Added support for transparency in rotation code

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@5950 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/image.cpp

@@ -2608,8 +2608,7 @@ IMPLEMENT_DYNAMIC_CLASS(wxImageModule, wxModule)
 unsigned long wxImage::CountColours( unsigned long stopafter )
 {
     wxHashTable h;
-    wxNode *node;
-    wxHNode *hnode;
+    wxObject dummy;
     unsigned char r, g, b, *p;
     unsigned long size, nentries, key;
 
@@ -2624,20 +2623,13 @@ unsigned long wxImage::CountColours( unsigned long stopafter )
         b = *(p++);
         key = (r << 16) | (g << 8) | b;
 
-        hnode = (wxHNode *) h.Get(key);
-
-        if (!hnode)
+        if (h.Get(key) == NULL)
         {
-            h.Put(key, (wxObject *)(new wxHNode));
+            h.Put(key, &dummy);
             nentries++;
         }
     }
 
-    // delete all HNodes
-    h.BeginFind();
-    while ((node = h.Next()) != NULL)
-        delete (wxHNode *)node->GetData();
-
     return nentries;
 }
 
@@ -2699,7 +2691,6 @@ struct wxRotationPoint
     double x, y;
 };
 
-static const wxRotationPixel gs_BlankPixel = {0,0,0};
 static const double gs_Epsilon = 1e-10;
 
 static inline int wxCint (double x)
@@ -2741,7 +2732,8 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
         data[i] = data[i - 1] + img.GetWidth();
     }
 
-        // pre-compute coefficients for rotation formula (sine and cosine of the angle)
+    // pre-compute coefficients for rotation formula
+    // (sine and cosine of the angle)
     const double cos_angle = cos(angle);
     const double sin_angle = sin(angle);
 
@@ -2769,7 +2761,6 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
         *offset_after_rotation = wxPoint (x1, y1);
     }
 
-
     wxRotationPixel ** result_data = new wxRotationPixel * [rotated.GetHeight()];
 
     result_data[0] = (wxRotationPixel *) rotated.GetData();
@@ -2779,10 +2770,28 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
         result_data[i] = result_data[i - 1] + rotated.GetWidth();
     }
 
+    // GRG: if the original image has a mask, use its RGB values
+    //      as the blank pixel, else, fall back to default (black).
+    //
+    wxRotationPixel blankPixel = {{ 0, 0, 0 }};
+
+    if (HasMask())
+    {
+        unsigned char r = GetMaskRed();
+        unsigned char g = GetMaskGreen();
+        unsigned char b = GetMaskBlue();
+        rotated.SetMaskColour( r, g, b );
+        blankPixel.rgb[0] = r;
+        blankPixel.rgb[1] = g;
+        blankPixel.rgb[2] = b;
+    }
+
     // Now, for each point of the rotated image, find where it came from, by
     // performing an inverse rotation (a rotation of -angle) and getting the
     // pixel at those coordinates
 
+    // GRG: I'd suggest to take the (interpolating) test out of the loops
+
     int x;
     for (x = 0; x < rotated.GetWidth(); x++)
     {
@@ -2854,7 +2863,7 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
                 }
                 else
                 {
-                    result_data[y][x] = gs_BlankPixel;
+                    result_data[y][x] = blankPixel;
                 }
             }
             else
@@ -2869,7 +2878,7 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
                 }
                 else
                 {
-                    result_data[y][x] = gs_BlankPixel;
+                    result_data[y][x] = blankPixel;
                 }
             }
         }