From 1988baa62b8aa90e270bfb669849af7c3f03448d Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Sat, 9 Feb 2008 15:32:04 +0000
Subject: [PATCH] added alpha support to wxImage::Paste() (patch 1883497, bug
 1831612)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@51617 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 docs/changes.txt     |  1 +
 src/common/image.cpp | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/docs/changes.txt b/docs/changes.txt
index 442fdde907..68c25e76dd 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -114,6 +114,7 @@ All (GUI):
   charset in ANSI build.
 - wxGrid now indicates focus by using different colour for selection
   and hiding cell cursor when it doesn't have focus.
+- Added alpha support to wxImage::Paste() (Steven Van Ingelgem)
 
 All (Unix):
 
diff --git a/src/common/image.cpp b/src/common/image.cpp
index 239d754c5c..75b99ff2eb 100644
--- a/src/common/image.cpp
+++ b/src/common/image.cpp
@@ -1289,6 +1289,26 @@ void wxImage::Paste( const wxImage &image, int x, int y )
         return;
     }
 
+    // Copy over the alpha channel from the original image
+    if ( image.HasAlpha() )
+    {
+        if ( !HasAlpha() )
+            InitAlpha();
+
+        unsigned char* source_data = image.GetAlpha() + xx + yy*image.GetWidth();
+        int source_step = image.GetWidth();
+
+        unsigned char* target_data = GetAlpha() + (x+xx) + (y+yy)*M_IMGDATA->m_width;
+        int target_step = M_IMGDATA->m_width;
+
+        for (int j = 0; j < height; j++,
+                                    source_data += source_step,
+                                    target_data += target_step)
+        {
+            memcpy( target_data, source_data, width );
+        }
+    }
+
     if (!HasMask() && image.HasMask())
     {
         unsigned char r = image.GetMaskRed();