diff options
Diffstat (limited to 'area_unix.go')
| -rw-r--r-- | area_unix.go | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/area_unix.go b/area_unix.go index fe67641..71a9edb 100644 --- a/area_unix.go +++ b/area_unix.go @@ -57,26 +57,27 @@ func our_area_draw_callback(widget *C.GtkWidget, cr *C.cairo_t, data C.gpointer) return C.FALSE // signals handled without stopping the event chain (thanks to desrt again) } i := s.handler.Paint(cliprect) - // pixel order is [R G B A] (see Example 1 on https://developer.gnome.org/gdk-pixbuf/2.26/gdk-pixbuf-The-GdkPixbuf-Structure.html) so we don't have to convert anything - // gdk-pixbuf is not alpha-premultiplied (thanks to desrt in irc.gimp.net/#gtk+) - pixbuf := C.gdk_pixbuf_new_from_data( - (*C.guchar)(unsafe.Pointer(pixelData(i))), - C.GDK_COLORSPACE_RGB, - C.TRUE, // has alpha channel - 8, // bits per sample + surface := C.cairo_image_surface_create( + C.CAIRO_FORMAT_ARGB32, // alpha-premultiplied; native byte order C.int(i.Rect.Dx()), - C.int(i.Rect.Dy()), - C.int(i.Stride), - nil, nil) // do not free data - C.gdk_cairo_set_source_pixbuf(cr, - pixbuf, - C.gdouble(cliprect.Min.X), - C.gdouble(cliprect.Min.Y)) + C.int(i.Rect.Dy())) + if status := C.cairo_surface_status(surface); status != C.CAIRO_STATUS_SUCCESS { + panic(fmt.Errorf("cairo_create_image_surface() failed: %s\n", + C.GoString(C.cairo_status_to_string(status)))) + } + // the flush and mark_dirty calls are required; see the cairo docs and https://git.gnome.org/browse/gtk+/tree/gdk/gdkcairo.c#n232 (thanks desrt in irc.gimp.net/#gtk+) + C.cairo_surface_flush(surface) + toARGB(i, uintptr(unsafe.Pointer(C.cairo_image_surface_get_data(surface))), + int(C.cairo_image_surface_get_stride(surface))) + C.cairo_surface_mark_dirty(surface) + C.cairo_set_source_surface(cr, + surface, + 0, 0) // origin of the surface // that just set the brush that cairo uses: we have to actually draw now // (via https://developer.gnome.org/gtkmm-tutorial/stable/sec-draw-images.html.en) C.cairo_rectangle(cr, x, y, w, h) // breaking the nrom here since we have the double data already C.cairo_fill(cr) - C.g_object_unref((C.gpointer)(unsafe.Pointer(pixbuf))) // free pixbuf + C.cairo_surface_destroy(surface) // free surface return C.FALSE // signals handled without stopping the event chain (thanks to desrt again) } |