Premultiply the alpha on wxMSW in the BitmapFromBuffer* functions so

[wxWidgets.git] / wxPython / src / _image.i

diff --git a/wxPython/src/_image.i b/wxPython/src/_image.i
index 3c639e0612ea4a2ec590e920c821f40b4476adc2..43e9f2462648ac0a098faba505bc1512feee166d 100644 (file)
--- a/wxPython/src/_image.i
+++ b/wxPython/src/_image.i
@@ -46,10 +46,10 @@ public:
     //bool LoadFile(wxImage* image, wxInputStream& stream);
     //bool SaveFile(wxImage* image, wxOutputStream& stream);
     //virtual int GetImageCount( wxInputStream& stream );
-    //bool CanRead( wxInputStream& stream );
 
     bool CanRead( const wxString& name );
-
+    %Rename(CanReadStream, bool, CanRead( wxInputStream& stream ));
+    
     void SetName(const wxString& name);
     void SetExtension(const wxString& extension);
     void SetType(long type);
@@ -153,19 +153,6 @@ key value from a RGB tripple.", "");
 
 //---------------------------------------------------------------------------
 
-%{
-    typedef unsigned char* buffer;
-%}    
-
-%typemap(in) (buffer data, int DATASIZE)
-    { if (!PyArg_Parse($input, "t#", &$1, &$2)) SWIG_fail; }
-
-%typemap(in) (buffer alpha, int ALPHASIZE)
-    { if (!PyArg_Parse($input, "t#", &$1, &$2)) SWIG_fail; }
-
-//---------------------------------------------------------------------------
-
-
 DocStr(wxImage,
 "A platform-independent image class.  An image can be created from
 data, or using `wx.Bitmap.ConvertToImage`, or loaded from a file in a
@@ -268,8 +255,8 @@ public:
         largest and most colourful one by the ICO handler.
 
 :see: `wx.ImageFromMime`, `wx.ImageFromStream`, `wx.ImageFromStreamMime`,
-      `wx.EmptyImage`, `wx.ImageFromBitmap`, `wx.ImageFromData`,
-      `wx.ImageFromDataWithAlpha`
+      `wx.EmptyImage`, `wx.ImageFromBitmap`, `wx.ImageFromBuffer`,
+      `wx.ImageFromData`, `wx.ImageFromDataWithAlpha`
 ");
     
     ~wxImage();
@@ -392,7 +379,7 @@ alpha data must be width*height bytes.", "
 
     // TODO: wxImage( char** xpmData );
 
-    // Turn it back on again
+    // Turn the typemap back on again
     %typemap(out) wxImage* { $result = wxPyMake_wxObject($1, $owner); }
 
 
@@ -779,7 +766,7 @@ data must be width*height.", "");
 
 
         
-        DocStr(GetDataBuffer,
+        DocStr(GetAlphaBuffer,
                "Returns a writable Python buffer object that is pointing at the Alpha
 data buffer inside the wx.Image. You need to ensure that you do not
 use this buffer object after the image has been destroyed.", "");
@@ -793,7 +780,7 @@ use this buffer object after the image has been destroyed.", "");
         }
 
         
-        DocStr(SetDataBuffer,
+        DocStr(SetAlphaBuffer,
                "Sets the internal image alpha pointer to point at a Python buffer
 object.  This can save making an extra copy of the data but you must
 ensure that the buffer object lives as long as the wx.Image does.", "");
@@ -1000,6 +987,70 @@ range -1.0..1.0 where -1.0 is -360 degrees and 1.0 is 360 degrees", "");
 
 
 
+// Make an image from buffer objects.  Not that this is here instead of in the
+// wxImage class (as a constructor) because there is already another one with
+// the exact same signature, so there woudl be ambiguities in the generated
+// C++.  Doing it as an independent factory function like this accomplishes
+// the same thing however.
+%newobject _ImageFromBuffer;
+%inline %{
+    wxImage* _ImageFromBuffer(int width, int height,
+                              buffer data, int DATASIZE,
+                              buffer alpha=NULL, int ALPHASIZE=0)
+    {
+        if (DATASIZE != width*height*3) {
+            wxPyErr_SetString(PyExc_ValueError, "Invalid data buffer size.");
+            return NULL;
+        }
+        if (alpha != NULL) {
+            if (ALPHASIZE != width*height) {
+                wxPyErr_SetString(PyExc_ValueError, "Invalid alpha buffer size.");
+                return NULL;
+            }
+            return new wxImage(width, height, data, alpha, true);
+        }                
+        return new wxImage(width, height, data, true);
+    }                              
+%}
+
+%pythoncode {
+def ImageFromBuffer(width, height, dataBuffer, alphaBuffer=None):
+    """
+    Creates a `wx.Image` from the data in dataBuffer.  The dataBuffer
+    parameter must be a Python object that implements the buffer interface, or
+    is convertable to a buffer object, such as a string, array, etc.  The
+    dataBuffer object is expected to contain a series of RGB bytes and be
+    width*height*3 bytes long.  A buffer object can optionally be supplied for
+    the image's alpha channel data, and it is expected to be width*height
+    bytes long.
+
+    The wx.Image will be created with its data and alpha pointers initialized
+    to the memory address pointed to by the buffer objects, thus saving the
+    time needed to copy the image data from the buffer object to the wx.Image.
+    While this has advantages, it also has the shoot-yourself-in-the-foot
+    risks associated with sharing a C pointer between two objects.
+
+    To help alleviate the risk a reference to the data and alpha buffer
+    objects are kept with the wx.Image, so that they won't get deleted until
+    after the wx.Image is deleted.  However please be aware that it is not
+    guaranteed that an object won't move its memory buffer to a new location
+    when it needs to resize its contents.  If that happens then the wx.Image
+    will end up referring to an invalid memory location and could cause the
+    application to crash.  Therefore care should be taken to not manipulate
+    the objects used for the data and alpha buffers in a way that would cause
+    them to change size.
+    """
+    if not isinstance(dataBuffer, buffer):
+        dataBuffer = buffer(dataBuffer)
+    if alphaBuffer is not None and not isinstance(alphaBuffer, buffer):
+        alphaBuffer = buffer(alphaBuffer)
+    image = _core_._ImageFromBuffer(width, height, dataBuffer, alphaBuffer)
+    image._buffer = dataBuffer
+    image._alpha = alphaBuffer
+    return image
+}
+
+
 ///void wxInitAllImageHandlers();
 
 %pythoncode {