src/common/rgncmn.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        rgncmn.cpp
   3 // Purpose:     Methods of wxRegion that have a generic implementation
   4 // Author:      Robin Dunn
   5 // Modified by:
   6 // Created:     27-Mar-2003
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Robin Dunn
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifdef __GNUG__
  13 #pragma implementation "rgncmn.h"
  14 #endif
  15
  16
  17 // For compilers that support precompilation, includes "wx.h".
  18 #include "wx/wxprec.h"
  19
  20 #ifdef __BORLANDC__
  21 #pragma hdrstop
  22 #endif
  23
  24 #include "wx/region.h"
  25 #include "wx/bitmap.h"
  26 #include "wx/image.h"
  27 #include "wx/dcmemory.h"
  28
  29
  30 //---------------------------------------------------------------------------
  31
  32
  33
  34 wxBitmap wxRegion::ConvertToBitmap() const
  35 {
  36     wxRect box = GetBox();
  37     wxBitmap bmp(box.GetRight(), box.GetBottom());
  38     wxMemoryDC dc;
  39     dc.SelectObject(bmp);
  40     dc.SetBackground(*wxBLACK_BRUSH);
  41     dc.Clear();
  42     dc.SetClippingRegion(*this);
  43     dc.SetBackground(*wxWHITE_BRUSH);
  44     dc.Clear();
  45     dc.SelectObject(wxNullBitmap);
  46     return bmp;
  47 }
  48
  49 //---------------------------------------------------------------------------
  50
  51 bool wxRegion::Union(const wxBitmap& bmp,
  52                      const wxColour& transColour,
  53                      int   tolerance)
  54 {
  55     unsigned char loR, loG, loB;
  56     unsigned char hiR, hiG, hiB;
  57
  58     wxCHECK_MSG((bmp.GetMask() != NULL) || transColour.Ok(),
  59                 FALSE,
  60                 wxT("Either the bitmap should have a mask or a colour should be given."));
  61
  62     wxImage image = bmp.ConvertToImage();
  63
  64     if (image.HasMask())
  65     {
  66         loR = image.GetMaskRed();
  67         loG = image.GetMaskGreen();
  68         loB = image.GetMaskBlue();
  69     }
  70     else
  71     {
  72         loR = transColour.Red();
  73         loG = transColour.Green();
  74         loB = transColour.Blue();
  75     }
  76
  77     hiR = wxMin(0xFF, loR + tolerance);
  78     hiG = wxMin(0xFF, loG + tolerance);
  79     hiB = wxMin(0xFF, loB + tolerance);
  80
  81     // Loop through the image row by row, pixel by pixel, building up
  82     // rectangles to add to the region.
  83     int width = image.GetWidth();
  84     int height = image.GetHeight();
  85     for (int y=0; y < height; y++)
  86     {
  87         wxRect rect;
  88         rect.y = y;
  89         rect.height = 1;
  90
  91         for (int x=0; x < width; x++)
  92         {
  93             // search for a continuous range of non-transparent pixels
  94             int x0 = x;
  95             while ( x < width)
  96             {
  97                 unsigned char R = image.GetRed(x,y);
  98                 unsigned char G = image.GetGreen(x,y);
  99                 unsigned char B = image.GetBlue(x,y);
 100                 if (( R >= loR && R <= hiR) &&
 101                     ( G >= loG && G <= hiG) &&
 102                     ( B >= loB && B <= hiB))  // It's transparent
 103                     break;
 104                 x++;
 105             }
 106
 107             // Add the run of non-transparent pixels (if any) to the region
 108             if (x > x0) {
 109                 rect.x = x0;
 110                 rect.width = x - x0;
 111                 Union(rect);
 112             }
 113         }
 114     }
 115
 116     return TRUE;
 117 }
 118
 119 //---------------------------------------------------------------------------