sketch

type Graphics_api interface {
	Clear()
	Clear_subpage(colour string)
	Close()

	Delete_subpage(pname string)
	Draw_arc(xo float64, yo float64, radius float64, alpha1 float64, alpha2 float64)
	Draw_circle(xo float64, yo float64, radius float64, outline bool)
	Draw_image(xo float64, yo float64, iimage interface{})
	Draw_line(x1 float64, y1 float64, x2 float64, y2 float64)
	Draw_pie(xo float64, yo float64, radius float64, alpha1 float64, alpha2 float64, outline bool)
	Draw_poly(points []*sktools.Point, outline bool)
	Draw_rect(xo float64, yo float64, height float64, width float64, outline bool)
	Draw_text(xo float64, yo float64, text string)

	Engague()
	Mk_page(pname string, h int, w int, title string) error
	Mk_subpage(pname string, xo float64, yo float64, height float64, width float64)
	Mk_locked_subpage(pname string, xo float64, yo float64, height float64, width float64)
	Pop_state()
	Push_state()
	Rotate(degrees float64) bool
	Select_page(pname string)
	Select_subpage(pname string) bool

	Set_fill_attrs(cname string, fill_style int)
	Set_font(fname string, points int, weight int, ital bool)
	Set_colour(cname string)
	Set_dimensions(height float64, width float64)
	Set_iscale(increment float64)
	Set_line_style(pattern []int)
	Set_line_width(width int)
	Set_page_colour(cname string)
	Set_scale(xscale float64, yscale float64)

	// --- these might not be implemented by all underlying gc providers ---
	Mk_scaled_image(fname string, scale float64) (iimage interface{}, e error)
	Mk_bounded_image(fname string, max_height int, max_width int) (iimage interface{}, e error)
	Mk_stacked_image(fnames []string, max_height int, max_width int) (iimage interface{}, e error)
	Close_image(iimage interface{})

	// ---- interactive elements; not implemented by all underlying gc providers --
	Add_button(bid int, x int, y int, height int, width int, label string, colour string, txt_colour string, kind int, pushed bool)
	Add_listener(lchan chan *sktools.Interaction)
	Press_button(subpage_name string, button_id int)
	Release_button(subpage_name string, button_id int)
	Drive()

	Show()
	Translate(x float64, y float64)
	Translate_delta(delta_x float64, delta_y float64)
}