func cfgSurf(ps *C.cairo_surface_t, eps bool, header, setup Comments) {
var ceps C.cairo_bool_t
if eps {
ceps = 1
}
C.cairo_ps_surface_set_eps(ps, ceps)
for _, c := range header {
s := C.CString(c.String())
C.cairo_ps_surface_dsc_comment(ps, s)
C.free(unsafe.Pointer(s))
}
if len(setup) > 0 {
C.cairo_ps_surface_dsc_begin_setup(ps)
for _, c := range setup {
s := C.CString(c.String())
C.cairo_ps_surface_dsc_comment(ps, s)
C.free(unsafe.Pointer(s))
}
}
//ensure calls to AddComments apply to page even if no drawing has been performed.
C.cairo_ps_surface_dsc_begin_page_setup(ps)
}
// 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
}