//ToImage returns a copy of the surface as an image.
//
//Originally cairo_image_surface_get_data.
func (is ImageSurface) ToImage() (*image.RGBA, error) {
if err := is.Err(); err != nil {
return nil, err
}
C.cairo_surface_flush(is.s)
data := C.cairo_image_surface_get_data(is.s)
n := is.height * is.stride
img := &image.RGBA{
Pix: make([]uint8, n),
Stride: is.stride,
Rect: image.Rect(0, 0, is.width, is.height),
}
pseudoslice := (*[1 << 30]C.uchar)(unsafe.Pointer(data))[:n:n]
for i := 0; i < n; i += 4 {
img.Pix[i+0] = uint8(pseudoslice[i+oR])
img.Pix[i+1] = uint8(pseudoslice[i+oG])
img.Pix[i+2] = uint8(pseudoslice[i+oB])
img.Pix[i+3] = uint8(pseudoslice[i+oA])
}
return img, nil
}
// GetSnapshotCustom runs asynchronously, taking a snapshot of the WebView.
// Upon completion, resultCallback will be called with a copy of the underlying
// bitmap backing store for the frame, or with an error encountered during
// execution.
//
// See also: webkit_web_view_get_snapshot at
// http://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebView.html#webkit-web-view-get-snapshot
func (v *WebView) GetSnapshotCustom(region SnapshotRegion, options SnapshotOptions, resultCallback func(result *image.RGBA, err error)) {
var cCallback C.GAsyncReadyCallback
var userData C.gpointer
var err error
if resultCallback != nil {
callback := func(result *C.GAsyncResult) {
var snapErr *C.GError
snapResult := C.webkit_web_view_get_snapshot_finish(v.webView, result, &snapErr)
if snapResult == nil {
defer C.g_error_free(snapErr)
msg := C.GoString((*C.char)(snapErr.message))
resultCallback(nil, errors.New(msg))
return
}
defer C.cairo_surface_destroy(snapResult)
if C.cairo_surface_get_type(snapResult) != cairoSurfaceTypeImage ||
C.cairo_image_surface_get_format(snapResult) != cairoImageSurfaceFormatARGB32 {
panic("Snapshot in unexpected format")
}
w := int(C.cairo_image_surface_get_width(snapResult))
h := int(C.cairo_image_surface_get_height(snapResult))
stride := int(C.cairo_image_surface_get_stride(snapResult))
C.cairo_surface_flush(snapResult)
data := unsafe.Pointer(C.cairo_image_surface_get_data(snapResult))
//(miha) fix endianes depended byte order, and copy to go slice at the same time.
data_fixed := make([]byte, stride*h)
C.gowk2_cairo_endian_depended_ARGB32_to_RGBA((*C.uchar)(data), (*C.uchar)(&data_fixed[0]), C.uint(stride*h))
rgba := &image.RGBA{data_fixed, stride, image.Rect(0, 0, w, h)}
// slower but doesn't use Go pointers inside C. See https://github.com/golang/go/issues/8310 !!!!!!!
//C.gowk2_cairo_endian_depended_ARGB32_to_RGBA((*C.uchar)(data), C.uint(stride*h))
//rgba := &image.RGBA{C.GoBytes(data, C.int(stride*h)), stride, image.Rect(0, 0, w, h)}
resultCallback(rgba, nil)
}
cCallback, userData, err = newGAsyncReadyCallback(callback)
if err != nil {
panic(err)
}
}
C.webkit_web_view_get_snapshot(v.webView,
(C.WebKitSnapshotRegion)(region),
(C.WebKitSnapshotOptions)(options),
nil,
cCallback,
userData)
}
//export our_area_draw_callback
func our_area_draw_callback(widget *C.GtkWidget, cr *C.cairo_t, data C.gpointer) C.gboolean {
var x0, y0, x1, y1 C.double
var maxwid, maxht C.gint
s := (*sysData)(unsafe.Pointer(data))
// thanks to desrt in irc.gimp.net/#gtk+
// these are in user coordinates, which match what coordinates we want by default, even out of a draw event handler (thanks johncc3, mclasen, and Company in irc.gimp.net/#gtk+)
C.cairo_clip_extents(cr, &x0, &y0, &x1, &y1)
// we do not need to clear the cliprect; GtkDrawingArea did it for us beforehand
cliprect := image.Rect(int(x0), int(y0), int(x1), int(y1))
// the cliprect can actually fall outside the size of the Area; clip it by intersecting the two rectangles
C.gtk_widget_get_size_request(widget, &maxwid, &maxht)
cliprect = image.Rect(0, 0, int(maxwid), int(maxht)).Intersect(cliprect)
if cliprect.Empty() { // no intersection; nothing to paint
return C.FALSE // signals handled without stopping the event chain (thanks to desrt again)
}
i := s.handler.Paint(cliprect)
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()))
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, x0, y0, x1, y1) // breaking the nrom here since we have the coordinates as a C double already
C.cairo_fill(cr)
C.cairo_surface_destroy(surface) // free surface
return C.FALSE // signals handled without stopping the event chain (thanks to desrt again)
}
func (i *imagelist) Append(img *image.RGBA) {
var width, height C.gint
surface := C.cairo_image_surface_create(C.CAIRO_FORMAT_ARGB32,
C.int(img.Rect.Dx()),
C.int(img.Rect.Dy()))
if status := C.cairo_surface_status(surface); status != C.CAIRO_STATUS_SUCCESS {
panic(fmt.Errorf("cairo_create_image_surface() failed in ImageList.Append(): %s\n",
C.GoString(C.cairo_status_to_string(status))))
}
C.cairo_surface_flush(surface)
toARGB(img, uintptr(unsafe.Pointer(C.cairo_image_surface_get_data(surface))),
int(C.cairo_image_surface_get_stride(surface)), false) // not NRGBA
C.cairo_surface_mark_dirty(surface)
basepixbuf := C.gdk_pixbuf_get_from_surface(surface, 0, 0, C.gint(img.Rect.Dx()), C.gint(img.Rect.Dy()))
if basepixbuf == nil {
panic(fmt.Errorf("gdk_pixbuf_get_from_surface() failed in ImageList.Append() (no reason available)"))
}
if C.gtk_icon_size_lookup(scaleTo, &width, &height) == C.FALSE {
panic(fmt.Errorf("gtk_icon_size_lookup() failed in ImageList.Append() (no reason available)"))
}
if int(width) == img.Rect.Dx() && int(height) == img.Rect.Dy() {
// just add the base pixbuf; we're good
i.list = append(i.list, basepixbuf)
C.cairo_surface_destroy(surface)
return
}
// else scale
pixbuf := C.gdk_pixbuf_scale_simple(basepixbuf, C.int(width), C.int(height), C.GDK_INTERP_NEAREST)
if pixbuf == nil {
panic(fmt.Errorf("gdk_pixbuf_scale_simple() failed in ImageList.Append() (no reason available)"))
}
i.list = append(i.list, pixbuf)
C.gdk_pixbuf_unref(basepixbuf)
C.cairo_surface_destroy(surface)
}
func (self *Surface) Flush() {
C.cairo_surface_flush(self.surface)
}
// Flush is a wrapper around cairo_surface_flush().
func (v *Surface) Flush() {
C.cairo_surface_flush(v.native())
}
//Flush performs any pending drawing and restores any temporary modifcations
//that libcairo has made to the surface's state.
//
//Originally cairo_surface_flush.
func (e *XtensionSurface) Flush() error {
C.cairo_surface_flush(e.s)
return e.Err()
}