Remove platform-dependent code from Fl_PNG_Image.cxx

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3-porting@11574 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

2 files changed, 9 insertions, 0 deletions

diff --git a/src/drivers/WinAPI/Fl_WinAPI_System_Driver.H b/src/drivers/WinAPI/Fl_WinAPI_System_Driver.H
index e5bfb41b8..5e580f15c 100644
--- a/src/drivers/WinAPI/Fl_WinAPI_System_Driver.H
+++ b/src/drivers/WinAPI/Fl_WinAPI_System_Driver.H
@@ -83,6 +83,7 @@ public:
   virtual char *preference_rootnode(Fl_Preferences *prefs, Fl_Preferences::Root root, const char *vendor,
                                     const char *application);
   virtual void *dlopen(const char *filename);
+  virtual void png_extra_rgba_processing(unsigned char *array, int w, int h);
 };
 
 #endif // FL_WINAPI_SYSTEM_DRIVER_H
diff --git a/src/drivers/WinAPI/Fl_WinAPI_System_Driver.cxx b/src/drivers/WinAPI/Fl_WinAPI_System_Driver.cxx
index 9df5b2f71..529f9ade7 100644
--- a/src/drivers/WinAPI/Fl_WinAPI_System_Driver.cxx
+++ b/src/drivers/WinAPI/Fl_WinAPI_System_Driver.cxx
@@ -868,6 +868,14 @@ void *Fl_WinAPI_System_Driver::dlopen(const char *filename)
   return LoadLibrary(filename);
 }
 
+void Fl_WinAPI_System_Driver::png_extra_rgba_processing(unsigned char *ptr, int w, int h)
+{
+  // Some Windows graphics drivers don't honor transparency when RGB == white
+  // Convert RGB to 0 when alpha == 0...
+  for (int i = w * h; i > 0; i --, ptr += 4) {
+    if (!ptr[3]) ptr[0] = ptr[1] = ptr[2] = 0;
+  }
+}
 
 //
 // End of "$Id$".