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;
m_handle = (HBITMAP)::LoadImage
(
wxGetInstance(),
- filename.fn_str(),
+ filename.t_str(),
IMAGE_BITMAP,
0, 0, // don't specify the size
LR_CREATEDIBSECTION | LR_LOADFROMFILE
#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];
return wxNullImage;
}
- if ( m_hasAlpha )
+ const int bpp = GetDepth();
+
+ // Remember if we have any "real" transparency, i.e. either any partially
+ // transparent pixels or not all pixels are fully opaque or fully
+ // transparent.
+ bool hasAlpha = false;
+ bool hasOpaque = false;
+ bool hasTransparent = false;
+
+ if ( bpp == 32 )
{
+ // 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.
image.SetAlpha();
}
// this is the same loop as in Create() just above but with copy direction
// reversed
- const int bpp = GetDepth();
const int dstBytesPerLine = w * 3;
const int srcBytesPerLine = GetLineSize(w, bpp);
unsigned char *dst = image.GetData() + ((h - 1) * dstBytesPerLine);
unsigned char *alpha = image.HasAlpha() ? image.GetAlpha() + (h - 1)*w
: NULL;
- const bool is32bit = bpp == 32;
const unsigned char *srcLineStart = (unsigned char *)GetData();
for ( int y = 0; y < h; y++ )
{
dst[1] = *src++;
dst[0] = *src++;
- if ( is32bit )
+ if ( bpp == 32 )
{
- if ( alpha )
+ // wxImage uses non premultiplied alpha so undo
+ // premultiplication done in Create() above
+ const unsigned char a = *src;
+ *alpha++ = a;
+
+ // Check what kind of alpha do we have.
+ switch ( a )
{
- // wxImage uses non premultiplied alpha so undo
- // premultiplication done in Create() above
- const unsigned char a = *src;
- *alpha++ = a;
- if ( a > 0 )
- {
- dst[0] = (dst[0] * 255) / a;
- dst[1] = (dst[1] * 255) / a;
- dst[2] = (dst[2] * 255) / a;
- }
+ case 0:
+ hasTransparent = true;
+ break;
+
+ default:
+ // Anything in between means we have real transparency
+ // and must use alpha channel.
+ hasAlpha = true;
+ break;
+
+ case 255:
+ hasOpaque = true;
+ break;
+ }
+
+ if ( a > 0 )
+ {
+ dst[0] = (dst[0] * 255) / a;
+ dst[1] = (dst[1] * 255) / a;
+ dst[2] = (dst[2] * 255) / a;
}
src++;
srcLineStart += srcBytesPerLine;
}
+ if ( hasOpaque && hasTransparent )
+ hasAlpha = true;
+
+ if ( !hasAlpha && image.HasAlpha() )
+ image.ClearAlpha();
+
return image;
}
projects / wxWidgets.git / blobdiff