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/dcmemory.h"
  27
  28
  29 //---------------------------------------------------------------------------
  30
  31
  32
  33 wxBitmap wxRegion::ConvertToBitmap() const
  34 {
  35     wxRect box = GetBox();
  36     wxBitmap bmp(box.GetRight(), box.GetBottom());
  37     wxMemoryDC dc;
  38     dc.SelectObject(bmp);
  39     dc.SetBackground(*wxWHITE_BRUSH);
  40     dc.Clear();
  41     dc.SetClippingRegion(*this);
  42     dc.SetBackground(*wxBLACK_BRUSH);
  43     dc.Clear();
  44     dc.SelectObject(wxNullBitmap);
  45     return bmp;
  46 }
  47
  48 //---------------------------------------------------------------------------
  49
  50 bool wxRegion::Union(const wxBitmap& bmp,
  51                      const wxColour& transColour,
  52                      int   tolerance)
  53 {
  54     unsigned char loR, loG, loB;
  55     unsigned char hiR, hiG, hiB;
  56
  57     wxCHECK_MSG((bmp.GetMask() != NULL) || transColour.Ok(),
  58                 FALSE,
  59                 wxT("Either the bitmap should have a mask or a colour should be given."));
  60
  61     wxImage image = bmp.ConvertToImage();
  62
  63     if (image.HasMask())
  64     {
  65         loR = image.GetMaskRed();
  66         loG = image.GetMaskGreen();
  67         loB = image.GetMaskBlue();
  68     }
  69     else
  70     {
  71         loR = transColour.Red();
  72         loG = transColour.Green();
  73         loB = transColour.Blue();
  74     }
  75
  76     hiR = wxMin(0xFF, loR + tolerance);
  77     hiG = wxMin(0xFF, loG + tolerance);
  78     hiB = wxMin(0xFF, loB + tolerance);
  79
  80     // Loop through the image row by row, pixel by pixel, building up
  81     // rectangles to add to the region.
  82     int width = image.GetWidth();
  83     int height = image.GetHeight();
  84     for (int y=0; y < height; y++)
  85     {
  86         wxRect rect;
  87         rect.y = y;
  88         rect.height = 1;
  89
  90         for (int x=0; x < width; x++)
  91         {
  92             // search for a continuous range of non-transparent pixels
  93             int x0 = x;
  94             while ( x < width)
  95             {
  96                 unsigned char R = image.GetRed(x,y);
  97                 unsigned char G = image.GetGreen(x,y);
  98                 unsigned char B = image.GetBlue(x,y);
  99                 if (( R >= loR && R <= hiR) &&
 100                     ( G >= loG && G <= hiG) &&
 101                     ( B >= loB && B <= hiB))  // It's transparent
 102                     break;
 103                 x++;
 104             }
 105
 106             // Add the run of non-transparent pixels (if any) to the region
 107             if (x > x0) {
 108                 rect.x = x0;
 109                 rect.width = x - x0;
 110                 Union(rect);
 111             }
 112         }
 113     }
 114
 115     return TRUE;
 116 }
 117
 118 //---------------------------------------------------------------------------