Global platform header (<PalmOS.h>) removed from public wx-headers (but included...

[wxWidgets.git] / include / wx / image.h

diff --git a/include/wx/image.h b/include/wx/image.h
index c4737d727342b82a4b1fc3c4d82180389513d7c6..36843a4122bbd4f00cb4bf3dfc7ef5a9f2f6ecab 100644 (file)
--- a/include/wx/image.h
+++ b/include/wx/image.h
@@ -46,6 +46,13 @@ enum
     wxIMAGE_RESOLUTION_CM = 2
 };
 
+// alpha channel values: fully transparent, default threshold separating
+// transparent pixels from opaque for a few functions dealing with alpha and
+// fully opaque
+const unsigned char wxIMAGE_ALPHA_TRANSPARENT = 0;
+const unsigned char wxIMAGE_ALPHA_THRESHOLD = 0x80;
+const unsigned char wxIMAGE_ALPHA_OPAQUE = 0xff;
+
 //-----------------------------------------------------------------------------
 // classes
 //-----------------------------------------------------------------------------
@@ -240,7 +247,7 @@ public:
 
     // converts image's alpha channel to mask, if it has any, does nothing
     // otherwise:
-    bool ConvertAlphaToMask(unsigned char threshold = 128);
+    bool ConvertAlphaToMask(unsigned char threshold = wxIMAGE_ALPHA_THRESHOLD);
 
     // This method converts an image where the original alpha
     // information is only available as a shades of a colour
@@ -290,6 +297,11 @@ public:
     void SetAlpha(unsigned char *alpha = NULL, bool static_data=false);
     void InitAlpha();
 
+    // return true if this pixel is masked or has alpha less than specified
+    // threshold
+    bool IsTransparent(int x, int y,
+                       unsigned char threshold = wxIMAGE_ALPHA_THRESHOLD) const;
+
     // Mask functions
     void SetMaskColour( unsigned char r, unsigned char g, unsigned char b );
     // Get the current mask colour or find a suitable colour