// CreateImageSurface is a wrapper around cairo_image_surface_create().
func CreateImageSurface(format Format, width, height int) *Surface {
c := C.cairo_image_surface_create(C.cairo_format_t(format),
C.int(width), C.int(height))
s := wrapSurface(c)
runtime.SetFinalizer(s, (*Surface).destroy)
return s
}
// Format is determined from filename extension
// Supported formats: eps, jpeg, pdf, png, ps, svg
//
// Width and height are in pts for eps, pdf, ps, and svg; pixels for jpeg and png.
// Pixel measures will be truncated into integers
//
// Close the graphic to write the file
func Create(filename string, width float64, height float64) (*Graphic, error) {
g := &Graphic{}
var err error
filename = filepath.Clean(filename)
g.filename, err = filepath.Abs(filename)
if err != nil {
return nil, err
}
g.format = filepath.Ext(filename)[1:]
// create the surface
switch g.format {
case "pdf":
g.surface = C.cairo_pdf_surface_create(
C.CString(filename),
C.double(width),
C.double(height),
)
case "png", "jpeg":
g.surface = C.cairo_image_surface_create(
C.CAIRO_FORMAT_ARGB32,
C.int(width),
C.int(height),
)
case "ps", "eps":
g.surface = C.cairo_ps_surface_create(
C.CString(filename),
C.double(width),
C.double(height),
)
if g.format == "eps" {
C.cairo_ps_surface_set_eps(g.surface, 1)
}
case "svg":
g.surface = C.cairo_svg_surface_create(
C.CString(filename),
C.double(width),
C.double(height),
)
default:
return nil, errors.New("cairo: unsupported format: " + g.format)
}
err = g.cairoSurfaceStatus()
if err != nil {
return nil, err
}
// create the cairo context
g.cr = C.cairo_create(g.surface)
err = g.cairoStatus()
if err != nil {
return nil, err
}
return g, nil
}
// Create an image of the given size
func Create(w, h int, mode ColorSpace) *Image {
var img Image
var format C.cairo_format_t
switch mode {
case MODE_RGB, MODE_G8:
format = C.CAIRO_FORMAT_RGB24
case MODE_RGBA:
format = C.CAIRO_FORMAT_ARGB32
default:
format = C.CAIRO_FORMAT_A8
}
img.ColorSpace = mode
img.Surf = C.cairo_image_surface_create(format, C.int(w), C.int(h))
img.Ctx = C.cairo_create(img.Surf)
img.W, img.H = w, h
return &img
}
//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 NewSurface(format Format, width, height int) *Surface {
s := C.cairo_image_surface_create(C.cairo_format_t(format), C.int(width), C.int(height))
return &Surface{surface: s, context: C.cairo_create(s)}
}
func NewSurface(format Format, width, height int) *Surface {
surface := new(Surface)
surface.surface = C.cairo_image_surface_create(C.cairo_format_t(format), C.int(width), C.int(height))
surface.context = C.cairo_create(surface.surface)
return surface
}
//NewImageSurface creates an image surface of the given width, height,
//and format.
//
//Originally cairo_image_surface_create.
func NewImageSurface(format Format, width, height int) (ImageSurface, error) {
is := C.cairo_image_surface_create(format.c(), C.int(width), C.int(height))
stride := int(C.cairo_image_surface_get_stride(is))
return newImg(is, format, width, height, stride)
}