+ wxCHECK_RET( bmp.IsOk(), wxT("Invalid bitmap in wxCairoContext::DrawBitmap"));
+
+ cairo_surface_t* surface;
+ int bw = bmp.GetWidth();
+ int bh = bmp.GetHeight();
+ wxBitmap bmpSource = bmp; // we need a non-const instance
+ unsigned char* buffer = new unsigned char[bw*bh*4];
+ wxUint32* data = (wxUint32*)buffer;
+
+ // Create a surface object and copy the bitmap pixel data to it. if the
+ // image has alpha (or a mask represented as alpha) then we'll use a
+ // different format and iterator than if it doesn't...
+ if (bmpSource.HasAlpha() || bmpSource.GetMask())
+ {
+ surface = cairo_image_surface_create_for_data(
+ buffer, CAIRO_FORMAT_ARGB32, bw, bh, bw*4);
+ wxAlphaPixelData pixData(bmpSource, wxPoint(0,0), wxSize(bw, bh));
+ wxCHECK_RET( pixData, wxT("Failed to gain raw access to bitmap data."));
+
+ wxAlphaPixelData::Iterator p(pixData);
+ for (int y=0; y<bh; y++)
+ {
+ wxAlphaPixelData::Iterator rowStart = p;
+ for (int x=0; x<bw; x++)
+ {
+ // Each pixel in CAIRO_FORMAT_ARGB32 is a 32-bit quantity,
+ // with alpha in the upper 8 bits, then red, then green, then
+ // blue. The 32-bit quantities are stored native-endian.
+ // Pre-multiplied alpha is used.
+ unsigned char alpha = p.Alpha();
+ if (alpha == 0)
+ *data = 0;
+ else
+ *data = ( alpha << 24
+ | (p.Red() * alpha/255) << 16
+ | (p.Green() * alpha/255) << 8
+ | (p.Blue() * alpha/255) );
+ ++data;
+ ++p;
+ }
+ p = rowStart;
+ p.OffsetY(pixData, 1);
+ }
+ }
+ else // no alpha
+ {
+ surface = cairo_image_surface_create_for_data(
+ buffer, CAIRO_FORMAT_RGB24, bw, bh, bw*4);
+ wxNativePixelData pixData(bmpSource, wxPoint(0,0), wxSize(bw, bh));
+ wxCHECK_RET( pixData, wxT("Failed to gain raw access to bitmap data."));
+
+ wxNativePixelData::Iterator p(pixData);
+ for (int y=0; y<bh; y++)
+ {
+ wxNativePixelData::Iterator rowStart = p;
+ for (int x=0; x<bw; x++)
+ {
+ // Each pixel in CAIRO_FORMAT_RGB24 is a 32-bit quantity, with
+ // the upper 8 bits unused. Red, Green, and Blue are stored in
+ // the remaining 24 bits in that order. The 32-bit quantities
+ // are stored native-endian.
+ *data = ( p.Red() << 16 | p.Green() << 8 | p.Blue() );
+ ++data;
+ ++p;
+ }
+ p = rowStart;
+ p.OffsetY(pixData, 1);
+ }
+ }
+
+
+ PushState();
+
+ // In case we're scaling the image by using a width and height different
+ // than the bitmap's size create a pattern transformation on the surface and
+ // draw the transformed pattern.
+ cairo_pattern_t* pattern = cairo_pattern_create_for_surface(surface);
+ wxDouble scaleX = w / bw;
+ wxDouble scaleY = h / bh;
+ cairo_scale(m_context, scaleX, scaleY);
+
+ // prepare to draw the image
+ cairo_translate(m_context, x, y);
+ cairo_set_source(m_context, pattern);
+ // use the original size here since the context is scaled already...
+ cairo_rectangle(m_context, 0, 0, bw, bh);
+ // fill the rectangle using the pattern
+ cairo_fill(m_context);
+
+ // clean up
+ cairo_pattern_destroy(pattern);
+ cairo_surface_destroy(surface);
+ delete [] buffer;
+ PopState();
projects / wxWidgets.git / blobdiff