fgen.py 文件源码

def pango_render_string(s,spec=None,fontfile=None,size=None,bg=(0.0,0.0,0.0),fg=(0.9,0.9,0.9),pad=5,
                        markup=1,scale=2.0,aspect=1.0,rotation=0.0):
    """Render a string using Cairo and the Pango text rendering interface.  Fonts can either be given
    as a fontfile or as a fontname.  Size should be in pixels (?).  You can specify a background and
    foreground color as RGB floating point triples. (Currently unimplemented.)"""
    S = pango.SCALE
    face = None
    if fontfile is not None: raise Exception("can't load ttf file into Pango yet; use fontname")
    # make a guess at the size
    w = max(100,int(scale*size*len(s)))
    h = max(100,int(scale*size*1.5))
    # possibly run through twice to make sure we get the right size buffer
    for round in range(2):
        surface = cairo.ImageSurface(cairo.FORMAT_ARGB32,w,h)
        cr = cairo.Context(surface)
        if spec is not None: fd = pango.FontDescription(spec)
        else: fd = pango.FontDescription()
        if size is not None: fd.set_size(int(scale*size*S))
        pcr = pangocairo.CairoContext(cr)
        layout = pcr.create_layout()
        layout.set_font_description(fd)
        if not markup:
            layout.set_text(s)
        else:
            layout.set_markup(s)
        ((xbear,ybear,tw,th),_) = layout.get_pixel_extents()
        # print(xbear, ybear, tw, th)
        tw = tw+2*pad
        th = th+2*pad
        if tw<=w and th<=h: break
        w = tw
        h = th

    cr.set_source_rgb(*bg)
    cr.rectangle(0,0,w,h)
    cr.fill()
    cr.move_to(-xbear+pad,-ybear+pad)
    cr.set_source_rgb(*fg)
    pcr.show_layout(layout)

    data = surface.get_data()
    data = bytearray(data)
    a = array(data,'B')
    a.shape = (h,w,4)
    a = a[:th,:tw,:3]
    a = a[:,:,::-1]
    if rotation!=0.0: a = rotate(a,rotation,order=1)
    a = zoom(a,(aspect/scale,1.0/scale/aspect,1.0),order=1)
    return a