return true;
}
-bool wxDIB::Create(const wxBitmap& bmp)
-{
- wxCHECK_MSG( bmp.Ok(), false, wxT("wxDIB::Create(): invalid bitmap") );
-
- if ( !Create(GetHbitmapOf(bmp)) )
- return false;
-
- m_hasAlpha = bmp.HasAlpha();
-
- return true;
-}
-
bool wxDIB::Create(HBITMAP hbmp)
{
+ wxCHECK_MSG( hbmp, false, wxT("wxDIB::Create(): invalid bitmap") );
+
// this bitmap could already be a DIB section in which case we don't need
// to convert it to DIB
DIBSECTION ds;
#if wxUSE_IMAGE
-bool wxDIB::Create(const wxImage& image)
+bool wxDIB::Create(const wxImage& image, PixelFormat pf)
{
wxCHECK_MSG( image.Ok(), false, wxT("invalid wxImage in wxDIB ctor") );
// if we have alpha channel, we need to create a 32bpp RGBA DIB, otherwise
// a 24bpp RGB is sufficient
- m_hasAlpha = image.HasAlpha();
- const int bpp = m_hasAlpha ? 32 : 24;
+ const bool hasAlpha = image.HasAlpha();
+ const int bpp = hasAlpha ? 32 : 24;
if ( !Create(w, h, bpp) )
return false;
const int srcBytesPerLine = w * 3;
const int dstBytesPerLine = GetLineSize(w, bpp);
const unsigned char *src = image.GetData() + ((h - 1) * srcBytesPerLine);
- const unsigned char *alpha = m_hasAlpha ? image.GetAlpha() + (h - 1)*w
- : NULL;
+ const unsigned char *alpha = hasAlpha ? image.GetAlpha() + (h - 1)*w
+ : NULL;
unsigned char *dstLineStart = (unsigned char *)m_data;
for ( int y = 0; y < h; y++ )
{
- // copy one DIB line
+ // Copy one DIB line. Note that RGB components order is reversed in
+ // Windows bitmaps compared to wxImage and is actually BGR.
unsigned char *dst = dstLineStart;
if ( alpha )
{
- for ( int x = 0; x < w; x++ )
+ int x;
+
+ switch ( pf )
{
- // RGB order is reversed, and we need to premultiply
- // all channels by alpha value for use with ::AlphaBlend.
- const unsigned char a = *alpha++;
- *dst++ = (unsigned char)((src[2] * a + 127) / 255);
- *dst++ = (unsigned char)((src[1] * a + 127) / 255);
- *dst++ = (unsigned char)((src[0] * a + 127) / 255);
- *dst++ = a;
- src += 3;
+ case PixelFormat_PreMultiplied:
+ // Pre-multiply pixel values so that the DIB could be used
+ // with ::AlphaBlend().
+ for ( x = 0; x < w; x++ )
+ {
+ const unsigned char a = *alpha++;
+ *dst++ = (unsigned char)((src[2] * a + 127) / 255);
+ *dst++ = (unsigned char)((src[1] * a + 127) / 255);
+ *dst++ = (unsigned char)((src[0] * a + 127) / 255);
+ *dst++ = a;
+ src += 3;
+ }
+ break;
+
+ case PixelFormat_NotPreMultiplied:
+ // Just copy pixel data without changing it.
+ for ( x = 0; x < w; x++ )
+ {
+ *dst++ = src[2];
+ *dst++ = src[1];
+ *dst++ = src[0];
+
+ *dst++ = *alpha++;
+ src += 3;
+ }
+ break;
}
+
}
else // no alpha channel
{
for ( int x = 0; x < w; x++ )
{
- // RGB order is reversed.
*dst++ = src[2];
*dst++ = src[1];
*dst++ = src[0];
{
// 32 bit bitmaps may be either 0RGB or ARGB and we don't know in
// advance which one do we have so suppose we have alpha of them and
- // get rid of it later if it turns out we didn't (in particular, don't
- // trust m_hasAlpha which is not set correctly when the image was
- // loaded from file).
+ // get rid of it later if it turns out we didn't.
image.SetAlpha();
}