     return 1;
1245 }
1246
1247 bool wxImageHandler::CanRead( const wxString& name )
1248 {
1249     if (wxFileExists(name))
1250     {
1251         wxFileInputStream stream(name);
1252         return CanRead(stream);
1253     }
1254
1255     else {
1256         wxLogError( _("Can't check image format of file '%s': file does not exist."), name.c_str() );
1257
1258         return FALSE;
1259     }
1260 //    return FALSE;
1261 }
1262
1263 #endif // wxUSE_STREAMS
1264
1265
1266
1267 //-----------------------------------------------------------------------------
1268 // wxBitmap convertion routines
1269 //-----------------------------------------------------------------------------
1270
1271 #if wxUSE_GUI
1272
1273 #ifdef __WXGTK__
1274 wxBitmap wxImage::ConvertToMonoBitmap( unsigned char red, unsigned char green, unsigned char blue ) const
1275 {
1276     wxImage mono = this->ConvertToMono( red, green, blue );
1277     wxBitmap bitmap( mono, 1 );
1278     return bitmap;
1279 }
1280 #endif
1281
1282 wxBitmap wxImage::ConvertToBitmap() const
1283 {
1284     wxBitmap bitmap( *this );
1285     return bitmap;
1286 }
1287
1288 wxImage::wxImage( const wxBitmap &bitmap )
1289 {
1290     *this = bitmap.ConvertToImage();
1291 }
1292
1293 #endif
1294
1295
1296
1297 // A module to allow wxImage initialization/cleanup
1298 // without calling these functions from app.cpp or from
1299 // the user's application.
1300
1301 class wxImageModule: public wxModule
1302 {
1303 DECLARE_DYNAMIC_CLASS(wxImageModule)
1304 public:
1305     wxImageModule() {}
1306     bool OnInit() { wxImage::InitStandardHandlers(); return TRUE; };
1307     void OnExit() { wxImage::CleanUpHandlers(); };
1308 };
1309
1310 IMPLEMENT_DYNAMIC_CLASS(wxImageModule, wxModule)
1311
1312
1313 //-----------------------------------------------------------------------------
1314
1315 // GRG, Dic/99
1316 // Counts and returns the number of different colours. Optionally stops
1317 // when it exceeds 'stopafter' different colours. This is useful, for
1318 // example, to see if the image can be saved as 8-bit (256 colour or
1319 // less, in this case it would be invoked as CountColours(256)). Default
1320 // value for stopafter is -1 (don't care).
1321 //
1322 unsigned long wxImage::CountColours( unsigned long stopafter )
1323 {
1324     wxHashTable h;
1325     wxObject dummy;
1326     unsigned char r, g, b;
1327     unsigned char *p;
1328     unsigned long size, nentries, key;
1329
1330     p = GetData();
1331     size = GetWidth() * GetHeight();
1332     nentries = 0;
1333
1334     for (unsigned long j = 0; (j < size) && (nentries <= stopafter) ; j++)
1335     {
1336         r = *(p++);
1337         g = *(p++);
1338         b = *(p++);
1339         key = (r << 16) | (g << 8) | b;
1340
1341         if (h.Get(key) == NULL)
1342         {
1343             h.Put(key, &dummy);
1344             nentries++;
1345         }
1346     }
1347
1348     return nentries;
1349 }
1350
1351
1352 // GRG, Dic/99
1353 // Computes the histogram of the image and fills a hash table, indexed
1354 // with integer keys built as 0xRRGGBB, containing wxHNode objects. Each
1355 // wxHNode contains an 'index' (useful to build a palette with the image
1356 // colours) and a 'value', which is the number of pixels in the image with
1357 // that colour.
1358 //
1359 unsigned long wxImage::ComputeHistogram( wxHashTable &h )
1360 {
1361     unsigned char r, g, b;
1362     unsigned char *p;
1363     unsigned long size, nentries, key;
1364     wxHNode *hnode;
1365
1366     p = GetData();
1367     size = GetWidth() * GetHeight();
1368     nentries = 0;
1369
1370     for (unsigned long j = 0; j < size; j++)
1371     {
1372         r = *(p++);
1373         g = *(p++);
1374         b = *(p++);
1375         key = (r << 16) | (g << 8) | b;
1376
1377         hnode = (wxHNode *) h.Get(key);
1378
1379         if (hnode)
1380             hnode->value++;
1381         else
1382         {
1383             hnode = new wxHNode();
1384             hnode->index = nentries++;
1385             hnode->value = 1;
1386
1387             h.Put(key, (wxObject *)hnode);
1388         }
1389     }
1390
1391     return nentries;
1392 }
1393
1394 /*
1395  * Rotation code by Carlos Moreno
1396  */
1397
1398 // GRG: I've removed wxRotationPoint - we already have wxRealPoint which
1399 //      does exactly the same thing. And I also got rid of wxRotationPixel
1400 //      bacause of potential problems in architectures where alignment
1401 //      is an issue, so I had to rewrite parts of the code.
1402
1403 static const double gs_Epsilon = 1e-10;
1404
1405 static inline int wxCint (double x)
1406 {
1407     return (x > 0) ? (int) (x + 0.5) : (int) (x - 0.5);
1408 }
1409
1410
1411 // Auxiliary function to rotate a point (x,y) with respect to point p0
1412 // make it inline and use a straight return to facilitate optimization
1413 // also, the function receives the sine and cosine of the angle to avoid
1414 // repeating the time-consuming calls to these functions -- sin/cos can
1415 // be computed and stored in the calling function.
1416
1417 inline wxRealPoint rotated_point (const wxRealPoint & p, double cos_angle, double sin_angle, const wxRealPoint & p0)
1418 {
1419     return wxRealPoint (p0.x + (p.x - p0.x) * cos_angle - (p.y - p0.y) * sin_angle,
1420                         p0.y + (p.y - p0.y) * cos_angle + (p.x - p0.x) * sin_angle);
1421 }
1422
1423 inline wxRealPoint rotated_point (double x, double y, double cos_angle, double sin_angle, const wxRealPoint & p0)
1424 {
1425     return rotated_point (wxRealPoint(x,y), cos_angle, sin_angle, p0);
1426 }
1427
1428 wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool interpolating, wxPoint * offset_after_rotation) const
1429 {
1430     int i;
1431     angle = -angle;     // screen coordinates are a mirror image of "real" coordinates
1432
1433     // Create pointer-based array to accelerate access to wxImage's data
1434     unsigned char ** data = new unsigned char * [GetHeight()];
1435
1436     data[0] = GetData();
1437
1438     for (i = 1; i < GetHeight(); i++)
1439         data[i] = data[i - 1] + (3 * GetWidth());
1440
1441     // precompute coefficients for rotation formula
1442     // (sine and cosine of the angle)
1443     const double cos_angle = cos(angle);
1444     const double sin_angle = sin(angle);
1445
1446     // Create new Image to store the result
1447     // First, find rectangle that covers the rotated image;  to do that,
1448     // rotate the four corners
1449
1450     const wxRealPoint p0(centre_of_rotation.x, centre_of_rotation.y);
1451
1452     wxRealPoint p1 = rotated_point (0, 0, cos_angle, sin_angle, p0);
1453     wxRealPoint p2 = rotated_point (0, GetHeight(), cos_angle, sin_angle, p0);
1454     wxRealPoint p3 = rotated_point (GetWidth(), 0, cos_angle, sin_angle, p0);
1455     wxRealPoint p4 = rotated_point (GetWidth(), GetHeight(), cos_angle, sin_angle, p0);
1456
1457     int x1 = (int) floor (wxMin (wxMin(p1.x, p2.x), wxMin(p3.x, p4.x)));
1458     int y1 = (int) floor (wxMin (wxMin(p1.y, p2.y), wxMin(p3.y, p4.y)));
1459     int x2 = (int) ceil (wxMax (wxMax(p1.x, p2.x), wxMax(p3.x, p4.x)));
1460     int y2 = (int) ceil (wxMax (wxMax(p1.y, p2.y), wxMax(p3.y, p4.y)));
1461
1462     wxImage rotated (x2 - x1 + 1, y2 - y1 + 1);
1463
1464     if (offset_after_rotation != NULL)
1465     {
1466         *offset_after_rotation = wxPoint (x1, y1);
1467     }
1468
1469     // GRG: The rotated (destination) image is always accessed
1470     //      sequentially, so there is no need for a pointer-based
1471     //      array here (and in fact it would be slower).
1472     //
1473     unsigned char * dst = rotated.GetData();
1474
1475     // GRG: if the original image has a mask, use its RGB values
1476     //      as the blank pixel, else, fall back to default (black).
1477     //
1478     unsigned char blank_r = 0;
1479     unsigned char blank_g = 0;
1480     unsigned char blank_b = 0;
1481
1482     if (HasMask())
1483     {
1484         blank_r = GetMaskRed();
1485         blank_g = GetMaskGreen();
1486         blank_b = GetMaskBlue();
1487         rotated.SetMaskColour( blank_r, blank_g, blank_b );
1488     }
1489
1490     // Now, for each point of the rotated image, find where it came from, by
1491     // performing an inverse rotation (a rotation of -angle) and getting the
1492     // pixel at those coordinates
1493
1494     // GRG: I've taken the (interpolating) test out of the loops, so that
1495     //      it is done only once, instead of repeating it for each pixel.
1496
1497     int x;
1498     if (interpolating)
1499     {
1500         for (int y = 0; y < rotated.GetHeight(); y++)
1501         {
1502             for (x = 0; x < rotated.GetWidth(); x++)
1503             {
1504                 wxRealPoint src = rotated_point (x + x1, y + y1, cos_angle, -sin_angle, p0);
1505
1506                 if (-0.25 < src.x && src.x < GetWidth() - 0.75 &&
1507                     -0.25 < src.y && src.y < GetHeight() - 0.75)
1508                 {
1509                     // interpolate using the 4 enclosing grid-points.  Those
1510                     // points can be obtained using floor and ceiling of the
1511                     // exact coordinates of the point
1512                         // C.M. 2000-02-17:  when the point is near the border, special care is required.
1513
1514                     int x1, y1, x2, y2;
1515
1516                     if (0 < src.x && src.x < GetWidth() - 1)
1517                     {
1518                         x1 = wxCint(floor(src.x));
1519                         x2 = wxCint(ceil(src.x));
1520                     }
1521                     else    // else means that x is near one of the borders (0 or width-1)
1522                     {
1523                         x1 = x2 = wxCint (src.x);
1524                     }
1525
1526                     if (0 < src.y && src.y < GetHeight() - 1)
1527                     {
1528                         y1 = wxCint(floor(src.y));
1529                         y2 = wxCint(ceil(src.y));
1530                     }
1531                     else
1532                     {
1533                         y1 = y2 = wxCint (src.y);
1534                     }
1535
1536                     // get four points and the distances (square of the distance,
1537                     // for efficiency reasons) for the interpolation formula
1538
1539                     // GRG: Do not calculate the points until they are
1540                     //      really needed -- this way we can calculate
1541                     //      just one, instead of four, if d1, d2, d3
1542                     //      or d4 are < gs_Epsilon
1543
1544                     const double d1 = (src.x - x1) * (src.x - x1) + (src.y - y1) * (src.y - y1);
1545                     const double d2 = (src.x - x2) * (src.x - x2) + (src.y - y1) * (src.y - y1);
1546                     const double d3 = (src.x - x2) * (src.x - x2) + (src.y - y2) * (src.y - y2);
1547                     const double d4 = (src.x - x1) * (src.x - x1) + (src.y - y2) * (src.y - y2);
1548
1549                     // Now interpolate as a weighted average of the four surrounding
1550                     // points, where the weights are the distances to each of those points
1551
1552                     // If the point is exactly at one point of the grid of the source
1553                     // image, then don't interpolate -- just assign the pixel
1554
1555                     if (d1 < gs_Epsilon)        // d1,d2,d3,d4 are positive -- no need for abs()
1556                     {
1557                         unsigned char *p = data[y1] + (3 * x1);
1558                         *(dst++) = *(p++);
1559                         *(dst++) = *(p++);
1560                         *(dst++) = *(p++);
1561                     }
1562                     else if (d2 < gs_Epsilon)
1563                     {
1564                         unsigned char *p = data[y1] + (3 * x2);
1565                         *(dst++) = *(p++);
1566                         *(dst++) = *(p++);
1567                         *(dst++) = *(p++);
1568                     }
1569                     else if (d3 < gs_Epsilon)
1570                     {
1571                         unsigned char *p = data[y2] + (3 * x2);
1572                         *(dst++) = *(p++);
1573                         *(dst++) = *(p++);
1574                         *(dst++) = *(p++);
1575                     }
1576                     else if (d4 < gs_Epsilon)
1577                     {
1578                         unsigned char *p = data[y2] + (3 * x1);
1579                         *(dst++) = *(p++);
1580                         *(dst++) = *(p++);
1581                         *(dst++) = *(p++);
1582                     }
1583                     else
1584                     {
1585                         // weights for the weighted average are proportional to the inverse of the distance
1586                         unsigned char *v1 = data[y1] + (3 * x1);
1587                         unsigned char *v2 = data[y1] + (3 * x2);
1588                         unsigned char *v3 = data[y2] + (3 * x2);
1589                         unsigned char *v4 = data[y2] + (3 * x1);
1590
1591                         const double w1 = 1/d1, w2 = 1/d2, w3 = 1/d3, w4 = 1/d4;
1592
1593                         // GRG: Unrolled.
1594
1595                         *(dst++) = (unsigned char)
1596                             ( (w1 * *(v1++) + w2 * *(v2++) +
1597                                w3 * *(v3++) + w4 * *(v4++)) /
1598                               (w1 + w2 + w3 + w4) );
1599                         *(dst++) = (unsigned char)
1600                             ( (w1 * *(v1++) + w2 * *(v2++) +
1601                                w3 * *(v3++) + w4 * *(v4++)) /
1602                               (w1 + w2 + w3 + w4) );
1603                         *(dst++) = (unsigned char)
1604                             ( (w1 * *(v1++) + w2 * *(v2++) +
1605                                w3 * *(v3++) + w4 * *(v4++)) /
1606                               (w1 + w2 + w3 + w4) );
1607                     }
1608                 }
1609                 else
1610                 {
1611                     *(dst++) = blank_r;
1612                     *(dst++) = blank_g;
1613                     *(dst++) = blank_b;
1614                 }
1615             }
1616         }
1617     }
1618     else    // not interpolating
1619     {
1620         for (int y = 0; y < rotated.GetHeight(); y++)
1621         {
1622             for (x = 0; x < rotated.GetWidth(); x++)
1623             {
1624                 wxRealPoint src = rotated_point (x + x1, y + y1, cos_angle, -sin_angle, p0);
1625
1626                 const int xs = wxCint (src.x);      // wxCint rounds to the
1627                 const int ys = wxCint (src.y);      // closest integer
1628
1629                 if (0 <= xs && xs < GetWidth() &&
1630                     0 <= ys && ys < GetHeight())
1631                 {
1632                     unsigned char *p = data[ys] + (3 * xs);
1633                     *(dst++) = *(p++);
1634                     *(dst++) = *(p++);
1635                     *(dst++) = *(p++);
1636                 }
1637                 else
1638                 {
1639                     *(dst++) = blank_r;
1640                     *(dst++) = blank_g;
1641                     *(dst++) = blank_b;
1642                 }
1643             }
1644         }
1645     }
1646
1647     delete [] data;
1648
1649     return rotated;
1650 }
1651
1652 #endif // wxUSE_IMAGE